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What's the best chain for a single speed ?

MilitantGrahamMilitantGraham Posts: 220
edited April 2008 in MTB buying advice
It's not a single speed. it's a Rohloff, but the principles the same.
I did 42km today with a break half way. I had to adjust the chain before the return trip or I'm sure it would have jumped off again on the way home.
My usual commute to work is about 14km, mostly off road. I normally adjust and lubricate the chain at work and at home, that is, twice a day. Sometimes it still gets so slack it jumps off.
It is definitely not the wheel moving in the drop outs, it is the chain stretching.
I'm in Worcestershire. The red sandstone around here seems particularly abrasive. When I had rim brakes it would shred brake blocks in a few dozen miles.
It's not a problem when the ground's dry, but as soon as it gets wet and the mud is thrown off the tyre on to the chain, the chain starts stretching.
I had a Gusset half link chain and wasn't very impressed with its lifespan so I replaced it with a YBN chain. It's worse.
I'm using a teflon spray lube.
I weigh about 100kg so I'm putting the chain under more strain than a lighter rider travelling at the same speed.
A lot of my riding is along the Severn river bank under the shade of trees. It stays wet and muddy long after other trails have dried up.

What's the best chain/lube combination for not stretching ?
I'm currently using the big ring of a three ring chainset and a 7/8 speed chain.
Would I be better off going for a 1/2"x1/8" chain and sprockets ?
The chainring and sprocket were slightly out of line so I swapped the bottom bracket spacers to bring it in to line. It helped, but it didn't cure the problem.
I am a mountain biking god.
Unfortunately, my bike's an atheist.

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    well what size cogs are you using? 9sp or single speed width? (back cog info needed).

    what tensioning device? Horizonta ldropouts? eccentric bb? tensioner?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • 44t chainring and 16t sprocket.
    Chain is a standard 7 or 8 speed derailleur chain. Is that 1/2"x 3//32" ?
    I thought Rohloff did two widths of sprocket to allow use of a 1/2"x 1/8" single speed chain, but I just checked their site and they don't list one.
    No tensioner. I've got the one that came with the hub, but I really don't want to use it. I love the simple, straight chain run look and reliability.
    Fixed BB and horizontal dropouts. Santa Cruz Chameleon frame. Only a limited amount of adjustment because of the fixed caliper, but by the time I've run out of adjustment the chain is worn anyway.

    Can I run a 1/2"x 1/8" single speed chain on 1/2"x 3//32" sprockets ?
    Would there be any advantage to doing that ?
    Presumably if the chain is not designed to flex like a derailleur chain, not only will it have a greater bearing area as it's wider, there will be less clearance between the pins and bushes so less chance of mud getting in.
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
  • nicklousenicklouse Posts: 81,520 Lives Here
    well then any quality 7/8 spd chain and if you need it a half link to allow half a link adjustment if a full link is to much (sounds like it is as you used a full half link chain. Also look at means to make your caliper adjustable, or use the tensioner supplied.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thanks Nick. I was hoping for a recommendation of a particular make or model of chain that is best for not stretching.
    I bought the half link chain the first time because of the limited adjustment at the dropouts. It turned out I needed an even number of links anyway and by the time I ran out of adjustment and wanted to take half a link out, the chain was pretty well worn out, so next time I bought a regular chain.

    I haven't got one of those fancy chain wear measuring tools. I go by the old pull the chain away from the chainring, if you can see a whole tooth, it's worn out method.
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
  • nicklousenicklouse Posts: 81,520 Lives Here
    a chain that does not ware. does not exist.

    Rohloff make their own........ Or for low cost what about the Sram PC 1.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • I'm not looking for a chain that doesn't wear at all. Surely some chains must be better than others, I was hoping that someone who has tried different brands could tell me which was best.
    From my own limited experience, all I know is that Gusset is better than YBN. What's better than Gusset ?

    Funny you should mention the SRAM PC1. I bought one thinking it would be better than a derailleur chain, then realised that it was 1/2"x1/8" so I didn't use it.
    Is there any reason why I shouldn't use the wider chain on narrower sprockets ?
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
  • nicklousenicklouse Posts: 81,520 Lives Here
    No reason. they work.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thanks for that. I'll give it a go then.
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
  • I've just thought of something else which may be of interest to anyone else with chain tension problems on a single speed.
    I started out with a Middleburn chainring on XT Hollowtech 2 cranks.
    Something wasn't machined quite concentric so I always had a tight spot and a loose spot 180 degrees apart.
    I've got a Vuelta chainring now and the inner diameter of the chainring is slightly larger than the outside diameter of the crank spider.
    By tightening the chainring bolts just enough to grip the chainring lightly, I was able to centralise the chainring on the cranks, then tighten the bolts fully.
    The chain tension is the same with the cranks in any position now.
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
  • ride_wheneverride_whenever Posts: 13,279
    I use a connex stainless steel chain. Hasn't worn yet!
  • Update;

    I still have to adjust the SRAM PC1 chain occasionally, but not as often as the previous chains.
    Two things to take in to account though. The ground's a bit drier and I have started using motorcycle chain spray.
    I stopped using motorcycle chain spray before because I found it seemed to clog up the chain so it wouldn't flex round the little idler sprockets on the derailleur tensioner. That's not a problem with the Rohloff.

    I did the Merida event last weekend.
    35km on Saturday night. Adjusted the chain on Sunday morning. Didn't really need to, but as I had a long ride ahead I thought I had better start out with it spot on.
    55km on Sunday. Extreme mud in the woods. The chain ended up looking like a 1/2" wide string of mud, impossible to see the links underneath. Guys with derailleurs were stopping to poke the mud out with sticks to get them working again.
    After all that, my chain doesn't need adjusting.

    I can put more wear on a chain in 6km of commuting along the banks of the River Severn in Worcestershire than in 80km of racing over the Brecon Beacons.
    I told you this red sandstone was abrasive.
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
  • Looks like I spoke too soon.
    9.54am I posted a message about how good SRAM chains are.
    1.15pm I was kneeling down at the side of National Cycle Route 45 repairing it.
    So that lasted two weeks and about 300km then. :roll:
    It was the connecting link that broke. I carry a few spare links so I put an ordinary link in its place.
    I am a mountain biking god.
    Unfortunately, my bike's an atheist.
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