roadracing a 450 supermoto

I would buy a 38( smallest vortex offers because the hub) a 40, and a 42 I doubt you'll like the 42 my bet is a 38 or 40 would he perfect.
Also what bar or psi are you running in the forks?

 

I can’t remember what I put in the forks, I’d have to check, I like things pretty firm

 

I feel it puts unnecessary stress on the motor, and doesn't do much. But, feel free, your engine guy may love you for it.

 

I’ve always been interested in this. I always had a hard on for those super single road racer builds that were all the rage a few years back. How often do the motors on these blow up though? I can’t imagine a 450 thumper motor liking the abuse of a road track.

 

Fun on a short track. Long straights will shake them to pieces, even with the right gearing. They used to routinely get trounced by kids on RS125s and Moriwaki 250s, but I guess those are all gone now. Motard race line can differ from the typical road racer line, and intersect mid corner.

 

i ride it like a sport bike.. even on the go cart track and my lines suck regardless of the bike i’m on


interesting thoughts about the vibrations though. if you gear it right, the bike will run no different RPM wise than on a shorter track.

unless you’re saying that just a higher top speed and wind will cause it to vibrate apart, which i don’t see happening either.

i can understand popping the motor if i was pinned on the rev limiter around the whole track, but that’s the whole point of running different gearing, so i won’t have to.




and fast kids are fast kids, regardless of the bike. i’m just some old out of shape dude looking to have fun.

 

Running the bike at higher speeds will put more strain on the engine, even if you gear it perfectly. 100 MPH at 10,000 is much harder on the engine than 50 MPH at 10,000 RPM. The loads on all of the engine and drivetrain parts is exponential. I ran a YZ 426 with WR gearing and 15/40 (or 16/40? I forget excatly) and it would go faster in 4th gear than 5th gear even with all of the calculations worked out. I had to adjust the gearing for quite a while until I just sacrificed top speed for better acceleration.

 

smallest rear you can go with is a 41. beyond 42 they don't pull the bike well. I have hit 100mph GPS verified with stock gearing (14/45) on my 18 FS450.

 

The aerodynamics of the sportbikes plays a big part in the kids/400s etc being competitive against the supermotos btw

 

i mean, i won’t disagree with you there, but i’ve been passed by kids on 85’s and 150’s on the kart track.


kids are fearless and made of rubber lol

 

good to know. looks like 15/42 will get me 109mph which should be fine.. i’ll probably just run that gearing.


how do you like yours? any issues, suggestions? i just picked this one up and so far i’ve only got 1.6 hours on it.. one practice, 4 races and a crash haha.

 

The Husky doesn’t need that small of a rear. Get a 42 and 44.

that what we ran on the miles last year and you ain’t going faster than that anyways.

new style motors like yours are fine for longevity. When it’s time to refresh make sure you buy the cylinder/piston oem matched set. They are numbered.

you should have a lot of fun. If you do want a brake upgrade hit up Philippe at beringer. Your stock
Brake will feel like shit after going to a rear brake.

 

Lmao fair I was just saying all things equal the aero plays a big park on the track

 

thanks dude

 

Is the FS rear sprocket bolt pattern different from the normal Yamaha/KTM/etc pattern? I've got 37t rears for that.

 

37 rear?

0-60 in never?

 

I’ve been considering one of these as well -

am I crazy for thinking I can slap a set of moto x tires on it once In A while and go play in the dirt ? Or is the suspension set up purely for road racing ?

 

For a fs450? Yes you're crazy for thinking that.
Pretty much everything is special for supermoto

 

that, and i'm pretty sure it has a wider rear swingarm than the FC to accommodate the wider wheel.... so i'm not even sure a stock FC wheel would bolt up, you'd have to get some laced up.

but now i can't find that info.. i swear i read that


https://www.husqvarna-motorcycles.com/en-us/models/supermoto/fs-450-2020.html

 

I believe the frame, engine and swingarm are the same as the fc.