Belt drive fat bike frames?

Hello!

I am about to build my first e-bike and am looking for frame recommendations. Complete bike recommendations are also welcome as long as I don’t have to replace too many parts. I can build bikes from scratch and can do electronics work, although I hate soldering if crimping will work instead.

I’m picturing a belt drive mid drive fat bike. About 30 mile rangew96h reserve to spare, about 15-20 mph is fine. It will be a commuting bike with a rear rack / baskets at the minimum with an option for a front rack.

I found this soma sandworm frame:
http://www.somafab.com/archives/product/sandworm-fat-bike-26-27-5

Which looks pretty perfect although I don’t know if the iscg tabs would help or hinder mounting a Bafang? It seems like using the tabs or an adaptor would be a great way to secure the motor but maybe they just need to be ground off instead?

Can anyone recommend any other known good fat bike frames that can accept a belt drive? the fat part is actually optional. I could do a regular mountain bike frame with a rigid fork too. I saw that a member here used a soma b-side. I just figured that if I can build it fatter I might as well!

For complete bike recommendations i’m currently thinking hydraulic disc brakes and an 3 or 8 speed hub in the back, either nuvinci / alfine / sa with a Gates / Bafang setup. I don’t know what issues there may be getting the Bafang unit into the bottom bracket so if anyone has measurements I could call the frame companies and ask them to measure or something? I want to use a rigid fork. I live in Denver which is pretty flat. The reason that I’m looking at an 8 speed rear is because I think I would like to be able to ride the bike unpowered easily but also be able to pedal it at full power if I want. I figure I need a wide gear range for that. But I am open to suggestions from you more experienced riders. Probably if I can just pedal at a few common city speeds that would be good enough too.


Thank you for your advice!

Someone else here cut off / grinded off the front iscg tab on a bike they put a mid-drive onto, it was not a fat bike, but that will work for any bike with those tabs.

ScooterMan101 said:

Someone else here cut off / grinded off the front iscg tab on a bike they put a mid-drive onto, it was not a fat bike, but that will work for any bike with those tabs.

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thank you!

I'm bumping this not too old thread of Overkill's. I too just ordered a Soma Sandworm, having also come to the conclusion that it seems particularly well suited for a Rohloff hub, AND a belt if I want to go that route. https://www.bikemania.biz/frames/fat-bike-frames/soma-sandworm-fatbike-frame.html

I'll be using a third BBSHD, from LUNA, I have had excellent service out of those motors and geared right am satisfied with the power. More then satisfied, stoked! I have no idea if a belt cog can be used on the BBSHD, if not that's OK as having a straight chain line means a more robust less stressed chain anyway. If I can go belt with BBSHD, I'll have to consider it I guess.

I have never built up a bare frame bike before, I guess I got the confidence to take this project on by what I have learned here, and with my three prior conversions of store bought complete bikes. Finding a good wheelwright (?) who is savvy on the Rohloff requirements will be the first thing on my list. I went through CycleMonkey on my Montague Rohloff install, and would again, except it appears that I can buy the hub online for MANY hundreds of dollars less then through them. Sending them a hub to lace up bought elsewhere is probably something they are not fond of, it may be simpler to go elswhere this time. NOT badmounthing them, not at all, they did a great job plus they talked me through my first IGH install. But an $800.00 difference in pricing makes me want to consider other options this time around. I never thought at the age of damn near 70, I'd be getting excited about a new bicycle, but I am.

craneplaneguy said:

I'm bumping this not too old thread of Overkill's. I too just ordered a Soma Sandworm, having also come to the conclusion that it seems particularly well suited for a Rohloff hub, AND a belt if I want to go that route. https://www.bikemania.biz/frames/fat-bike-frames/soma-sandworm-fatbike-frame.html
...

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A close friend had this idea too, but did abandon and returned to chain. He has all the components on the wall, not likely to ever use them.

Roholf +1
That is a very good addition to a BB drive build.

Belt... I wouldn’t use any of the bicycle belt drives that I have seen.

I did a bit of research, and found what I would need to adapt the belt to the BBSHD, and it looks pretty straightforward. Gates has always been on top of all things belt related, that is of course what they are all about. Any issues with them not working properly is no doubt due to installation errors, the main thing being it seems the cogs demand a very high level of accuracy, in trueness to each other. And that alone may be a good reason not to mess with it, a chain install isn't so picky. I've had good luck with all my chains anyway, they are not a major problem for me so I don't feel a overwhelming need to go beltless.

G'day people's
I must be missing something here, but a belt being endless, how do you thread it around the chain stay? I saw a Mercedes branded commuter bike many years ago with a belt drive & a very clever CVT but I didn't pay attention as to how you got the bugger through the frame.

AussieRider

AussieRider said:

G'day people's
I must be missing something here, but a belt being endless, how do you thread it around the chain stay? I saw a Mercedes branded commuter bike many years ago with a belt drive & a very clever CVT but I didn't pay attention as to how you got the bugger through the frame.

AussieRider

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Crikey, can't anyone answer this?

There are actually two ways to accomplish this.

one:
An opening in the rear triangle. You open it. You work the belt through. You close it. Easy enough.

two:
To highten the chain stay out of the way. Riese und Müller do this.

To answer the original question:
The Jagamoasta by Maxx has a dedicated Rohloff frame which will take a belt and an IGH.