Not the most exciting component on your list, I’d guess, but certainly one of the most important. The last thing you want is to cycle a couple of thousand kilometres and have your bottom bracket disintegrate, only to find that no bike shop stocks a replacement to match your cranks. (Just ask Mark.) If you’re really unlucky, that’ll also mean new chainrings, and if your drivetrain is sufficiently worn to induce chain suck, a new chain and cassette. It makes sense, therefore, to get hold of a bottom bracket that you can literally fit and forget.
We did a lot of research. We looked at Shimano’s offerings and at those of various mountain-biking brands. But what we really needed was something that would last for tens of thousands of miles, not something that was designed more for rough trail and downhill treatment than longevity. And we wanted something based on open compatibility, not one of the various proprietary systems which would tie us to (insert brand here)’s components forevermore.
Eventually, we happened upon a new offering from German bearing specialists SKF. Their first foray into the cycling market was a series of ISIS-compatible bottom brackets for cross-country and downhill riders, based around their rather clever bearing engineering, details of which we won’t go into here. For the cross-country models, they list touring as one of their recommended applications, and with the units designed to last 10 years, we were convinced enough to give their high-end cross-country bottom bracket, the BXC 600, a try.
We fitted them and attached our personal choice of ISIS cranks and pedals. Since that moment, there wasn’t a creak, squeak, rumble, rattle or any other noise from them – until one day in July 2008, when Andy’s drive-side spindle suddenly sheared off entirely when he was riding unloaded in Tbilisi. The unit was replaced, and since nothing of this sort has happened to either the replacement or to my unit which has been running for over three years, we believe it must have been a freak defect.
My unit was removed after some 17,000 very tough kilometres for inspection, and the rotation was found to be somewhat rough. I forced some grease into the sealed unit (not recommended!) to get it spinning smoothly again. It was a little surprising to find the lubrication dissolving, but it doesn’t appear to have caused any problems. As for the long-term, this remains to be seen, but the unit has overall lasted well, compared to other bottom bracket units, and especially considering the punishment it’s taken.
We’ll recommend them based on their performance so far. Time will tell whether the advertised 10-year design life took into account the rigours of full-time adventure cycle-touring…