Bicycle Mechanics - Life of drive system

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Sculptor7
09-04-11, 07:16 AM
My Trek 1.1 which I bought in 2010 (a year ago last spring) has been a very enjoyable bike to ride. I am concerned however, about the life of the drive system (the chainrings, rear sprockets and chain). Had them replaced this spring for a cost of $210. This seems to be hard to understand when I used my old Centurion Le Mans for many many years and never even replaced the chain. I am told by the LBS that in two or three thousand miles I will have to replace everything again. Is this normal on modern bikes?

On the flip side the Bontrager front tire has shown little signs of wear in three thousand miles or road cycling. This surprises me because all the reviews I read talked about these being cheap tires that should be replaced. (I did replace the rear tire with a slightly more expensive tire). I am always careful to keep the tires inflated and brush off any debris before and after riding.


reptilezs
09-04-11, 07:38 AM
at 3k miles i would expect maybe a chain replacement if you do your part in lubrication. the chainrings last a long time if you replace the chain at reasonable intervals. cassette will go 2-3 chains. front tires dont wear as fast as rear tires. when the rear tire shows cords i rotate the front to the back and new one goes in the front. i would shop for a different shop

HillRider
09-04-11, 07:58 AM
Your shop ripped you off unless you badly abused your bike or there was other physical damage. I would NEVER go back there.

A chain and cassette will require replacement periodically and you have two ways to approach it. Either run them until the chain is "stretched" about 1%(it will measure about 12-1/8" over 24 pins while a new chain will measure 12" exactly) and then replace both. Or replace the chain every 1500-2000 miles and get three or more chains per cassette. I do the first and get 6000 to7000 miles on a chain and relatively low cost cassette like a 105 or Veloce. Chainrings last for much longer with over 30,000 miles being common even with my 6000+ mile chain life.


BHOFM
09-04-11, 08:26 AM
I have an old Trek 720 Multi Track I bought in April and went completely through it
before riding it. New tires, Bontrager H1 ECOs. All new cables, brake pads, pedals.
Checked and cleaned, packed all bearings. New rear wheel.

The bike had the original tires and showed little wear, just sat for years.

I just turned 6000 miles on it. I have cleaned and oiled the chain once a week.
Cleaned the sprockets and lubed every thing at the same time.

I rotated the tires at 4000 miles, they look fine. Adjusted the RD once.

Nothing shows any signs of wear yet. LBS checked the chain, said it was
like new.

How are you people wearing out, and tearing up things in half that distance?
I ride pretty hard at times, average about 17+ mph and hit 30+ almost every
ride. I don't stand and mash very often. I do keep the bike clean and stored
indoors.

2manybikes
09-04-11, 08:54 AM
6-7-8 speed chains last a lot longer. The 9-10 speed chains are narrower and don't last as long. Also different component groups have different materials for the cogs or the rings. Not always. My 9 speed Dura ace drive train has soft titanium big rear cogs they wore out quickly. The next group down, Ultegra does not have ti big cogs and will last longer. The technical books I have list all the differences between the groups.
The wear is also highly dependent on how you ride, and the enviroment. Rididng in the rain will wear out parts faster for instance. Riding in one gear a lot will wear out that one gear early. Many different factors for wear.
My 7 speed tourig bike has 10,000 miles on the chain, cogs and rings, it's fine.

MudPie
09-04-11, 09:06 AM
Your shop ripped you off unless you badly abused your bike or there was other physical damage. I would NEVER go back there.

A chain and cassette will require replacement periodically and you have two ways to approach it. Either run them until the chain is "stretched" about 1%(it will measure about 12-1/8" over 24 pins while a new chain will measure 12" exactly) and then replace both. Or replace the chain every 1500-2000 miles and get three or more chains per cassette. I do the first and get 6000 to7000 miles on a chain and relatively low cost cassette like a 105 or Veloce. Chainrings last for much longer with over 30,000 miles being common even with my 6000+ mile chain life.

I'm a practitioner of the a little of both. I tend to replace chains at .75%, using both the Park chain tool measuring device and a steel machinist rule. I get ~2500-3000 miles per chain and at least two chains per cassette. I've used SRAM PC1090 chains for about 10k miles and recently switched to KMC X10SL, and cost is ~$55 per chain. I've been using SRAM 1070 cassettes (exclusively), and ~$90 per cassette. So in terms of cost, I spend about $55 every 2,500 miles, and $150 every 5,000 miles. These parts are easy to install, so perhaps you can save some labor costs here.

Also, maintenance is the key for longevity. I lube my chain every 80-100 miles (I know, probably way more frequent than necessary). I do take the time to dab one drop on each roller.

mconlonx
09-04-11, 09:29 AM
1.1 is an 8sp and I have a real hard time imagining that you wore out the chain and cassette in a year.

But it depends. Harsh conditions in your area? (sand, dirt, water, moisture, salt?) Ride year round, even through the nasty weather? Don't wash your bike? Don't lube your chain? If so, could very well go through chain and maybe even cassette in short order.

HillRider
09-04-11, 09:39 AM
6-7-8 speed chains last a lot longer. The 9-10 speed chains are narrower and don't last as long.
The 6000-7000 mile cassette and chain life I mentioned above is based on 9 and 10-speed chains and cassettes.

bradtx
09-04-11, 09:42 AM
Sculptor7, I just don't understand why your chainrings would require replacement so early. I'm not so sure I'd use that LBS again.

On my crit bike I only could get ~1K miles out of a chain and about twice that for the cassette while the chainrings were never an issue. Now that I'm older and don't bang gears like I used to I feel I can get two or three times that (I've become somewhat mechanically sympathetic).

Brad

desertdork
09-04-11, 09:47 AM
If you had a 10-sp drivetrain and put 3k miles on it, it would be possible that the chain would have worn enough to require replacement of both the chain and cassette. But 10-sp chains and cassette cogs are relatively thin and wear more rapidly. Your 8-sp chain and cogs are robust in comparison. With even modest maintenance, I'd be very surprised to reach 0.5% (1/16" stretch) in under 5k miles, and that minimal amount of wear would require nothing more than chain replacement (~$30 at the LBS). Unless you run your components into the ground, a cassette will last multiple chains, and chainrings should last multiple cassettes.

If you think your maintenance procedure could be revised to extend chain life, start there. Understand how to measure your chain as wear progresses, and know how to detect a worn cassette. It's not difficult, and you'll have a greater sense of control and be far less likely to be had by an unscrupulous shop.

davidad
09-04-11, 10:19 AM
http://draco.nac.uci.edu/rbfaq/FAQ/8d.2.html

Sculptor7
09-04-11, 01:10 PM
Thanks for all the advice. I should have added that I pretty regularly service the chain. Not taking if off but dusting off any sand or grit and wiping it down both before and after lubricating it with a good light lubricant.
Also, I avoid sandy or dusty conditions. I guess I don't want to believe my shop is ripping me off because I have had a pretty good feeling about doing business with them but perhaps I am not being realistic. Both the owner and at least one of the repairman both told me that the drive train would need replacing after just a few thousand miles. In fact I was told that when I bought the bike. Think I am going to get a chain wear indicating tool and start doing my own maintenance. I have not hesitated to take apart vintage bikes but have been intimidated about doing anything to this new bike. Perhaps its time to change that.

desertdork
09-04-11, 02:22 PM
You gave them your business, and you gave them the benefit of doubt. You sound like you'll take this as a learning experience and move forward with the incentive of doing your own maintenance. That's a positive attitude, and I'm sure you'll find home maintenance rewarding.

This is probably as good of a chain wear tool as you will find:
http://s7d5.scene7.com/is/image/Staples/s0083345_sc7?$sku$
http://www.staples.com/Westcott-15-Stainless-Steel-Ruler/product_103986

Just follow the simple advice for measuring wear as instructed at sheldonbrown.com. Mine is marked in 1/32"; I can't tell if this particular one is. I measure from the 1" mark to the 13" mark, either positioning the mark at the center of the pin or at the edge of the pin.

When chain replacement time eventually arrives, you'll find the task to be about as complicated as putting a pan of rice on the range.

Sculptor7
09-06-11, 03:36 PM
I still had questions on my mind about this so I wrote to Trek Consumer Division and this is the answer I got:

"Thanks for writing. Most drive components will last about 2500-300 miles before needing replacement.

PAUL ANDREWS - TREK BICYCLE"

So I guess my question is still this: Is this really progress? For example, there's my old garage sale bike that I used for 20 years and paid $30 for without ever even cleaning the chain (that was before I became converted) and here's this $700 plus bike that needs to have the chain, the chainrings and the rear cluster replaced every 3000 miles. Okay, maybe I did not put the kind of mileage on then as I am doing now that I am retired and have time to ride every day but still...

deacon mark
09-06-11, 04:30 PM
Chainrings last for years period. You might wipe a cassette out in 3000 miles but frankly it better be because of something completely unusual. I have just crossed the 3000 mile mark on my Motorbecane Immortal Spirit. I put a new set of tires on at 2600 but they had some life left. I have the original chain with zero stretch on my machinist ruler, and the cassettee looks new once I cleaned it up. Now I do live in the flatlands and try to spin not mash, but something is up with what the LBS said. Being an old guitar repairman I can measure down to the amount of error in the thickness of a piece of paper.

chandltp
09-07-11, 06:01 AM
I have found I am replacing my chain every 1500 - 2000 miles. I ride several times a week on a road surrounded by beaches, and pick up a lot of sand. My first year with my bike, I went about 3500 miles and didn't pay attention to my chain (since I'd never had to replace one on my old Huffy MTB). I had to replace the chain and freewheel at that time. Last year I replaced my chain at 2000 miles and the freewheel was fine. This year, at around 7000 - 7500 miles total on the drive-train, I have a whole new drive-train.

This was a cheap Trek 7000. My repairs last week cost almost as much as the bike, but I have much better components now. I can now replace a single chain ring on the front. My OEM set was pressed together.

I'm not meticulous about keeping the drivetrain clean, and I ride in all weather conditions since this is my commuter as well. So some of this is self inflicted, but I believe the environment I ride in contributes to a shortened drive-train life.

LeeG
09-07-11, 06:33 AM
I still had questions on my mind about this so I wrote to Trek Consumer Division and this is the answer I got:

"Thanks for writing. Most drive components will last about 2500-300 miles before needing replacement.

PAUL ANDREWS - TREK BICYCLE"


I can't imagine needing to replace the chainrings in 3000miles. Maybe a chain but not chainrings.

bradtx
09-07-11, 07:24 AM
I still had questions on my mind about this so I wrote to Trek Consumer Division and this is the answer I got:

"Thanks for writing. Most drive components will last about 2500-300 miles before needing replacement.

PAUL ANDREWS - TREK BICYCLE"


"Most drive components", not "All drive..." was written in this purposely vague response.

Yesterday I swapped cranksets on my crit bike to have a 39T inner chainring for my knee, the replaced crankset is the same crankset I did my gear banging with in post #9. Both are FC-6400s, one with about 4K miles and the other less than 100 (both I'd bought new). I just compared the two and they're identical WRT wear. I also compared the 13-21 cassette that recieved the brunt of those full power shifts and it's only slightly more worn than the 13-23 that's on the rear now.

Unless there was a serious issue with the chain, which would've been evident in other problems or severe cross chaining I don't understand why the chainrings would've required replacing. Did the LBS return your worn parts to you?

Brad

Sculptor7
09-07-11, 07:35 AM
"Did the LBS return your worn parts to you?

Brad"

Actually, no. They also did not return the original clip pedals when I bought a pair of clipless, now that I think of it.

2manybikes
09-07-11, 07:39 AM
When one asks for a general answer to a complicated situation, there will be many, many, exceptions. The answer you got is as meaningless as the question. The real answer is, it depends on many things.

I have a bike with 9,500 + miles on the cogs , chain, and rings. It works perfectly. I have two that are over 6,000, and others past 3,000. It varies a lot depending on the environment, the exact group components, how you ride, and how you maintain your chain. Some people have gone 20,000 miles on the chain rings and cogs. some mtb riders that ride in muddy, dirty conditions can wear out those parts in 1,000 miles.

To quote another forum member from a long time ago, "How long is a rope?".

rydabent
09-07-11, 07:42 AM
The best idea here is to get a chain wear tool or good steel ruler, and check the wear yourself. It follows that chain wear will affect sprocket wear.

BTW I ride a LWB recumbent which of course has a chain almost 3 times as long as a DF bike. At 8000 miles it still does not show .75% wear. I service the chain well, and use Mobil 1 ext to lub it.

Kimmo
09-07-11, 08:05 AM
"Did the LBS return your worn parts to you?

Brad"

Actually, no. They also did not return the original clip pedals when I bought a pair of clipless, now that I think of it.

Ripoff merchants.

Sixty Fiver
09-07-11, 09:11 AM
If a bike sits still and is never ridden it will last forever... the measure to be used is how many miles have you put on the bike and the question is, how did you ride enough in one year to wear out your chain rings ?

Cassette and chain life is variable depending on quality and the conditions you ride in as well as how well you maintain the drive... generally... a cassette will last through 2 chains and a good lifespan for a cassette is 5000 - 6000 miles.

Because they distribute load better and have more teeth a set of chain rings should last in excess of 25,000 miles unless they are cheaply made... I have chain rings on my touring bikes that have seen more than 25,000 miles and they are still in fine shape.

Basically... your bike may have needed a new cassette and chain but think you got taken on the chain ring replacement as few peopel can ride enough in a year to wear these out.

Kimmo
09-07-11, 11:46 AM
I wouldn't be at all surprised if his rings, cassette and pedals were all on other bikes right now.

Sculptor7
09-07-11, 04:34 PM
There seems to be a need for clarification as to how much I rode and the conditions I rode in. As a retiree I have a lot of time to ride and my average has been around 100 miles per week during the ride season here which is only from May to October generally. This year it has been even shorter because of a lousy spring. I bought the bike a year ago last spring and the best estimate (since one of my computers broke down) is that I had around 2500 to 3000 miles on it when I paid for the drivetrain replacement this past spring. Probably 1500 on the bike since then.
I ride on paved roads averaging 14 mph or less and am careful to avoid shifting under load and riding with crossed gears (chain on large front, large rear or small chainring, small sprocket). My maintenance has consisted of periodically (one to two weeks) brushing down and wiping down the chain on the bike and lubricating it with a good quality lightweight oil. After oiling the chain I wipe off the excess. If this is really what is needed to own a modern bicycle I think it is excessive. In fairness to the LBS I was told about the need to replace the rear sprocket after 3000 miles before I paid for it. I was somewhat shocked but by that time I had made up my mind I was going to own this pretty blue lightweight bicycle with brake/shifters. So I guess anyone who owns a quality bike must expect to shell out a few hundred dollars each year to keep it running properly. Since mine was the lowest entry Trek at $700 I can't imagine what the guys buying the 3,4 or more thousand dollar bikes have to pay for their sport.

lostarchitect
09-07-11, 04:50 PM
I wouldn't be at all surprised if his rings, cassette and pedals were all on other bikes right now.

Yeah, sounds like they ripped him off more than once. Not cool.

Mondoman
09-07-11, 05:57 PM
Sculp, I think what most here are surprised about is the need to replace the front chainrings.

It certainly makes sense that you would need to replace the chain once or even twice after 3000 miles, but chains only cost around $15-20 each, and are very easy to replace yourself with only a chain tool needed (maybe $10-15).

Replacing a rear cassette after you've gone through a couple or more chains is reasonable; a PG-850 12-26 cassette runs about $30. Cassettes require a few more tools to replace them yourself, but are still quite easy. You'll need a chain whip and a cassette lockring tool, maybe $20 total for both, and a wrench or ratchet that fits into the lockring tool to apply torque. A torque wrench is useful when installing the lockring, but not strictly necessary once you learn how tight they should be.

Having the bike shop do either/both of the above will add their labor charge and probably at least double the parts cost, so you can see why so many decide to learn to do at least these simple recurring jobs themselves.

Glad you are enjoying the bike, and hope you didn't get too flooded recently!

Sculptor7
09-07-11, 07:30 PM
Yes I am going to have to be more alert. Don't know why it never occurred to me to ask about either the pedals or the drivetrain parts, particularly since I have gotten into overhauling a few vintage bikes and am becoming parts-conscious. Think I already have most or all the tools necessary to do the job as I have been acquiring some for the past two years including a basic kit from PricePoint that seems pretty complete for basic repairs. Also picked up a few Parks tools, and now have my own stand. Lousy rainy week here. Have not been out riding for the past three days.

bradtx
09-07-11, 07:48 PM
"So I guess anyone who owns a quality bike must expect to shell out a few hundred dollars each year to keep it running properly."
--Sculptor7

I disagree. Not to the penny, but fairly close I could budget (one really shouldn't budget a hobby ;) ) about $100 for a set of tires, $20 for a chain every year, $40 every two years for a cassette. Chainrings? I haven't had to replace any because of wear yet. Doing my own maintenance saves some money also.

Chain maintenance for me is generally alternating between a petroleum based lube and a wax lube. The petroleum based lube protects the metal, the wax is good for flinging off dirt, something I picked up on for the mountain bike. I'll clean the chain when it looks bad with WD40 and a toothbrush and apply the oil based lube. I'll also measure the chain at this point and if it's stretched in the least, it's replaced and recycled.

Brad

jrickards
09-19-11, 07:19 AM
Given the discussion here about looking after your chain, rings and cassette, I am a bit embarrassed to admit that I haven't been very good to my bike, despite having only one and needing it for commuting. I am thinking that perhaps I should just bite the bullet this winter and replace the chainrings, cassette and chain. I have a '02 Norco Bigfoot which according to the Norco site as seen through the Web Archive (2002 Norco Site (http://web.archive.org/web/20020203055611/http://www.norco.com/bikes/2002bikes/bigfoot.htm)), have Truvative chainrings (???), a Shimano Alivio cassette and a KMC chain. My favourite store is MEC.ca which stocks Sunrace and SRAM components, plus a couple of Shimano items too. Can I mix brands such as putting Sunrace chainrings and cassette and chain on my non-Sunrace bike?

KenCarlson
09-19-11, 11:33 AM
some mtb riders that ride in muddy, dirty conditions can wear out those parts in 1,000 miles.

Just to give an example, my commuter bike that I ride year-round in the northeast on salted roads, I wear out a chain every 2k miles, and I had a chainring that needed to be replaced at 2100 miles once. Deraillers last me two winters. I put about 1700-2000 miles per year on that bike. That's for a bike that has chunks of semi-frozen salty slush sitting on all the drivetrain components for 4 months at a stretch until spring arrives.

Ken

2manybikes
09-19-11, 05:04 PM
Just to give an example, my commuter bike that I ride year-round in the northeast on salted roads, I wear out a chain every 2k miles, and I had a chainring that needed to be replaced at 2100 miles once. Deraillers last me two winters. I put about 1700-2000 miles per year on that bike. That's for a bike that has chunks of semi-frozen salty slush sitting on all the drivetrain components for 4 months at a stretch until spring arrives.

Ken

It would be nice if the salt was not used.