Chain too short?

cframe
cframe Posts: 171
edited March 2011 in Workshop
Hey all,

Just been setting up my new Rival groupset and followed all the SRAM instructions but can't help thinking my chain is too short when in the big ring/big sprocket, what do you guys think? Too short?

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edit:
And in case that image embed doesn't work properly: http://twitpic.com/4eko1o
How's that for a slice of fried gold?

Comments

  • andrewjoseph
    andrewjoseph Posts: 2,165
    Can you get onto that easily?

    That might be ok on an MTB or triple setup where you would not be trying to get into big/big, but not sure about standard/compact road setup.

    to be on the safe side I'd put in a link or two so the rear mech is not so horizontal.
    --
    Burls Ti Tourer for Tarmac, Saracen aluminium full suss for trails
  • I always set the chain length on small/small and use as much chain as the derailer will take up. Check that there's enough on big/big afterward though, just to be sure.
    Dolan Preffisio
    2010 Cube Agree SL
  • cframe
    cframe Posts: 171
    @andrewjoseph: to be honest it's only been on the trainer a couple of times very briefly so I don't think I've tried trying to shift into it under load. Will give it a go tonight.

    @CarlosDSanchez: I've not tried small/small yet, will give that a go tonight too.
    How's that for a slice of fried gold?
  • John.T
    John.T Posts: 3,698
    edited March 2011
    It is safe but shorter than I would have it. With a standard 53/39 I use the Shimano method of jockey wheels vertical when on the big ring and small sprocket. For a compact especialy if pushing the mech limits (50/34 with12/27 or 28 ) then I use Carlos' method. Never had any problems.
  • Bobbinogs
    Bobbinogs Posts: 4,841
    Blimey, that does look tight. Have you tried this website:

    http://www.machinehead-software.co.uk/b ... hcalc.html

    I found it to work really well and you just need one measurement (chainstay length) to get your min length in links.
  • Can you get onto that easily?

    That might be ok on an MTB or triple setup where you would not be trying to get into big/big, but not sure about standard/compact road setup.

    to be on the safe side I'd put in a link or two so the rear mech is not so horizontal.

    Looks about right to me. The Park site says that a chain's too tight if there's no deflection caused by the jockey wheels. The best way to measure is to get one full link overlap when the chain is wrapped directly over the two biggest cogs. I reckon you're fine, it's not like you should use that combination anyway. ;)
  • keef66
    keef66 Posts: 13,123
    I'd leave it like that. As mentioned above, you shouldn't be using that combination except by accident.

    I'd rather have it on the shorter side.
  • Mister W
    Mister W Posts: 791
    I think that looks spot on as it's not a combination you're actually going to use when riding.
  • Velonutter
    Velonutter Posts: 2,437
    IMHO that chain is two links too tight, if you could add two links then you would feel the difference, everything will rotate much more easily.
  • John.T
    John.T Posts: 3,698
    Well we can not seem to agree on this, can we.
    The OP says he set it up as per SRAM's instructions. If he did it correctly then it is right. If in doubt he should re-check it. If OK then forget it. The best advice I got when I was an apprentice and a job came back was to assume the last person to work on it was an idiot, even if it was yourself. This has served me well over the years.
    Most of us have our personal preferences and as long as they stay within the limits of the equipment then it does not matter.
  • cframe
    cframe Posts: 171
    Hey guys, cheers for the all the advice/help!

    Didn't get around to trying much last night but I did try the small/small combo and it looked pretty much right on the money there, there wasn't much more that the housing could've moved further.

    I will admit that the big/big combo does feel a bit tight compared to most of the other ratios, one of my mates in the lbs suggested maybe adding one or 2 links and using one of the powerlinks to rejoin the chain.

    Think I gotta just try it on the trainer again and get a feel for it.
    How's that for a slice of fried gold?
  • John.T
    John.T Posts: 3,698
    Be careful lengthening the chain. The cage must be able to take up tension in all gears including small / small.
    I assume you are not using wider than recommended ratios.
  • cframe
    cframe Posts: 171
    @John.T nope, that cassette is a 12-25 I think and I'll be running an 11-25 once I get it switched out.

    Was just setting up my mates new Force kit last night on a 50-34 / 11-28 and his was looking alright after a bit of adjusting of the b-screw to clear the biggest cog
    How's that for a slice of fried gold?