Saturday, June 25, 2022

First thoughts and frequent comments....

 When the decision was made to build the last racer, the first 3 thoughts went through my head:

  1. This is going to be a lot of work.
  2. This should be a lot of fun when it is done.
  3. This is going to generate a lot of stupid comments.
1) It was. And it was worth it!
2) It was. More fun than anybody else knows!!
3) Far less than I expected in the real world - virtually none, really! And then there's Facebook and Youtube:
  1. Low CG motorcycles are hard to balance - ever try balancing a short broom?
  2. That's just a copy of the Gurney Alligator!
  3. You'll die if you crash or run into something!
  4. All those ball joints and rods kill steering feel!
  5. Can't see where you're going on the track!
  6. Can't steer properly if you can't move your body!
  7. Can't stand on the pegs while riding over bumps!
  8. Why don't I see them racing in GP or the IoM TT?
  9. KANEDA!
1) Motorcycles, at operating speed, are not balanced by the rider they don't fall down on their own. There are plenty of videos out there of riderless roadracing motorcycles rolling right along without anybody balancing them. Sure, at low speeds, such as waiting in line for tech, stopping at the grid, or heading back to your pit, the rider has to balance the bike. But at operating speed, a motorcycle is a dynamically stabilized system, NOT an "Inverted pendulum" or static unstable object like a broom. 

2) Considering the liquid cooled twin cylinder engine, 2 wheel steering, no steering head, virtual hub center steering front suspension, remote mount handlebar, and reclined seat and rider position, there are more differences than similarities. OK: The 'Gator was the only recumbent motorcycle to get any decent coverage in this country from the legacy motorcycle media this century.

3) Crashed at medium speed early 2013 - crashed at high speed later 2014 - didn't die either time, as far as I can remember. And if you are colliding with stationary objects at the track, well, you're doing it wrong - roadracing in this century is not for you - stick with video games.

4) No, they do not. Or at least they don't if teflon lined rod ends are kept out of the system. Even quite  a bit of play is better than a little bit of binding - the play will only be noticeable when parked - while cornering, there is a load on the handlebars (That's where feedback comes from!) taking up any play that might exist, leaving that crucial front end feel completely intact.

Front end feel comes from changes in the steering load - a little change means a lot. NOTHING kills that feel more than having the rider's weight on the handlebars while trail braking. With a recumbent motorcycle, the handlebars are just that - bars for the hands - the level of feedback from the front end is amazing if there is enough trail to provide it. Hub center steered front ends often need less trail for stability, which also makes the steering lighter, but that also reduces front end feel - something too often blamed on "All those linkages". 

Another change in perception comes from the effects of stiction - a binding telescopic fork (There is no other kind) functionally feels rigid and "Transmits" feedback very clearly. A rigid fork also loses traction very easily. What too many perceive as "Signal" from the front end is actually "Noise". It is too easy to confuse the absence of noise with a loss of signal; the lowest level signals were lost under a high noise threshold all along. Confidence in the front end shouldn't come from noise, but apparently, it does. 

Speaking of feel: Nothing else provides a better level of feedback than a riding position that spans the wheelbase - any change in traction and/or yaw shift is immediately felt. 

No, you won't read or hear any of that from the moto-infotainment outlets. They have no experience with the subject, nor do they want any - disapproval from their old chums and even older audience will keep it that way. Breakthroughs only happen by testing new ideas in the real world, not by consulting the peripheral noisemakers. 

5) Yes, my line of sight while riding straight and level is quite a bit lower than usual - yes, that changes one's perspective quite a bit - one gets over it very quickly with some seat time. But when leaned over, my line of sight is no lower than usual - look at how high the rider's helmet is from the track when he's dragging his elbows. If you ever need to sit up higher to see where you're going on the track, again, you're doing it wrong - roadracing in this century is not for you - stick with video games.

6) WRONG! Calisthenics are part of the operation of current racing binary unicycles, but single track vehicles designed to use both wheels full time are steered with the handlebars. 

7) Functional suspension works better than standing on the pegs - or at least it does on paved racetracks. That reclined seat and rider position makes spinal injuries from bumps nearly impossible anyway.


The FIM rejected Morbidelli's request to race one in the Grand Prix classes.

That leaves USA club racing and track days - I'm more than happy with that.

9) Akira references really are fun! A friend made me really cool race team logo from "Bartkira" many years ago. The movie bike is wonderful art for fictional anime/manga, but, sadly, terrible design for the real world. But unlike too many hopelessly stalled Akira projects, my old racer was finished, tested, raced, and it worked. 


Yes, I terminated my Facebook account back in August 2021. Only in social media is ignorance considered an uncorrupted form of wisdom. There are no negative consequences for stupidity there. Thankfully, Youtube gives me the option of reviewing comments or turning them off completely. 

I still find a great deal of enthusiasm online from what I call the "Enthusiast Motorcycle Media" (As opposed to the "Clickbait Motorcycle Media" and "Legacy Motorcycle Media"). More about all that happy stuff was published in a fun interview at Bike-urious - thanks, Abhi!

Saturday, December 4, 2021

Day at the Museum...

The racer has spent almost 3 years stuck in the workshop, welcoming me every time I walked in the door. While it still is an unusually amusing sight, it isn't otherwise doing me a whole lot of good. The original plan of parking it in our living room seemed like an increasingly bad idea - a split level mid-century house, oddly enough, isn't optimized for motorsports displays. What about loaning it to a museum, so others can marvel/point and laugh at it? A call was made to That Big Motorcycle Museum in Alabama - the word "Loaning" didn't get finished before the other end of the line snapped back a snotty "We only accept donations - on OUR terms - NO LOANED MOTORCYCLES!". Oh, really: Not at my current net worth.

So the next call went out to the nearby St. Francis Motorcycle Museum. I asked if they were interested in displaying an experimental homebuilt roadracer. They said they would be interested - if it is something different. This sure sounds like the right place!

Last night, the racer was loaded up in the van and rolled in through their front door this morning. Would the spot between the ELR and unmolested R90/6 be OK? Oh, yes. 



The museum opened up in 2016 - it isn't on the usual internet lists of motorcycle museums, or at least not yet. It is run by enthusiasts - and it shows. No idea how long my old racer will be there - if all goes well, I'll retire not too many years from now and it'll end up in someone else's living room, office, or . . . museum.

In the mean time, the next racer is in that stage where lots of work has been done, but it doesn't look that way - just an increasing spread of small parts waiting to become one big part. Boring, indeed. 


That's one of the wheel uprights - one of two welded assemblies of 6 machined 4130 tubes each that gets finish machined after welding. It is far more work than the similar bolted-up solid aluminum one at the back of the last racer, but the new ones weigh less than half and look a lot better (Yes, that matters!). A fiber wound forging would look even better and weigh even less - not happening with the resources at hand. The last racer's rolling chassis assembly weighed 290 lbs - if the next one can get down to 190 lbs, we'll be in great shape. 

Saturday, July 31, 2021

One Step Forward, Two Steps Sideways...

One of the big challenges for the next racer was building an engine with my own crankcase. The built and fully developed engine was expected to weigh under 100 lbs and produce over 100 hp. The initial engine build is the relatively quick, cheap, and easy part - the development is where time, money, and work can be severely challenging. All of that isn't entirely necessary any more - the recent KTM 890 engine fills that requirement reasonably well. A KTM Duke 890 has just rolled in the shop, and a lot of the previous donor engines and parts have been sold to help pay for it. This project was about a year behind schedule - this moves things forward quite a bit! Absolutely no changes are required for the rest of the motorcycle. A 4-stroke twin also provides greater opportunities for racing in clubs that accommodate real purpose-built race bikes. 


Unlike the EX500 engine in the last racer, the 890 engine has a very advanced ECU. A lot of learning and work lies ahead getting that to work in a racing application with different dynamics and no ABS. At this point, I don't know how well the stock ECU will work with the next racer. Or if it'll need a race ECU, like the one on the just released KTM RC 8C. Should know a bit more about the subject when this is done...

Building and running the 2-stroke engine design that I had in mind would have made for a good story. While lap times and all that don't care about "The Story", the most intriguing racing motorcycles have a good story behind them beyond the race results. I don't believe that racing is strictly about the racer and not the motorcycle, otherwise we could just discard those unnecessary machines and just race unburdened the purest way imaginable: Running barefoot and naked! No, that's really not my idea of fun, either. But a finished story is always better than an unfinished one - right now, the 890 engine is the fastest and easiest way to get the happy ending I'm expecting.

That 2-stoke engine concept is still worth pursuing later: Modern casting methods could result in a far lighter engine than any backyard foundry can render. A simple, cheap, and easy to work on engine with over 100 hp but under 50 lbs will take a real design and development team and facility - it certainly won't be one man's story - same thing with an under 150 lb pivotless carbon rolling chassis for said engine. Won't happen 'til the current project generates some real results and excitement. Motivation, enthusiasm, and all that happy stuff.... 

In the mean time, work is still in progress. Ever wonder what a 2WD motorcycle differential looks like? The inner (Rear wheel) pulley is solidly mounted to the spool - the outer (Front wheel) pulley is mounted to the spool with a one way clutch bearing. The spool itself mounts in the drive arm and is chain driven by the engine.

Before tearing down the KTM, it'll require some break-in mileage. It is the first "Normal" motorcycle I've ridden since race school, early 2012. It seems like a shame to take apart a perfectly good bike (And I really like the Duke 890 an awful lot!), but the next racer should be faster, more fun, and have a pretty good story behind it when it is done...

Sunday, July 18, 2021

What's Become of Motorcycle Roadracing in America?

If you’re new to motorcycle roadracing, then “Bagger Racing” is the most exciting development to the sport. But if you weren’t born yesterday, then it is a grotesque symptom of what is wrong with roadracing in America. Sure, I understand the appeal of racing a trendy consumer product - bagger racing is certainly a spectacle. Sure, there is some serious talent and money both behind the racers and on the racers. But just as absurdly captivating as racing old Dodge vans might be (No, seriously – watch some “Dajiban” video out of Japan), those baggers aren’t racers any more than my old departed Dodge Ram 350 van was a racer. It seriously illustrates just how lazy, uninspired, and corrupt Indian, Harley-Davidson, MotoAmerica, and legacy motojournalism has become. 

And if that isn’t brutally obvious, shift your gaze a bit to the excellent movie “Ford v Ferrari”. It is far from a documentary and certainly not a reenactment – but the screenplay's story is as timeless as it is relevant. With that in mind, imagine that same story, but with a different company – say, one that makes motorcycles – one with a currently identical sales, demographic, and performance image problem:

1) They want to buy, say, the 2 wheeled equivalent of Ferrari. Except that they did (MV Agusta), and they sunk tons of money into them, didn’t know what to do with them, and gave the company back.

2) They want their own Carroll Shelby – one that can take their engines and stick them into something a lot more exciting while developing something even better. Except that they buy both his company and his name (Erik Buell). Then they didn’t know what to do with them, dumped the bikes on the marketplace (Doing the same thing they accused the Big Four of doing when they demanded – and got – tariffs placed on Japanese motorcycles 750cc and over). Then they dumped Erik Buell.

3) They want to go racing. But instead of racing at the highest level with the best racers the world would see, they want their own special short races with the largest, slowest, and heaviest product they sell. How much credibility would Ford (Or the soon to be laughed out of the room and fired executive) have had if they demanded that the FIA run special short races in conjunction with international events for their new series of Econoline vans, along with Dodge A100 series vans? After all, that’s what they make and sell! 4) Technical rules regarding mandatory luggage capacity aren't comic relief this time. Read rulebook 2.7.10.11 (d.) yourself!

Epic screenplay material – writes itself! 

Didn’t think so.


One more reason why I want to watch “One Man’s Dream – the John Britten Story” again – no screenplay required for that one. Racing in America used to be inspiring enough to motivate John Britten and the team halfway around the world to build something and race it here. If there were a modern John Britten incarnation, MotoAmerica would have nothing to offer – ideas aren’t welcome – please pick from the homologated OEM list that nobody wants to watch, let alone sponsor. It should be no wonder that AHRMA’s Barber Vintage Festival – the only big event where Brittens and other bikes by enthusiasts serious enough about the sport to build their own can enter – is by far the largest event in America and has been since the Daytona 200 event imploded. But guess what racing class and organization is talking about running at Daytona next year. Hint: There won’t be any race bikes, the race will be very short, and the gap in just the top 10 will still be terribly high (And not the only reason why it is a very short race).



Remember the malaise era and the performance car scene? Yes, “Custom Vans” were all the rage! Why, there were even AFX Custom Van racing slot car sets, complete with a set of customizing stickers – what could Bellbottoms Jr. find more exciting than racing HO scale vans, just like the ones Groovy Baby Mom & Far Out Man Dad bought? Disco is forever!



But there is cause for optimism: Going slow the hard and expensive way gets old quickly. Grossly unbalanced rules that obviously favor a certain OEM kills whatever credibility they had in the first place - live by the OEM, die by the OEM. Something far better has to fill that void. Something exciting! Something that looks, sounds, and acts like....victory.

Thursday, December 24, 2020

...But Why....?

 According to the gossip from social media experts, I'm doing everything wrong! They don't know what I'm doing, so clearly I must not know what I'm doing...

Roadracing motorcycle design has evolved itself into a dead end - they can't accelerate or decelerate any harder without flipping, or corner any harder without running out of clearance. Any changes to one or more areas to improve one aspect will result in an overall loss of performance. Tires are optimized to accelerate or brake, not both, leading to cooling/overheating events. Suspension has to be optimized for load transfer extremes. All the above leads to both slow roll response and high polar inertia about the roll axis. And that results in terrible aerodynamics. ALL of the above problems can be successfully addressed IF you discard the old configuration and derive a functionally superior new configuration. 

Here are those problems (And causes):

  1. Stoppies (High CG, short WB) 
  2. Wheelies (High CG, short WB) 
  3. Lean angle limitations (Oversized rear tires)
  4. Roll rate limitations (High roll axis, high polar moment)
  5. Suspension sub-optimization (High CG, short WB) 
  6. Tire sub-optimization (High CG, short WB)
  7. Aerodynamic sub-optimization (High CG, short WB)

And here are the solutions:
  1. Long WB, low CG, linked brakes
  2. Long WB, low CG, 2WD
  3. 2WS, appropriate tire selection
  4. 2WS, low roll axis, low CG
  5. Long WB, low CG
  6. 2WD, 2WS, linked brakes, long WB
  7. Long WB, low CG 
And here's the how, why, and all that:

1. Pretty obvious, really. If load transfer under braking can't flip the bike, then there must still be some load on both tires. The lower the CG, the less load transfer, and the more both wheels will do the work. It also means that trail braking will be a lot more effective as the tire's loads transfer from braking to cornering.

2. Also pretty obvious. Same as the above, but from the opposite direction - just a lot more difficult to implement. Doing it beats complaining about it. The ultimate solution to that problem is addressed near the end of this post.

3. Not obvious, at least with the 2WS part. The tire part ought to be obvious: With 2WD and linked brakes, a big fat rear tire is no longer necessary or even desirable. A narrow tire at both ends provides enough footprint area - more about that in #6, below.

With 2WS, cornering force deviates from perpendicular to the roll axis, thus reducing lean angle (Simple trigonometry, if you must). If 2WS is taken to an extreme, a single track vehicle dynamically transforms into a purely 2-tracked vehicle known as a "Di-cycle": NO lean angle required at all for cornering. That isn't practical for obvious reasons, but steering the rear wheel in the same direction of the turn at any proportion much over 25% (Ideally over 33%) contributes to the same effect, thus significantly reducing lean angle. 

Both the narrower rear tire and 2WS effects greatly offset the negative effects of lower CG on lean angle. No, this isn't in any of the books. Yet. 

4. Not as obvious as it ought to be, sort of: Obviously, the reduced polar moment makes changing lean angle easier and also importantly, makes stopping changes to the lean angle easier. Less obviously, the lower the roll axis, the greater the lean angle changes with displacement of the contact patch relative to the roll axis when countersteering. 2WS normally wouldn't help at all with a high roll axis in that regard, since most of the effort in countersteering is exerted in overcoming wheel inertia - but with the lower roll axis and that increased displacement effect, countersteering becomes a LOT faster with the same effort.

5. Extreme load transfer is no longer happening, which means that a suspension range and rate to accommodate those extremes is no longer required. And with less suspension travel comes less sag under cornering, thus improving ground clearance and increasing potential lean angle even more. Lower CG and long WB, and less travel also means drastically reduced chassis pitching to bump response, acceleration, and braking, resulting in far greater chassis stability. Steering geometry can be optimized full time. And greater chassis stability reduces the appeal of conjuring pro/anti(Fill in the blank) magic geometry, thus making that pursuit irrelevant.

6. With 2WD, linked brakes, 2WS, low CG, and long WB, both tires are working all the time - a relatively constant load should result in a relatively constant tire temperature - tire cooling/overheating shouldn't be such a major source of drama anymore. And since extreme load transfer isn't happening anymore, much lower tire pressures (With the obvious benefit of a larger footprint) are both possible and desirable without developing stability and control issues. Having interchangeable front and rear wheels and tires is a welcome benefit. I doubt that existing tires are close to optimized for such implementation, but the choice of racing slick tires with different compounds and carcass stiffness is a huge help.

7. Brutally obvious: Much lower frontal area results in much less drag. Like totally free horsepower, man. Really. No kidding. 

The rationale (And obvious physics) behind all 7 points guided the design of my next racer. All 7 points are necessary, if not convenient, to work. No, I don't expect said social media techno-gossipers to grasp any/all of those points. Nothing in the real racing world depends on their comprehension or consent. 

Yeah, OK, so what else is it good for? Well, electric motorcycles exhibit a LOT of functional shortcomings relative to their internal combustion relatives. Horseless carriages were usually terrible cars - gasless motorbikes are usually terrible motorcycles. But a lightweight streamlined low CG, 2WS, 2WD electric street motorcycle would solve range, speed, cost, packaging, and weight issues while providing uncommonly high comfort, performance and protection right now. Electric 2WD almost designs itself. Truly effective regenerative braking is only possible with 2WD, low CG, and long WB. With 2WS and 2WD - and smart steering control - it would be possible at a stop to steer both wheels to the side to some degree and balance the bike without human intervention - no dippy outriggers or ludicrous gyroscope system necessary. A minimum turn radius of half the wheelbase would make it far more maneuverable. Then park it by lowering it all the way onto an integrated stand. Wind gust response would be counteracted by that smart 2WS. Smart 2WS (Or even active steering dampers) would also allow the use of tires optimized for traction rather than ease of steering. And so on and so forth - the design and dynamic potential is mind-blowing - something far beyond my next internal combustion powered racer. None of that is in the motorcycle advertorials.  Yet.



In the mean time, work is progressing nicely if not quickly on the next racer. Got questions? You know how to contact me. Got gossip? You know how to contact them.

Oh yes - MRA race video was shot one day only in the abbreviated 2020 racing season. There was no awards banquet, which meant nobody produced an awards banquet video. So I compiled my better video clips - no effects or soundtrack - just racing: 


The video camera was sold soon afterwards - need to focus more on building the next racer....

Monday, June 22, 2020

Here we go again...

In addition to design work and parts acquisition, the last two years were spent getting the new shop set up and tooled up. The shop is ready to go now -  work is in progress on the new racer! The first steps were making a face plate fixture for the wheels and boring the wheel hubs. Then the split hub center steering hubs get machined and installed in the wheel bores. After that, all that's left to do is everything else. It is going to be a lot of work and take a lot of time - can't think of anything else better to do. This is also going to be an awful lot of fun...



Monday, December 9, 2019

Hunting and Gathering...

All of this year's track time was spent behind the viewfinder shooting with a new JVC GY-HM620. A lot of my clips made it into this year's MRA Awards Banquet video. Already looking forward to wandering around and shooting at HPR next year!



After the Quail event, Jason Cormier at Odd Bike asked me for an article on the racer project and some of the background - that gave me a good excuse to explain a little how I got to this point and a little more about where I'm going. It's been a fun experience so far, which made it a lot of fun to write. Thanks, Jason!

All of the custom ordered parts have arrived: Connecting rods, crank pin, and hybrid Kawasaki KX500/Ducati 999 primary gear (All from England), Poly Chain GT 8 mm pulley stock (For final drive), and 56 mm Lectron downdraft carburetor (For feeding 706 cc crankcase displacement). And then there's the one and only part I just pulled off the last racer that goes on the next one - it's a part that's getting a lot harder to find.





The engine casting will have to work well with the 2WD final drive arm, so those get designed and built together - after that, the frame and 2WS system pretty much fall into place. The big plan for the bodywork is to have as little as possible, as simple as possible, and as cheap and easy to replace, vinyl wrap, and install as possible - wasting time and money on dysfunctional over-styled plastic that gets vinyl wrapped anyway seems really stupid on a racer, where bodywork is considered a consumable item, like tires, safety wire, cash, collarbones, etc...

So where does a home built supercharged single cylinder 2 stroke 2WS 2WD motorcycle race? Obviously not any of the "Professional" OEM-centric racing organizations. The local club's rulebook is very helpful - since I'm making my own racer, the supercharger isn't aftermarket:


And then there are always those therapeutic track days....

But there's many years of work left to be done in the shop. Thankfully, it now has something every race shop needs: Lots of hot air!


Saturday, April 13, 2019

A Retirement Party....

A few months ago, I read an article on The Quail Motorcycle Gathering show for this year. Well, the old racer was never built for show (And never entered in one, either), but it sure is a great conversation piece. So a show application was submitted - and it was accepted! The 2014 crash damage repairs have been finished and painted. Seven years worth of neglected and ignored cosmetic flaws have been mostly fixed. The battery and some fuel are back in it - it'll get fired up and ridden a little one last time before it gets retired. It sometimes seems like a waste just to park it when it is so much fun to ride, but that would be time and money from the next one, not to mention the possibility of getting too enthusiastic and crashing the old one again.


19 May update:

The racer was loaded in a van and driven about 1400 miles to the show. The weather was perfect, the guests were a lot of fun, and the judges were very enthusiastic. No trophy this time, either, but the experience was priceless - there's no better show in the USA. After the show ended and the field cleared out a bit, the racer was fired up and ridden back to the van. That was a short, slow, yet very satisfying final ride.


The racer also received very enthusiastic media coverage by Julia LaPalme from Motorcyclist Magazine, and Abhi Eswarappa from Bike-urious !

And that's the end of that project - on with the next one.

Last photo: Michael Moore

Sunday, January 13, 2019

What's Next...

The final race of 2018 was the first and only weekend out for the racer. Bad weather resulted in no practice. The racer behaved very well, but that lack of practice resulted in really awful lap times. Many of the other racers ahead of me were battling for season championships - I didn't think that one person's proof of concept development program should interfere with the sporting intentions of the other racers, so I pitted before I got lapped. One racer followed me from the start - after I pulled off, his lap times dropped a lot - I hope he enjoyed the show. Unless someone else needs to test the racer, that's the last time I take it to the track. From now on, I'll get a kick out of looking at it in the shop until it makes it upstairs into my living room/office.



My favorite thrill is pinning the throttle after the apex of T3 at HPR, especially with an untested bike. My second favorite thrill is getting an idea out of my head and turning it into a design before making it real, loading it into the van, and taking it to the track. The next racer is into that "Second favorite" stage. The details are a lot different than the first racer, with a few exceptions. The shocks will end up in the same area, and the upper A-arms and single sided steered upright will return at both ends (With vastly lighter and better looking design and fabrication). I'm really excited about the design of the lower suspension arm - it is VERY exotic and unique (One arm for both wheels) - it solves all of my prior 2WS/2WD design nuisances and headaches.


Another good thrill is having a photo pass for MRA events and shooting video. While nothing beats the view of the race from a race bike, being able to wander around the track and scout out vantage points for capturing the action is about as close as anyone else can get. A lot of my footage made it into the MRA's Award Banquet video - thanks for the credit!



Getting the shop together and tooled up is still in progress. All of the lighting and outlets were removed and replaced. A heater should be installed very soon. Real machine tools have been moved in. As always, good help is necessary for rigging heavy machines!


There's a LOT of work in the shop to be done in 2019. And MRA racing action to shoot at HPR with a new camera this upcoming season well.

T3 awaits...

Top video: Jeremy Alexander

Monday, June 11, 2018

...Now What?

I'm shooting video at MRA's race weekends at HPR.


If all goes well, I'll race at HPR later in the season. Then that bike retires in the living room, and I get rolling in the shop on the next racer...

The next racer is still in the phase before "Connect the Dots" that I like to call "Collect the Dots". While working on some of the design headaches involving a belt drive primary connecting the KX500 engine to the 999 transmission, I wondered if there was a remote chance that a 999 primary drive gear system would fit, since the KX500 primary gearing is terrible for roadracing. The KX500 stroke is a lot higher, so I assumed it wouldn't fit. With the help of a few parts on hand and a few more cheap parts from eBay, the answer became obvious:


The drive side of the crank, 999 primary gear, and KX500 primary gear were promptly boxed up and shipped off to a gear making specialist in England, where a few hybrid 999/KX500 primary gears will be made. Longer connecting rods will also have to be made (The original rod/stroke ratio is not optimal for a higher revving roadracing engine). A longer crank pin will be required for my counterbalancer/inlet valve/supercharger design. Patterns and castings will have to be made for the engine cases.  Then those case castings have to be machined. It'll be a lot of work, but the results should be a lot of fun. 

While there are certainly lots of excellent engines available, none of them fit my next chassis design very well and/or produce an interesting amount of power. Once the engine is "Finished" (Development work on a racer is never finished, it is only interrupted when it goes through tech before the race weekend starts) then work will proceed on the rolling chassis. I'm really excited about the performance potential of the "Finished" combination of the next engine and chassis - lap times will answer the question if it was worth it.  

I think I'll know the answer the first time it exits Pit Out, rolls into T3, then goes wide open after the apex...

Sunday, November 19, 2017

Going to a better place...

Earlier this year, the rear steering ratio was changed from 20% to 34%. I finally got to test it at the track in early September.  That morning at the track, we also got a visit from some good friends (Jeff and Sally) that I haven't seen since my USAF assignment (1981-1983) at RAF Bentwaters!


The improvement in steering and handling boosted my confidence enough to register for the MRA's final HPR event of the season.Then I got a job offer in Yuma, Colorado. Race registration was then cancelled due to new demands on my attention. Time to sell my Englewood home (And 8' x 8' shed) and move into a much better home (With a 30' x 50' insulated 240V workshop and 27' x 31' garage)! There's a lot of romance and mythology about building bikes in sheds - it was a fun and challenging way to start  - but the Rohorn Industrial Complex has outgrown that.


There is a lot of work to be finished on the workshop (And money to be spent on machine tools) before a lot of work gets started on the next racer. But getting this far is a huge step forward. 

The rest of 2017's involvement with motorcycle racing was from behind video cameras at the MRA's HPR events. Time spent at the track, as close to the action as I could get, with an old JVC GY-HM70U and GC-PX100 was an excellent experience. If you love motorcycle roadracing and want to get involved and up close to the action without actually racing, I highly recommend working as a Corner Marshal for a season, then getting a media pass and shooting photo and/or video. I shot most of the off-bike video content in the 2017 MRA Awards Banquet video:


Monday, May 29, 2017

Final racer project

My first 2WS bike proved to me that the concept worked at low speed, but high speed behavior on the track was unknown. My first 2WS racer proved to me that the concept worked at high speed on the track, but not at a competitive level. A competitive racer will demand more time and money than all the previous bikes combined, but each bike has been preparation for the next one; not making the next one makes all the previous bikes almost a waste of time and money. I really want to see how fast we can go. Parts are accumulating to make this happen:
  • 17 x 3.5" wheels with split hub center steering at both ends. If I can steer the rear wheel, I can drive the front wheel. An overrunning clutch to the front wheel will eliminate the need for a differential. Initially, entirely machined wheels were planned, but previous generation R1 front wheels are ideal - they are very light for a production wheel, and the hub area is big enough to bore out and install a smaller universal joint in the center with a lighter machined hub. A cheap damaged wheel verified that it will work. Two new wheels are now on hand. 
  • 500 single 2-stroke power, with a combination counterbalancer/intake valve (My design), and a 6 speed transmission with a dry clutch. A KX500 engine (On hand) will provide most of the mechanical parts, a Ducati 999 engine (On hand) will provide most of the transmission and clutch parts, and some foundry work will provide the cases necessary to put it all together. That will take a lot of work, but it should make a lot of power for a very small engine, with much less maintenance, tuning work, exhaust fabrication, and cost than a multi-cylinder engine. 
  • Very narrow and light tubular steel chassis and suspension. Exotic materials and construction techniques were studied with a lot of enthusiasm, but none of them had any practical appeal. The ergonomics of the first racer were excellent, as viewed from the side, but the hands, knees, and feet need to move a LOT closer together to improve safety and aerodynamics.
No effort is being taken to build anything remotely national or international racing class friendly. Why design and build a bike to fit rules that would only make it more expensive and/or slower? I want to go as fast as possible for the least amount of money; rulebooks are generally written to produce the opposite result for the business corporations the rulemakers are working with/against. Club racing organisations are far more accommodating to the active racing enthusiast anyway.

When? Not soon enough.

I better use that engine before they get any more ideas...


Sunday, May 21, 2017

2WS With Split Hub Center Steering

"Split Hub Center Steering" is what I call the system used in the racer's steered rear suspension. A wing bearing universal joint connects the left side drive hub to the right side steering hub. Rear steering is 34% of the front, and in the same direction. 


Yes, steering geometry matters at the rear wheel as much as the front. A LOT of work was done to determine which geometry works and which doesn't. Instability from weaves, and speed wobbles with just the rear wheel, is no fun. That hasn't happened to this bike, but has happened with the electric one.

The drum brake rear wheel from the EX500 worked very well for this experiment. It is red because the donor bike came with a parts bike that had red wheels - no clever or creative aesthetics involved. The wheel was sent to Kosman Specialties to have the hub bored out back in 2009. That was the only machine work for this project that I didn't perform, since the wheel didn't fit in my lathe/mill.

The rest of the machined parts came out of my Grizzly G0516 lathe/mill. I got a lot of good parts out of that machine, but it has since been sold. The next racer will need more serious machinery located in a serious shop, rather than my kitchen (Seriously!).













Sunday, September 25, 2016

Race #7, 5, 1, and *

Ran the warm-up lap and gridded for the Formula Colorado class in MRA's Round 7, which was my 5th race ever, 1st race in 2 years, and pulled out at the end of lap 1: DNF. I thought I could quickly work my way back to previous lap times chasing the back of the grid, but it didn't work out that way. The hardware works great; the liveware, not so great. It is one thing to battle with someone else at the back of the grid (That is still racing), but when the entire field disappears in the first half lap and getting lapped within 3 laps is inevitable, then I don't feel like I belong out there. That said, I did get a lot more comfortable on it. Chicken strip reduction rate was ahead of expectation. Riding mistakes were getting easier to identify. Lines around the track were getting more obvious. The 2WS system was never a distraction: It steers far better, making it a lot less work to go faster. Trail braking is far more effective. We're going to have a lot more fun generating better results.


Yes, it is a lot of fun to show up at a racetrack with an exotic motorcycle, but motorcycle racing is ultimately about about the racing rather than the motorcycle. Other than some minor bodywork restoration and steering column modification, there's nothing left to do except race it. And work on a completely new design based on the same configuration and very little else.


Top photo: Tracy Helmhold

Monday, August 29, 2016

Track Time! Again!

This morning's track time at High Plains Raceway went very well. The track was initially opened to first time track riders to familiarize themselves with the track layout. That was a great opportunity to go out slowly and not worry about interfering with other people's idea of fun. And there were other things to worry about. Those first two laps were probably the most terrifying thing I've ever done, not that the racer did anything wrong, but rather, I didn't know what it might do wrong and without warning. There is no prior art available for the category of two wheel steering road racers or any experience to lean on. What I was riding was the culmination of earlier experiments and more unanswered questions: Will the front/rear coupled steering result in some sort of instability over bumps, or while cornering? Will the rear end wobble and structurally fail? Will the rear steering geometry that behaves while coasting misbehave while under power, braking, and/or hard up/down shifts? What about trail braking with linked brakes and linked steering? Will steering that works well at modest lean angles work under more severe cornering attitudes? Or worst worry of all: Is it merely another way to generate bad lap times with curious hardware, only to be pushed back into the shed and languish as a habitat for spiders?


After those first 2 laps and an hour or so of inspection (No loose or missing hardware! No adjustments needed at all!) and introspection (Do I really want to do this anymore? The turns are where I remember them 2 years ago, but where did my sense of timing go?), the doubt, confusion, and overwhelming sensory input that race tracks can provide somehow evolved into that powerful feeling that gets leathers, boots, helmet, and gloves back on with enthusiasm: Must! Go! Back! Out! That is a really good feeling!


The next 2 laps went a lot better. Even though I haven't ridden it (Or anything else) in 2 years, I still instinctively slid over on the seat to hang off into the corners. That isn't necessary anymore, since the 2WS system reduces lean angle a lot more than hanging off. The linked braking system is a huge improvement over the old system. Hard braking is drama free, as is trail braking into corners. Great brakes and steering systems might not sound too useful when they aren't being used properly, but they do wonders for improving confidence in the bike.


The last 3 laps were just a lot of fun trying to use what I learned earlier in the day. No lap times were recorded, but I'm looking forward to learning a lot more. The last MRA race of the season is at High Plains Raceway, 17-18 September, Formula Colorado class, car port #7.