BB30

[gummibear]

What is BB30 and what advantages are there over normal English or Italian BB?

 

I have been looking at a few frames and they are BB30.Do you get a converter to use normal English BB or is it a special BB?

 

Thanks.

[AndreZA]

1. the bearing are bigger so they last longer

 

2. crank spindle can be bigger so it's stiffer

 

3. no more thread in the frame, bearings are pressed in like a headset

 

4. you do get adapters that can convert from BB30 to normal

[gummibear]

Ok i see, but the cranks are damn expensive.

[JasonW]

I know Cannondale often bundle their BB30 cranks with the frame and you can often pick up some pretty good deals.

[Johan Bornman]

BB 30 is a great concept from an engineering perspective. As Mampara said, it has all those features that are real, not BS features.

 

To me the most important is the bigger bearing and then the press-fit bearings. Bearings in threaded cups are a big no-no. Small fine threads like that in today's bearing cups are really not suited to load bearing. They precess and unscrew themselves, hence the reverse (LH) thread on the right side.

 

Whenever you have a left hand thread on a load bearing structure other than a turnbuckle, you have an engineering flaw. We've been living with a flaw for many years. When I was a laaitie, my fathers car was a Valiant and its wheels had left hand threaded bolts on the one side. That was before they used the conical wheel nuts/studs of today and the load was  borne on the thread, not a smooth section.

 

Today all cars have conical wheelnuts and no more problems with unscrewing wheel nuts on the one side.

 

Same with BBs, we have to get rid of the thread on the load-bearing interface.

 

 

[Weight Weenie]

On this topic, Ill be getting a new mtb frame thats BB30 but want to use my M970 XTR crank.

I see allot of different adapters on CRC, any help as to what I'll need to run it ?