I am planning to upgrade a few of my bikes .. some due to faulty BBs and some just to upgrade the crankset. Here are the questions I have:
1) Road vs MTB
I read from the another post about Road vs MTB Hollowtech that the BB and Cranksets gotta be the same category.
- What about other types of BBs like square tapered/Octalink?
- Is it universal for both MTB and Road?
2) BB spindle width and crankset compatibility
Was browsing some online stores for cranksets, and saw a few that mention that the particular crankset is compatible with spindle width 103-113.
- Why is there this spec?
- What is the difference?
My issue is that 2 of my foldies have BB width of 125 and 127mm ..
- So what bad things could happen if I used a crankset designed for narrower BBs?
- Or for the reverse?
3) Tolerance for difference in BB width
- Assuming I cannot can a BB same as the old one, what is usually a safe tolerance range + or - from the existing?
- Is it better to get one that's longer or shorter?
4) Changing from square tapered to hollowtech
- Hollowtech BBs don't have a spindle width specified. What do I need check if I am converting from square to hollow?
- Can I convert my foldies to hollowtech? Given their BB is at the wider end of 125mm?
5) Changing from square tapered to Octalink
- what is the width that I'll need to add or subtract if I want to convert from square to Octalink?
6) Changing from to Truvativ's Powerspline to Octalink or Hollowtech
I've got a road bike from 2006/7 that is using Powerspline .. which is a dying/dead product so am thinking of converting.
- what is the width that I'll need to add or subtract if I want to convert from square to Octalink?
7) Adjustments for change in Chainring/Rear Cog
Do I need to change BB with a different spindle width if:
Change the crankset between 1/2/3 chainring?
Change the rear from a 6sp to a 9sp? Thought I remember that I'll change different hub size if I want to change to a cassette of different speed.
8) Ceramic Ball bearings
- I've seen some BBs using ceramic bearings. What are the advantage of ceramics?