fieldspring

I have noticed a bent over tooth on the middle chainring of my 1999 specialised rockhopper mtb and wondered whether it is supposed to be like this for chain pick up purposes ? Otherwise I will attempt to straighten it as it seems to be causing interference in the lower gears - in the smallest chainring and higher rear sprocket gears a clicking and causing of a jumping sensation whilst peddling . Does anyone have any ideas ? Thanks

soyabean

It prolly rolled over a curb, I see it all the time.

Vise grip and eyeball it.

Andrew R Stewart 

Except I prefer an adjustable wrench if it can fit. Andy

Bill Kapaun

IF it's a "shift aid", they'll typically be "several", evenly spaced around the circumference of the ring.

alcjphil

It would be vanishingly rare for a tooth on a middle chainring to be bent. Teeth on big chainrings often hit things as you ride over obstacles however

Andrew R Stewart 

Agreed. I can't count the "broken off teeth tops" I have fixed over the phone with a customer Andy

soyabean

Wanna bet?

JohnDThompson 

Unlikely on a middle ring, at least without damaging teeth on the outer ring as well.

That usually works, and if it doesn't, you're really no worse off.

soyabean

Why does everyone think curbs are perfect with straight edges?

And for those that didn't know, rocks in the park are also just as imperfect.

Hondo6

"Unlikely" doesn't mean "impossible". But since the typical chainring spacing is about 5mm - and the large chainring protrudes farther towards the ground and is outboard - it would almost certainly take an incident involving relatively unusual geometry to damage a single tooth on the middle chainring without also damaging the large chainring next to it.

Yeah, it could happen. But that's not a bet the proverbial "smart money" would make.

fieldspring

Thanks for all comments to do with bent tooth on middle chainring. I decided that it had been damaged and bent due to some incident, though we could not remember what it would have been. Took the chainrings apart and hammered the bent tooth flat and the shifting and clicking has been resolved- hoorah ! Must have been a freak accident. Just goes to show that sometimes the unlikely event can be the cause of a problem even though our rational minds are telling us otherwise.

Pop N Wood

I've bent all sorts of chainring teeth when the chain gets hung up shifting under power.

Just bend them back, replace the rings when they wear.