Am I confused....

[PutAwayWet]

or are the cups on my external bearing BB just wicked tight? Just for clarification, the drive side cup is supposed to loosen by turning counter-clockwise (opposite of crank rotation), and the non-drive side is supposed to loosen clockwise - right? I tried taking them off today, and I almost stripped the cup/tool interface. I even tried tapping the tool with a hammer to break it free, to no avail.

Secondly, anyone got a good recommendation for replacement bearings for a Truvativ Stylo SS external bearing crankset? I've heard there are better aftermarket bearings out there.

[@thegates]

I'm pretty sure you're turning them the wrong way.

Phil Wood makes some bearings that might work.
http://www.philwood.com/Price%20List/P10.pdf

[jerman]

You are definitely going the wrong direction. Clockwise on drive side to loosen. Just installed one on friday.

[plume_mtb]

or are the cups on my external bearing BB just wicked tight? Just for clarification, the drive side cup is supposed to loosen by turning counter-clockwise (opposite of crank rotation), and the non-drive side is supposed to loosen clockwise - right? I tried taking them off today, and I almost stripped the cup/tool interface. I even tried tapping the tool with a hammer to break it free, to no avail.


Whoa. You've got it backwards there. Try switching the direction for better results! ;) That said those cups can be awfully tight, but not so tight that you'd need a hammer. Something's not quite right. When you get them off you may consider chasing the BB shell threads if they seem ultra tight going back on. Use a high quality grease too. Not that you have chasing tools just laying around but I bet your LBS would do it for cheap if you brought it in ready to go. Something I would consider if the new BB doesn't go right in.

Remember for a BB the drive side has left handed threads and the non-drive side has 'normal' right handed threads. You need to turn the drive side with the direction of the pedal rotation to loosen. It's lefty loosey on the non-drive side.

If you can do it, try a non Truvativ product. I rate my XT cranks much higher than any thing else I've tried.

[DirtRagArt]

Don't you hate it when the TV news runs one of those promos "How you could die tonight, tune in at 6"?

Well, next issue we're running a bottom bracket tech feature. ;)

[rockyrider]

The Race face Deus/Atlas/Evolve external BB bearing cups correct for operator brain fade, they have an arrow on them shows which direction to rotate them to tighten 'em.

If you've been tightening them this long, they are likely to be on there very very tight now, so a tool that fits well will be important.

You might consider giving the Enduro BB bearing cup set a try

http://www.enduroforkseals.com/id136.html

[PutAwayWet]

Yep, luckily I realized I was a moron before I did any major damage. It's funny how helpful those manuals can be when you read them. I'd love to get some Enduro cups, but I'm not sure they make them for the truvativ cranks.

Isn't it kind of counter-intuitive the way they tighten/loosen? I mean, for pedals they tighten in the direction you pedal so as not to loosen up while you're riding, right? Why not for BB?

[tryandgetme]

It's a different piece that's threaded in in each case. Pedals, it's the spindle side, BB it's the bearing's outer race side. There's something about rolling a smaller object inside a larger diameter one (ball bearings in a bearing race) that makes the race try to turn backwards. or something like that. any engineers or physics professors here?

[PutAwayWet]

You know, that kind of makes sense. I learned something new today. :)

[tryandgetme]

maybe it's moving the BB around inside the shell (pushing down moves it down, and as the pedal comes down the pressrue point moves rearwardss), because that does happen (at micron sizes...can't remember what that's called either)...something like that. I wish I took more mechanical physics

[rockrider]

You're on the right track. As you pedal you rotate in inner race clock wise (looking from the drive side) the bearings move in a clockwise direction as a whole, but they rotate counterclockwise individually, this exerts a counterclockwise force on the outer race, thus tightening your BB.

[Jahnov]

http://www.philwood.com/Price%20List/P19.pdf

check out this Outboard Bearing R/R tool

Not sure if ol' Phil has the bearings that would work for Truvativ though...

This guy says he'll pay anyone who can provide him with the info for this specific BB:

http://www.bocabearings.com/main1.aspx?p=quicksearchkit&cat=9

Enter the Manufacturer, application, and model and look what comes up...

[kpomtb]

http://www.philwood.com/Price%20List/P19.pdf

check out this Outboard Bearing R/R tool

Not sure if ol' Phil has the bearings that would work for Truvativ though...

This guy says he'll pay anyone who can provide him with the info for this specific BB:

http://www.bocabearings.com/main1.aspx?p=quicksearchkit&cat=9

Enter the Manufacturer, application, and model and look what comes up...

why don't they just go to a shop and buy one and take it apart? seems simple to me.