'05 KX250F supermoto build

[CarbonB]

New to the forum and supermoto in general so I figured I'd introduce myself and document my build at the same time. I've raced MX on and off for 15+ years and even did some competitive stunt riding for a few years but I have zero road racing and supermoto experience so I'm looking forward to a new challenge.

On to the build...Starting with an '05 KX250F

Mods so far include:
Stiffer springs front/rear
Pro Circuit triple clamps
Renthal fat bars
Excel 17" wheels and hubs
Braking 320mm rotor
Nissin 4 piston caliper
SS brake line
Infinity Carbon front sprocket guard
Infinity Carbon rear shock guard
Infinity Carbon header guard
Annodized billet bling here and there

Still to come:
Carbon Fiber fork guards, engine guards, frame guards, rear disc guard, chain guide, rear caliper guard, bike bonz catch can, hand guards, sumo front fender, new chain/sprockets, exhaust, silicone radiator hoses, powdercoat frame/swingarm




I'll post up new/better pics as more work is done.

[dave911]

Nice. From what I've been reading, you may not need / want all those engine-type guards, as they help keep the heat in too much. d911

[CarbonB]

Nice. From what I've been reading, you may not need / want all those engine-type guards, as they help keep the heat in too much. d911

Thanks for the tip, never heard of that before. I had the same parts on it when I rode MX and never had any problems so I'm going to run them and I'll post up if there are any issues.

[SHAWNatBMS]

Looking good my friend! It will be nice to get some time in at Stark this weekend!

~Shawn

[CarbonB]

I finished up a few of the carbon parts we've been working on and took some better pics of the bike. Check it out..

Rear Disc guard


Shock guard


Exhaust guard


Frame guard


Frame guard and sprocket guard


Pro Circuit Triples


Braking 320mm rotor, Nissin 4 piston caliper, ss line, excel rim/hub

[Bacon]

Very nice bike.

[SHAWNatBMS]

Yo B Rye. Were's the updates?
~Shawn

[CarbonB]

Finally got some new pictures uploaded. Since the last post I've added a Yoshimura titanium full system, carbon fiber fork guards, cf front number plate, cf chain guide, cf rear caliper guard, chain guide, silicone radiator hoses, Renthal sprockets, DID chain, Bonz catch can and Acerbis fender and handguards (in the last few pics).

[matthewlyndon]

hi bryan,

great bike really does look good

i'm looking to buy a kx250f and supermoto it for the road.

i'm in the uk and i've tried to make myself aware of every flaw in the conversion.

the only issue im struggling with is knowing the width of the front and back wheel for the conversion. i sourced a pdf which stated the front tyre will be a 120 / 60 - 17 and the rear 190 / 70 -17 or something like that. what wheel width will i be needing and what tyre width do you recommend bearing in mind its for the road.

Thanks!

[moeracing]

Hey if you are thinking of putting a KX250F into SM trim the rear swing arms are very very tight. I have a 160 rear tire on a 5" rim and it has to be set far back in the swingarm which is not optimal for racing and turn in. I would go with a 4.25 or a 4.5 " rear rim with a 150 tire, probably a pilot power. Hope that helps. I ended up shaving down the right side of my race slick to get it in.

[matthewlyndon]

hey,

ye that helps. i probably sound like a geek right now but i had an Aprilia SX50 (sm) and i ran a 140 rear tire and that only just fit in the swingarm.

would you be able to check this link out and tell me what you think, and wether theres any better or any cheaper etc

http://www.motostrano.com/sucokistle.html

thanks alot

[SHAWNatBMS]

Iv worked on this bike before. It is a 4.25 rear wheel. 165 Slick. The both work really well together. No shaving the tire or adjusting the wheel incorrectly. Tire fits the wheel correctly* and dose not distort the profile. Solid set up.

~Shawn

[dave911]

I am currently running 4.25 rear. I have a 120/60 front, and 150/60 rear....Feels really good. However, after much research I bought some Dunlop slicks in 120/70 front for a bit better feel, and 155 rear for optimal contact patch. Unless you're pro racing, probly doesn't matter too too much. GOod luck. Dave

[matthewlyndon]

ye the set up it comes with is 3.5" front with a 120 i think. and the rear is 4.25 with a 150 on the continental road tyres.

the bike will be used one the road, i'm not a super hard, thigh down rider. no doubt i will be in time but this set up seems like a good plan for what im looking for.

also do you guys know whats srpings i'll be needing as im building from a standard mx kx250f.

cheers
matt

[dave911]

Due a search on "sag" and measure where you're currently at for both "static" and "race" sag. Couple quick measurements should help you figure out where to set your shock collar, and also let you know IF you need another spring. Chances are if you're between 150 and 185 pounds, you're probably fine asi-is.

[matthewlyndon]

Yeah I'm 6ft 2 and weigh 140pounds, so we will have to see how I get on. I'm a newbie when it comes to setting up a 2wheeler but I've got a lot of experience setting up cars, so hopefully once I get sorted and I have a few hours under my belt, I will be able to do some productive testing. Also what tyre pressures should I start out with?

Cheers for your help

[dave911]

6' 2" and 140lbs!! Is this Jimmy button? Kidding...
Anyway, tire pressure can really vary depending on application, weather, and tire temp.
I run about 24 psi hot on the small go kart track. On the street I would think 26 psi cold would be an ok starting place, but try searching the site for more insight. Dave

[matthewlyndon]

yeah cheers dave - sounds about right, when i had my sx i tried high and low pressures to feel the attitude entering/during/exiting a corner, and i found that if i ran anything above about a 25 it skipped around alot at the back obviously because im abnormally light (lol) and the bike had no real weight!