Hi My trusty Truativ howitzer bottom bracket is on its way out. I want to replace it with something lighter but can’t afford to replace my cranks just yet. It seems like quite a unique set up external cups with almost an old style crank bolt. Any ideas on what would work?

AFAIK, the Howitzer is a proprietary system that’s not compatible with anything else. Replace the BB with another Howitzer otherwise you’ll need cranks and a BB.

How about a used crank from the forum or eBay
Shimano bb are very cheap from rose bikes etc

Cheers folks. On Chain reaction cycles it has the howitzer bb’s reasonably priced and as well as the 67/73mm measurement it also has options for chainline; 51 or 56mm. What does this mean or relate to?

I had some once, if i remember rightly the chainline options make the crank sit further out or closer to the frame, (for odd shaped full sus frames with wierd rear wheel dishing?) and I think it said on my bottom bracket whether it was the 51 or 55mm one: try having a look at your bb and see if it says one way or the other and then get the same.