I'm considering a custom bike build but can't make sense of the bottom bracket situation. I understand the different types but can't work out if the crank arms are compatible with all BB30 and PF30's? Reason I ask is I can't find a PF30 specific crank. All cranks seem to be BB or GXP (I figure the GXP needs a GXP BB).

I won't be putting the BB in myself but still need to know which cranks to buy... If I can get a custom build within budget (which is gonna be hard).

Has anyone used a Shimano Zee crank set yet? How are they different to the other Shimano range of cranks? I'm thinking of putting a set on my single speed to replace my existing one. Anyone tried this yet?

Interesting vid from a german road bike site. Apparently the UCI is set to legalise discs for road racing in 2016, so all the roadies are madly checking out what it all means.

This is a worst-case test, where they load a road bike up with 200k of weight including rider. I'm not sure about the rotor size, my deutsch is long since forgotten, perhaps the native speakers on this site might be able to help, but comment from the site I picked this up from seems to indicate they are only 140s.

The interesting bit is about a minute from the end.

Hiya,

New to the sport and have a recurring problem. I am riding a 29er hardtail and keep dropping my chain when riding on rougher terrain, usually downhill. It slaps about pretty hard as well.

I have looked up chain guides and the like, but note that they seem to work for one or two chain ring set ups, where I have 3. Also, I was wondering whether a chain tensioner might do the trick - or both.

I would appreciate any advice anyone has on what I can do equipment or set up wise to try and minimise this.