dennis@rlgvax.UUCP (Dennis Bednar) (11/14/85)
I have a Specialized Touring Expedition bicycle which only has
5000 miles on it, yet the chain has stretched apparently a lot,
and needs replacement, along possibly with a front aluminum gear.
What I would like to know is chain stretchage supposed to happen
on such low mileage? If I remember correctly, I have a maniac
cyclist friend who, reportedly, gets about 50,000 miles per chain!!
I first noticed symptoms of this problem riding into work: if I
put a lot of torque on the pedals, the chain would "slip", and
sometimes even come off the front chainwheel. The chain would not
shift to another gear on the back freewheel, though. At first I thought
it was something in the rear drivetrain (either the freewheel
or the derailleur) that was the cause of the problem. But today
a co-worker helped me diagnose the true problem: the chain has
stretched so much, that it has worn an irregular pattern into
the teeth of the front middle chainwheel. If you look at the
front chainwheel, it is very visible to the naked eye that the
chain doesn't seat totally into the "valleys in the teeth".
I have one other question for advice: If I had to skimp, and not
replace both the chain and the front chainwheel, at the same time,
then which would be better to replace first, the chain or the
chainwheel?
--
Dennis Bednar Computer Consoles Inc. Reston VA 703-648-3300
{decvax,ihnp4,harpo,allegra}!seismo!rlgvax!dennisreintom@rocky2.UUCP (Tom Reingold) (11/15/85)
I think you did pretty well by getting 5000 miles from your chain. Given the choice between replacing the chain and the freewheel, definitely replace the chain. I manage to do this many times in a row. The trick is to replace the chain before IT wears out the freewheel. If you find yourself wearing out both of these parts with alarming frequency, you may be using your small (rear) sprockets too much. Switch to larger ones.
jan@ascvax.UUCP (Jan Woellhaf) (11/15/85)
According the the tenets of *my* chain religion:
Chains don't really stretch. What happens is the pins and bushings
wear and lengthen the chain minutely at each pivot point. Check this
by pushing out a pin on an old chain. The wear is visible.
5000 miles is *way* longer than I have ever run a chain. 50,000 miles
on a single *bike* is unbelievable, let alone 50,000 miles on a single
chain!
The best chain is the Sedis Sport. Buy their cheapest one and replace
it every couple thousand miles. Don't waste your money on more expensive
chains.
If the new chain skips sometimes on the smaller rear cogs, you'll need
to replace them also. You won't have to do this every time you replace the
chain, but some of my friends do just to avoid problems. Check, but I
don't think you'll have to replace the chainwheel.
Keep the chain clean by scrubing it *often* with 409 and a toothbrush.
Rinse with clear water, dry it some with a rag, lubricate with WD-40, and
wipe dry.
Above all, don't listen to anyone who preaches a different chain
religion. Mine is the only *true* one. :-)
Jan Woellhaf
seismo!hao!ascvax!janbarrys@hercules.UUCP (Barry Steel) (11/15/85)
In article <839@rlgvax.UUCP> dennis@rlgvax.UUCP (Dennis Bednar) writes: >I have one other question for advice: If I had to skimp, and not >replace both the chain and the front chainwheel, at the same time, >then which would be better to replace first, the chain or the >chainwheel? Trust me, if you don't replace freewheel, chainring AND chain things will not work right. If you put on a new chain without replacing the freewheel, the chain WILL skip on the freewheel when torqued. You already know what is happening without replacing the chainring. A new chainring with the old chain will be a short-lived chainring. I base my statements on first-hand experience and Eugene Sloane's "Complete Book of Bicycle Maintanence". BTW, 5000 miles for a chain (used in various weather) does not sound unreasonable). barry steel (X-Reston)
howarde@mmintl.UUCP (Howard Eglowstein) (11/17/85)
I have a '73 Raleigh on which the chain died after 15,000 miles from rust. There was no appreciable wear or stretching, so I'd say that 5,000 miles sounds a bit early to me. "whoops Mr. Moto, I'm a coffee pot..."
kehoe@reed.UUCP (Dave Kehoe) (11/20/85)
> The best chain is the Sedis Sport.
Sedis Sports are too flexible. The new Everest is
much better shifting, and is the same price.
--
"Why my thoughts are my own, when they are in, but when they are out
they are another's." -- Susanna Martin, executed for witchcraft.
Dave Kehoe tektronix!reed!kehoe (503) 230-9454 (h) 684-3314 (w)dennis@rlgvax.UUCP (Dennis Bednar) (11/20/85)
Heres a direct reply, in case anyone else is interested.
From: Roger Hayes <seismo!arizona.CSNET!rogerh>
To: dennis@rlgvax.uucp
Newsgroups: net.bicycle
In-Reply-To: <839@rlgvax.UUCP>
Organization: University of Arizona, Tucson
Cc:
You gotta clean them! Especially if you ride in rain, or if your bike
gets muddy or sandy.
What happens is that dirt gets into the bearings between the links. Then
the holes that the link pins go through in the inner links, turn from
round to oblong. This is called "stretch" because it makes your chain get
longer. It also makes it sloppier from side to side; a new chain will
have perhaps 1/2 inch sideways slop between chainwheel and freewheel. An
old, dead chain will have an inch or more. Try it; just move the middle
of that stretch of your chain sideways. (Narrow chains have more side
flex than regular ones). Note that the sideways stiffness of the chain
is what lets you change gears.
If you ride with a dead chain, you (as you learned) carve the teeth on your
chainwheel and freewheel into funny shapes. Once this happens, there's really
no help but to replace chain, chainwheel, and (almost certainly) freewheel.
See, if you put a new chain on, it will skip (because it only contacts one
or two teeth solidly) and wear out very quickly; if you put on a new
chainwheel, it will wear out rapidly because the chain is still bad (which
is what wore it out in the first place, right?) In both situations, the
new part is gonna wear very rapidly -- a waste of money.
Vetta makes a handy-dandy gadget that makes it much easier to clean your
chain -- you can do it right on the bike. It's called a "Chain Cleaner",
of all unusual names, it is a little fluid bath with brushes that fits
over the chain right on the bike, and retail is less than $20. (I get
no kickback, I just think it's a great idea).
All the Best,
Roger Hayes
Tucson, AZ
rogerh@arizona.CSNET
ihnp4!arizona!rogerh
--
Dennis Bednar Computer Consoles Inc. Reston VA 703-648-3300
{decvax,ihnp4,harpo,allegra}!seismo!rlgvax!dennismink@cfa.UUCP (Doug Mink) (11/20/85)
Chain life seems to depend a lot on how you ride (cadence and gearing), where you ride (terrain variation, frequent starts and stops), when you ride (rain, snow, etc.), and how you take care of your chain. I've managed to stretch a Sedisport in 1000 miles of fast, hilly riding and too-infrequent cleaning. I would guess that loaded touring has an effect, too. -Doug Mink
barrys@hercules.UUCP (Barry Steel) (11/20/85)
In article <2164@reed.UUCP> kehoe@reed.UUCP (Dave Kehoe) writes: >> The best chain is the Sedis Sport. > >Sedis Sports are too flexible. It helps to have some flexibility with an 18 speed, even though you don't use the fully crossed combination. It also helps to have a flexible mind, superlatives are dangerous. barry steel