New chain

Oldtrier

Typically how many links do you have to take out of a new chain when fitting. Its a Shimano 9 speed Ultegra. It seems a bit floppy in the small ring.

Golfanatic

i used this once and the bike is perfect now its real easy. its kind of hard for us to no because we need to know most of that info
http://www.epicidiot.com/sports/chain_length_calculator.htm

Idleater

7, no wait, 8....



Can you not measure against the old chain?

Beasty

nereid wrote: »

Can you not measure against the old chain?

That's the idea - don't just measure the length though (the old one will have stretched) - count the links

ED E

Largest ring, derailleur at 90*, job done.

Unless I'm doing it all wrong...

victorcarrera

Lethal_Bullet wrote: »

Largest ring, derailleur at 90*, job done.
Unless I'm doing it all wrong...

For double chain wheels.
Feed the broken chain over the larger front chain ring and the smallest rear sprocket. Tension the chain so that the rear derailer arm is vertical. Then break the chain at the nearest point that will suit the type of joint you intend to use. (rivet= 1 inner + 1 outer) or (soft link = 2 inner links).
PS: If reusing rivet don't push it all the way out.

blorg

victorcarrera wrote: »

PS: If reusing rivet don't push it all the way out.

Also- you can't reuse the rivet on modern narrow chains, e.g. those with a high number of speeds at the back. You need to use a special use-once joining pin, or a quick link. I've done it with a standard rivet on a 7 speed chain but even there Shimano suggest using the special joining pin.

victorcarrera

blorg wrote: »

Also- you can't reuse the rivet on modern narrow chains, e.g. those with a high number of speeds at the back. You need to use a special use-once joining pin, or a quick link. I've done it with a standard rivet on a 7 speed chain but even there Shimano suggest using the special joining pin.

OK agreed, and the shimano chain tech doc is here.

Not recomended of course, but FWIW I have reused 9sp +10sp rivets on my own bikes and they are working OK (thus far).

doozerie

The Park Tool website describes several methods, of which the easiest is to wrap the new chain around largest front chainring and largest rear sprocket, tension chain and check where you'd have to break the chain and then add two links before breaking it.

I used to use the method described by victorcarrera earlier. It has always worked for me but I think it errs on the side of the chain being a bit on the long side. I suspect the above method on the Park site leads to a slightly shorter chain, although I haven't actually compared the results of both methods - my preference is a shorter chain if I can get away with it so these days I use the above method.

victorcarrera

doozerie wrote: »

I used to use the method described by victorcarrera earlier. It has always worked for me but I think it errs on the side of the chain being a bit on the long side.

Fair enough. But I like to have the option of putting on a 27cog for a day in the hills without having to lengthen the chain.

doozerie

victorcarrera wrote:

Fair enough. But I like to have the option of putting on a 27cog for a day in the hills without having to lengthen the chain.

To be honest I've had no real problems arise from having extra length on my chain, but I have had a few minor glitches that I'd rather avoid. Mind you, it's only a theory of mine that those glitches were caused by extra length in the first place and I could well be wrong.

The odd thing about the method you describe though, is that it takes no account of the largest rear cog so in some respects whether a 27 cog will work at all is down to a little bit of luck in your gear spacing. As I say, it's the method I've happily used myself for years too on both mountain bikes and road bikes and it has always worked for me but I think that under certain circumstances it might well fail. For example, it'll give you the same length chain whether you measure against a 12-23 cassette or a 12-32 cassette but obviously you might hit issues on those lower gears depending on your rear mech. In fairness you'd need a long cage mech for a 32 anyway I think so the likelihood is that you wouldn't hit problems, but that could be quite a bit of unnecessary length of chain bouncing around when you are riding the 12-23. And yes, that is a huge jump going from a lowest gear of 23 to a 32 and not something many people would want to do but in the past I was told by one bike shop that lots of people that did made that swap in the lead up to the Wicklow 200.

Using the method described on the Park site does means having a chain per cassette alright, so wouldn't be everyone's choice. I prefer that option myself though.