is my chain too short? (pic)

chatlow

Just replaced 36 chainring with 34t and the 12-26 cassette with 11-30. brand new sora 3500 medium cage. Have taken a few links out and worried I've taken one too many. Here's a pic of the chain in the big ring/big ring combo.

Does it look OK?

thanks

me-109

I would say that's too short. What does it look like on inner ring and large sprocket?

chatlow

Here is a pic of inner ring, big sprocket. thanks

topdude

That looks perfect

zx6man

For a compact I would have gone short cage though, looking to do the 11-30 change to my carrera.

chatlow

I wanted to get the short cage but was advised to get medium due to potential issues with the short RD managing 28t+ sprockets. Assume if I returned for short cage - I'd end up having to resize then chain again - to make up for the chain slack?

thanks

arthur_scrimshaw

topdude wrote:

That looks perfect

This ^^^
That's spot on.

zx6man

chatlow wrote:

I wanted to get the short cage but was advised to get medium due to potential issues with the short RD managing 28t+ sprockets. Assume if I returned for short cage - I'd end up having to resize then chain again - to make up for the chain slack?

thanks

I dont think cage size has anthing to do with managing the 28t sprockets, I thought medium cage are suited to triples with the bigger teeth gap. Don't suppose it harms though in reality

chatlow

Arthur Scrimshaw wrote:

topdude wrote:

That looks perfect

This ^^^
That's spot on.

smashing, thanks!

zx6man wrote:

chatlow wrote:

I wanted to get the short cage but was advised to get medium due to potential issues with the short RD managing 28t+ sprockets. Assume if I returned for short cage - I'd end up having to resize then chain again - to make up for the chain slack?

thanks

I dont think cage size has anthing to do with managing the 28t sprockets, I thought medium cage are suited to triples with the bigger teeth gap. Don't suppose it harms though in reality

Well, it works, which is the main thing, but I have read that short cages are better for shifting. They obviously look better as well, but this is for my winter bike so not massively fussed on it's appearance. Ribble suggested the medium cage for any cassette over 28t

Ouija

If road rear mechs are anything like mountain bike rear mechs the cage size has nothing to do with how large a cassette it can take. That's determined by the distance from the top jockey wheel to the pivot point on the frame. Cage length (distance from top jockey wheel to bottom jockey wheel) only determines how much chain slack it can take up, with long cage used for triples, mediums for doubles and short for singles. If all three versions have the same distance from pivot point to top jockey wheel then they all have the same cassette capacity.

chatlow

AFAIK you're right, the cage length won't impact the RD physically handling the larger sprocket, just help with the chain slack when using a cassette/chainset with wide ratios. For what it's worth - I've not had to touch the B-Limit screw on the sora GS. Perhaps Ribble were being cautious, but the Shimano website states both GS and SS can handle up to 32t and a max capacity of 37. My max (35) was with the SS spec so could have gone for either.

chatlow

Other than looks - are they any other good reasons to consider returning the GS for a SS? Ribble happy to reimburse my postage costs if I do decide I want the short cage. Short cage is 72mm between jockey wheels, medium is 81mm. Will only do so if worth it...

zx6man

I wouldnt bother as long cages seem to look ok when you have huge cassettes anyway

zx6man

side note, which 11-30 is it? Acera HG41 8 speed, as they are super cheap at CRC at the moment

chatlow

zx6man wrote:

side note, which 11-30 is it? Acera HG41 8 speed, as they are super cheap at CRC at the moment

yeah that's the one - £7.50 free delivery. Bit of a steal!

Ouija

On a side note, i always cut my chains short. Most chain length calculators tend to give you a figure that would allow you to have everything working on the two biggest rings (front and back), but in actuality you would never use that combo so you should cut the chain short enough for the biggest combo you would actually use (hence the reason you were asked to provide a picture of it on the inner ring (front) and large ring (back) as that's the correct way to use the 32 tooth ring). This has two advantages. The tighter chain stops it bouncing about, creating less chain slap on the rear chain stay and makes the shifting tighter and punchier, especially over rougher stuff.

maddog 2

If you want to be able to run big-big then it's too short in my opinion.

If you don't run big-big then it doesn't matter if it's too short...

zx6man

my MTb's look like that on big big

Semantik

If you are bothered about your chain's performance and lifespan you will never use the big-big combination in any situation and so your chain length will be fine as is.

bigflangesmallsprocket

At first glance, that looks too tight to me. I'd have thought, on a road bike (I assume it's a road-bike as you mentioned using a compact), chainslap would be less of an issue than on an mtb. Also, as you're using a mdm cage, that would slightly lower the chain away from the stays, maybe not much, but it'll help.

A cage thats being pulled very tight is going to increase resistance to pedaling*. It'll put more stress on the chain and the mech and bb drive-side bearings, again, maybe not much, but it's accumulative (big word for the day). I use a short cage, but set mine up with the chain just tight enough so that when on a small/small, the chain isn't likely to be banging on itself up against the mech rollers. With the extra play you get from the mdm cage you may want to take just a little more off, but not as tight as that seems. Having said all that, if loosening the chain up makes it non-functional, then obviously your judgement was right

What we really need to see is a small ring small sprocket pic.

*I've done this myself, both on a geared bike and fixed. The effect on the fixed bike was most obvious, but still there on the geared to a lesser extent. Adjusting the fixed rear wheel I' had it quite tight (chain jump paranoia), with the bike turned upside down, and gave it a spin, it didn't roll very well at all.

John.T

I always have the chain as long as possible while retaining tension on small / small. You should always be able to go into big / big safely as one day you surely will do so and it can get very expensive. Shimano recommendation used to be that the jockey wheels should align vertically when on big ring and small sprocket. I have used this for years with no trouble at all.

chatlow

Thanks all! From what I've gathered I'm happy with the setup and will leave it as is. It shifts really well too.

Here are two pics for the users interested..

Big ring, small sprocket:



Bad picture but the jockey wheels are almost perfectly vertical!

Small ring, small sprocket:




Cheers

bigflangesmallsprocket

I admit, it does look hard for me to tell how much extra play you've got there. As long as you don't go onto the big/big your set-up is probably fine. But, If you do want to use that combination, which I sometimes do to save having to shift at both ends just for a few seconds use, it may be worthwhile just popping those couple of extra links on to see how the mech behaves, it's only a few minutes work. if it's too much, then at least you'll know

shmooster

Short cage 3500 is good up to 32t. Difference between SS and GS is in front capacity which is 16T for the short and 20T for the long. In other words it seems you only need the long if you're on a triple.

http://cycle.shimano-eu.com/publish/con ... _road.html