NorCalTuna
1 W
- Joined
- Mar 24, 2010
- Messages
- 58
Before my epic fail I want to express my gratitude for this awesome forum. I'm really, really impressed by both the purpose as well as the technology coming around!!!
SO, Epic fail time. I've been hanging around and reading forums here for months and now I'm building a really nice ebike that I've been dreaming of for a while: X5303, rear, 6 packs worth of fatpackness, 72v please, Lyen controller... nothing complex, nothing crazy... In my previous life I worked on SCCA Cars, then went to Jim Russell racing school for a year before working on Porsches, then I went and built customs, motards and superbikes for a friends's AFM/AMA shop. I'm even Dynojet certified. So, i'm not exactly a nOOb, but I'm also a chubby college student now and not a dashing formula car driver and mechanic anymore, I just lurk around LEV Forums now. ehh. On to the epic fail.
I was installing the rear wheel tonight and, following electric riders instructions, buttered the bag out of the deralleur side threads. I have a snap-on torque wrench which is about as expensive as the rear wheel and 5303, with recent calibration, and I'm fairly certain- being that I was torquing in a three step sequence- 50, 55, 60, which was the figure electric rider states for the m14x1.5 thread. It seemed high, but so does the load on the setup. The left side came up to 55, but the right never made it over about 52.5, which in retrospect was probably more than tight enough ( for instance... mono bolted rear wheel on formula mazda race car? 110 Lbs. One bolt, 3/4" shank, 170 hp, 2600 lbs, 150+ mph...) but it was buttered by then anyhow so it needed to come off. I wondered if ER meant 60 Nm, but thats, what, like 45lbf? Oh retrospect. That sounds pretty reasonable, and would have clicked on the wrench on either side.
I'm pretty sure the nut failed before the threads, but then again I'm not entirely sure the pitch of these nuts ER included is as reliable as those on the really, really nice axle I just hogged. Honestly, after reading the torque plate murder thread, I was pretty impressed by the construction of the Clyte parts. I can't believe I did this. I'd include a pic, but really, I don't wanna look at it right now.
I'm going to try to chase the threads and then have my fabricator make me a double deep nut on his lathe, unless somebody knows where to find this (metric allthread is 14x2, thought of a coupling nut), which will (hopefully) reduce the individual load on each thread section and then lock that in place with low strength loctite, which shouldn't pose any more problem to get off than the 60 lb-ft bolt anyway, and gets around alignment issues.
Any other suggestions or experience which seems pertinent here? Whole thing scares me now until my fab dude- who was one of my teachers at mech school and former Penske indy crew- visits and blesses it. One thing which may come out of this is Massive Torque Plates for rear hardtail applications, if for nothing else than a reinforcement which would make the axle completely captive and possibly keyed.
thanks sphere!
SO, Epic fail time. I've been hanging around and reading forums here for months and now I'm building a really nice ebike that I've been dreaming of for a while: X5303, rear, 6 packs worth of fatpackness, 72v please, Lyen controller... nothing complex, nothing crazy... In my previous life I worked on SCCA Cars, then went to Jim Russell racing school for a year before working on Porsches, then I went and built customs, motards and superbikes for a friends's AFM/AMA shop. I'm even Dynojet certified. So, i'm not exactly a nOOb, but I'm also a chubby college student now and not a dashing formula car driver and mechanic anymore, I just lurk around LEV Forums now. ehh. On to the epic fail.
I was installing the rear wheel tonight and, following electric riders instructions, buttered the bag out of the deralleur side threads. I have a snap-on torque wrench which is about as expensive as the rear wheel and 5303, with recent calibration, and I'm fairly certain- being that I was torquing in a three step sequence- 50, 55, 60, which was the figure electric rider states for the m14x1.5 thread. It seemed high, but so does the load on the setup. The left side came up to 55, but the right never made it over about 52.5, which in retrospect was probably more than tight enough ( for instance... mono bolted rear wheel on formula mazda race car? 110 Lbs. One bolt, 3/4" shank, 170 hp, 2600 lbs, 150+ mph...) but it was buttered by then anyhow so it needed to come off. I wondered if ER meant 60 Nm, but thats, what, like 45lbf? Oh retrospect. That sounds pretty reasonable, and would have clicked on the wrench on either side.
I'm pretty sure the nut failed before the threads, but then again I'm not entirely sure the pitch of these nuts ER included is as reliable as those on the really, really nice axle I just hogged. Honestly, after reading the torque plate murder thread, I was pretty impressed by the construction of the Clyte parts. I can't believe I did this. I'd include a pic, but really, I don't wanna look at it right now.
I'm going to try to chase the threads and then have my fabricator make me a double deep nut on his lathe, unless somebody knows where to find this (metric allthread is 14x2, thought of a coupling nut), which will (hopefully) reduce the individual load on each thread section and then lock that in place with low strength loctite, which shouldn't pose any more problem to get off than the 60 lb-ft bolt anyway, and gets around alignment issues.
Any other suggestions or experience which seems pertinent here? Whole thing scares me now until my fab dude- who was one of my teachers at mech school and former Penske indy crew- visits and blesses it. One thing which may come out of this is Massive Torque Plates for rear hardtail applications, if for nothing else than a reinforcement which would make the axle completely captive and possibly keyed.
thanks sphere!