Lysander":29kbdo1e said:God help us when he discovers his balls............
lewis1641":33ce6o6d said:Lysander":33ce6o6d said:God help us when he discovers his balls............
That's why they turned to external againhamster":3pmx38dd said:My pals seem to have had nothing but trouble with external BBs on road bikes. I shudder to imagine the lifetime on MTBs with all that mud.
Cartridge BBs are OK and I have a couple of UN72 which have lasted over 20,000 miles. However, to get it all to fit in a cartridge the bearings are smaller than a cup and cone, which has 11x 1/4" balls. That's fine on a solo bike, but tandems have much higher bearing loadings and cartridge BBs only last a couple of thousand, whereas the cup and cone ones last longer in terms of bearing wear.
hamster":113e6zxd said:BB30 was also another approach, with the advantage of the bearing shells getting some support from the frame, unlike external. However, I've heard a couple of disappointing stories about BB30 too. It amazes me, surely such a bearing would be well-understood by now and after a century people would be able to make a durable one? :?