Tarmac AF

[570mitch]

Finally finished my Supermoto'd AF. Its a 2007 450 chassis with a 1992 500 engine. I race the bike in the UK on tarmac, so it's got a 16.5" front and 17" rear wheel.

And before you ask, yes it has got a 4 stroke silencer on at the moment. It's off a CRF250 and we wanted to see if it let the pipe breathe better. The front pipe is a CPI sand pipe off a CR. I have never heard the engine rev so high before.

Hope you all approve.

[squeak]

Very nice. I bet that's a wicked ride.  Did you build it yourself? Let's see some close up pics of the frame mods!

[570mitch]

Competed on it Saturday and the power comes in with a bang, going to try and soften the bottom end a bit.

Friend of mine did all the welding and fabrication, the exhaust was probably the biggest job. He builds trials cars and was british sidecar enduro champ a few years ago, so was full of good ideas.

The best idea was for the cylinder head mount, there's a cross member linking the frame rails and all the electrics are mounted on the top. Engine comes out again tomorrow, so will take some more pics then.

[DoldGuy]

570,
Definetly interested in some more pics (especially the pipe)!
DoldGuy

[Dutch-K5 Fan]

It's a beauty Mitch!

Any idea's how you gone smooth out the power??
Maybe a old cilinder from Paul Malin

Dutchie

[570mitch]

I think a v force 3 reed valve is first on the shopping list, that should help the spread of power. But we have some ideas to try on the barrel.

[Coop]

That's sweet.

[demographic]

Competed on it Saturday and the power comes in with a bang, going to try and soften the bottom end a bit.

Friend of mine did all the welding and fabrication, the exhaust was probably the biggest job. He builds trials cars and was british sidecar enduro champ a few years ago, so was full of good ideas.

The best idea was for the cylinder head mount, there's a cross member linking the frame rails and all the electrics are mounted on the top. Engine comes out again tomorrow, so will take some more pics then.

I was just going to say that the pictures looked like they were taken in the UK, looked awfully green grass

Where are you based?

[ktmdude]

Nice job. That looks very clean and will be very fun. You mite try a heavy fly wheel weight to smooth out power.

[570mitch]

I live in Cornwall in the UK and the flywheel trick sounds promising, would probably help with traction off the line also. Barrel's away at the moment having a new coating, then a Wiseco piston in going in. I've been talked ito trying a 41mm carb aswell.

[dave916]

I live in Cornwall in the UK and the flywheel trick sounds promising, would probably help with traction off the line also. Barrel's away at the moment having a new coating, then a Wiseco piston in going in. I've been talked ito trying a 41mm carb aswell.

seems like your going two different directions with the flywheel weight and big carb!  think the 92 kx5 have a pretty heavy flywheel for road racing already, the kx  PV motor should have loads of low down power [compared to CR5]  due to long stroke and KIPS,  make sure you dont have any other issues with motor, ie  leaking crankcases or carb problems
nice  bike , good luck. i will try and go see u racing some time but most of the track seems  to be a long way from LONDON

[570mitch]

We have all different kinds of hill climb tracks in the UK, so you need a motor to suit fast tracks and tight twisty tracks. Benny Lindberg (Bempa) has talked of an adjustable kips also in his AF conversion document. It's going to be a year of trying different engine configurations.

[ktmdude]

I'm not sure about a 92, but my uncle put a 13 oz fww in his 91 and he is all smiles. I have a 11 oz in my 01 250, it defiantly improves traction. The snap is not as violent, and you have less wheel spin. Of course all my experience is on the dirt. Good luck.

[570mitch]

Thanks for the info KTMdude, will take note and play around with these ideas. Next event has a flat out uphill finish in 5th, hoping to pull over 100mph with the new pipe. The bike handles much better now than in the old KX5 frame. Much stiffer but steering is really precise.

[ktmdude]

I can't see in the pics if you run a steering damper or not. If you don't... you should. They improve your handling, the steering is much more precise. You will really appreciate it at high speed. Scotts are infinitely adjustable so you can play with at different tracks and conditions. I don't like riding without one. Check them out. I'm sure some of the guys on the circuit use them, ask them what they think. I don't know anyone that has ridden with one that didn't like them and what they do.