Really?Even an MXUS 3k is overkill for this project.
I guess the next step down would be the 5 Kg. geared motors: Mac, EZ, BMC and BPM and I don't think they would get you there, especially if by "decent amount of torque" you mean climbing hills that a guy would find hard to walk up. They would be hard pressed to do that and still top out at 30 Mph.Needs to top out at around 50km/h with a decent amount of torque.
Those 4s and 6s packs with 16ah handles twice the amps compared to 20ah packs (icecube57 tested 5c peak ability to them). They actually have two pairs of 8ah packs in parallel inside the pack instead of 1 pack like on 20ah. I have run 20s 16ah pack with heavy use on 100A peaks and they perform very well. I think I will make second wiring for 16s 32ah pack (add 3 more) and try 150A peak with them. Can't fit over 8 pack.motomech wrote: ↑Jun 08 2018 12:48amReally?Even an MXUS 3k is overkill for this project.icecube57, did some testing and felt that a 16 Ah pack could only sustain a 60 Amp dis-charge rate. My own experience is, I can see some sag on my 20Ah pack at the lower end of the dis-charge cycle and that is w/a rated controller of only 30 Amps.
You don't think you are working the Multistar too hard?
The multistars can dump insane amounts of amps, thats why people use them.
That looks awesome, well done! Does it still feel heavy at the back wheel? I can't even bunnyhop my bike at the moment let alone jump it, back wheel stays planted.
While I agree on the “weighing too much part” it sounds like your brake sucks. I have a QS 205 in a 17 moto rim with Shinzo 3” tire on it (read- way more weight!) and can easily lock it up at any speed on any surface.....on one of the grippiest tire you can buy. I run Hayes Stroker Ace but any good 4 piston with an 8” rotor will do. Also, going to a bigger motorcycle tire is a necessity in my opinion. A bicycle tire just doesn’t have the size nor strength to handle heavy hub motors. They add weight but make the motor weight disappear on smooth and lightly rough surfaces. By the time the terrain is rough enough that the tire is leaving the ground over 1-2 inches the weight can’t be masked. I run about 12 psi (I think....been awhile!) and adds a lot of cushion to the ride and really masked the weight well on curb jumps and the like.spektrolyte wrote: ↑Jun 13 2018 7:54pmNo you don't understand. The back wheel weighs 19kg, Thats almost 50% of the bike and is causing problems with traction and manouvreability - the rear wheel has so much rotating mass that the brake can't lock the tyre making it very hard to ride offroad. Instead of rolling over things the back wheel slams into everything and getting it off the ground is just dodgy because its so unbalanced.
Yes, unfortunately that is the nwer q76r which has a curved bottom on the frame to purposely accommodate a bafang mid drive unit.Antenor wrote: ↑Jun 15 2018 12:09pmMaybe first try to dial the rear suspension rate and the pressure of the tyre...i think that will help a lot
If doesnt work, then try a new motor.
I think that frame cam acommodate a BBSH, tilted back. I saw once a 76R frame with one, but dont know if is a special type of frame
There is no such thing. With a different turn count (if you achieve equal to factory copper fill) you will have exactly the same motor with only different combination of voltage and current required for exactly the same performance and efficiency. Since we are voltage limited at the top end, increasing the turn count of the windings only results in a slower lower power motor.
From speaking to you in the past, I get the impression that you want more of a helping hand at getting up hills and general assist than just all out speed without pedalling. If you are just riding general woodland trails with no jumps or very rough terrain i think a MAC could work for you as long as you keep it within tested limits and dont over volt it. Geared motors are most stressed when full throttle feom a stand still.