kadir
100 mW
- Joined
- May 22, 2009
- Messages
- 38
Btw, before anyone reads anything... Is there anyone else who broke their 12g spoke on the crystalytes? Please answer below, inorder to make me feel better that I am not the only person who suffered
My Rim got damaged recently. Broke a 12g spoke on my crystalyte kit.
Btw, 12guage is almost twice as much metal/diameter as 15g spokes(generally 14 gauges are seen).
Normally 12g were used in horse racing carts(atleast in Southern Ontario). Now try to imagine the strength.
The cause of the failure was probably my fault.
I was carrying 2 people of 180lbs, including me(180lbs), and the bike's own weight of 42lbs at the rear wheel. Totaling to around 500Lbs just on the rear wheel.
Now add 120Nm torque on the axle, PLUS going at 60km/h, and then going over pot-holes.
The spokes didn't fail in the beginning. The spokes beside the one that broke cause the Rim's inside to bulge, releasing stress from those spokes, and eventually putting stress on one of the spoke (the one what was not associated with the bulge). The good spoke now underwent fatigue and thus failure.
Even though without one spoke, the wheel is holding up quite good. I have clocked over 150km WITHOUT a spoke, and carrying passengers. There was a slight wobble issue, but I true-ed the wheel a little bit to minimise it. There was a bit of hopping because of the bulge, that caused the rim to bulge out at that portion.
Another thing to let you know. The spoke length calculator was somehow off on the Justin's site (ebike.ca).. My wheel diameter was 525mm exactly. The resulting calculated spoke length was 153mm. I had cut them at 155mm. But I was having trouble getting the nipples to the threads of the spoke. Realising I am short of a few more milimeter. So for assurance, I increased the spoke length to 165mm
The threads were rolled, NOT cut. This ensured that the major diameter of the threads bigger than the diameter of the spoke itself. This happens because, when the threads are rolled, the metal are squeezed into the thread. Thus no metal is lost, resulting in some squeezed in, some out along the spoke, making the thread.
This ensures superior performance, as the threads are less prone to getting sheared off.
Resulting in 3 mm of excess spoke length that was grinded off.
The cost was
60$ - for Rim
50$ - for 70+ spokes(includes the 36 short ones, few other damaged by the spoke threader )
5$ - for the 'super' rim tape. I was atleast 3mm thick.
Free - hole drilling/enlarging of rim, use of the grinder, use of spoke threader
Totalling to 115$.. pretty expensive if you break your spokes :S.. the least you could go away would be 30$ for a good rim, 30$ for spokes.. yet totalling $60..
Btw.. do consider the hours wasted trying to put the 12g spokes into the holes.. its harder than you think.. unlike the 13/14g, they are MUCH harder to bend.
I hope these spoke last a loooong time
.
Btw, now I have .3mm of hop and around 0.5 of offset. Pretty good for 1st time trueing
My Rim got damaged recently. Broke a 12g spoke on my crystalyte kit.
Btw, 12guage is almost twice as much metal/diameter as 15g spokes(generally 14 gauges are seen).
Normally 12g were used in horse racing carts(atleast in Southern Ontario). Now try to imagine the strength.
The cause of the failure was probably my fault.
I was carrying 2 people of 180lbs, including me(180lbs), and the bike's own weight of 42lbs at the rear wheel. Totaling to around 500Lbs just on the rear wheel.
Now add 120Nm torque on the axle, PLUS going at 60km/h, and then going over pot-holes.
The spokes didn't fail in the beginning. The spokes beside the one that broke cause the Rim's inside to bulge, releasing stress from those spokes, and eventually putting stress on one of the spoke (the one what was not associated with the bulge). The good spoke now underwent fatigue and thus failure.
Even though without one spoke, the wheel is holding up quite good. I have clocked over 150km WITHOUT a spoke, and carrying passengers. There was a slight wobble issue, but I true-ed the wheel a little bit to minimise it. There was a bit of hopping because of the bulge, that caused the rim to bulge out at that portion.
Another thing to let you know. The spoke length calculator was somehow off on the Justin's site (ebike.ca).. My wheel diameter was 525mm exactly. The resulting calculated spoke length was 153mm. I had cut them at 155mm. But I was having trouble getting the nipples to the threads of the spoke. Realising I am short of a few more milimeter. So for assurance, I increased the spoke length to 165mm
The threads were rolled, NOT cut. This ensured that the major diameter of the threads bigger than the diameter of the spoke itself. This happens because, when the threads are rolled, the metal are squeezed into the thread. Thus no metal is lost, resulting in some squeezed in, some out along the spoke, making the thread.
This ensures superior performance, as the threads are less prone to getting sheared off.
Resulting in 3 mm of excess spoke length that was grinded off.
The cost was
60$ - for Rim
50$ - for 70+ spokes(includes the 36 short ones, few other damaged by the spoke threader )
5$ - for the 'super' rim tape. I was atleast 3mm thick.
Free - hole drilling/enlarging of rim, use of the grinder, use of spoke threader
Totalling to 115$.. pretty expensive if you break your spokes :S.. the least you could go away would be 30$ for a good rim, 30$ for spokes.. yet totalling $60..
Btw.. do consider the hours wasted trying to put the 12g spokes into the holes.. its harder than you think.. unlike the 13/14g, they are MUCH harder to bend.
I hope these spoke last a loooong time
. Btw, now I have .3mm of hop and around 0.5 of offset. Pretty good for 1st time trueing
