Why is my bottom bracket unscrewing?

[Xanda2260]

Hey guys, needing a bit of bike knowledge help please!

When I pedal my trike, the BB unscrews! I thought the lock ring was supposed to stop that? Am I doing something wrong?

Any help appreciated....
Ta

Alex

 

[lazarus2405]

If pedaling loosens it, you've probably got it installed backwards. The drive side (right side) of the BB should be reverse threaded and tighten counter-clockwise, otherwise precession will work it loose. From your build pics I can't tell what sort of BB you're running. Tell us (show us?) exactly what sort of bottom bracket you're using, and what you used as the BB shell when you built the trike.

 

[Xanda2260]

Hey Laz,
The bb and tube were cut from a donor bike. I just welded a clamp to it installed it. Should the lock ring be on the side with the chainrings? Cos mine is.

I'll get a pic, back soon

Okydoke, this is a shot from the front of the trike, camera pointing down (please ignore rust a nd crappy welds)

Chainring side unscrews when pedalling. (left if pic is right of trike)

Thanks guys

 

[d8veh]

You could try removing all the grease/oil from the threads with petro;. Mine kept coming loose too until I degreased it. Now it's OK.

 

[dennyt]

Sorry to say you welded your BB shell backwards. The lockrings should be on the non-drive side. The reason there are left-hand and right-hand threads is to prevent loosening.

Try loctite?

 

[Xanda2260]

Sorry to say you welded your BB shell backwards. The lockrings should be on the non-drive side. The reason there are left-hand and right-hand threads is to prevent loosening.

Try loctite?

Arse. Boy do I feel like an idiot! Do you know if I can simpky swap the threaded caps over? Doubt this will work due to left-handed threads...

Muppet.

Thanks guys,

 

[Chalo]

Sorry to say you welded your BB shell backwards. The lockrings should be on the non-drive side. The reason there are left-hand and right-hand threads is to prevent loosening.

Try loctite?

Arse. Boy do I feel like an idiot! Do you know if I can simpky swap the threaded caps over? Doubt this will work due to left-handed threads...

Muppet.

Thanks guys,

Easiest in the long term may be to chop that sucker off and do it over. You could easily invest more time and trouble coping with the side effects than just taking the cure.

Chalo

 

[neptronix]

turn it into a delta and pedal backwards.. problem solved!

 

[voicecoils]

lazy option:

http://store.velo-orange.com/index.php/grand-cru-threadless-bottom-brackets.html

Also, feel free to say... ' i had no idea such things even existed!'

 

[neptronix]

^--- We have a winner, please step up to claim your prize

 

[Xanda2260]

I had no idea such things even existed!

Thanks guys, think I'm gonna just cut of the clamp and reweld it. Technically I can turn the whole thing around, but the tube holding the derailer will point forwards then!

Can't believe I did that....

 

[Harold in CR]

Just give it a quick Tack weld ?? Easy to remove, later.

 

[Xanda2260]

Just give it a quick Tack weld ?? Easy to remove, later.

Ooh, I'm liking that idea!

But I really should do it properly... Damn it, why do I have to be so lazy!

 

[iamsofunny]

Yea man, just bend two small pieces of flatbar at 90 and tack them on one on either side