Cafe Racer Thread

[patz]

They don't. It's custom.

[Flieger]

Wow, I never knew Alfa made a flat four. Pushrod I assume?

[LakeCleElum]

Originally Posted by intakexhaust

Speed Craft Enterprises » Abarth

If I have a few drinks and close one eye, I can see a Goldwing engine?

[creaturecat]

buddy's bike. incredible
i could not even begin to list the innovations. internal rear disc brake, for starters.

[motion]

Beautiful! Swingarm looks a bit spindly and not sure about the enclosed discs, but that's some very nice craftsmanship.

[creaturecat]

more than just a looker.
unreal innovations.
info here: Goldammer Cycle

[Schumi]

Hey cafe racer dudes...

I mentioned a long ways back about how I was working on a pretty big build of a small race bike... I thought I might share some specs and details of what I'm doing... Project started about a year and a half ago with gathering parts and data and I'm just getting back on it now with finishing up design details surrounding the body and rear suspension. It's going to be a 500cc (514cc will be what it ends up as I think) 2T Honda-derived single cyl powerplant in an aluminum spar frame with a monocoque one piece body. Big thumper, except built for revs not torque. Entire bike is designed to be a 'hot-lap' bike- designed to do an out lap or two and a hot lap- not for anything longer. A single lap GP TT bike essentially.

The under-seat area doubles as a cooling duct for the radiator which mounts slanted under the seat and pulls air from the front of the bike.

Wheels are Aprilia 250GP bike wheels (which was my first purchase, even before the motor. Had to have those beautiful wheels).

Front end is GSX-R derived. Rear susp is a 'pro-link' design of my own.

I am considering the ability to build multiple copies of the bike, potentially up to 4 or 5 in total, as a few people have asked if I would consider it.... but the price is, well, a bit much to admit :-/


If I can find time to get my life together I should have the first parts out to CNC in about two months, and the body molds off to CNC shortly after.

Here is the side shot as it is now from one of the overall engineering drawings. A few things are left out still but you get the idea:




What do you all think?

[Yorkie]

I like it. The Bodywork has an element of Britten V1000 going on which is definitely not a bad thing. I also like the idea of a light fast single in the Manx Norton theme. Perhaps as I am aging bike bikes are not as appealing as the quick and nimble. I know its Old School but one of the most enjoyable bikes I ever owned was a little Honda GB500TT. That thing was so much fun on the Angeles Crest Highway up to Newcomb Ranch. Horrible on the Freeway but it was not built for that. Good luck with the project and keep everyone updated as to your progress.

[motion]

Originally Posted by peteremsley

I'm thinking that this would be a win-win... (bus looks like a '70 - just like I used to have )

Slow goin'!

[motion]

Originally Posted by Schumi

Hey cafe racer dudes...

I mentioned a long ways back about how I was working on a pretty big build of a small race bike... I thought I might share some specs and details of what I'm doing... Project started about a year and a half ago with gathering parts and data and I'm just getting back on it now with finishing up design details surrounding the body and rear suspension. It's going to be a 500cc (514cc will be what it ends up as I think) 2T Honda-derived single cyl powerplant in an aluminum spar frame with a monocoque one piece body. Big thumper, except built for revs not torque. Entire bike is designed to be a 'hot-lap' bike- designed to do an out lap or two and a hot lap- not for anything longer. A single lap GP TT bike essentially.

The under-seat area doubles as a cooling duct for the radiator which mounts slanted under the seat and pulls air from the front of the bike.

Wheels are Aprilia 250GP bike wheels (which was my first purchase, even before the motor. Had to have those beautiful wheels).

Front end is GSX-R derived. Rear susp is a 'pro-link' design of my own.

I am considering the ability to build multiple copies of the bike, potentially up to 4 or 5 in total, as a few people have asked if I would consider it.... but the price is, well, a bit much to admit :-/


If I can find time to get my life together I should have the first parts out to CNC in about two months, and the body molds off to CNC shortly after.

Here is the side shot as it is now from one of the overall engineering drawings. A few things are left out still but you get the idea:




What do you all think?

Yes, very Britten-esque design. Don't forget to swap out that 4-stroke exhaust

I applaud you for undertaking a project like this. Wish I had the design and fab skills to do the same.

My biggest question is... why a CR500 motor? They have a reputation for not lasting very long at WOT, and also engine vibes are very hard on the chassis. If I had your skills, I would be stuffing in an RG500 motor.

At any rate, I'm guessing this is a $30K bike?

[epbrown]

Socks with sandals, Steve? Eff you, too! ;-)

[Don Ro]

Originally Posted by epbrown

Socks with sandals, Steve?

Keeps your feet sweat from ruining footwear from the inside out.
BTDT.

[varmint]

[Schumi]

Originally Posted by motion

My biggest question is... why a CR500 motor? They have a reputation for not lasting very long at WOT, and also engine vibes are very hard on the chassis. If I had your skills, I would be stuffing in an RG500 motor.

I would kill to have been able to do an RG500 motor. I heavily thought about doing a big-bore Banshee two cylinder even. Anything but a single.
But it came down to availability and cost. Anything I did on an RG motor would require importing parts and everything is x4...

The CR500 is a trail beast, not a high RPM ripper.... but I don't need it to last long and the entire thing can be rebuilt in an hour essentially. Also, the power-to-weight was important as the goal for the entire bike is to be in the low-200lbs range and the power to weight of the cr500 motor by itself is nearly unmatched. To start the motor is getting the ports raised and the head decked back down to match, shifting the power band up by about 1500-2000 rpm. It will be a handful but that is the idea.. a bike with character, something that is straight up scary to ride. It will not have an onboard kick starter mechanism to save weight. Working with someone on a design for a twin-plug digital ignition, versus the old analog reluctor based ignition.

That exhaust is indeed a two stroke exhaust, it just looks a bit big; the real deal will likely wind up shorter. The pipe I'm having made is a bit of a short fatty to match the high RPM powerband.

The body design is styled like the Britten on purpose. It is my favorite bike, and where the inspiration for the cooling system comes from.

I'll post some 3d views and other drawings in the future.

[Schumi]

Originally Posted by peteremsley

Couple of local guys have built and are racing super-singles based on 450 motocross frame and engine. 50+ horse and really light.

I have a friend who was an engineer contracted to design some of the parts they sold for those bikes. It was my original motivation to build a 'super-single' of my own, but lighter and two stroke.

Those are surely fun, light, reliable bikes but I really wanted something more wild...

[motion]

Originally Posted by Schumi

I have a friend who was an engineer contracted to design some of the parts they sold for those bikes. It was my original motivation to build a 'super-single' of my own, but lighter and two stroke.

Those are surely fun, light, reliable bikes but I really wanted something more wild...

Mike, its pretty straightforward to stick a CR500 motor into a CRF450 chassis. You could do something like this pretty easily.

[nikita76]

Finish the engine, wire the bike, make brake arm...broad strokes but, that's what's left! I may change the headlight holders, I think I'd like to pull the light back a little and probably drop the clip ons to under the top fork plate.


NRD

[jorian]

Love the Gulf livery!

[Schumi]

nikita those clipons are also flipped from what they normally are supposed to be. It is far more common to have the bars on the front side of the forks, not the back. If you have them like that you won't have room for your hands between the bars and the tank when turning.

Putting them between the triples will make it look a tad sportier as well.

[nikita76]

Thanks guys!

Thank you Mike! that makes sense...much appreciated!!

NRD