Originally Posted by
Sixty Fiver
Cartridge bottom brackets are often not as smooth but for an economical and trouble free set up there is nothing better... when anyone says a part lasts decades that is meaningless... if you don't use something it will last forever and mileage and the conditions under which you ride are a better gauge of how durable a part is.
To be clear, I didn't say that I've had bottom brackets last for decades. I said that I've never had one fail which is a big difference. I've used cup and cone BB extensively before the advent of cartridge bearing BB. Some were sealed but many were not. I've had more of them fail than I can count due to pitting of both the spindle and the cups from infiltration of contaminants. The contaminants were usually grit and water from mountain biking.
That infiltration is the major failing of the cup and cone BB. If you ride off-road, you can't avoid throwing dirt and grit at your bottom bracket. If you want to preserve the cup and cone BB, you should tear it apart and rebuild it after every off-road trip or else you end up with grit in the bearings and that's never good. Cartridge BB are far better sealed and require zero maintenance. In other words you run them until they don't work anymore and the replace them. For me, that replacement interval has always been so long that I replace them with upgraded equipment before they wear out.
Originally Posted by
GeoKrpan
Thanks for sharing your knowledge.
What did we gain from cartridge bearing BBs?
We gain time. Maintaining a cup and cone BB is a time consuming and rather complicated procedure. The maintenance interval makes the task even more onerous. A UN54 BB like Sixty Fiver uses is cheap. He may only get 20,000 km (12,000 miles) out of one but that's 12,000 fiddle free miles for $12 to $20 probably in really crappy conditions. His cup and cone BB may get 30,000 km (18,000 miles) but in order to get that kind of service life out of his cup and cone BB, he's going to have to service it on a very regular basis. The number of times is dependent on how crappy the conditions that he rides in. If he rides in nice conditions, he might get away with 3 or 4 rebuilds. Throw in lots of winter slush, salt and grit or ride it hard off-road and he could double or triple that service interval.
And let's look at the service that's involved. Remove the cranks, remove the lock ring, remove the NDS cup, remove the spindle, perhaps remove the DS cup (not all that easy to do if it's on there properly), clean out the old grease, install new bearing (you
should do this every time you take the bearings apart because you don't know what the grit may have done to the bearings), reinstall the fix cup, reinstall the spindle, reinstall the adjustable cup, adjust the load on the bearings, lock the NDS cup in place with the lock ring, perhaps readjust the NDS cup because the bearing load isn't right, install the cranks.
Compare that to a cartridge bearing install which is basically 4 steps. Remove the crank, remove the BB, install the new BB, install the cranks. Easy peasy. External bearings are even easier because you only have one crank arm to tighten.
I used cup and cone BB from the late 70s to the early 90s and replaced innumerable spindles and slightly fewer cups. I rebuilt my bottom brackets on such a regular basis that it seemed like I was doing it weekly but was still replacing spindles. I haven't had a
single cartridge BB (which I never service) fail since I switched. By any measure the reason that
I use cartridge BB seems crystal clear. I'd rather be riding then fiddling with my bottom bracket.
Originally Posted by
Bekologist
I would just get the new Deore crank with the trekking ring ratio 48-36-26, swap the 26 out for a 24, and call it good. steel rings on 2 or all 3 out of the box.
the newer higher end mountain cranks from shimano all use their new carbon/ally rings which are both expensive and goofy overkill for a touring bike IMO.
I've always like the sugino cranks but the new external BB stuff is much easier to install and take cranks off of bike. i think its a big step up. a rider on a global scaled trip could carry an extra BB for those cranks, they weigh less than a fart. or, overnighted in the mail for little cost as they are under a pound.
i've got frames that, once the threads were chased, allowed the BB cups to be installed by hand except for the final tightening. a rider could replace them on the side of the road with a rock, a belt, and a swiss army knife.
What I've been saying all along
Make your life easier. The less tools required to fix something, the better.