Is my bottom bracket shell backwards?

Just fitting BB to new frame and the Drive side wants to take the anticlockwise cup. This is surely knackers? Checked on Shimano and yep says DS clockwise (73mm BB) shirley the cups will loosen over time? If it was just the wrong cup then shirley it wouldn’t take the thread? Is it time for bike seller HULK SMASH? Or have i got my little head all confusededed?

Is it an Italian road bike?

What frame? Not an Italian BB shell is it?

Genesis grapil one of the cheapo ones that cropped up on in the psa here

Are you working with your bike upside down on the floor? 😳 (I know someone who did that once).

Anti-clockwise on drive side and clockwise on non-drive side is correct. It isnt rotational friction that keeps the cups tight, its due to precession linky

Ahhh was looking at 70mm bb instructions. Presumably thats the italian version. Normal service resumed.

It should be opposite to the pedals if that helps

Yep, it’s the Wankel effect. It would wind itself loose otherwise.

Well you learn something new everyday..

Always wondered why it was counter to what the friction drag would dictate.

Thanks

You can test the principal with a pen with a screw on lid. Loosen the lid slightly then hold the pen body and wobble the pen lid in circles with the tip of your finger. It should screw or unscrew the opposite way to the direction of the circles you make.

you can do it with a wine glass too. Swirl the wine round anti-clockwise and the glass itself will try to rotate clockwise. Red wine is better 8)

This is where reading instructions gets you…

The easy way I always remember it is with drivetrain bits it always* unscrews the direction it would turn if everything seized up.

*except for some exceptions 😉

Okay Clever clogsies
Why isn’t the derailleur jockey wheel counter threaded.
Guarantee in any MTB event I will always see some poor sod crawling round looking for the shaft and bushes.

I even carry a spare these days in my puncture kit

Guarantee in any MTB event I will always see some poor sod crawling round looking for the shaft and bushes.

Really?

I’ve never seen a jockey wheel come off in use, or seen anyone else with that problem, in a long time* riding bikes.

*not as long as some, but a good 25yrs+

Jockey wheels don’t need to be reverse threaded as the applied load is always in the same direction, whereas with a bb or pedal the direction of load on the axle rotates.

I’ve never seen a jockey wheel come off in use, or seen anyone else with that problem, in a long time* riding bikes.

*not as long as some, but a good 25yrs+

I was on a ride with Sean Kelly once, and it happened to him. I actually found the bolt in some stones, after lots of other people spent 10mins looking for it. I think people thought I’d hidden it.