Question re: Racetechs

[chemicalsmile]

I've read just about every thread out there (including DI's awesome how-to) but I'm having some problems dialing in the sag. The only other person I've seen around my weight that's installed these posted that they cut their spacers at 190mm - I weigh 10 lbs more than that person posted so I figured I'd stay safe and cut my spacers first at 215mm. Checked sag after somehow managing to force them in there and I got 15 mm loaded sag. Ok, no biggie, cut the spacers down to 200mm and measured again - now I'm getting 16mm of sag. Does this make sense? Shouldn't lopping 15mm of preload off make a bigger diference? I don't see how lopping off another 15mm is going to net me another 15mm of sag BTW - 1.0kg springs, 310lb geared up. Checking sag with zip tie (sitting on bike in riding position then propping it up with the centerstand and jack to get the front in the air, then measuring from dust seal to zip tie). Any help would be greatly appreciated!

 

[DefyInertia]

Is someone holding the bike while you sit on it? Are you doing so geared up? Are you sure that the zip tie is not moving around on your unnoticed?

Aside from measurement issues above, I'm not quite sure what the relationship between 15mm of spacer length to sag length is but I can say that 1kg springs with 200mm of sag is pretty damn stiff.

I would recommend using PVC to experiment with spacer lengths all while being extra careful that you have eliminate measurement error. PVC is cheap and easy to cut...then you'll just have to cut the metal once.

Side note, what weight oil are you running?

 

[chemicalsmile]

Yeah, they are ridiculously stiff - Unloaded (static?) sag is next to nothing. Using 15w Repsol oil. I was going to go the PVC route but I couldn't find any with the right OD. I've got a good tube cutter so it's easy enough to shorten the spacer.

 

[oldfast007]

Just as an addition, if you cut too much off and end up with too much sag, you could always gain back a few mm by adding a few correct thickness washers..:thumbup: Good luck.

 

[chemicalsmile]

Oddly enough, shortening the spacers down another 10mm made a huge difference...I went from 16mm of loaded sag to 28mm. Unless there's a certain preload amount that once reached, won't affect the sag anymore, I'm not sure what the deal is. Haven't had a chance to ride it yet due to a freak October snow we got this weekend but I measured sag with the stock springs and oil before starting and got 63mm of sag so I'd imagine halving that will make a big difference. Even without leaving the garage I can already tell the weak point will be the rear shock now....hyperpro shock spring may be the next mod...