Are there any mini hubs that will take 7 spd in 135mm?

[Kevinator]

Since I wasn't able to get the "cute" motors, I'm now leaning towards a BMC motor. Especially because they will take a 7spd freewheel and weigh less than a standard hub motor. Before I start pricing the BMC's, are there any mini hubs that will take a 7spd freewheel in 135mm dropouts?

Seems like bafang, GM mini, cute, amped bikes geared all max out at 6spd in 135mm dropouts.

 

[cell_man]

The Puma (Mac) motor will fit in 135mm dropouts with disk and 7 speed freewheel. Similar size, power and construction to the BMC V2 600W but quite a bit cheaper. If you are happy with 22/23mph at 36V and about 27mph plus at 48V and don't want to push mega power through it, they are a nice motor. Like any geared hub motor the gears do have their limits but as long as you stay within reasonable power levels, they are reliable and perform well. If you want to dump mega power through a hub motor I'd recommend going DD or fit 2 geared hub motors like I have.

 

[Kevinator]

thanks for the suggestion cellman! The puma looks like a good alternative to the BMC.

 

[cell_man]

Sorry Kevin, just re read the title, you did say Mini hub. I wouldn't qualify the Puma as a mini hub motor at about 4kg. The Bafang BPM climber is also a nice but not mini geared motor. I have 1 here, I'll have to check if you can fit a 7 speed freewheel.

 

[Kevinator]

Yeah, originally I was trying to get the smallest hub motor I could find. I am putting together an ebike for my mom and wanted to go with something light enough for her to carry off a truck. BMSbattery hasn't had them in stock for over a month so now I've decided she can probably handle another 5 lbs of weight and if I can get 7 gears, I wont have to change out the shifters. Right now the ones I'm considering are the GM mini 250w, BMC 600w v2, and Puma 500w.

What are the dimensions of the Bafang BPM?

 

[kriskros]

i have a puma running with 7 speed in an arrow tadpole[ l aced by john holmes] 36v 20amp foxx power.... getting 25.2mph.... also have a bafang from holmes ,,front mount ,..he can lace a bafang for 7 speed in a rhynolite for $300.00

 

[cell_man]

The Bafang BPM is very similar size to the Puma and BMC, maybe just a tad smaller. Maybe a touch lighter as well. I've left the climber that I have somewhere, not sure if it will accept a 7 speed with a 135 dropout, but you should still be able to add a small spacer and spread the dropout if it's a bit wide. I can't really knock the climber, they are a nice motor and i think Bafangs geared hub motors are about the guietest geared hub motors I've used.

 

[dogman dan]

So why do you need all 7 gears if the bike has a motor? With a 7 speed bike, you are into the less pricy shifters and such, and all you need to do is adjust the limiting screws on the derailur, and adjust the shifter cable to the new 5 speed cluster. The 7 speed shifter will still index fine for 1-5, and just not use 6-7.

She most likely will not be using the entire gear range once motorized, so get the cute or bafang if you want to. Likely you can still have the range anyway, just more space between each gear, which again, when motorized makes no difference now. You won't need close ratios like when only pedaling.

It's not like the 9 speeds, that use special chain the 5 speed cluster cant take. Heck, even then it's just a matter of getting a different chain in many cases, or at most replacing the chain and the crank.

 

[cell_man]

Agreed, I hardly ever change gear on an ebike. Just leave in a high gear all the time and the motor still gives you plenty of acceleration off the line.

 

[Kevinator]

You guys make great points, but think of it this way... we're all into bikes on this forum. So much that we constantly modify them and thats a big part of the fun. For normal people (let's call them civiilians), they don't care about the details.

Forget about the motor for a second, I'm simply trying to avoid the never-ending "my bike keeps getting stuck in 5th/6th gear!" complaints :lol:

 

[dogman dan]

You keep the good shifter and derailur. Simply adjust them to run just the 5 gears instead of 7. Losing gears is easy as pie, adding them is not.

 

[kmxtornado]

You guys make great points, but think of it this way... we're all into bikes on this forum. So much that we constantly modify them and thats a big part of the fun. For normal people (let's call them civiilians), they don't care about the details.

Forget about the motor for a second, I'm simply trying to avoid the never-ending "my bike keeps getting stuck in 5th/6th gear!" complaints :lol:

How about an internal gear hub in the back like something from Sturmey Archer. That'll let you change gears while stationary. You can match that up with a front hub motor and that should solve all your issues. That would be an awesome setup. Pricey though.

 

[shock]

My ebikekit geared hub fits with a 7 speed freewheel on a FS mtn bike frame.

 

[d8veh]

My BPM motor is fitted with a 7 speed gear-set. You have to make a very slight modification, and that's to add a washer or two that fit over the axle, but still goes inside the free-wheel, which might mean turning down a standard washer unless you can find one the right size. Without the washers, you'll be clamping the free-wheel when you do up the wheel nuts.

 

[TonyReynolds]

I use a 11-32, 7-speed freewheel with my MAC 500W in 135mm drop-outs. It replaced a 9-speed cassette and works fine. In my case, no adjustment to the derailleur was necessary. Like dogman said, taking away gears is easy....