Drivetrain wear strategy

[overmind]

I am thinking of changing the way I maintain the drivetrain on my commuter bike.

I have a 21 speed (amazon purchased) cheap racing bike. I use this bike for commuting. I ride about 50 miles per week on it. When I had ridden it for approximately 4 years with zero drivetrain maintenance (apart from oiling) the chain used to jump. It got progressively worse until eventually the chain would just slip over the freewheel.

At this point I was going to bin the bike but after doing some research (and watching a few youtube videos) I decided to replace the chain (£6), freewheel (£10) and chainset (£FREE, old 2nd hand one from a 1980's Raleigh).

Since then I have been checking the chain length and whenever it reaches approx. 0.5% stretch I have been replacing it. I have probably been using up about 2 chains, and 1 freewheel per year with this method.

Recently I checked the chain and discovered that I may have left it too late as it is between 0.75% and 1% so if I replace the chain I will probably need to change the freewheel as well. So I have decided to just ride the thing into the ground on the basis that the last time I did this it lasted several years.

I am wondering if this is actually a better strategy than replacing the chain every 6 months and whether it will work out cheaper. The only drawback I can see is that I may wear out the chainset also but in my case I have about 4 spare ones on these from old bikes (I got these from a bicycle recycling centre for about £2.50 each).

Any thoughts ? What would you do ?

 

[pclay]

When you say 'freewheel', do you actually mean 'cassette'?

There is no need to replace the chain until it is 0.75% worn. 3 chains per casette. How are you measuring 0.5% wear?

I guess it's your choice to either run it into the ground or change components when needed. Only you can work out which one is the most beneficial and cost effective.

 

[Drago]

Shimano did both cassettes and freewheels in 7 speed.

I replace my chains at 0.75 and manage 3, perhaps 4 per cassette.

 

[I like Skol]

There is merit in both strategies, especially on a cheap bike that may be binned at any point. I have built a couple of bitsa bikes in my time and knowingly installed chain sets that are considered worn (i.e, beyond the 0.75% mark) but these have performed well for a considerable time with just timely oiling. If you think you are happy to get a further 12 months then throw the bike away then why not?

 

[Yellow Saddle]

[QUOTE 4805384, member: 9609"]I'm mi way through a long term experiment doing something simillar to this. I fitted a new cassette about 2 years ago and have changed the chains at 0.5% wear (one chain got to 0.58%), after 7 chains and 6800 miles the eighth chain started to slip. So I have went back to the semi worn chains (I kept 4 of them) and am swapping them over evry week (100mile) the chains are at 1.28% wear now with the cassette up to nearly 10,000 miles. No slipping at the moment and will just keep going until destruction, I am guessing I will get the chains up to about 2% wear, but not really sure what will happen.

(if some of the figures I have noted don't tally up exactly with a previous post it is because I'm doing this one from memory, evrything is on the other computer)[/QUOTE]

I am desperately (semi-desperately actually) looking for a chain with 2% wear. When you get there, please save me a few links.

Have you noticed any vibration or noise coming from the chainrings yet? How has the extra wear affected them?

 

[overmind]

When you say 'freewheel', do you actually mean 'cassette'?

No, I mean freewheel. It screws onto the back wheel (old style ratchet mechanism not cassette). 7 speed shimano.

There is no need to replace the chain until it is 0.75% worn. 3 chains per casette. How are you measuring 0.5% wear?

I measure chain stretch with a chain measuring tool. It has 2 sides. If one side drops into the chain it is 0.75% or greater. If the other side drops it is 1.0% or greater. On a new chain neither side will fit/drop.

0.5% wear is kind of an estimate based on how far the (0.75% side) tool drops into the chain (i.e. it almost drops).

 

[overmind]

If you think you are happy to get a further 12 months then throw the bike away then why not?

I don't have to throw the bike away. I just replace the freewheel (£10) and the chain (£6) and use up one of my 2nd hand chainsets (I have 4). Then repeat the exercise.

 

[I like Skol]

It got progressively worse until eventually the chain would just slip over the freewheel.

At this point I was going to bin the bike but after doing some research

OK, I thought you were on the verge of skipping the bike anyway and had no attachment to it, but yes, it can be kept going almost indefinitely in the manner you describe and very cheaply too

 

[overmind]

OK, I thought you were on the verge of skipping the bike anyway and had no attachment to it, but yes, it can be kept going almost indefinitely in the manner you describe and very cheaply too

Yes, it was a bit ambiguous. No, the reason (back then) that I was going to bin the bike was because I knew next to nothing about how to fix the drivetrain. This meant I would have had to take the bike to a bike shop which would not have been cost effective. Now that I know how to do it myself (and have the necessary tools) it changes the economics.

Edit: there is also a value to me in riding a bike that looks all beaten up but that mechanically is in top-notch condition. This makes it far less likely to be stolen.

 

[I like Skol]

Excellent, and there is no better way to learn these skills than on a worthless bike that is taking a one way trip to the scrap yard otherwise.

 

[Fab Foodie]

When the chain wears on my handbuilt custom carbon bike with Dura-Ace Di2, I just buy a new bike.

 

[Pale Rider]

When the chain wears on my handbuilt custom carbon bike with Dura-Ace Di2, I just buy a new bike.

Is the ashtray full on the Dacia yet?

 

[mjr]

The other obvious drawbacks are that I suspect a worn chain is more likely to break and a broken chain can trash various other parts as it whips off, possibly lashing your right leg if you're really unlucky; plus it can be a farking long walk home after that. Those are the reasons I replace chains sooner.

 

[gbb]

The other obvious drawbacks are that I suspect a worn chain is more likely to break and a broken chain can trash various other parts as it whips off, possibly lashing your right leg if you're really unlucky; plus it can be a farking long walk home after that. Those are the reasons I replace chains sooner.

You beat me to it by 6 minutes
I was reading the top posts and was already thinking what you state...safety in simple terms.
Meh, I suppose if you're not one to put a lot of force through the transmission, maybe it'd be OK...but I like to feel some level of safety.
Alternatively I'd be checking my chain ever more frequently.

 

[gbb]

I am desperately (semi-desperately actually) looking for a chain with 2% wear. When you get there, please save me a few links.

Have you noticed any vibration or noise coming from the chainrings yet? How has the extra wear affected them?

Bugger, I once brought a shiny chain in plastic packaging from a car boot once (yes I know...and I did get what I deserved ) dear God it was so sloppy it was incredible, I Binned it instantly.

On the question of vibration...I often noticed when I put a new chain on a not too worn cassette, I got a mechanical kind of whirr for a maybe 50 / 100 miles, then it goes. Any known reason ?...just intrigued .