Tevano crank bb length and bb type

[carpenter]

Any one know what length of bb should be used with this Tevano crank:




I have tried Sheldons database, but I don't know the TA model number.
I have also tried fitting on a bb and worked out that a 116mm bb would give me about 2mm clearance from the frame, so 118.5 mm (from Sheldon, TA type 334) would work.
What sort of gap between inner ring and frame do people usually go for - does 4mm sound better than 2mm?

Also, before I buy a bb - what type do people prefer (give me pros and cons please). Votes for cartridge or separate cups/bearings, I think it may be lighter and more robust to go for separate, am I mistaken?

 

[Chris S]

A chainring can easily wobble 2mm. Go for 4mm at least.

 

[mjr]

Also, before I buy a bb - what type do people prefer (give me pros and cons please). Votes for cartridge or separate cups/bearings, I think it may be lighter and more robust to go for separate, am I mistaken?

I think I prefer loose BB. If you pay it a little attention, splitting it down, cleaning and repacking with fresh marine grease when needed, it will run almost forever and slightly more freely than most cartridges which often seem tight at first... but the drawback is it is more work than a cartridge and it does need cleaning before axle or cups pit else it is a lot more work, which is much more often than a cartridge which might work for years... but if you do really leave one alone for years then the cartridge may well be seized in the frame and need almost-abusive tools to extract it! So if you should check it annually anyway, you might as well clean and grease a loose one. I think.

In reality, my bikes have what they came with. Installing and especially removing fixed cups is too annoying for me.