hillslayer@
Regular
I guess I am just lucky running a 1500 watt hub in an aluminum frame with a cheap AliExpress torque arm, it is installed correctly and regen also, my axle nuts have never loosened.
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LeafBike 1000 watt axel size??
- Thread starter Kayscotts
- Start date
Kayscotts
New here
The two grins I was just looking at V3 (front and back) comes to $1400 not including tax or shipping (pickup) while the leafbike set up was closer to $500 so that is the biggest split for me…it’s starting to feel not worth it, if a proper installation of flats with hq torque arms is good enough.
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Not sure I'd recommend any of the above when I read this:
You'd need a voltage higher than 48V to achieve such speed with the motors I mentioned, and 35mph (=56km/h!) for an ebike is not what I consider safe. I'd wear at least thick clothing and a helmet at that speed to avoid serious injuries and ditch the rigid fork because it will vibrate like hell.
Kayscotts
New here
Yes that’s the fork I was looking at. It seems I’m over thinking a lot. So go with good torque arms even if hose clamp and leaf motor and call it a day I think should be my game plan. The leaf bike motors are only a third the cost of the v3 grin (with wheels)..if the qr dropouts are really doable as well then I’ll probably go with a surly troll fork as it matches my geometry very well and should serve well for this 1000 watt load. The battery from Grin I am looking at would technically need to be limited as well to 38amps, so technically not even 1000 watt load per wheelThose are some of them.
Other issues are using clamps with improperly made parts or poor materials (none of the harbor freight clamps I have ever had, for instance, have been even sufficiently well made to use for their intended purpose--the slots strip out even before they are tightened on a hose of the diameter they are for, etc. Some of them actually tore across the strap at a slot during tightening on a rubber hose. Some the entire screw-holder assembly simply came off the strap, etc.. Similar failures, with just the intended usage, for other sources of them. the only really great ones I've ever had were by Ideal, made before this century).
Another issue is that most of the torque arm designs intended to use hose clamps to secure them to the frame have sharp corners or edges where the clamp strap passes thru or over them. For many cheap clamp materials this will cause a stress point and it can crack or tear at that point as the arm applies force to it. For strong clamp materials they may remain curved around this point instead of reshaping to it, and so they can allow the arm itself to move a bit underneath.
There are other failure modes that are hard to describe, but you can find images of them.
However, if the fit and the materials are correct, the hose clamped designs work well enough.
Leaf is a good motor (you should read that thread, starting from the end since that's more recent applicable info). Unless you specifically want a different axle / torque arm solution, or have some other specific concern, there's not really any reason not to go with them I can think of.
Kayscotts
New here
Are you running a rear wheel configuration?
Kayscotts
New here
The 48v leaf motors I was looking at really did seem pretty good. They are listed running at 92% efficiency, at (unloaded?) 45mph/71kmh but I think real world would still be close to the target mentioned earlier. It would be nice to have a higher top speed than you anticipate to ride at is all. With ditching the rigid fork, how would one do this with torque arms etc? Bc that was my original intent (suspension) until I read more about needing rigid forks for this..I really don’t like the idea of a rigid fork but could live with it if it’s the only reasonable method.
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hillslayer@
Regular
Rear I don't trust running a powerful hub in 90 percent of the forks out there. Don't want to send you down another rabbit hole but I am running dual motors my other one is a 750 watt mid -drive.
Kayscotts
New here
What did you have to do? The absolute “best I’ve got” that I can come up with, that I only am pretty sure would be compatible, is a surly dinner fork 15mm with the grin v3 (15x110mm dropout adapter). A lot of input has been that if the fork is steel, torque arms are installed correctly, and within reason it’s good to go. So I’m fairly torn. 1 option seems by far the best but 3-4 times the cost, the other option I’m told is good enough but a lot of potential for disaster..
I’d skip the whole thing for now. Ebiking should be fun and not fraught with anxiety. Maybe with more research and reading you’ll find the middle ground that’s acceptable to you. Search on the word “dual” in the builds thread subforum to see what others have done, which would provide additional data points.
ZeroEm
Minor legend
Think I see the issue. It is not safe to build a fast bike based on a front wheel only motor. A front motor is not an issue with 1000w. Wanting to run 3-5000w on the front is asking for trouble. Do a simple build and work up to a fast bike later after some experience. Later it will all be easer.
Sure, that can be done if you have the necessary skills and experience pertaining to understanding mechanical forces and reactions and best practices for dealing with them. As well as knowledge and experience with hardware materials and strengths.
Emphasis on your description "installed correctly."
Judging by the questions and reporting here on ES, this set of skills and experience are somewhat rare.
hillslayer@
Regular
Why are you putting the hub in the front, I missed reason
You are right the cheap torque arm works fine if installed correctly, if not installed correctly you are better off not running a torque arm. There is a bunch of pictures of these not installed correctly it is one reason they have a bad reputation.
