Component model numbers: what's the difference?

[Piernas Flacas]

Hi guys,

 

I'm in the process of replacing worn components on my bike. I've noticed the difference in model numbers like a Shimano BB SM50, 51 and 52. Or a Shimano chain HG50 and HG54. What's the actual difference apart from price? Is it sizing related, weight, quality?

 

Thanks and cheers

 

PF

[madbradd]

It's more than just a number in some cases, sometimes completely incompatible.

 

The HG50 is a 7/8 speed chain

The HG53 is a 9 speed chain

The HG 54 is a 10 speed chain

 

Bottom Brackets look like they are the same just that the 52 is an upgrade to the 51 (better seals according to The Google).