What is this little chainring screw thing for...?

[Maz]

Hi

Ok, so my new chainring arrived and I've watched the Bicycle Tutor tutorial on how to replace a chainring, but there's no mention of what to do (if anything) with this little screw thing.

Presumably, it fits in one of the 2 drilled holes in the chainring, but I'm clueless. This is for my Allez.

Any ideas?

Thanks.

 

[PapaZita]

Is it the bit that stops a dropped chain falling down between the chainring and the crank? Is so, one of the holes should line up with the crank when the chainring is mounted, and the screw bit should be screwed into the outside of the chainring.

 

[PoweredByVeg]

Isn't that the pin that fits in the chainring, to stop the chain getting jammed between the chainring and crankarm?

Some people leave them out to save weight

 

[HLaB]

Is it the bit that stops a dropped chain falling down between the chainring and the crank? Is so, one of the holes should line up with the crank when the chainring is mounted, and the screw bit should be screwed into the outside of the chainring.

+1 Thats what I thought it was, it lines up with my crank but maybe PbVeg is on the right track with his latter suggestion

 

[youngoldbloke]

remember to fit the pin before bolting on the chainring - dry run desirable.

 

[ColinJ]

I was doing a 200 km audax with a pal once and I happened to notice that the chainring pin wasn't aligned with his crank. I rode up alongside him and told him what I'd spotted. He said that he would sort the chainring out when he got home. 30 seconds later, he overshifted at the front and got his chain stuck between the big ring and the crank ...

 

[Maz]

Thanks for the replies. Makes perfect sense, fellas.

 

[Maz]

Job done, thanks everyone!