Bicycle Mechanics - Help me out pt2 -> bottom bracket

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operator
02-22-05, 02:37 AM
My bb vaguely looks like this.

http://www.bicycletires.com/images/American%20Classic/BB/Ti%20103.jpg

The problem is, the two large rings on the side. I have one that screws on clockwise and one on counterclockwise. I surmised that the drive side bb should thread on clockwise. However it seems to only want to thread halfway into the shell, then it seems like I really have to force it before it budges (didn't do it).

The weird thing is if I try to thread the same ring on the other side, it goes in fine. But then i'll have two rings that will unscrew itself from pedalling motion?

Am I missing something obvious again?

It's my 87 bianchi once again.

P.S are the outer lock rings necessary? Or can I just leave them off.

sydney
02-22-05, 07:06 AM
My bb vaguely looks like this.

http://www.bicycletires.com/images/American%20Classic/BB/Ti%20103.jpg

The problem is, the two large rings on the side. I have one that screws on clockwise and one on counterclockwise. I surmised that the drive side bb should thread on clockwise. However it seems to only want to thread halfway into the shell, then it seems like I really have to force it before it budges (didn't do it).

The weird thing is if I try to thread the same ring on the other side, it goes in fine. But then i'll have two rings that will unscrew itself from pedalling motion?

Am I missing something obvious again?

It's my 87 bianchi once again.

P.S are the outer lock rings necessary? Or can I just leave them off.If one is right hand thread and one is left, it's either english thread or swiss. We'll dismiss the Swiss. Countrwise threading on is left hand thread and it goes on the drive side. They won't unscrew when pedaling. ya need the lockrings.
moxfyre
02-22-05, 08:48 AM
The weird thing is if I try to thread the same ring on the other side, it goes in fine. But then i'll have two rings that will unscrew itself from pedalling motion?

Am I missing something obvious again?

It's my 87 bianchi once again.

P.S are the outer lock rings necessary? Or can I just leave them off.

Correct, the right handed thread goes on the LEFT side, while the left handed thread goes on the RIGHT side. The pedaling motion is NOT what might unscrew the rings (as long as they are tight), in fact it is precession, a much subtler effect that goes in the opposite direction. Article on left-hand threads and precession (http://www.sheldonbrown.com/brandt/left.html) by Jobst Brandt.

Don't try screwing the rings into the wrong side!!! You may ruin your bottom bracket or, worse, your frame!!!

operator
02-22-05, 12:29 PM
Thanks Sydney. Never seen that article on sheldon either thanks!

Edit: BB is now installed the correct way

Oh yeah is it geeky to have a chainguard?
sydney
02-22-05, 04:31 PM
Thanks Sydney. Never seen that article on sheldon either thanks!

Edit: BB is now installed the correct way

Oh yeah is it geeky to have a chainguard?Only with a handlebar basket and mudflaps.
moxfyre
02-22-05, 05:13 PM
Oh yeah is it geeky to have a chainguard?
I would love a chainguard for my fixed gear bike. Where'd you get yours? (Assuming it's not stock...)