how many chain links?

[e-rider]

I have just put a new chainset on my road bike so I';m now using 39/53 with a 12-25 cassette.


How many chain links?



I'm currently using 110 links but it looks a little short when in large ring. Should I increase to 112 links? Although in small small combination this could be quite long!!!

 

[brockers]

try 112. if it's too long and things clatter about in small/small, then shorten.

simples. *squeaking noise*

 

[buddha]

I used this calculator.

 

[JonnyBlade]

110 links sounds like a big old chain. 55 perhaps?

 

[HLaB]

I run the same gears but I've never bothered counting. When ever I changed size of gears Ive wrapped the chain around the big rings at the front and the back (not using the derailleur and an overlap of 2 links is all thats required (simpler maths for me ) Unfortunately you have to pay now for the bike tutor vids but hopefully the text will explain it better.

 

[GlasgowGaryH]

I run the same gears but I've never bothered counting. When ever I changed size of gears Ive wrapped the chain around the big rings at the front and the back (not using the derailleur and an overlap of 2 links is all thats required (simpler maths for me ) Unfortunately you have to pay now for the bike tutor vids but hopefully the text will explain it better.

+1 Thats the method I use too

 

[e-rider]

cheers all - I have narrowed it down to 110 or 112 links for optimal chain length. I'm currently running 110 links which I was using with my old set-up of 39/50 12-27 but I'm going to try and add another 2 links (1 'real' link) for my new 39/53 12-25 setup. All I need is a couple of shimano joining pins as I still have the left over links from before.



If you are wondering why I'm still using the old chain it's because it's actually quite new (500 miles) and a Shimano 6600 10 speed so fairly expensive.

 

[e-rider]

I put the extra link in and now the chain is quite long (but not too long) - as I suspected both 110 or 112 links work fine. The 112 seems better if you spend more time in the large ring whereas the 110 link chain would suit more small ring use. Not sure what I'm going to settle on yet!

Another question about the use of ALL 20 gears. My small-small combo is a no go as the chain hits the outer ring (39/53). However, the large-large combo seems to work OK but the chain rubs the front mech; if I adjust it I then have trouble with large ring-smallest sprocket combo (which I use a lot on rollers).

How does this compare to other people using Shimano 10 speed groupsets? Can you get all gears to work without rubbing?

 

[HLaB]

I can't use the full 10 sprockets on my 105 equipped bike either but the large-large and small-small combos are supposed to be bad so its no biggie, its just an audible warning, although I get hardly any rubbing on the large-large combo and a fair bit of rubbing on the small-small.

 

[ohnovino]

What's the downside of an over-long chain?

 

[HLaB]

What's the downside of an over-long chain?

Your derailleur rides up into your cassette for one, and I wouldn't be surprised if there was other pitfalls.

 

[rockyraccoon]

I've just shorten my chain based on shimano tech instruction. I didn't have to count the number of links.

According to it, the the guide pulley and tension pulley should be in line with the centre of the cassette (90 degrees to the floor) when the chain is on the largest chainring and smallest sprocket.

 

[e-rider]

I've just shorten my chain based on shimano tech instruction. I didn't have to count the number of links.

According to it, the the guide pulley and tension pulley should be in line with the centre of the cassette (90 degrees to the floor) when the chain is on the largest chainring and smallest sprocket.

I like this method - I'll check mine tonight but I have the feeling that it was slightly in front with 110 links and slightly behind with 112!

And what happens if the largest sprocket is very large (not that mine is though)? Or if the small ring is very small?

 

[e-rider]

What's the downside of an over-long chain?

the rear mech can only take up so much slack, after which the chain will just hang loose!

 

[rockyraccoon]

...And what happens if the largest sprocket is very large (not that mine is though)? Or if the small ring is very small?

Nothing I'd think!

Just the rear derailleur would move accordingly

I would choose to keep it slightly behind with 112. This would avoid any problem due to the force applied to the chain when the it is on largest sprocket and largest chaining. However you should not use these gear together because of cross chain issue.