Chain, cassette, chainring- what would you do?

[geomannie]

Folks I am dithering and need moral support. What would you do in my situation?

The story.

Last Friday cleaning my good bike prior to a weekend tour.
1. Before cleaning the chain I decided to check the chain for wear. it was at 1% so I decided to change.
2. This resulted in skipping on the rear so the cassette needed changing.
3. Cassette changed & now no skipping but a grinding noise under load. After much faffing realised I isolated the noise as only occurring when I was in the middle ring of my triple chainset. No noise when using the inner & outer rings.
4. I ride about 90% of the time in the middle chainring leading me to suppose that only it is worn

This is my question. Should I just put the old chain and cassette back on and just ride the transmission into submission, or should I replace the middle chainring (its a Stronglight Zicral ring & it costs £30)?

Upside of putting the old stuff back on is delayed cost. Also it works fine so why not?
Downsides of putting the old chain back on is that it will wear the inner & outer chainrings at a faster rate plus at some (undoubtedly inappropriate) point the chain may fail. Also the cost of buying a new middle chainring now.

Upsides of replacing the middle ring now (as well as casette/chain) be less wear on the inner & outer chainrings plus its my good bike which I like to keep nice.
Downside is to spend money replacing chain, cassette & chainring when they are actually working fine, just worn.

I'm stumped. Please help.

[NATURAL ANKLING]

Hi,
If I got this right a no brainer for a new middle ring, as you use that most and you now have a very good set up.
Assuming the top and bottom are not bad at all.

I tend to stuff the middle ring too, all my grinding up hills is done on this

[keyboardmonkey]

Middle ring replacement. No brainer as already noted.

[SimonCelsa]

On a high mileage commuter used in all weathers I would probably ride the transmission into the ground through this upcoming winter and change it all in the Spring (try to minimize use of the big and small chainrings whenever possible to avoid trashing them).

On a best bike then I would probably fork out £30 for a new middle ring and keep everything good.

All depends, I like being frugal and avoid waste. Sometimes it's best to not check for 'chainstretch' etc and live in blissful ignorance......just wait until the chain snaps and hope you're not grinding up a hill at the time!

[rjb]

Can you turn the middle ring around. Sometimes you can if the ring isn't dished and doesn't have profiled teeth for easy changing. Sometimes the bolts are recessed which may or may not be problematical till you try it.

[Brucey]

I'd probably either

a) put up with the noise (IME it will only last a few hundred miles) until the chainring is 'run in' again and/or

b) rotate the middle chainring on the spider (eg by two bolt holes from five) so that an unworn part of the chainring sees the load when you push hardest on the pedals.

A downside to b) is that if you have fancy-pants shift ramps they will no longer be 'timed' to the other chainrings.

Downsides to a) are that the noise is annoying and it might wear the chain a bit faster than normal. I'd clean the chain (so that chainring wear debris doesn't persist in the chain lube) more often than usual, until the chainring is happy again.


The advantage of a) is that it can work as something of a penance, such that you will probably never ever forget to check your chain for wear again, and just replace it at 0.5% which avoids most cassette and chainring grief.

cheers

[pwa]

I used to deliberately run compatible stuff on my commuter and my best bike so that, for example, I could demote a part worn chain and cassette to the bike I was less fussy with and put nice new stuff on the best bike.

[NATURAL ANKLING]

Hi,
I use reclaimed secondhand spares on my skip trainers, But your best bike has to be nice and definitely no graunching

[PH]

Just buy a new bike

[bgnukem]

You're just chasing wear around the tranmission because the chain has been left on too long and has damaged the chainrings and sprockets.

Just replace all the 'rings and then use 3 chains in rotation, replacing them when they reach 0.5% wear, then re-use the original chain and keep using them in turn. Will be cheaper in the (very) long run!

[Samuel D]

A new chain always makes for a rough drivetrain on my bicycle. But that soon resolves itself: whether because the chain elongates slightly or the chainrings wear in the right way, I don’t know. Give it a few hours and things may improve greatly.

[Brucey]

FWIW if I had replaced a chainring every time I Iet a chain go to 1% wear on it, I'd have bought several thousand pounds worth of new chainrings over the years, quite needlessly....

cheers

[geomannie]

Thanks everyone. My dithering is over & I have fitted a new chainring. Comparing the old with the new I am surprised just how much wear there was given that I have only done about 3,500miles on it but there you go.

The existential problems remains

1. Check chains often and replace at 0.5%
or
2. Never check and run the transmission into the ground

Option 1 I think for the best bike, Option 2 for the hack.

Cheers

[NATURAL ANKLING]

Hi,

FWIW if I had replaced a chainring every time I Iet a chain go to 1% wear on it, I'd have bought several thousand pounds worth of new chainrings over the years, quite needlessly....

cheers

But we don't know what state of wear the chain ring is of the OP?
I let my chains go to 1% on my skip trainers otherwise I would need a contract with my LBS for chains
We are not talking lined up one speed transmission's like your shopper
I think about changing the middle ring when I get bad chain suck, by then the graunching is noticeable.

[nigelnightmare]

As stated Get a new middle ring.
You already have the chain & cassette, so if the inner & outer rings are NOT worn too much you'll end up with a practically new drive train.

It is your MAIN bike after all, spoil it and yourself.


Go-on you know you want to.