Transmission life

For discussions about bikes and equipment.
fatboy
Posts: 3455
Joined: 5 Jan 2007, 1:32pm
Location: North Hertfordshire

Postby fatboy » 19 Jun 2008, 8:20am

Last night I measured my chain (SRAM PC48 after 3500 miles) and it was just under 12 1/8" long. Oh heck I thought and have now had to go shopping for a new cassette (and tools to fit) to add to the order of the new chain I bought yesterday.
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly

User avatar
lauriematt
Posts: 963
Joined: 24 Apr 2008, 10:26pm
Location: shropshire

Re: Transmission life

Postby lauriematt » 19 Jun 2008, 10:03am

lauriematt wrote:
neilob wrote:Now an old fxxt I ain't, but I started cycling about 40yrs ago. Since then I have adopted the principle of changing my chain every year or so, of course oiling and cleaning it regularly. I don't really remember ever throwing away a freewheel, probably I just changed for new ratios but they seemed to last for ever. Last week I went to my LBS who advised me that chains have a life of 1000 miles and cassettes 3000 miles. Is this advice commercial (ie sell more) or are modern chains/cassettes so much less durable? I don't want to be a cynic but sometimes you can't help it!!


i recently replaced my chain after two years hard use...alot more than 1000miles. it was very worn...my lbs recommended replacing the cassette too...so that they would both run well together.

in my opinion the cassette didnt look too worn...but i went with the shops recomendation and replaced it anyway!

if a chain only lasts 1000miles...i would need to change mine every 10weeks!!! which seems a little extreme...5 chains a year?!?!?!?!


PW wrote:I post this every time, but here goes...
A chain when new has the pins at 1/2" centres. As it wears the chain elongates. When a nominal foot length measures 12 1/16" bin the chain and the cassette will be undamaged. Go beyond that measurement and the new chain will skip on the old cogs. If the foot length measures over by 1/8" then the chainrings start to wear and that's when things get expensive..


i also had to replace my middle chainring when i got new chain & cassette...chainring set me back £30!!! :twisted:
WHAT DOESNT KILL YOU .... CAN ONLY MAKE YOU STRONGER

byegad
Posts: 3232
Joined: 3 Sep 2007, 9:44am

Postby byegad » 19 Jun 2008, 12:27pm

Just been to my LBS to bum a bike box off him and he trotted out the 1000 to 1500 miles for a cassette line.

I wonder if one of the Big Manufacturers has sold them all on this idea. I have several bikes with more than 3000 miles on them with cassettes that look like new and have accepted a new chain without any problem.

PW
Posts: 4519
Joined: 23 Jan 2007, 10:50am
Location: N. Derbys.

Postby PW » 19 Jun 2008, 12:57pm

As I said, the mileage varies. I get around 1400 from a chain, the cassettes so far are lasting at least 3 chains, the only one I've ditched had somehow snapped a tooth on 3rd which was acting as a shifting gate making the gears jump past and then drop down again. Otherwise it wasn't worn out after 4,200 miles.
If at first you don't succeed - cheat!!

Khornight
Posts: 129
Joined: 5 Jun 2008, 10:56pm

Postby Khornight » 19 Jun 2008, 2:10pm

What about for fixies?

Wider chain, not changes... should I still worry about changing my chain before my (albeit it single) gear?!

Hmmm, does trying to break by pushing backwards change the way it wears? Better or worse?

pliptrot
Posts: 609
Joined: 12 Jan 2007, 2:50am

Postby pliptrot » 19 Jun 2008, 2:42pm

Now Campagnolo are coming out with 11 speed systems (even narrower chains and sprockets) and so we can look forward to even further reductions in durability. (Yes, currently only on exotica, but it will spread across the ranges and, of course, the Japanese will follow suit).

As they are now touting lubrication free bearings, perhaps they should rename themselves Fisher Price. Or Fishero Pricero. They've obviously got our moniker: mugs.

pigman
Posts: 1724
Joined: 11 Jan 2007, 12:23pm
Location: Sheffield UK

Postby pigman » 19 Jun 2008, 2:45pm

pliptrot wrote: perhaps they should rename themselves Fisher Price.


nah, you mean "hike-up price"

PW
Posts: 4519
Joined: 23 Jan 2007, 10:50am
Location: N. Derbys.

Postby PW » 21 Jun 2008, 11:18am

Khornight, the fixie chain runs in a straight line, not bending like a derailleur system, so it should last far longer. The old Sturmey Archer 3 speed chains used to literally last years for the same reason.
If at first you don't succeed - cheat!!

User avatar
robbo
Posts: 51
Joined: 12 Jan 2007, 3:29pm
Location: Barsac/Ulverston

Postby robbo » 23 Jun 2008, 9:53am

I use NOS Renold chains (Just got two 3/32" chains for £4.50) and they do last for years. I fitted one to my fixed in 2004 and it is still on it. The one on my Rohloff is still going strong after 3 years and 20 000+ miles. During the brief time I was using 8 sprockets the Sram chains needed changing twice a year. Apparently modern chains break sometimes, almost unheard of with Renold chains. On the other hand you cannot match your cadence to the optimum without at least 20 gears preferably 30.

User avatar
robbo
Posts: 51
Joined: 12 Jan 2007, 3:29pm
Location: Barsac/Ulverston

Postby robbo » 23 Jun 2008, 10:01am

Khornight wrote:What about for fixies?

Wider chain, not changes... should I still worry about changing my chain before my (albeit it single) gear?!

Hmmm, does trying to break by pushing backwards change the way it wears? Better or worse?


3/32" bushed i.e "old fashioned" 5/6 speed chains are stronger than 1/8" other things being equal, so the sprocket lasts a bit longer but the chain less.

I wouldn't worry about the limited effects of leg braking, compared to the time you are propelling forward the time you spend pushing back is minute.

ian s
Posts: 118
Joined: 24 Jun 2008, 12:59pm

Chain wear

Postby ian s » 24 Jun 2008, 1:10pm

One of the reasons chains last such a short time these days is the awful (but cheap) design. Take apart a used chain of the "Sedis" type and you will find two very narrow wear marks on each pin, whereas on a decent chain the wear mark will be the entire length of the pin between the outer plates. Sadly I can no longer find decent chain available.

Ian

ianr1950
Posts: 1336
Joined: 16 Apr 2007, 9:23am

Postby ianr1950 » 24 Jun 2008, 1:50pm

I have never measured a chain in my life and don't spend half as much time as Mickf does on cleaning them ( I have more important things to be doing than stripping it all down) :lol: but I get 3000 miles easily from a chain and my cassettes still accept the new one.

User avatar
Mick F
Spambuster
Posts: 50328
Joined: 7 Jan 2007, 11:24am
Location: Tamar Valley, Cornwall

Postby Mick F » 24 Jun 2008, 2:42pm

Good on 'yer!

We hear of 1500 miles sometimes.

I managed 7500 on my last 9sp chain, it would have gone on longer had I not converted to 10sp. I still have it in a tin. Don't know why!
Mick F. Cornwall

pigman
Posts: 1724
Joined: 11 Jan 2007, 12:23pm
Location: Sheffield UK

Postby pigman » 24 Jun 2008, 3:17pm

how does one determine the length of chainlife? Is it (1) the stretch aspect, (2) the wear on the inner link plates or (3) the floppiness of the joints?

some seem to be concerned with (1) and go on to say that regular cleaning improves chainlife. How? - stretch has nothing to do with cleaning, it depends on mileage, terrain (hills/flat) , pedalling style (heaving/twiddling).

However (2) and (3) are affected by cleaning, but have a lot do with variation in chainline (tough terrain means more gears used and 11 speedwill be more extreme than 5). In short, its impossible to simply quote mileage and to say cleaning is the panacea for a longer-lasting chain.

byegad
Posts: 3232
Joined: 3 Sep 2007, 9:44am

Postby byegad » 24 Jun 2008, 7:29pm

The Park tools gadget gives a measure for when the chain is 0.75% and 1% over length. I tend to throw at 0.75% and the last 3 Cassettes I've changed were for ratios and not wear.