Sizing a New Chain - which method?

[StinkFist]

If you don't have the old chain, how do you correctly size / fit a new chain please?

Seems to be quite a few techniques - I watched one on YT which said to thread over large cog on the front and large on the rear (didn't say if you thread through the rear Mech / Der though!!) and then add two (2) links and cut there.

Is for a Road Bike running 10spd Ultegra if that helps, but suspect the method will apply to all sizing??

Just out of curiosity, how do you size for a Full Sus MTB ??

 

[42x16ss]

The method you described is the one that I use and yes, thread the chain through the rear derailleur. The chain should be *just* long enough to run the largest rear cog on the big chainring.

If this isn't something you've done before keep some joining pins/quick release links spare in case you break the chain too short or long.

 

[StinkFist]

thanks for the quick reply!

OK, so through the rear Mech as well & both large cogs front and rear - bit strange as you would never ride big / big.....although, someone could I suppose

I have done this before, but ages ago. Do you place a small thin lube on the joining pin before pressing through?

Any help on the MTB Full Sus??

 

[winkybiker]

Re:

thanks for the quick reply!

OK, so through the rear Mech as well & both large cogs front and rear - bit strange as you would never ride big / big.....although, someone could I suppose

I have done this before, but ages ago. Do you place a small thin lube on the joining pin before pressing through?

Any help on the MTB Full Sus??

Although you don't (shouldn't) deliberately ride with big:big, the issue is that you might sometimes accidentally do this. If your chain is too short, you'll rip your rear derailluer off!

 

[StinkFist]

If your chain is too short, you'll rip your rear derailluer off!

Trying to avoid this (not my bike) hence the question re sizing

Are 10 spd Shimano Ultegra Chains directional??....I seem to remember reading / seeing somewhere that the DA ones are.

 

[ustabe]

6700 chains are directional. 6600 chains are not. If you're running a triple, Shimano recommends a non-directional chain.

And on full-suspension mountain bikes, travel will change chain tension, so add a pair of links.

 

[StinkFist]

Thanks ustabe.

Quick google check says that the shimano writing should be on the outside ( Facing me) when installing.

Didn't know that about running a Triple!

Any thoughts / comments on a quick link?? Friends on MTB's love them for the quick clean up etc, what about Roadies??

 

[winkybiker]

Re:

If your chain is too short, you'll rip your rear derailluer off!

Trying to avoid this (not my bike) hence the question re sizing

Yep, so make sure you have just enough chain on the big:big combo (plus a couple of links for full sus).

 

[StinkFist]

Hmmm - I was thinking that a full sus would be a different technique to allow for the travel in the Shock.....yes, no??

I was referring to a Road Bike set up 10 Speed, Shimano Ultegra with the Big:Big through the rear Mech and then add two links......are you saying use the same approach with a full sus MTB??

Thanks for all the help so far.

 

[King Boonen]

Re:

The method you described is the one that I use and yes, thread the chain through the rear derailleur. The chain should be *just* long enough to run the largest rear cog on the big chainring.

I never do this. Can't see why that's a good idea as you length will then completely depend on what angle you pull the mech cage to.

Big front, big back and add two INCLUDING the magic link if you are using one.


For an FS you may need to account for chain growth depending on the suspension design, so you need to size it up, add a couple extra links, fit it with a magic link and then let the air out of the rear shock and compress it. If it doesn't bottom out then the chain is too short, so leave it long if you are worried and break it again afterwards. As long as there is some up and down play in the mech it's fine.

Once you know the correct length for your FS write it down and just make the chain this length each time.

 

[Bustedknuckle]

If you don't have the old chain, how do you correctly size / fit a new chain please?

Seems to be quite a few techniques - I watched one on YT which said to thread over large cog on the front and large on the rear (didn't say if you thread through the rear Mech / Der though!!) and then add two (2) links and cut there.

Is for a Road Bike running 10spd Ultegra if that helps, but suspect the method will apply to all sizing??

Just out of curiosity, how do you size for a Full Sus MTB ??

Small, small, make sure the chain is just off the pulley/body of the rear der. Like this.

 

[StinkFist]

I'm confused...BIg / Big - no mech V's Small / Small through the mech ( am I still adding 2 links to both these methods?)

I never do this. Can't see why that's a good idea as you length will then completely depend on what angle you pull the mech cage to.

Big front, big back and add two INCLUDING the magic link if you are using one.


this makes sense - thanks.

Small, small, make sure the chain is just off the pulley/body of the rear der. Like this.

Ok, so now we have small, small and including the rear mech and off the pulley body as.....do I add 2 links to this method as well Bustedknuckle??

 

[avanti]

Why not just download the instruction sheet from the supplier of your chain. I use Shimano chains and always use their instruction sheets.

 

[StinkFist]

Re:

Why not just download the instruction sheet from the supplier of your chain. I use Shimano chains and always use their instruction sheets.

Thats a good idea, thank you

 

[twothirds]

What bustedknuckle was explaining is the other end of chain length sizing. Big:big is to make sure you don't rip the rear deraileur off. The small:small is to make sure that the jockey wheels are not contacting the cogs. You need to accomodate both situations.

 

[StinkFist]

OK - thanks twothirds.

I thought the "B" screw adjustment was for that purpose??

 

[King Boonen]

Re:

OK - thanks twothirds.

I thought the "B" screw adjustment was for that purpose??

I think BK is actually talking about the method that stops the chain coming off the second jockey wheel contacting the chain running through the top jockey wheel. If you look at the picture he posted you can see the card indicating the gap.

Using the big/big method I described I've never had any problems with this either, on my MTB (hardtail) or road bike.

 

[richwagmn]

If you don't have the old chain, how do you correctly size / fit a new chain please?

Seems to be quite a few techniques - I watched one on YT which said to thread over large cog on the front and large on the rear (didn't say if you thread through the rear Mech / Der though!!) and then add two (2) links and cut there.

Is for a Road Bike running 10spd Ultegra if that helps, but suspect the method will apply to all sizing??

Just out of curiosity, how do you size for a Full Sus MTB ??

Small, small, make sure the chain is just off the pulley/body of the rear der. Like this.

Exactly. If you go small, small and have no chain tension, you've got big problems. Also, all rear derailleurs list max cog size and max capacity. Don't exceed that, and the small/small method is the way to go.

 

[StinkFist]

I have the new chain (not the old one as above).
I'm also installing a new cassette....going from a 25-11 to a 27-12.

I'm going to use both methods listed above Big:Big no Rear Mech add two links, mark it and then try the Small:Small - through the Rear Mech and see if they are the same.

Limit screws and indexing will need attention also......I may be posting some more questions in the next few hours

Will report back.

Thanks for all your help.

 

[Bustedknuckle]

Re:

I'm confused...BIg / Big - no mech V's Small / Small through the mech ( am I still adding 2 links to both these methods?)

I never do this. Can't see why that's a good idea as you length will then completely depend on what angle you pull the mech cage to.

Big front, big back and add two INCLUDING the magic link if you are using one.


this makes sense - thanks.

Small, small, make sure the chain is just off the pulley/body of the rear der. Like this.

Ok, so now we have small, small and including the rear mech and off the pulley body as.....do I add 2 links to this method as well Bustedknuckle??

No, no add links, that's the actual length. Either use the push thru pin(shimano/Campag) or replace the outside link with a snap link.

 

[StinkFist]

Thanks for the follow up Bustedknuckle.

The chain is a Shimano and using a "Quick-Link" as that is what is currently on there.

 

[jmdirt]

Re: Re:

The method you described is the one that I use and yes, thread the chain through the rear derailleur. The chain should be *just* long enough to run the largest rear cog on the big chainring.

I never do this. Can't see why that's a good idea as you length will then completely depend on what angle you pull the mech cage to.

If I remember correctly Shimano recommends that the pulley bolts be directly vertical when in the big ring/small cog. Its been at least 10 years since I've not had the old chain to measure with so I might be wrong.

Here's a video of the small/small method: http://www.artscyclery.com/learningcenter/installshimanoroadchain.html

 

[StinkFist]

Re: Re:

The method you described is the one that I use and yes, thread the chain through the rear derailleur. The chain should be *just* long enough to run the largest rear cog on the big chainring.

I never do this. Can't see why that's a good idea as you length will then completely depend on what angle you pull the mech cage to.

If I remember correctly Shimano recommends that the pulley bolts be directly vertical when in the big ring/small cog. Its been at least 10 years since I've not had the old chain to measure with so I might be wrong.

Here's a video of the small/small method: http://www.artscyclery.com/learningcenter/installshimanoroadchain.html

Thank you.

I should have time this weekend to get the work done.