K2 / Proflex Riders Group

General => Tech Forum => Topic started by: tmaybee on September 28, 2003, 08:46:04 am

Title: Ti and Alloy bolts?
Post by: tmaybee on September 28, 2003, 08:46:04 am

Are there any bolts on an 856 or a crosslink that should NOT be switched to Ti or aluminum?  

This is what I have though of so far:

Frame:
Shock to strut         steel?
Shock to frame        Ti
Seatpost Binder       Ti
Main pivot axles   (cross bolt?)      Ti
Swingarm Pinch bolts      Ti
Strut to Swingarm bolts     Ti or Alloy?
Strut brake bosses    Ti
replaceable derailleur hanger chainring bolt     Alloy

Headset cap bolt      Alloy
Stem and barend pinch bolts          Ti
Magura rim brakes    Alloy bolt kit

Crosslink:
All bolts replaced with  Ti
All washers replaced with alloy or drilled out Ti   (anyone have a preference or know which is lighter?)

The syncros seatpost I have came with alloy mirco-adjust bolts on it.  They are working fine now but should I switch these to Ti for extra strenght?  Has anyone had any problems with these?

And the last question, anyone know the best place to get Ti or Alloy bolts/washers from?  I live in Canada so most US retailers will ship here.


Thanks,
Trevor

Title: Re: Ti and Alloy bolts?
Post by: Simon on September 28, 2003, 09:52:25 am

Any bolts subjected to high shear loads or require a high torque value should be steel,shock mounting bolts,strut to s/arm,and stem pinch bolts,preferably grade 10.9 though 8.8 may be sufficient,though Ti is stronge relative to its weight I believe its known to be more brittle than steel, I've seen postings on this site where some have replaced the top M6 shock bolt and replaced it with an M8 bolt,I've replaced some bolts on my bike with Ti but only one's that take lighter loads,eg s/arm pivot pinch bolts headset preload bolt,shifter bolts,also the s/arm bearing main pivot bolt but thats an M8 and relies on clamping the bearings into the frame and the torque required is achivable with a grade 5.5 Ti bolt,replacing a steel bolt for a Ti one when the component is designed to use a steel bolt is not always good practice, steel is not always used just to keep costs down,not sure about replacing all crosslink bolts with Ti either, in the end you don't really save a lot of weight anyway, just you could end up making some components more liable to fail.Simon