Torque Arm for Giant Anthem rear hub motor?

[m52 power!]

I am trying to source a good torque arm for a giant anthem MTB for a rear hub motor. The motor is a crystalyte HS4065R so it should be a bit beefy. I wanted to use the caliper mount, but the caliper mounting isn't IS compatible, but "post mount" style like on front forks.

The rear brake section looks exactly like this:

Thanks for any help!

 

[Drunkskunk]

Nothing off the shell will handle what the HS4065 is capable of, but then no stock torque arm would mount to those posts. Doc's Torque arms would be the best option for a place to start. You have to propperly bond them to the frame. Otherwise, You're going to need to build something custom.
Can you weld?

 

[m52 power!]

Nothing off the shell will handle what the HS4065 is capable of, but then no stock torque arm would mount to those posts. Doc's Torque arms would be the best option for a place to start. You have to propperly bond them to the frame. Otherwise, You're going to need to build something custom.
Can you weld?

I cannot weld but there are plenty of welding shops in the area. The MTB dropouts are aluminum so Doc's steel torque arms can't be welded on.

 

[dogman dan]

Copy those m52, in steel.

 

[Drunkskunk]

The idea with Doc's torque arms is they are bonded to your frame with an industreaal epoxy that will be stronger than most welds. once bonded, it's perminately part of your frame.

4mm aluminum plate is totaly unsuitable for making torque arms for any ebike, especialy something as powerfull as a 4065. 4mm of steel would still be awefully thin.

 

[TheBeastie]

Yeah I been eyeing dropouts for the Trek DS frame, I notice they are quite weird and lumpy awkward not straight and simple.
Seems like a trend on modern higher end frames, maybe they are trying to deliberately ruin torque-arm setups.

 

[teklektik]

I am trying to source a good torque arm for a giant anthem MTB for a rear hub motor. The motor is a crystalyte HS4065R so it should be a bit beefy. I wanted to use the caliper mount, but the caliper mounting isn't IS compatible, but "post mount" style like on front forks,

You might be able to fab a small bracket from a bit of angle stock that attaches via the post bolts and presents the other leg of the angle parallel with the dropout face. Use longer post bolts and sandwich the bracket under the bolt heads. A little harware store angle stock and hacksawing/filing should do the trick - no close tolerances at all. Picking up both posts would be best, but just the rear will likely do.

Then use one of these non-flat-dropout TAs and just drill a 6mm hole in the bracket face wherever the TA hole lines up - or drill both TA and bracket if the existing hole ends up poorly positioned. You only really need one of the TA bolts, so you can trim the other off the TA if necessary to get clearance. This should give you a thick steel TA to prevent deformation of the axle hole and a longish TA reach to the post to resist turning so there won't be huge torque on the bracket/post fixing point.

If you PM migueralliart, you can get a PDF of the TAs to cut out and try to fit.

Just a thought...