Shimano UN55 BB Bottom Bracket Review

3.67 out of 5
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February 26, 2015
Model/Year: 2014

Pros: Price

Recommendation: There's probably better more expensive options, but for the money this one has been just fine.

September 13, 2014
Pros: Price seems reasonable for the quality. Quality & smoothness. Way better than stock. Easy to install if you have the correct tools.

Cons: None really, except that it's a square taper.

Recommendation: Been a good replacement for the off brand OEM BB I wore out on my Trek SS - much smoother and quieter. Good installation instructions. Looks to be of good quality. I've only got one 10-mile ride on it so far, but I think it will work well. Make sure to go back and re torque the BB and the cranks after riding the first few times.

December 22, 2012
Pros: Standard issue on older and cheaper Shimano cranks that use an internal bottom bracket rather than external cups.

Cons: Same issues that come with all square taper BBs...heavy, a pain to maintenance, and prone to wallowing out the square tapered holes in your crank arms which causes major slop and creaking over time.

Recommendation: If you need a replacement BB for a square taper crank, this isn't a bad choice. It doesn't roll incredibly well but that could be a function of cheap grease or so so bearing quality. There are more expensive options out on the market from companies like Phil Wood but if you really want better performance, ugrade your entire BB to something with external cups and bearings.

Shimano UN55 BB 3.67 out of 5 based on 3 ratings. 3 user reviews.