Ok been told by LBS that my chain line is well out, this of course was after my chain came off and wrapped around rear wheel, twisting and bending as it did so, with a rear wheel lockup to follow. He tells me that the Langster is a big pile of poo of which I`m now in some agreeance. However he has suggested a rebuilt back wheel with a differant hub which will push out the rear cog further allowing, hopefully a straightish chain line, its 5mm out by the way ! Would I better buying a new front chainset and BB in the vain hope that I could get it more or less bang on ?
chainline
- Thread starter MrGrumpy
- Start date
Page may contain affiliate links. Please see terms for details.
MajorMantra
Well-Known Member
- Location
- Edinburgh
Could you maybe do something simpler (and cheaper) with spacers? How bad is the chainline? If your Langster is stock, shouldn't it be possible to get a perfect chainline? I thought they were right-on from new.
Matthew
Matthew
Amanda P
Legendary Member
- Location
- York. Well, York-ish...
Bottom brackets come in different lengths. Could you fit one that's 5mm shorter?
There are also adjustable ones, where the axle can be shunted through the shell to get perfect chainline.
Does your chainset have a removable ring? What about putting it on the inside of the spider, rather than the outside (assuming it is on the outside now)?
There are also adjustable ones, where the axle can be shunted through the shell to get perfect chainline.
Does your chainset have a removable ring? What about putting it on the inside of the spider, rather than the outside (assuming it is on the outside now)?
5mm out. Who cares? No one cares about chain-line on a multi-geared bike. A chain can easily cope with 5mm. It may not be perfect and may be noiser than if the chain-line was bang-on but it doesn't matter.
As Phil says though. A new BB is probably easiest/cheapest way to fix it, if it bothers you that much.
I'd be wary of a shop that immediately suggests the most expensive option of building a new wheel. Especially as a chunk of the cost is for labour.
As Phil says though. A new BB is probably easiest/cheapest way to fix it, if it bothers you that much.
I'd be wary of a shop that immediately suggests the most expensive option of building a new wheel. Especially as a chunk of the cost is for labour.
MajorMantra
Well-Known Member
- Location
- Edinburgh
skwerl said:
I agree about not rushing to build a new wheel but I think if he's already thrown the chain once (not nice I imagine!) then it needs fixing.
Matthew
depends what caused it to throw. 5mm off-line I doubt was the cause or at least not on it's own. Likely the chain was loose and that alone, or coupled with chainline being out, caused it to unship.
After all. How often to geared bikes unship their chains? Usually only when going over a bumpy bit of ground which overcomes the rear-mech tension, i.e. caused by chain slack.
After all. How often to geared bikes unship their chains? Usually only when going over a bumpy bit of ground which overcomes the rear-mech tension, i.e. caused by chain slack.
mickle
innit
- Location
- 53.933606, -1.076131
MrGrumpy said:
As has been said, the chain came off because it was too loose. Not because the chain was 5mm out. There are plenty of easy and cheap solutions, non of which involve replacing the chainset or the back wheel. The shop is totally taking the piss.
In case you missed that; The shop is totally taking the piss.
no i`ve got you 
You know it probably was loose come to think of it as keeping it tight seems an issue, however surely its always gonna try and run off if its not straight ? Its just a tad worrying especially going down hill. Just my history ith this bike is tiresome to say the least.
You know it probably was loose come to think of it as keeping it tight seems an issue, however surely its always gonna try and run off if its not straight ? Its just a tad worrying especially going down hill. Just my history ith this bike is tiresome to say the least.
mickle
innit
- Location
- 53.933606, -1.076131
I have just one thing to say to you Mrgrumpy; chain-tugs.
I'd agree, chaintugs rule. I know a lot of people who say you don't need them, but by god they make chain tensioning so much easier. Dirt cheap too. I wouldn't be without them.
I'd also agree with Uncle Phil. Have you tried mounting the chainring on the inside of the spider (assuming it's currently on the outside)? I have an FSA Vero crankset that should really be used with a 103mm BB for the perfect 42mm chainline, but the bike came as standard with a 110mm BB with the chainring mounted on the inside (I guess because 110mm JIS BB's are cheaper and easier to come by). It's not pretty but it works, and I've never thrown the chain.
Rebuilding the wheel seems like a pretty expensive option. Sounds like the LBS is taking the piss and trying to make some money. A new hub won't sort the problem unless the sprocket is spaced out somehow, and you can do that with the hub you already have. Hubs are fairly standard in their sizing, it's almost certainly a BB, chainset compatability issue. A shorter BB would be cheaper than a new hub and wheel rebuild, but trying the chainring on the inside of the spider costs nothing.
I'd also agree with Uncle Phil. Have you tried mounting the chainring on the inside of the spider (assuming it's currently on the outside)? I have an FSA Vero crankset that should really be used with a 103mm BB for the perfect 42mm chainline, but the bike came as standard with a 110mm BB with the chainring mounted on the inside (I guess because 110mm JIS BB's are cheaper and easier to come by). It's not pretty but it works, and I've never thrown the chain.
Rebuilding the wheel seems like a pretty expensive option. Sounds like the LBS is taking the piss and trying to make some money. A new hub won't sort the problem unless the sprocket is spaced out somehow, and you can do that with the hub you already have. Hubs are fairly standard in their sizing, it's almost certainly a BB, chainset compatability issue. A shorter BB would be cheaper than a new hub and wheel rebuild, but trying the chainring on the inside of the spider costs nothing.
mickle
innit
- Location
- 53.933606, -1.076131
The event may have damaged the drive side spokes of course.
mounting the chain ring on the inside of the spider looks pants. be much easier to get a shorter BB axle or even easier to just not worry about what is a minor amount of offset.
Hold your fingers 5mm apart. Not much is it?
Hold a chain at one end and extend it out horizontally. See how much it bends by? Chains aren't that rigid in the horizontal plane, they're designed to cope with chain-line offset
Hold your fingers 5mm apart. Not much is it?
Hold a chain at one end and extend it out horizontally. See how much it bends by? Chains aren't that rigid in the horizontal plane, they're designed to cope with chain-line offset
Amanda P
Legendary Member
- Location
- York. Well, York-ish...
skwerl said:
Being a pedant here, I agree that a chainring on the inside of the spider looks pants (if you care about that sort of thing. Is this a fashion fixie, or a functional one?)
But there's no way it's easier to fit a shorter bottom bracket axle than it is to move the chainring from one side of the spider to the other.
And depending on Mr Grumpy's consitution, it may not be so easy to stop worrying about it, either!
ok guys think chain tugs are the answer here and at £6 a pop not to be sniffed at, as for the BB its a brandnew one 103mm which is what the original was. Was actually thinking about mounting the chain ring on the inside but they`re aint enough clearance. Its certainly been a slack chain issue and nothing else, my fault end off.
Dave5N
Über Member
- Location
- Outside The Little Nibble
What am I missing here?
What do chaintugs do that a properly tightened nut doesn't?
Are they for conversions?
What do chaintugs do that a properly tightened nut doesn't?
Are they for conversions?