Chainset done for ?

[MichaelW2]

That is not wear, it is just indexing ramps.

 

[Adam4868]

That's because it's a compact and the big ring is small anyway.

Lovely expensive hollowtech chainring though !

Said bike...I think I've had it since around 2018,maybe 19 and bought second hand.Still on original parts so not done too badly.

 

[Alex321]

Yes thanks I will do.Ill start with the easiest chain and cassette.
@Ajax Bay will the worn front chain ring damage new chain if it's not jumping about ?

Mine was looking fairly similar to yours, and when I changed the chain for a new one, I found it was jumping and skipping quite a lot.

To the extent I really couldn't start off in the big ring, it would usually drop the chain.

Replaced the chainset (105 - not cheap!), and haven't had a single skip since. The old one had not been skipping with the old chain.

 

[T4tomo]

now I'm thinking it's a pressfit bottom bracket do I change whilst I've everything off ? Can't say I've noticed it giving me any problems(famous last words) but is it easy enough of a job,what specialist tools would I need or can I swap it to a threaded?

if it isn't creaking leave well alone. just slip the crankset out and replace the outer ring and re fit. tool for that is cheap and worth having, a little wheel thing to remove NDS crank is all you need IIRC or some just have an 8mm allen bolt.

when BB does go you need a tool dritt thing to knock the bearings out, worth taking to trusted mechanic to do properly without damaging shell or defo get proper tool if self doing, dont be tempted to improvise and knock them out on the wonk.

Replace with a Token BB who do screw fit BB's to fit press fit shells - just choose right variant - would be my advice.

 

[Adam4868]

if it isn't creaking leave well alone. just slip the crankset out and replace the outer ring and re fit. tool for that is cheap and worth having, a little wheel thing to remove NDS crank is all you need IIRC or some just have an 8mm allen bolt.

when BB does go you need a tool dritt thing to knock the bearings out, worth taking to trusted mechanic to do properly without damaging shell or defo get proper tool if self doing, dont be tempted to improvise and knock them out on the wonk.

Replace with a Token BB who do screw fit BB's to fit press fit shells - just choose right variant - would be my advice.

Yea thanks I'm pretty sure if my memory serves me right I swapped the pressfit on my carbon bike for a screwfit years ago.Well my mechanic did ! I'll do as you say above 😁

 

[Ajax Bay]

@Ajax Bay will the worn front chain ring damage new chain

No, the wornish chain ring will not cause any wear to the chain.
I will try to find a thread (and add it as an edit here) which deals with what causes wear to what,
Edit: https://www.cyclechat.net/threads/why-a-worn-cassette-cannot-damage-a-new-chain.255700/
but the main ' wear chain' is:
Ride chain, chain elongates as pins wear - main occasion of this wear is when the chain link at the top of the sprocket under tension articulates to 'straight', and a much lesser proportion at the top of the chainring (far less angle of articulation). Dirt makes chains wear faster.
Elongated chain starts wearing cassette (because all the load is taken and then 'slid off' by the top tooth on the sprocket)
If chain replaced before 0.7% (say) - mine take about 2500km to get there - then the cassette will not have worn much and will be happy to operate with another chain
And repeat (3 chains per cassette is 'reasonable')
Or don't replace the chain, and let chain and cassette grow old in style
Either way, the sprockets' teeth wear - eventually you'll get skating on the most used sprockets eg 16t
Replace chain AND cassette together
Ride on
After 25000+km (Edit: YMMV) the most used chain ring will wear and need replacing.

 

[Alex321]

After 25000+km the most used chain ring will wear and need replacing.

Mine only lasted about 5000 miles, so 8000Km.

Mind you, I did discover afterwards that I'd put one chain on the wrong way round - I never knew that some chains are directional. The new KMC chain that I'd just put on when I changed the chainset is not directional.

 

[gbb]

50/34 with a 11/34 cassette I very rarely use the smaller front ring.
Hills pah....rather walk than use the small ring !

I found the same, 34 was as good as useless. Consider putting a 38, 39 or 40t on there, makes it much more useable ( I got a 40t, not very expensive)...although we don't have proper hills here, more rolling inclines.

 

[Adam4868]

Does this look about right to replace my outer ring ?

 

[Ajax Bay]

Yes thanks I will do.Ill start with the easiest chain and cassette.

Got those yet. Thought you were going to leave the chainring till later?

Does this look about right to replace my outer ring ?

Since you don't share your current model of chainset (apart from the half-T teaser) the specs are x (either 5 or 4) bolts, the correct BCD, interface with crankset, oh and the right colour of course.

 

[Adam4868]

Got those yet. Thought you were going to leave the chainring till later?

Since you don't share your current model of chainset (apart from the half-T teaser) the specs are x (either 5 or 4) bolts, the correct BCD, interface with crankset, oh and the right colour of course.

Sorry yes I have the chain and cassette and I'll fit this week sometime.As you suggested I'll try it first but was just looking in case of the worst !
Thanks.

 

[Ajax Bay]

The chainring will not deteriorate 'fast' "in case of the worst". Sooner or later it will cause skipping (but probably later) - and because you know it's not the chain/cassette combo, you'll know it's the ring. Also if you shift to the inner ring and put on the power, it will not skip. So if it does skip (on the large ring) just shift down and select the rear sprocket accordingly. And ride on.
Look at the overlap you've got:
https://www.gear-calculator.com/?GR...21,23,26&UF=2215&TF=90&SL=2.6&UN=KMH&DV=teeth

 

[Jameshow]

Does this look about right to replace my outer ring ?
View attachment 666371

Yes I think so...

 

[Adam4868]

That gear calculator is the work of the devil to my eyes !

 

[Adam4868]

Thanks for the replies...i was going to wait but got impatient and decided to fit the new chain and cassette.Quick ride tells me all seems good ! Thanks @Ajax Bay no jumping from the front chainring yet as far as I can tell So I'll leave as is for now.One more quick question do I really need to oil new chain or can I leave a while.