Originally Posted by tvrla
Thanks Woody! I appreciate your sharing your knowledge with us.
Could you tell us how you go about straightening one of these rims once it's unlaced?
I spent a major amount of time one week (about 40 hours) trying to true a front R100GS wheel. I got it much better than it was originally, but still not good enough for me. What tended to happen (once I'd figured out how to tighten the spokes down - I tore it down and started over many times) was that it was absolutely true until the last tightening, and then it would wow out.
Evidently the rim was slightly bent. Now, Ricardo says that you can adjust that by adjusting the spokes - but totally opposite to the way you true a normal wheel. Do you disagree with that?
sooo...you'd like to know how i straighten these rims,,,hmmmmmnnnn...OK
1..i spin the wheel and mark the hi and lo spots with my sharpie,,,,as well as the lateral hi/lo spots
2..i check to see if there are any loose /broken spokes that may be contributing to this condition...
3..i loosen all the spokes and see if the rim straightens out or if it has a definite bend or wave/wobble in it
4..if it 's bent ,,,i remove it and place it on my surface plate and confirm where it wobbles with the marks i made the at the time i spun it,,,,
5..then it's either onto my press or one of several jigs i've built over the years to push/pull it back in place,,numerous trips back and forth til that sucker lies absolutely flat on the table and the diameter is within .5mm/.020"
6..reassemble and center it laterally and then longtitudinally..then tighten and torque them to 5Nm/85in/lb,,,followed by inserting grub/set screws and tightening them to 1Nm/7in/lb....shooting for less than 1mm /.040"runout ie:+/-.020'' in all directions
FYI<<<,those specs were my standard 10 years ago,,,in recent yeaars, I have perfected my techniques and shoot for 1/2 of my old standard In recent time we routinely get our final runout to be closer to +/- .010'' or >020 '' /.5mm TOTAL run-out....This was achieved by scrutinizing /checking the rims more carefully on our surface plate,,,We assumed brand new OEm replacement rims were straight,,,got snookered by the ASS-U-ME syndrom....Now we KNOW better...''measure twice/cut once!!!
7.. that's essentially all there is to it!!!
ps..once again...if you value your sanity,,,i'll say it again,,,,starting out with anything less than a true rim,,,is a descent into the hell you have been experiencing,,,if you all visualize the importance of EACH SPOKE PERFORMING THE SAME AMOUNT OF WORK,,,,imagine what goes on when you try to straighten the rim from where it is bent,,,ya gotta add MORE torque,,,and then even more torque to move it alittle more in that direction,,,and before ya know it...ya have a wheel that has a few spokes doing more work than they were designed to do and others just loafing off,,,,,and ya apply pressure to the wheel and ,,,,the spokes want to even the load out,,,and the only way they'll do that is by relaxing here and there and ya have a wobbly wheel again...whoooops