mrv 

me again
​​​​​​ I got a chain ring from my LBS. For not too much.
I didn’t notice the anti drop pin doesn’t line up with the arm.
I’m thinking one option is to drill /tap /lock tite in a short M5 pan head screw - behind the arm.
Barring that, is trailing the crank a better location than leading to avoid chain jamming?
thanks

bikeme

Isn't the pin supposed to be on the other side? Like you installed the ring flopped? But the graphics look like they should be the way to installed it. Hmmmm?

CliffordK

Nope.

The pins go between the crank arm and the chainring.

5 bolt spiders can either have one bolt hidden behind the arm, or can have the spider clocked so that all 5 arms are visible, which is what this ring is apparently designed for.

How does the pin attach to the chainring? Many of them were just drilled and tapped so you may be able to simply unscrew the pin. Tap and put it back in behind the crank arm if you wish.

I've ridden quite a bit without a chainring pin. As long as you rarely drop the chain to the outside, it doesn't really make a difference. Then if you do drop a chain, fix it rather than grinding the chain in.

CliffordK

Oh, also note, your countersink is likely on the wrong side behind the crank arm. I suppose that would be on the middle ring.

How does your chain ride and shift, probably on the inner tiny ring?

Also make sure the spacers for that ring are OK.

mrv 

Thanks for the comments.
The pin looks riveted or swagged (I think that’s the process to deform metal pins).
I’ll ride with it for a bit as is, and see if I screw things up.
I looked at drilling the ring behind the crank. The ring is some what contoured where I’d need to drill. I can see how I’d screw it up.

2_i 

If you managed to fit a plastic chain guard on the outer ring, it would prevent both pant staining and chain drop to the outside.

bikeme

Ah, yes, you're correct--I must've been being tired when reading the post.

mrv 

Follow up question not related to the drop pin
When I disassembled the chain rings, I failed to notice the shim washers falling on the floor and work bench.
Possibly I don’t need them if everything is shifting fine. But where do they go?
Do they shim the outer ring out? Or shim the middle ring toward the granny gear?
The gap to the granny gear is much bigger than the big to middle ring gap. So I’m thinking that’s where they go- if I have problems.
Thanks.

Crankycrank

Usually if you have shims from the factory they are needed but not always. If you find that everything works fine just leave it as is but don't lose the shims in case you find out you do need them and I can't say where they were supposed to be positioned as they can be used to space either chainring or even just as washers for the chainring bolts. Your new chainring may have solved any spacing issues that old one had.

2_i 

If the two rings are spaced too closely, the chain on the smaller one may start rubbing or catching the larger one when you do not want it. If the spacing is too large, the chain may fall in-between and get stuck. Other than that, you do not really care, as the the derailleur positions are regulated by cable tension and stop screws.

CliffordK

Try cross-chaining.
Small rear with the middle or small front.

You'll know if you need the washers!!!

Also make sure that you aren't bending the rings at the hidden bolt.

Many of the newer chainrings are designed with offset teeth. So, it is quite possible that a replacement ring will act differently than the original.