BBSHD and Full Suspension MTB or go hardtail?

[IzzyMandelbaum]

Hello,

I am wanting to put a BBSHD on a full suspension mountain bike. The problem is, some of these bikes have different sized bottom brackets.
I'm looking at buying a second hand one.
I found a Trek top fuel 7 2008 for a reasonable price but I couldn't find any information on the BB width. Something about a press fit? I've no idea.

So what I'm trying to find out is; are there certain mountain bikes which have a 68-73mm BB? The bike will mainly be used for a 30km round trip commute with some off road and rough roads. I was hoping for a cross country bike as they are more designed for speed(lighter/riding position) but any full suspension should be fine.
How would the mid drive fair with the swing bars/chain stay?

Or is it not worth the hassle and I should just get a hardtail MTB?

Thanks

 

[DanGT86]

There are tons of suspension bikes out there that take a 68-73mm bottom bracket. The press fit one you speak of will probably present a problem but 68-73mm bottom threaded bottom brackets are very standard.

The beauty of the particular mid drive kit that you are looking at is that from the cranks back it works exactly the same as the original mountain bike. As long as the drive will mount to the bottom bracket it will work just fine. That is exactly what its made for. You get to keep all your rear gears/shifters/derailleur.

Hard tail bikes are easier when you are doing a custom drive that does not use the original bike drivetrain or when you drive the wheel with a sprocket at a location other than the bottom bracket. Thats when you get into custom chain tensioners and clearance issues.

Best of luck shopping for a bike.

 

[IzzyMandelbaum]

Good to know, thanks Dan. I'll keep looking and waiting for the right bike to come along.

 

[Speady]

The Bafang BBSHD is available for different BB sizes, from 68mm to 120mm I guess. So this will not be an issue.
Better check you donorbike for a straight downtube, or you'll have your middrive hanging down like an udder.

 

[sather]

The press fit bottom brackets are completely non standard and vary by manufacturer. They vary by width and diameter. You can overcome the width problem by buying a wider BBSHD and using spacers available from Luna, Cal-E-bike and Lectric-Cycles, but the larger diameters will require some kind of diameter-reducing spacer to be fabricated.