[djfattony2000]

So I want to replace the useless chainguide on my Zumbi Dh Team.

I am using a set of Holzfeller triple ring cranks with only one chain ring.

My problem is I cant fit any large chainring on the middle chainring position. Its like the spacing is too small. I have tried an Azonic Dh ring and an old shimano LX one, with no luck. Both fit perfectly on the outside position.

Is there a trick to this or am I just being stupid

Thanks guys.
T

 

[jonKranked]

You might be using chainrings with an incorrect BCD:

http://sheldonbrown.com/gloss_bo-z.html

Are the bolt holes on the chainring lining up with the bolt holes on the tab?

Because you are using crankset designed for 3 chainrings, the middle position can only accept chainrings of a certain size. Wait nevermind. The middle and outer position share the same tabs, correct? Where are you having issues with the spacing being too small? Is the chainring coming in contact with the crank arm? Or is the chainring not lining up with the guide? Some pictures would be helpful to trouble shoot your problem.


What size chainring (in #of teeth) are you attempting to mount?


edit: you said you are trying to replace the chainguide. What is the chainguide you are trying to install?

 

[zebrahum]

Best guess is that you should be looking for a 104 BCD ring. It's better to measure yours, I just pulled that off of google. We definitely need the answers to Jon's last two questions if you want to get anywhere.

 

[Bicyclist]

Sounds to me like the profile of the ring and the profile of the little tabs to keep the ring in place are interfering, making it so the ring can't mount...maybe try filing the tab on the chainring a bit (seeing as the outer and middle chainring will have the same BCD I think that it isn't the problem).

 

[Lelandjt]

We need a better explaination of what is hitting or interfering.

 

[KavuRider]

I agree with the other posters, sounds like your sizing is off.
104 or 110?
Its important.
Otherwise there shouldn't be an issue.

 

[Racebike]

I recognize your problem. The ledges where the middle ring sits are a tad higher on certain crank sets and will not accept whatever you throw at it regardless if the BCD is correct.

If you have switched rings between different models of crank sets a few times you will run into some cranks where the middle ring does not fit.

If you wish to run the ring of your choice, you will have to remove some material from either the crank arm or the ring itself.

It's a pity to remove material from a crank arm, but it's the easiest way not to mess up centering of the ring.

 

[djfattony2000]

1st of all, thanks for everyones input.

I think RaceBike and Bicyclist are right, its the ledges on the middle that are obstructing the ring from going on.

Whats the best way to file these down? Just with a metal file and go for it?

The BCD is 104 incidentally.

I havent bought the chainguide yet but Im looking at the MRP G2 or E13 LG1.

 

[Racebike]

Yes, metal file and let loose.

Take care when filing, don't remove too much material!

If you are filing down the ring and not the arm, a soft jaw vice is good to have.

 

[djfattony2000]

Just to let ye know, I got a new chainring (Blackspire) and it fits, no need to file the crankset!

Thanks again guys.