Originally Posted by
aaronmichael
Hello All,
I have a customer that comes into the shop I work at with broken spokes quite often. He weighs probably 275-300lbs. He got rid of his old bike and bought a new one (not from me), thinking this would solve the problem. But low and behold, he is still breaking a spoke or two every couple weeks. He's riding a Jamis Boss (7 speed freewheel) at the moment, 26" rims. I think the ultimate solution is replacing it with a good heavy duty rim with good spokes. Problem here is, does any manufacture even make GOOD quality freewheel rims? Any advice would be greatly appreciated, thank you!
It's a build quality problem, not materials.
Spokes fail due to fatigue with the number of cycles survived dependent on magnitude of variation (about 60% of rider weight in the rear wheel as they pass the bottom of the wheel, which is more at 275-300 pounds than with smaller riders) and average stress.
Average stress is high in machine-built wheels because parts of the elbows are not taken past their elastic limit during the forming process, and it's less expensive to deal with occasional warranty returns than to buy a Holland Mechanics stress relieving machine or pay for hand labor.
All of the spokes see approximately the same conditions and fail at about the same time like popcorn kernels - a few, many, then the stragglers.
You could start with a $25 QBP wheel, bring it up to high uniform tension (105kgf drive side is OK for most rims), stress relieve by over-stressing the spokes, and probably be OK. You can squeeze near parallel spokes together with your hands (leather gloves make that more comfortable) or twist the crossings about each other using something softer like an old left crank, plastic screw-driver handle, or brass drift (my favorite).
Stress-relieve starting with quality butted spokes and they will both be OK and not unscrew as the non-drive-side spokes go slack passing the bottom of the wheel.
Other issues you risk are broken axles (which Shimano brand freehub hubs will eliminate) and bent rims (deeper double walled rims will be more durable).
Once paying or charging for wheel building ($40-$70) with new butted spokes ($32-$36) I'd add a budget priced new double-walled rim ($30) and Shimano brand hub ($30) at the same time to virtually rule out a $130-$170 second try to get it right.
FB's comments on specifics are good.