The Kneeslider

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Dirt Bike Based 450cc Single Cylinder Road Racer

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450cc dirt bike based road racer

450cc dirt bike based road racerGavin Trippe is at it again. Gavin is the man behind Supermoto and prior to that, played a huge role in AMA Superbike and Motocross racing as well as promoting racing in many other venues. Recently he had the idea of converting a 450cc 4 stroke single cylinder dirt bike into a road racer. Using a standard Honda CRF450X frame, sub-frame and swingarm, without any cutting or welding, Gavin, along with Troy Lee came up with a road racer.

They enlisted Roland Sands into the team to do the design and fabrication work and to do some track testing on the Streets of Willow and everything worked. They’ve also built a Kawasaki and a Yamaha. They introduced the bikes at Laguna Seca and found a great deal of interest.

The whole idea here is to create a race series where the entry costs are limited and the design is set enough that someone couldn’t easily buy his way to a win. The 450cc single lets racers start out at a more manageable level instead of trying to jump into 4 cylinder 600s at the start.

This is a pretty interesting project very much worth watching. If you think you would like to get involved or you want to follow the project, they’ve set up a web site to keep everyone up to date.

Thanks for the tip, Hugo!

Link: 450 Moto
Link: Gavin Trippe Interview

Comments

  1. SWEET! I love this type of racing. Match the machines as close as possible and really keep the mods limited, like pipes jets and filter changes only. Keeps the $$ down and the competition up. While the idea of multiple manufacturers being similarly setup is appealing from a business setup, I’d rather they just stick with whichever brand motor frame combo actually proves to be the most reliable. Stick with one brand and model. It’d be like the HD Thundertwin series, except it would have bikes that actually handled more like the bikes I imagine the stars of this series would progress to. This format makes for some of the most exciting racing to watch, and really tests the riders ability, not pocket book, while also placing a big emphasis on how critical suspension setup is for getting around a track quickly.

  2. I love the idea until I get to the stock frame and swingarm part.

    No thanks, but I hope it turns into a successful series.

    It would be funny if Buell’s first successful roadracer is based on a dirtbike……

  4. With any luck this may also spur the return of mid-sized single-cylinder streetbikes to the market. I want a 450-500cc single cafe racer, dammit!

  6. Those dirtbikes rip and I’ve always thought they would make a great sportbike.

    Mark – I like your comment about a single cafe bike, but I’d like to see the above bikes in race-ready stree-legal sportbike trim. A 600cc race repli would get ‘m-bear-assed on the right road….and wouldn’t that make you grin even wider?

    Big Twin sportbikes & small single cylinder sportbikes coming to market would round out my moto needs.

  7. A used SR500 with Flanders bars fits the bill pretty well as a cafe single. The NX650 is pretty close too. Any number of dual sports are adaptable to a cafe, roadster, or street-tracker style with out too much gnashing of teeth (or knuckles.)

  8. A friend of mine has a 450 dirtbike that is now street legal with a lighting kit and stuff, so one of these sportbikes could be street legal in the same manner.

    extremely cool

  9. How about powering them with old 500cc two stroke dirt bike engines.

    Apart from the unmanageable pops and burbles while tipping in and the insane power and deathly torque, combined with emissions that could flood Bangladesh and the….

    Forget it, I think I just answered why.

    Tom

  10. Next step, they produce a conversion for your street titled XL650R or KLR650! Bring it on Roland!

  11. I am totally looking for a dirt bike now and trying my hand at designing a dirt/sportbike combo or dirt/cafe or even more fun dir/streetfigher. The only think would be the rear section becase there using the stock swing arm how the hell are they getting sportbike tires and wheels in there, there must be enought room to fit the wheels with different spacers. The only other thing that bugs me is the shock, they said it was custom made. I wonder if a reqular rear shock from a sport bike would work..mmm something to think about..

  12. It seems that everyone says they want something like this to ride on the street (myself included) but no one ever builds one. The Cagiva Mito 500 seemed like a slight chance but now that will no longer happen with BMW at the controls.

    Why is it so hard for manufacturers to build one of these things and make it street legal. It would be just the ticket for those of us who want to be different and don’t want or need a big heavy 600-4.

    -todd

  13. “The whole idea here is to create a race series where the entry costs are limited and the design is set enough that someone couldn’t easily buy his way to a win.” This is an excellent idea.

  14. todd,
    I think that bikes like this really have the potential to make a dent in any manufacturer’s bottom line. The problem is that a potent thumper is definitely going to detract from the supersport sales. There’s no way a bike like this should sell for more than $1500 more than the moto-x version, but that probably kills someone like Honda’s sales because it will definitely take sales from the CBR 600, which is much more $$$.

    I honestly believe the 3 majors they have on board with this project at the moment are there because it’s only a track bike, and the 450 aren’t being sold as street machines with emissions gear. If Roland produces a conversion for the street legal 650s he’s probably not going to be getting the same cooperation.

  15. I love this idea, a cheap way into racing. Now why on earth, with so many people almost begging for them, would the big 4 be ignoring the fact that a potent half litre single with a fairly modular frame allowing various parts to be bought such as fairings, perhaps a kit to change out to a cafe-style look, or maybe even a kit to bolt on and make it a dual-purpose. These would boost the aftermarket, which would boost the bikes as sellers. I’ve seen a few stonking singles (there’s a bloke on a GB500 in my city, and his bike RIPS) so the performance would be there. Either or, this idea is a good one in my books.

  16. Matt in NC, you make a solid point. There is sort of a bell curve in sales numbers that could make or break this idea. If it’s only a few bikes, it might not be worth the time and money to the Big 4. However, it wouldn’t eat into their sport bike sales so much that it would cause them not to make it if they could adapt an existing platform at a reasonable price. Then if it were to sell enough units, it wouldn’t matter much if it eroded low end sport bike sales, because the volume would be large enough that they would more than make up for the losses on 600/4s. The in between area is where this whole thing runs into trouble.

    Generally, I think this makes sense. The people who want this kind of bike are not the kind of people who want to buy a 4 cylinder crotch rocket. The overwhelming majority of people buying entry level sport bikes aren’t really planning on going racing. They are buying it because it offers some “badass” cred and it’s fast. They aren’t going to want smaller displacement thumper. However, whether or not the Big 4 will see that is another story entirely.

  17. this is the coolest thing i have EVER seen on two wheels. where do i sign up to reserve a conversion kit?!?!

  18. Airtech Streamlining among others sells all sorts of fairings and brackets that can be adapted to most bikes.

  20. I’d like a single 500-650cc in a streetfighter style. KTM is rumored to be putting the 690 sm motor in either the streetfighter/ mini duke or a faired sportbike version. Something like that would be my next bike.
    Or someone should do a retro style sr500 or srx600 with modern suspension and brakes.

  21. I think it is a great idea . Unless you are into vintage racing there isn’t much else to race in the light weight classes . I would like to see this take off .

  23. This is The Coolest Thing I’ve seen in a long time!
    I can’t wait til KTM puts out their RC4…

  26. I’d pay 600/4 prices for a street going 450 thumper racer built on a RS or TZ chassis. Funny, I’ve never been tempted to pay 600/4 prices for a 600/4.

    To be realistic, after they get the thing past EPA, CARB, and DOT They will probably be putting out around 40HP and sound like a lawn mower. This is where their aftermarket catalog comes in handy; the HI-PO parts are already there for the engines. But just off the show room floor, a 40HP 300lb sport bike still sounds good to me. My GB500 is 350lb and 33HP and it does just fine – if it only had better suspension.

    -todd

  28. I built one of these bike starting with a Honda RS 125 rolling chassis and, used an 02 CRF 450 for power. Let me tell you, these things fly. The first time out it finished 3rd in the singles class at Infineon Raceway, going up against bikes that were as big as 800cc’s. It was so light and handled so well that it just eat em’ up in the tight stuff, it had a 48′ wheelbase and weighed around 200 lbs. I think this would be a great class that would make for exciting racing.

  29. Man, I hope at least one big 4 designer reads this thread…

    I’m tired of the whole bigger is better trend, both for cruisers and sportbikes.

    Looks pretty obvious to me that a whole bunch of people, if this thread is just a small sampling, want to have a “back to basics”, nimble sportbike.

    Did everyone visit the 450moto blog and vote?

  30. I totally did. I bet if the aftermarket people make these bikes into a kit form were you use a donor bike, they would make a ton for money.

  31. This sounds like something right up KTM’s alley. The original Duke/Duke II was getting there (and I _love_ my Duke II). But was more motard/standard than sport bike (at least in stance and ergo’s). But then thats what makes it so fun around town.

    Big singles like that do have some drawbacks for folks with just one bike. They aren’t that great on the highway (though a sportbike style would be better than the duke probably). And they shake. Alot. And a hi-po single like the current 450 motox bikes probably would be kind of bad on gas for a small bike. Especially the way the bike will warp your mind into riding it.

  32. Well KTM will answer the bill for a lot of you with the 690 supermono:
    http://www.motociclismo.es/rcs/noticias/2007/07_Jul/1207-ktm-rc4690-ap.jpg
    http://www.motociclismo.es/rcs/noticias/2007/07_Jul/1207-ktm-rc4690-3.jpg
    with probably some more hp and less weight then the SM version.
    Off course this one still has the 916 fairing, etc. but apparantly the track times were very good so maybe a trend has been set. Hopefull the sale of Husqvarna to BMW means the Mito 500 will come to the market soon…

  33. i most seriously hope bikes like this become more common. and if KTM don’t build that little thumper i will cry. maybe. okay i’ll just be annoyed. either way the market desperately needs something like this. PLEASE!!!

  34. i totally forgot that yamaha builds a thumper cafestreetfighter called the mt-03. Not quite as cool looking as the mt-01 but still a single with a unique look.. Too bad neither is available in the USA. Why theysell the mt-o1 in canada and not the states still baffles me.

  35. RH said:
    “It would be funny if Buell’s first successful roadracer is based on a dirtbike……”

    Buell has had many successful roadracers…just not in any classes you’ll see on TV.

    I like the idea. With a shortened swingarm they’d be about perfect. I was considering purchasing a Supermoto for a streetbike and racing my current streetbike. I may just do this instead. I always wondered how that idea would work out VS using a 125/250GP frame.

    If they can nail down the rules and keep ’em enforced I think it’d be a very viable idea.

  36. Buells certainly have had some success at the track – but none of the purpose built racers have resulted in much success.

    It didn’t help Buell at all when the F1 class was killed when he brought out the RR750.

    Whether or not Buell comes out with a 450 Moto or the AMA (or whatever deposes the AMA) recognizes the class is what I’m waiting to see. I’m not holding my breath for either one, but I’d sure love to see both happen.

  37. Have you ever seen the modified Buell Blast engined bike that Chris Carr raced at the Peoria TT nationals? 103 mph on the straight. Put something even close to that in roadrace/street trim along with the rest of the manufatures.