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Chainring Drilling


Balooba
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Need help please. 

 

I bought an Absolute Black 32t oval chainring. Trying to fit it on my XT M8000 but the holes are too small.

 

The holes are threated (did not notice when I bought it). I believe this chainring was meant for the XT M785.

 

The ring is not new. NOW- can I drill the holes to get rid of the tread.

 

PS Spelling of "tread" I am not sure of.

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Need help please. 

 

I bought an Absolute Black 32t oval chainring. Trying to fit it on my XT M8000 but the holes are too small.

 

The holes are threated (did not notice when I bought it). I believe this chainring was meant for the XT M785.

 

The ring is not new. NOW- can I drill the holes to get rid of the tread.

 

PS Spelling of "tread" I am not sure of.

 

of course. it's not a porcelain doll.

 

edit: you learn something new everyday

Edited by Shebeen
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Hang on a second before you grab the power tools. Those chain rings aren't threaded the thread is on the inside of the crank arm - do you mind posting a picture of the chain rings and holes? I have honestly never seen that the ring has a thread in it. 

 

Edit: I wanted to ask more questions

 

What's the BCD of the ring? You get two different kinds - a 96 BCD which will be for the XT crank and then the older version, 104 BCD. Neither of which has a thread in them. 

 

In my view: A chain ring should not be drilled

 

Need help please. 

 

I bought an Absolute Black 32t oval chainring. Trying to fit it on my XT M8000 but the holes are too small.

 

The holes are threated (did not notice when I bought it). I believe this chainring was meant for the XT M785.

 

The ring is not new. NOW- can I drill the holes to get rid of the tread.

 

PS Spelling of "tread" I am not sure of.

 

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post-51766-0-91123700-1582107921_thumb.png

post-51766-0-77260500-1582107930_thumb.png

Edited by RobertWhitehead
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I've sen those rings . they are for 1x systems where you are converting a 2x crank to run 1x.

the shoulder on the back provides a the correct spacing for the ring to get the chain line right. The thread is to make mounting easier. I would not drill it because you may have an extremely hard time finding chainring nuts that are the correct length to work with chainring bolts that are available.

 

NOTE: I say may have trouble as I do not know the dimensions of the chainring nor the crank nor the mounting bolts and nuts you have available to you.

Edited by DieselnDust
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The 32 tooth AB oval rings are definitely threaded.

 

DandD is correct, the XT8000 crank arms have a funny BCD so it looks like the chain ring is squinting when not mounted.

 

yours looks like it should fit. 

 

You literally just line up the holes (the side with the 'triangle' protruding under the crank arm) and screw in the male chain ring bolt.

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The 32 tooth AB oval rings are definitely threaded.

 

DandD is correct, the XT8000 crank arms have a funny BCD so it looks like the chain ring is squinting when not mounted.

 

yours looks like it should fit. 

 

You literally just line up the holes (the side with the 'triangle' protruding under the crank arm) and screw in the male chain ring bolt.

This. You don't need the female bolt when fitting those threaded chainrings. Those protruding threaded bits locate into the back of the crank, in place of the female bolts. 

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This. You don't need the female bolt when fitting those threaded chainrings. Those protruding threaded bits locate into the back of the crank, in place of the female bolts. 

 

The bolts I have (ones that came off the original chainring) do not fit into the oval chainring, they are too big. If I go smaller they do not fit into the crank???

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The bolts I have (ones that came off the original chainring) do not fit into the oval chainring, they are too big. If I go smaller they do not fit into the crank???

 

 

Can you measure with a vernier? Sometimes the thread start is a bit rough from the anodising.

Typically all chain ring bolts are M8 x 0.75mm pitch

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Can you measure with a vernier? Sometimes the thread start is a bit rough from the anodising.

Typically all chain ring bolts are M8 x 0.75mm pitch

 

I do not own a Vernier but know someone. Will have him check.

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