Setting up FE570 suspension for SM

Hey all,

I'm setting up my FE570 for SM and am trying to find out how much to lower the shock.

Front is KTM SMR forks 280mm of travel with a length of 861mm from bottom of shaft to top of cap. Stock FE is 891mm same measurement.

Rear is a spare FE570 shock I'm going to shorten to match the SMR forks.

I don't have a stock FS shock to measure exactly how much to shorten it so here's my logic.

FS rear travel = 310mm
FE rear travel = 335mm
FS is -7.46% travel

FE exposed shaft length = 66mm which gets you the 335mm of travel at the end of the swing arm
reduce that by 7.46% and you get 61.07mm

So removing ~5mm of exposed shaft should get me 310mm and the correct ride height. Or am I looking at this wrong?

Should I install the SMR forks and un-shortened shock without a spring, orient the bike to get desired rake (63.5 degrees), and measure the exposed shaft length? I think I'll do that anyway just to confirm.

Appreciate any thoughts or FS measurements any of you might be able to provide.

That's good info, thanks.

I think I'll go run it tomorrow as is and see how it works.

I had the fork tubes even with the triple clamps and had zero issues. As a matter of fact I liked it so much I'm not going to lower the rear just yet. I want to put some time in on it and have some faster riders ride it before I start messing with chassis geometry. Dave at http://www.durelleracing.com is doing my suspension work and has been very patient with my waffling and ignorance :mrgreen:

The only changes I'll be making for the first race are SM valving in the shock and stiffer fork springs.

Can one of you with an FS570 look in your owners manual and see what it lists for the shocks fitted length. The FE is listed at 411mm on page 89.

Thanks

If anyone is interested Elite Motorsports in Loveland CO has an FS on the floor right now.

I'll be getting my data from that bike and will post up here for posterity.

In summary the FS shock is 8mm shorter than the FE, forks are 20mm shorter.

If you want more info here are the fork and shock specs for the FS, from the owners manual.





And here's the FE