ultimaa380
1 µW
- Joined
- Jul 17, 2018
- Messages
- 4
Hi, I have a 1000w hub motor on the rear of my GT aluminum frame. It seems to have bent the dropouts a bit and slips out even when tightening under any significant throttle. How could I fix this?
Rear aluminum dropouts bent
- Thread starter ultimaa380
- Start date
Generally it can't be fixed. You can't just "bend it back" and you can't weld down there unless you are going to re-heat-treat the whole frame.
You can ameliorate the problem by adding good torque arms to prevent further bending. Ebikes.ca has some pretty good ones.
You can ameliorate the problem by adding good torque arms to prevent further bending. Ebikes.ca has some pretty good ones.
captain387
100 W
Take a look at this thread for ideas.
https://endless-sphere.com/forums/viewtopic.php?t=26444
https://endless-sphere.com/forums/viewtopic.php?t=26444
wturber
1 MW
Skaiwerd said:
Mostly is illustrates why using torque arms are a good idea.
At this point, it looks like making a pair of torque plates of one type or another are your best option, short of replacing the frame.
The thread linked above has a number of different methods of torque arms / etc.
The thread linked above has a number of different methods of torque arms / etc.
Philaphlous
1 kW
- Joined
- Mar 28, 2017
- Messages
- 431
Bummer dude! I always worry about mine since I'm running close to 2kw through my 1000w hub motor... I have a chromolly frame though with steel dropouts... I check them regularly and they're great thus far! I have plans for a torque arm..just haven't got around to it yet... that's my summer project!
Yup, looks like you have plenty of room there for a nice torque arm install. Done correctly, and if you keep an eye on proper axle nut torque, that could be a permanent repair. Just make sure to get a solid, quality, STEEL, torque arm.
And while you're at it, the slot in the axle should be pointed down, to avoid collecting any more moisture (rain, splashes) than necessary.
And while you're at it, the slot in the axle should be pointed down, to avoid collecting any more moisture (rain, splashes) than necessary.
RunForTheHills
1 kW
A local custom frame builder could replace the dropouts for you. However, I think most of them work with steel and not aluminum.
dogman dan
1 PW
Torque plates. Its like that D shaped tabbed washer but bigger, and bolts into holes you drill in the dropout area. Looks like you have enough metal there to bolt on a big enough piece of metal. One of the holes can be the same one your rack bolts to.
captain387
100 W
I'd get on the torque arms, 10 bucks for a 300 mm x 10 mm x 40 mm piece of steel, a couple hours with a grinder and a drill.Philaphlous said:
or,,,
nothing could happen
or,,,
The dropouts crack and break, the axle spins and shorts/cuts the phase wires, rounds the flats of the axle, the phase wires short and burn the controller, the wheel falls out of the remainder of the dropouts at 50 km/h.
Yes, a little dramatic
, but all potentials.Alluminium isnt really that strong for ebike frames. Same happend to me last week :x i tried to tighten it and it slips out and if it doesnt it comes of instantly when i apply throttle. what i am currently doing is i hammered the droupouts and bent them back ( this wont fix the problem and will go back to being bent) then i epoxied some nickel inside the droputs and currently im waiting for 2 torque arms for either side off ebay for £10 they seems like the torque arms everyone else is selling but for £15 more. Tommorow they should be arriving ill keep you updated.
https://www.ebay.co.uk/itm/1-Set-2-Set-E-Bike-Electric-Bike-Universal-Torque-Arm-For-Front-Or-Rear-Use-UK/123499875526?ssPageName=STRK%3AMEBIDX%3AIT&var=424044910914&_trksid=p2057872.m2749.l2649v
https://www.ebay.co.uk/itm/1-Set-2-Set-E-Bike-Electric-Bike-Universal-Torque-Arm-For-Front-Or-Rear-Use-UK/123499875526?ssPageName=STRK%3AMEBIDX%3AIT&var=424044910914&_trksid=p2057872.m2749.l2649v
Actually, if they're aluminum, they'll probably jsut break off. Depends how far they were pushed, type of alloy, heat treatments, etc.Yungyakz said:
If they're steel, they'll bend repeatedly before breaking. Also dependent on the above stuff, but much more tolerant than aluminum.
Regarding the cost of the torque arms in differnet sellers, sometimes tha't sjust greed. But it can also be the materials it's made of (soft or hard, etc), and the preciseness of machining (tightness of the axle fit preventing rocking/spinout).
FWIW, all of the ones like those are copies of Grin Tech's design, so if you want the real one, that may be better than the copies, go to http://ebikes.ca
Voltron
1 MW
Was it actually installed like the picture implies, with the tabbed washer on the inside of the frame, with the tab not catching anything?
amberwolf said:
I was very lucky mine didnt break off and the wheel came out in time. I would reccomend thick steel high quality torque arms but i was on a budget and too lazy to make one also dont have alot of tools. The torque arms came in the post and they seemed good enough but the hose clamps are too big and and one wouldnt decide to losen up so i cut it off and there thin cheap ones. I would reccomend buying thicker quality hose clamps and using high strength loctite or just try bolt the thing to the bike. Its been good so far (currently using one because i need another hose clamp) running the bike at 50a and its holding up.
Rsmk4turbo
1 mW
- Joined
- Dec 13, 2018
- Messages
- 11
I had same issue with my old GT AGGRESSOR mtb, used torque arms but still kept slipping out,ended up putting kit on steel framed bike in the end.
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