Sorry I didn't know what sub topic to post this in. I hope this is ok to post in the general forum :-)

I'm working on an odd project for my kids. One of those mini-bmx bike things. I bought one in rough shape...it was missing the left crank. No big deal I figured, I could fix it...until I got i tried to order one.

So long story short, its a standard 68mm wide bottom bracket with a 3 pcs square tapered crank. The crank measure 127.5mm wide.

The crank arms are 89mm long with 28t sprocket. That's not impossible to find (I had to resort to aliexpress)...but the fact that the cranks are flared out is the issue. The bike has really wide rear wheels...like fat bike wide so the rear of the frame is extra wide.

I purchased a set of 89mm long cranks with 28t sprocket and it contacts the rear frame of the bike during the pedal stroke. The crank arms need to be about 3/8" wider to clear the frame. So i'm trying to find a solution to this and figured there must be some way...

I figured I could buy a wider crank for the 68mm bottom bracket. It's 127.5mm wide currently. But looks like that nothing wider is available.
-Are there things such as tapered crank extensions? Like something that slips over the existing square tapered crank and extends it wider???
-Or can I use a fat bike crank in my 68mm bottom bracket?

The easiest would be to find a set of 89mm flared cranks arms...but I literally can find zero. Does anyone know of flared cranks in 89mm crank length with a square taper?

Any suggestions would be greatly appreciated! Thank you!


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