Bottom brackets - how do you prep yours??
Discussion
If you've never seen them before, the Santa Cruz Syndicate Downhill Edits are pretty fun. In their round up of Windham, after the cookery lesson, Greg Minaar's mechanic's overview of how he preps a bottom bracket is interesting, to say the least! Personally, I'd never considered using a power drill to almost knacker the bearings, but then again, I don't have a pool of automatic transmission fluid in my frames either! 
f
king Warning: Contains fking Missy fking Giove, so the fking language is fking definitely not fking safe for fking work! 
f
king Warning: Contains fking Missy fking Giove, so the fking language is fking definitely not fking safe for fking work! I watched that too, they don't half put some care and attention into set-up! Of course, that BB is going in the bin after about 5 mins of riding, but I wouldn't be surprised if a few riders are out there now with ATF sloshing around in their non-sealed frames or spinning BBs up with their Dad's drill "because Pro".
Personally, I put a bead off grease around the inside - the tube is meant to be stop it getting in contact with mud/water but every little helps I guess, grease the threads so they don't creak and wang it on, trying to remember which side is backwards threaded and praying I don't cross thread it (a turn the wrong way before tightening helps me with that).
Personally, I put a bead off grease around the inside - the tube is meant to be stop it getting in contact with mud/water but every little helps I guess, grease the threads so they don't creak and wang it on, trying to remember which side is backwards threaded and praying I don't cross thread it (a turn the wrong way before tightening helps me with that).
Edited by P-Jay on Wednesday 12th August 11:23
ROFL. Placebo/nonsense.
5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
upsidedownmark said:
ROFL. Placebo/nonsense.
5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Remember he removes the grease from the bearings before he spins them so it's not like-for-like, and I've never managed 10k miles from a BB, I do 2000kms a year at best and it's generally knackered by then.5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Edited by P-Jay on Wednesday 12th August 11:28
upsidedownmark said:
ROFL. Placebo/nonsense.
5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Given that he's the bike mechanic for the most successful male downhill racer of all time, you'd have to assume there's some method to his madness?5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Kermit power said:
upsidedownmark said:
ROFL. Placebo/nonsense.
5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Given that he's the bike mechanic for the most successful male downhill racer of all time, you'd have to assume there's some method to his madness?5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
http://www.vitalmtb.com/photos/features/PIT-BITS-W...
Personally I grease them and strip them down and regrease occasionally and get great life. Even for racing I wouldn't bother to break them in though, as a percentage of losses in the drivetrain due to bottom bracket friction must be minute.
Edited by W00DY on Wednesday 12th August 17:39
W00DY said:
Kermit power said:
upsidedownmark said:
ROFL. Placebo/nonsense.
5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Given that he's the bike mechanic for the most successful male downhill racer of all time, you'd have to assume there's some method to his madness?5 mins at 350rpm means the bearings are 'nearly knackered' - tosh. Broken in maybe, but knackered - compare that to 10,000 miles of riding. As for throwing away the plastic spacer 'because heavy' then adding ATF fluid which probably weighs as much, not to mention it's on a downhill rig, serious wtf.
Personally I grease them and strip them down and regrease occasionally and get great life. Even for racing I wouldn't bother to break them in though, as a percentage of losses in the drivetrain due to bottom bracket friction must be minute.
I wonder if they put the same amount of effort into setting up Bryceland's BB, given that he's famed for putting in about 8 pedal rotations per season?
Kermit power said:
Given that he's the bike mechanic for the most successful male downhill racer of all time, you'd have to assume there's some method to his madness?
In all seriousness no. 1) Racers still have lucky underpants and other such rituals - it does no harm, but that doesn't mean it actually does any good.
2) He's a bike mechanic, who happens to service the bike of a very fast rider. Bikes aren't black magic, mechanically they're pretty damn simple. If he was that genius, I rather suspect he'd be doing something a little more complicated.
To put it in context, if you ride for a couple of hours at 85rpm average, that's well over 10,000 revolutions. With real radial loads on the bearings. grease or no I'd not expect them to expire unless the bearings were made of cheese.
350 rpm for 5 minutes is 1750revolutions, with barely any load. You'd have to put some pretty special cutting compound in there to make any serious difference to the bearings in that time; it's lucky underpants territory, april fools day, or just playing mind games with the opposition.
[edit] - and while we're at it lighter grease/oil (just like ceramic bearings) will make it spin more freely off load - when you whizz the pedals round on the stand - because grease is sticky and provides most of the zero load drag. Has very little bearing on the friction when actually loaded though, and will wash out / lead to premature wear. In this case possibly not a concern, but probably a bad idea for anyone who has to buy their own stuff.
Edited by upsidedownmark on Wednesday 12th August 21:37
I wouldn't bet against it - GM is somewhat of a perfectionist, he puts a huge amount of work into set-up, also a bit nuts, did you see how he holds his hands on the bars pre-run so they don't feel narrow when he races.
Still, it's become a bit normal for me over the years, but they're all clearly bonkers, World Cup courses are ducking brutal!
Still, it's become a bit normal for me over the years, but they're all clearly bonkers, World Cup courses are ducking brutal!
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