Single speed chain that won't stretch...

BOXKARS
Advertise with us
shop deals on amazon
Rat Rod Bikes Bicycle Forum

Help Support Rat Rod Bikes Bicycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
More brittle than stretching... It work hardens, so the more wear, the more brittler it would become
edit.. I'd like point out I'm severely dysgraphic, not a moron... More brittler... That make my eyes bleed also sorry
 
Last edited:
I wan to chime in just to point out something obvious that cman brought up but we haven't gotten follow-up on: true chain-stretch is easily measured. Measure your chain off the bike to see if it has, in fact, elongated. My instinct tells me that it has not; more than likely (as others have suggested), your axles slipped a wee bit in the drop-outs. Tossing those tugs on there will make a big difference.

Being heavy probably wouldn't stretch your chain more quickly, unless you're WAY over geared, and your pedaling efforts went more towards stretching the chain than turning the rear wheel. If you've kept the stock gearing on your 29" Stu, then i doubt if that's the case.

FWIW, I'm fat as F(udge). 245lbs or so? Not sure. I kill parts routinely on bikes that see a lot of mileage, but my chains lead normal-length service lives. My favorite when it comes to practical considerations is the same as Kenny suggested: KMC 410H. This has more to do with the old-school bushing design than it does the beefiness; I like that it's easier to break and piece-together lengths of these chains than the riveted designs, which you really ought to be using master links at every juncture. But, they are also over-built, affordable, and they last a good long while if you've got proper chainline, tension, and lubrication. If you feel like you need something beefier, I'd avoid the half-link chains (others have already explained why) and i'd look at 415 chain (3/16") which can easily be run on 1/8" sporckets without issue.

Also, LTJ mentioned garage door chain. I've gone this route (it was cheap!) but I find that, at least in the case of the brand I bought, the chain isn't very stiff, laterally. I had to run higher-than-optimal chain tension to keep the chain from constantly hitting the tire. TBF, those were some fat knobbies and i was riding trails, but the same set-up with KMC chains, such contact was rare.

But yeah, first step: take that chain off, and measure it. Here's some directions i got from the Sheldon Brown site, verbatim:
The standard way to measure chain wear is with a ruler or steel tape measure. This can be done without removing the chain from the bicycle. The normal technique is to measure a one-foot length, placing an inch mark of the ruler at the side of one link pin, then looking at the corresponding link pin 12 complete links away. On a new, unworn chain, this link pin will also line up exactly with an inch mark. With a worn chain, the link pin will be past the inch mark. For accurate measurement, the chain should be held under some tension -- either on the bicycle, or hanging. Also, use a metal ruler or tape measure. Wood, plastic and cloth all can expand or shrink. Measurement is also possible with a metric ruler -- see below.

This technique gives a direct measurement of the wear to the chain, and an indirect measurement of the wear to the sprockets. first, let's look at how to do this with a ruler that measures in inches.

  • If the link pin is less than 1/16" past the mark, all is well.
  • If the link pin is 1/16" past the mark, you should replace the chain, but the sprockets are probably undamaged.
  • If the link pin is 1/8" past the mark, you have left it too long, and the sprockets (at least the favorite ones) will be too badly worn. If you replace a chain at the 1/8" point, without replacing the sprockets, it may run OK and not skip, but the worn sprockets will cause the new chain to wear much faster than it should, until it catches up with the wear state of the sprockets.
  • If the link pin is past the 1/8" mark, a new chain will almost certainly skip on the worn sprockets, especially the smaller ones.
Click to expand...
 
Last edited:
Thanks - I didn't mean to wave the suggestion off - sorry if that's how it appeared.
I'll get to measuring - but I think I have enough anecdotal evidence to conclude that it's stretch. I have the same chain on my Kos Kruiser - with the same tensioners fitted almost from new and it still gets sloppy over time. Properly lubed and maintained.
I don't think the axle moved in the dropouts. It was installed at the factory either by a gorilla or a rattle gun. It was seriously torqued. Enough to have left indentations in the paint from the 'frame protection washers' as mentioned in the specs. They show no indication of having moved when I adjusted and fitted the tensioners..
Regarding gearing - BMX Cruisers - the ratios are great for cruising and general tomfoolery. Starting uphill on soft ground e.g is where they take huge load. Not only enough to stretch the chain - but also enough to distort the chain ring. I've squished two 44t's out of round on the Kos. Disadvantage of one gear I guess.
 
Last edited:
Oh, i didn't want to give the impression that i was being critical; i was just curious if the stretch had been measured. Sounds like it could be. Something to keep in mind, with the 29"s, is that the bigger wheels give a higher final drive, so the ratios aren't the same for 29, 26, or 20s.... Stock is a 33/15, which gives about 61" on 29" wheels. The classic BMX gear is about a 52" (44/16 on 20s WBITD---nowadays, with the tiny front and rear sprockets, they still run a similar overall ratio; a lot of folks seem to run 44/22 or other config equalling 2:1 with 26s...) so I'd definitely suggest dropping the gear ratio; maybe try a 17t or 18t freewheel out back? That'd give you a 50.5" or 53.5" gear.

HTH
 
It does help, thanks - the 33/15 29er is taller geared than the 44/15 26" Kos - which while I'm using it primarily as an exercise bike I didn't think was such a bad thing but ...
 
As a fat guy, i'm hardly qualified to give exercise advice, but it is my understanding that a lot of racers will ride track bikes with a low gear to get their spin on, to help in terms of training. (Other guys roll geared bikes and do high/low/mid intervals; many use both methods.) I'd shoot for a 54" gear or so and see how ya like it; might not even help with the chain issue, but it's eminently spinnable and fun for crooozin'.
 
Roller-chains get hammered, but are relatively cheap & unchanged in design over the years. Better materials & tolerances have improved them a lot. Every now and again, just pull out your 12" scale and measure pin to pin the check for stretch. I can't imagine any chain going south in 4 days, no matter what it is made with. ??
 
Or that I'm 6'5", 285lbs and have legs like a pool table. Those links earn their keep.

Anyway - It didn't 'go south' - it's still perfectly serviceable. It just stretched some - and like I said - from experience it will probably continue to do so.

It's not even that I mind having to adjust it. I'm always tinkering with them - it's the hobby.

It's about having the right tool for the job. Efficiency in design and all that.
 
Last edited:
IMO, a stretched chain is a chain that has gone south. Let the deterioration of the cogs and sprockets begin. Just curious: What is your definition of a "stretched chain" and how do you measure it? Single-speeds don't seem to experience the negative effects from a stretched chain that a geared bikes do generally, but I could be wrong here.
 
SILVERKINGPC said:
IMO, a stretched chain is a chain that has gone south. Let the deterioration of the cogs and sprockets begin. Just curious: What is your definition of a "stretched chain" and how do you measure it? Single-speeds don't seem to experience the negative effects from a stretched chain that a geared bikes do generally, but I could be wrong here.
Click to expand...

Single-speed chains are going to hold up a lot longer, assuming you got your chainline and tension right, but a stretched chain will still destroy front and rear sprockets rather quickly.... you get "shark-fin" teeth and when that gets bad enough, fresh chains won't run properly if you put a new one on your worn-out drivetrain. 1/16"(1.5mm) out per 12" of chain is stretched enough where you want a new one.
 
The lowly but functional roller chain lives on, and very cheap to replace when stretched, and as B808 says, cogs and chain-rings are not. Wish I could say that about an NOS Diamond skip-tooth chain!
 
us56456712 said:
KMC Z510 HX might work as it is for fixie, track and BMX. My son rides a fixie and his chain looks like it came from a motorcycle it is so beefy. I think it is probably from a freight bicycle or a tricycle, which have wider chains. Some motorcycle chains are 1/2 inch pitch but the rollers are probably different and probably won't fit the bicycle sprocket. My son told me that you need a strong chain if you are going to rely on it to stop a fixie. I don't ride fixie so I know nothing about the chains for sure, just guessing ,but a tricycle chain might be stronger.
Click to expand...
This the chain I was going to say. It's a good strong chain it will even break a chain tool pins are so tight.
 
18b7721f756334c8a8e217d96a266e19.jpg
kmc Kool knight


Sent from my iPad using Tapatalk
 
Has nobody mentioned the SRAM chains? I always used a SRAM PC1 Nickel since my fixed gear days. They stretch a little, but it seems to stretch pretty evenly. You don't get the tight spots when pedaling and they stay very quite throughout their life. I think I replaced the chain after maybe 10 months of active fixed gear riding and only because I liked the idea of replacing stuff before they needed to be. I've still never felt like I needed to replace one on any of my cruisers.

Also, they are shiny chrome and I'm a sucker for that.
 
i used to rock SRAM pc1 chains bitd; they're awesome. i just tend to prefer the KMC offerings, mostly b/c they have so many more options in 1/8"; the jetfuel/neochrome color looks great, and i like the Kool series directional chain.... but my fave is the 410h-np. The nickel plating holds up nice, and the old-timey bushing design is my preference. But, no doubt the pc1 is a great chain, and many manufacturers offer nice chains these days.

I suspect the OP experiences excessive chain stretch b/c the tension is too high and/or the chainline is off.
 

Latest posts

Back
Top