The negative repercussions of spring cleaning
 

I've been riding the Coda just about a year now, with a shade over 3000 miles on it. Lovey had some spring cleaning and repair type errands for me to run in town, so I took the bike too and whilst taking care of things, went to the bike shop and had a new chain installed (SRAM, I forget which one). The bike was not acting up in any way, but with the prime riding time now here, and the birthday ride coming up soon, I thought PM was in order. I specifically asked the mechanic how the old chain looked and he said it was in pretty good shape, but time for a change. In retrospect, I think he might have been being kind, as he did mention that if I had any skipping, to bring it back and they would look it over some more. Went for a ride then and oh joy and whoopee, skipping whilst standing to climb in the third and fourth gears, both while on the inner and middle rings. I guess I don't generate enough torque to see any skipping while on the big ring. So I guess a new cassette is in order. The one that appears to be bad now is a SRAM 950, which is not one of their higher grade cassettes. Actually, it is the lowest grade 9 speed cassette so far as I was able to determine. Still, I was surprised that it is shot so what feels like soon to me. I've cleaned the chain, cassette and chain ring probably six or eight times over the last year, which seemed reasonable to me, and which is six or eight times more than I ever cleaned a chain and driveline before the age of 50.

The bike is at the shop with my instructions to keep the gearing the same, put on a better grade of cassette, to carefully check out the chain rings and if needed, to replace them.

I am a pretty good sized fellow, and do ride in hilly country a lot and occasionally in wet weather, but it seems to me that is pretty soon for a cassette to wear out. The riding is mostly on paved roads, very very little gravel.

Comments or suggestions?

My Trek 7600 is skipping too. And has been adjusted twice by my shop, who thought the chain and cassette were still good, but the skipping continues. So I think a chain & cassette swap is in order.

It only has about 1800 miles on it, if the mileage quoted to me by its original owner is to be believed.

Enough wear on a cassette to allow a chain to skip over the teeth is usually very evident to a visual inspection. (your taking a chain with about a 180deg wrap around the cassette and skipping over several teeth???) To do this, the cog teeth will have a distinct "sharks fin look" at the back edge of the cogs teeth.

The milage you are describing is pretty low for the destruction of a cassette. (especially a chain that has been cleaned a lubed.)

Unfortunately, the trouble needs hands and eyes on to solve so I will have to defer to your mechanics opinion................but.............................I'd adjust some more and check for stiff links and some other things before I'd buy a new cassette.

The fellow who will work on the bike next is a good and trusted mechanic. The guy who sold me the chain turned the issue over to him. We'll see what he says. I don't think he'll sell me stuff I don't need.

I better start paying attention to my chains. We don't have enough mileage on the new bikes to warrant a change but our old beater hybrids, wow. They have been around for ten years without a chain change. Luckily only a year of that involved substantial riding. I will dig into Sheldon's pages to figure out how to check the wear.

On the tandem- We break things so I always carry a spare chain with me. Might be lucky enough to catch the chain before it breaks- But a couple of years ago- I changed the chain as a matter of course- two nights before a big ride. You can guess the outcome and a 2 year old cassette starting jumping. This is one of the spares I always keep in stock so back home and change it. No cassette problems- but the middle chain ring showed it had wear on it by being unridable with the new chain. Next day down the LBS for a new chain ring and none in stock of the size I wanted. Quick phone round and no other shop had one either. So it was down to Plan "B". That spare chain we always carry on it as a spare- is a run in chain- put on the bike for 200 miles- and taken off to keep as a spare. So fitted that and just hoped that it would not break. Being run in- It would still run on the worn chain ring without jumping.

That was the wet muddy year in 2006 and the chain did not break- but 100 miles in mud cost me 3 new chain rings and yet another cassette after the ride. And I fitted a new chain again.


Now offroad- I would change the chain about every 1,000 miles as a matter of course. The tandem only lasted about 500 miles before breaking- or needed changing. These road things that I now ride- Last a lot longer- but the quality of the chain has a lot to say on that score. I have a chain checking tool and when it indicates that the chain has 1% wear on it-a new chain goes on my list for the next trip to the LBS. 3,000 miles on the cheap chain fitted to the OCR- 2,300 on Boreas and it is only showing .75% worn- and the TCR has not had enough miles yet to warrant checking. Only about 1,000 so far.

The standard chain will have 12 links in 12 inches. Chain stretch of up to 1/16" is ok. Replace chain at 1/16". Chain stretch of 1/8" per Sheldon is probably lights out for the cassette.

Chain "stretch" leads to problems with the teeth on the cassette. You either have to change the chain more frequently to limit cassette wear so it won't skip with a new chain or use both until a problem develops then change both. There's a good chance that you could have gotten many more miles out of the old combo before needing to replace both. Since it's a shop I'm sure the old chain is long gone. If it wasn't, putting it back on would solve your skipping problem.

That makes a hell of a lot of sense, and I will remember it in the future. Thanks

I buy cheap chains and replace them at the first sign of stretching or once a year. I usually go through several chains before needing to replace a cassette or freewheel.

Phone just rang, it was Scott, from the bike shop. I am out a $10.00 RD adjustment. He said the cassette was in good shape and it appeared that the bike was kept clean and lubed. I am embarassed for jumping to the wrong conclusion so readily. Here's hoping that is the entirety of the matter.

It's already been said but I will try to say it differently. The chain and gears will grind themselves into an self-interlocking puzzle. If one then changes one or the other with new then the new will no longer mesh with the old. So, either change out the chain more frequently (cheaper) or change everything at once (expensive).

Park sells an inexpensive chain gauge which can be used to monitor chain wear.

http://www.parktool.com/products/det...=5&item=CC%2D3

I have one and am not afraid to use it.

:lol: How often do we ignore the simplest answer? The eventual solution would have taken you far less time and motion than typing the OP.

The first guy who looked at my bike, which was skipping, said I needed a new chain and cassette but he didn't have them in stock.

So I went to another shop. They said I needed a RD adjustment. They adjusted it for $7. Took it out for a ride and after about 15 miles it started skipping again. There was a shop along the trail I was on so I rode it in there. They also performed a RD adjustment. Started riding home, made it maybe 8-10 miles before it started skipping.

No more RD adjustments for me on this problem.

I usually run my chains way past their normal life expectancy so
whenever I change a chain I always change the freewheel (cassette).
I've never had a problem. The freewheels aren't all that expensive
and it provides me a great opportunity to repack the bearings etc.
Of course I run low end equipment so 40 bucks and I'm on my way.

It hasn't been that long since somebody on this board said something about when you hear hoofbeats you should think horses not zebras. Which makes it even worse.:o

I think riders who frequently push high gears and stand on hills will wear out chains and bottom brackets faster than spinners who maintain higher cadences in lower gears. Being a spinner, my chains and bottom brackets tend to last longer than one might expect.

Or, I could be completely FOS.:o

But it's really great FOS, Mrs. Presky.

:lol: Didn't need the money, anyway.

Terrierman I think you have completey missed the problem and an extremely easy solution. Have you been reading the other posts lately? What you need sir, is a new bicycle.

I tend to the low end on most of my bikes too. $40 for a chain and freewheel or $10 for a chain? Seems like simple math to me.

I am quickly learning that this is the cycling community's equivalent to the computer community's "You need to format!" advice :D

No. I mean waaaaaaaay past their life expectancy. I'm somewhat lazy I guess.
I just replaced the chain and freewheel on the Trek after....well.....I really
don't remember, but the shop I purchased the previous parts from, Spokes & Wheels,
has been out of business for several years.

Your math is right on the mark for folks who maintain their machines properly.
I tend to service my bikes much less regularly...but then again, they are all
low end machines and they still serve me well even with the minimal maintainence.

I think I'll stick with my old school gearing systems, which use the more robust "8-speed" chains. I do follow Sheldon's 1/2-percent elongation rule (1/16" per 24 half-links), but I get very long service out of chains, freewheels, and chainrings, and I am not particularly fastidious about chain-cleaning. To get more life out of your driveline, avoid applying much pedal torque in any of the small chainring / small cog combinations