is my chain too short? (pic)

chatlow
chatlow Posts: 845
edited December 2013 in Workshop
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


lxeg.jpg

Comments

  • me-109
    me-109 Posts: 1,915
    I would say that's too short. What does it look like on inner ring and large sprocket?
  • chatlow
    chatlow Posts: 845
    Here is a pic of inner ring, big sprocket. thanks

    hzg0.jpg
  • topdude
    topdude Posts: 1,557
    That looks perfect :D
    He is not the messiah, he is a very naughty boy !!
  • zx6man
    zx6man Posts: 1,092
    For a compact I would have gone short cage though, looking to do the 11-30 change to my carrera.
  • chatlow
    chatlow Posts: 845
    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
  • topdude wrote:
    That looks perfect :D

    This ^^^
    That's spot on.
  • zx6man
    zx6man Posts: 1,092
    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
    chatlow Posts: 845
    topdude wrote:
    That looks perfect :D

    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
    Ouija Posts: 1,386
    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
    chatlow Posts: 845
    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
    chatlow Posts: 845
    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
    zx6man Posts: 1,092
    I wouldnt bother as long cages seem to look ok when you have huge cassettes anyway
  • zx6man
    zx6man Posts: 1,092
    side note, which 11-30 is it? Acera HG41 8 speed, as they are super cheap at CRC at the moment
  • chatlow
    chatlow Posts: 845
    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
    Ouija Posts: 1,386
    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
    maddog 2 Posts: 8,114
    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...
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • zx6man
    zx6man Posts: 1,092
    my MTb's look like that on big big
  • Semantik
    Semantik Posts: 537
    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.
  • 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.

    Jam butties, officially endorsed by the Diddymen Olympic Squad
  • John.T
    John.T Posts: 3,698
    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
    chatlow Posts: 845
    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:

    p3xl.jpg

    Bad picture but the jockey wheels are almost perfectly vertical!

    Small ring, small sprocket:

    i75e.jpg


    Cheers
  • 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 :)

    Jam butties, officially endorsed by the Diddymen Olympic Squad
  • 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