Determining Correct Chain Lenght - MTB

[levett]

Is there a 'secret' to determining the correct chain length

 

i.e. with the chain in this place on the front derailleur, and that place on the rear derailleur, the chain is the correct length when the rear derailleur looks like this

 

I'm not talking about chain 'stretch', I'm talking about fitting a brand new chain.

 

When I've replaced chains before, it's been a simple matter of 'counting the links' on the old chain and making the new chain the same number. Now I'm building a 29er, I don't have a 'starting point.

 

Advice much appreciated.

 

Cheers,

 

Dave.

levett2009-05-18 03:29:36

[Dirtbreath]

http://www.sheldonbrown.com/derailer-adjustment.html

[levett]

Thanks very much Dirtbreath.

 

From SheldonBrown:

 

The best technique for setting chain length is to thread the chain onto the large/large combination, without running it through the rear derailer. Mesh the two ends on to the large chainwheel so that they could be connected (outer link meets inner link), then make the chain one complete link (one inch) longer than that. In almost all cases, this will give the optimum length.

 

Seems very easy when you know how!

[Capricorn]

i've read about using the LARGE-LARGE circuit, but then add 2 chain links for the correct length, instead of one. The latter somehow sounds more correct though.

 

 

 

For rear suspended bikes, it changes a bit due to what they call chain-stay growth. Mr Brown didnt cover that in his link.

[levett]

Capricorn,

 

Both comments make sense to me - I might start with Large-Large + 2 links (eisier to take another one out, than add one!)

 

Fortunately, in this case, I don't have the rear suspension issue to worry about (HardTail) and can just copy the chain length on my SoftTail (assuming Giant got it right!).

 

Cheers,

 

Dave.

[Mr Mulebar]

Why does nobody ever read instructions? The same instructions are printed on the piece of paper in the box with every SHIMANO chain!

[levett]

Why does nobody ever read instructions? The same instructions are printed on the piece of paper in the box with every SHIMANO chain!

Handbags at 30 paces Mr Mulebar!

 

I guess you make mayn assumptions - is it a Shimano chain? is it packaged or loose? Can I read instructions? (Sheldon Brown has nice pictures!)

 

Chill out and be happy!

[javadude]

I see this method is the same as levett mentioned.

 

I use the Park Tool method, works fine for me:

 

Wrap the chain around the largest front and rear cogs without threading the chain through the derailleur. Find the nearest link where the chain could possibly be joined, and then count two links from that point to get the extra length.

 

velo2009-05-18 03:55:50

[Dirtbreath]

 

Why does nobody ever read instructions? The same instructions are printed on the piece of paper in the box with every SHIMANO chain!

Handbags at 30 paces Mr Mulebar!

 

I guess you make mayn assumptions - is it a Shimano chain? is it packaged or loose? Can I read instructions? (Sheldon Brown has nice pictures!)

 

Chill out and be happy!

 

I think its Mrs Mulebar using Mr Mulebars identity. There is no way a Mr would ever read any instructions!

 

[AndreZA]

I see this method is the same as levett mentioned.I use the Park Tool method' date=' works fine for me: Wrap the chain around the largest front and rear cogs without threading the chain through the derailleur. Find the nearest link where the chain could possibly be joined, and then count two links from that point to get the extra length.

 

[/quote']

 

 

 

if you still don't understand this method, look herehttp://bicycletutor.com/calculate-chain-length/