Chainring “pin” thing.

[dickyknees]

Any ideas on what these are on my 50 tooth chainring? One looks to be missing.

Deep clean still in progress!

Having a second look, the “missing” thing’s location hole looks a different profile to the others.

 

[Threevok]

Would there be a pin on the inside of the driveside crank, that fits snugly into that recess, to catch the chain, should it slip between the two ?

 

[the snail]

The pins/ramps are to give better/smoother shifting, or possibly a 'chain catcher' as tv says. If it works don't worry about it. Looks like it's not long for this world anyway.

 

[dickyknees]

The pins/ramps are to give better/smoother shifting, or possibly a 'chain catcher' as tv says. If it works don't worry about it. Looks like it's not long for this world anyway.

Yes I was thinking that but have nothing to compare it to. Would you replace now?

 

[wisdom]

It is indeed to help with shifting

 

[the snail]

Yes I was thinking that but have nothing to compare it too. Would you replace now?

I'd keep using it, IME you can use chainrings until they're completely FUBAR, so long as you're not getting problems with chainsuck or shifting gear. I usually replace them when I'm embarassed by the state of them.

 

[dickyknees]

Thanks for the help.

I’ve started looking for replacement rings but it’s a minefield trying to find compatible chainrings for the old Shimano 4600 in stock!

 

[migrantwing]

Thanks for the help.

I’ve started looking for replacement rings but it’s a minefield trying to find compatible chainrings for the old Shimano 4600 in stock!

Any 50t chainring will do.

 

[Ajax Bay]

Any 50t chainring will do.

5 bolt, 130mm BCD.
This: https://www.bikester.co.uk/shimano-tiagra-fc-4603-chainrings-357797.html
Doesn't matter that it's a 4603 (triple).

 

[migrantwing]

5 bolt, 130mm BCD.
This: https://www.bikester.co.uk/shimano-tiagra-fc-4603-chainrings-357797.html
Doesn't matter that it's a 4603 (triple).

Job done!

 

[dickyknees]

Great stuff. Thanks