Measuring chain tension for singlespeed, how?
Apologies for bimbo question but am unsure of how taught the chain needs to be. I came across mention of being able to lift up chain half an inch at the mid-way point, is this correct?
I do use a chain tensioner but feel chain may have become a little slack due to muddy trails. Obviously don’t want to over-tighten either.
As always, thank you. 🙂Posted 6 years agojulianwilsonMember
Also worth checking it with the crank in a few different positions: mine has definite ‘tighter’ spot (ie where the chainring is a tiny bit further forward relative to the rest of the time) so I get my chain tight-ish in the tight patch so it’s not too waggy in the ‘slack’ patch. (my crank is an xt so I am assuming it is the cruddy old no-name chainring at fault)…Posted 6 years agoMostly BalancedMember
I always thought the half inch of slack related to motorbikes where the chain tension will vary as the suspension moves. With bicycles I’ve always set the tension as tight as it will go with the pedals still able to turn freely. Bike frames are relatively flexible things and if you look at the lower chain run when you’re really leaning on the pedals you’ll see it sag quite noticably.Posted 6 years ago
julian – thanks for that, will check.
hey phil – how are you? I’m pootling but had an off last week in a slippery gully, landed on my bad side with the haematoma! More bruises to add to the collection. 😳
Still waiting on date for op though and trying to WTFU. 😉Posted 6 years agojonbaMember
I do it by feel but the inch thing would be about right – this is with horizontal track ends. On my mtb I use a tensioner and a halflink* chain and I normally make sure it is 1 or 2 links longer than the minimum to give me some room to repair in case it snaps (which it did last week!)
*initially had chainwrap issues, standard chain didn’t work and I’ve never tried again so I always buy halflinks now to save faff.Posted 6 years ago
Wee update – have been twiddling and reckon all’s OK. 8)
However, chain is single speed specific (Sram PC1) but doesn’t appear to have a power link. Am confused as to what needs to be done if chain breaks, not that it has so far.
Also, how often does an ss chain need replacing?
Thanks. 🙂Posted 6 years agoHicksyMember
From memory the SS Powerlinks are different to the 8/9/10 spd ones and just look like a standard link. Both the pins are attached to one of the side plates and the link is opened by flexing the 2 pins together. You can tell which one it is as the pins don’t have dimples in. I’ve only ever been able to get them apart with those Park Tools Powerlink plier things though.
I hope that makes some sense!Posted 6 years agoPaulDMember
The PC1 chain uses a 2 Piece Snap-Lock instead of the symmetrical quicklinks on 7-10 speed chains.
You would need to source a spare for trailside repair as well as a couple of spare links.
If your drive train has a 3/32″ sprocket and 7/8/9/10 speed chainring (basically not 1/8″), then I would buy one of these KMC Rustbuster chains for £6 which come with a 2 or 3 piece link but can use regular 8-speed quicklinks:
PaulDPosted 6 years ago
Chain came off yesterday, it had been hitting the chainstay and looked a little too slack. Increased tension but doesn’t appear to have made any difference, barely able to increase any more.
Might need to investigate whether chain has stretched but think as a first step I will remove chain tensioner, give it a clean and try again.Posted 6 years agoPaulDMember
The chain does not stretch, it just wears away.
That is the link pins (rivets) wear by abrasion.
All cycle chains use a hardened chrome steel rivet that will rust.
You have approx 100 of these, so if each wears 2/1000 inch that equals an extra 0.2″ chainlength, or nearly half a ‘link’.
It is recommended to change the chain before 1% extension, which is only 0.5″ on the whole length, or just 5/1000″ wear in each link.
Wear is faster on a derailleur geared bike because of the lateral bending that constantly moves grit through the link.
This is why a wax lube is the best, it keeps the muck out and is flexible.
So for the best life on a SS, I recommend the KMC Z610RB Rustbuster Singlespeed in 3/32″ width at £6 delivered from CRC.
Go on, spoil yourself.
PaulDPosted 6 years agoepicycloSubscriber
PaulD – Member
…for the best life on a SS, I recommend the KMC Z610RB Rustbuster Singlespeed in 3/32″ width at £6 delivered from CRC.
I’ve broken SRAM chains in the past. Haven’t used them since but I haven’t heard they have improved.
That much slack points to something wrong. Loose chainring maybe, but more likely the wheel has moved in the dropout.
What sort of chain adjustment do you have?Posted 6 years agocpSubscriber
Do singlespeed-specific chains stretch?
PC1’s do. Well, not technically as above, but they effectively elongate due to increased slack as all chains do over time. PC1’s seem particularly prone in my experience, particularly when new/newish. Over time they seem to settle down into a slightly worn state and don’t get worse as quickly! weird, but it’s happened with several PC1’s with me.Posted 6 years agothomthumbMember
pc1s aren’t as good as they used to be imo. seem to have a lot more play now & need to be tighter to stay put.
kmc are best ime.
😀Posted 6 years ago
Just back from the workshop aka kitchen. 🙂 It looked as though the slider had slightly dislodged itself. So I’ve removed the wheel, given everything a good clean and put it back together. Chain tension is now as it should be and I’m happy. 8)
Using a Surly Tugg Nut by the way.
Thank you again for suggestions. 🙂Posted 6 years ago
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