Can a bicycle chain be stretched?
Can a bicycle chain be stretched?
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Discussion

gazchap

Original Poster:

1,546 posts

212 months

Friday 3rd April 2015
quotequote all
I'm a bit of a novice when it comes to cycling, and have just set about removing the rear wheel from my hybrid bike to replace it with the FlyKly Smart Wheel that I received via Kickstarter the other day.

All seems to have gone relatively smoothly, the only fly in the ointment is that the chain does not seem to fit snugly over the teeth on the single sprocket on the FlyKly - the first few teeth are OK but then the chain "misses" a few teeth before going OK again on the underside.

I've measured the pitch between the teeth on both my old rear wheel and the FlyKly and it's the same - 1/2" - so I can't work out what the problem is - the only thing I can somehow think of is that I've managed to stretch the chain or something while taking the original wheel off.

Is this possible?

Any idea of remedies I could make use of before I take it to a bike shop?

dave123456

3,921 posts

176 months

Friday 3rd April 2015
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how old was the wheel you removed?

many people talk of chain stretch, it isn't. it's wear on the links that effectively create play and the links elongate. if you have a drivetrain (chain rings, chain and sprockets, the wear on the chain will, over time correspondingly wear the chainrings and sprockets.

as a youth i'd fastidiously clean my chain, cassette and chainrings to prevent this. now I tend to replace the chain more frequently.

so i'd say your bits are all worn and you may need a new chain. trouble is, you may need chain rings as well.

Wilmslowboy

4,762 posts

235 months

Friday 3rd April 2015
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This is what chain stretch looks like




gazchap

Original Poster:

1,546 posts

212 months

Friday 3rd April 2015
quotequote all
Yep, that looks about right. The bike itself is probably a year to 18 months old, but I've almost never ridden it and it spent a fair amount of time out in the back garden being exposed to various weather conditions. The chain itself and the running gear don't look to be in too bad a shape, in terms of rust etc. but I guess it may have caused some stretch.

I'll run the bike up to one of my local bike shops tomorrow and see if they can swap the chain out for me.

richardxjr

7,561 posts

239 months

Friday 3rd April 2015
quotequote all
Interesting product.

Installation video won't play on my pc but this looks similar to a singlespeed conversion so chain length will be critical and a sliding dropout, a way of keeping tension & being able to remove the wheel roadside will be necessary too.

Defo put a new chain on though.


Gruffy

7,212 posts

288 months

Friday 3rd April 2015
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It's worth picking up a chain wear indicator. It's just a little piece of metal that you slot into your chain and when it fits fully you know the chain has 'stretched' too much and needs replacing. When it does, it's starting to damage the cassette and chainrings, which are obviously a bigger expense so it's well worth keeping on top of this.


richardxjr

7,561 posts

239 months

Friday 3rd April 2015
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wavey Got that 32 cassette on yet G?

gazchap

Original Poster:

1,546 posts

212 months

Friday 3rd April 2015
quotequote all
richardxjr said:
Interesting product.

Installation video won't play on my pc but this looks similar to a singlespeed conversion so chain length will be critical and a sliding dropout, a way of keeping tension & being able to remove the wheel roadside will be necessary too.

Defo put a new chain on though.
It is a single speed conversion, but apparently it works fine with a derailleur, and my initial experimentation seems to confirm that - functionally it's fine, I just don't fancy the chances of the chain not slipping off in actual road usage.

richardxjr

7,561 posts

239 months

Friday 3rd April 2015
quotequote all
Derailleur will be working as a sort of chain tensioner then. For the sake of £15 a singlespeed tensioner will be better (it's just a single jockey wheel on a spring pivot). The new chain will defo need to be shortened either way and chainline as straight as poss.

Use a Singlespeed chainring too (ie without shifting ramps machined in) and you should get away without needing some sort of front chain guide.



Gruffy

7,212 posts

288 months

Saturday 4th April 2015
quotequote all
richardxjr said:
wavey Got that 32 cassette on yet G?
I'll be popping that on tomorrow. Sunday will be the test ride.

Dammit

3,816 posts

237 months

Saturday 4th April 2015
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From looking at the website it's a single sprocket? Might well be inch and an eighth, which is going to be wider than the chain you have - with will be ~3/32 or thereabouts.

i.e. you need a BMX (or other single-speed chain, but that won't fit through a derailleur, so you would need a method of keeping tension on the chain.

OR I guess you could get a 3/32 sprocket, which might be easier all round. If, of course, that's it.

You need to do some miles to stretch a chain, so if it's just been sat in the garden that probably won't be it.

BadgerBenji

3,534 posts

247 months

Sunday 5th April 2015
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Dammit said:
Might well be inch and an eighth
Eighth of an inch would be a more appropriate size wink

As for stretch, I don't believe they do, the first bit of elongation is the rollers bedding in, then after that is wear.

gazchap

Original Poster:

1,546 posts

212 months

Sunday 5th April 2015
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Bought a SRAM single speed chain on the advice of my local bike shop last night, and fitted it - seems to fit on the derailleur properly and fits around the single sprocket on the wheel too, so we're good to go smile

All I need to do now is find a foot pump so I can pump up the front wheel! :P

gazchap

Original Poster:

1,546 posts

212 months

Sunday 5th April 2015
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First test ride was promising, although it seems like the chain slips when going uphill, as if its trying to change gear and failing.

Would that just likely be worn sprockets on the front or something? Or could it just be that they need a bit more lubrication with the new chain?

dave123456

3,921 posts

176 months

Sunday 5th April 2015
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impossible to say without seeing it, unlikely to be lubrication..likely to be a worn chainring.

ClassicMercs

1,703 posts

210 months

Sunday 5th April 2015
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You say the bike is only 18 months old - and has hardly been ridden.
In those circumstances how would the chain get stretched. It needs some use.
Then as shown in other photos you get the stretch / wear on the chain ring.
I would look at all the componentry - fit and adjustment - especially the latter after the changes you have been making.

And my task tomorrow - to replace a stretched chain which I have held out for a few weeks while the weather has finally turned a bit nicer. Then consider the chainring if I'm unlucky.

Kermit power

29,622 posts

242 months

Monday 6th April 2015
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I have to admit, I'm somewhat bemused by that wheel you've bought.

From what I can see, it takes a perfectly normal geared bike, turns it into a singlespeed, then presumably uses electric power to compensate for the loss of all those gears, but only up to a top speed (15.5 mph) which is slower than most people would ride on the flat?

I suppose I could see some advantages if I lived in Snowdonia or somewhere, but even then I'm not sure it would be worth the loss of gears and the slower speed.

I wonder if maybe you could fit a rear mech which, even though you it wouldn't provide rear gears, would at least give you the spring-loading you'd need to let you fit a triple on the front to at least give you some range of gearing?