[KiwiMike]

I’ve been diagnosing a friend’s bike (Specialized Ruby Elite, 105), after I replaced a badly-worn chain (it was at 1%). Her LBS say they swapped the chain 1800 miles ago. The wear I found at 1% says to me that’s more like 6-7000 miles on that chain (Tiagra HG4601, correctly-oriented with writing on the outside, jointing pin in leading hole of plate, no link binding).

Also they say that they replaced the 105 5700 cogset (11-28T) – but the new chain now skips under heavy load on *all* cogs, not just the smallest few. So I doubt that got swapped either. And on the invoice it showed a new 105 BB5700 (not fitted, still the OEM Ultegra BBR60 on it), BBB jockey wheels (rear mech has the OEM Shimano ones still). Dodgy?

Looking at the cogs, the teeth have burrs on them commensurate with 6-7000 miles, comparing with a now-retired Tiagra cogset of mine the same age.

Hanger alignment, rear mech alignment, indexing are all fine (I did all-new cables).

Leonard Zinn (yes that Leonard Zinn) confirmed that a very badly-worn 11-28T cogset might skip on the larger cogs as well as the smaller ones if knackered enough. I’m used to seeing skipping on smaller ones due to the reduced diameter/fewer links engaged, this is the first time I’ve seen skipping on all of them.

I replaced the cogset and she took it for a 100-miler. So that’s new freehub/bearings (the original fault), new 5700 cogset, new HG4601 chain, BB has no play in it, indexing fine – but it’s still skipping under heavy load in all cogs, both rings. ~X(

So now I think the next step / likely / only cause remaining is the chainset.

Correct? anything else any can think of?

I did the ‘lift test’ and could only clear half a tooth at the front of the big ring with the new 10spd chain on – I’m used to thinking a chainring is OK until you can clear a whole tooth. Am I wrong?

To add insult to 5-6hrs of my time gone so far, she took it to a TT tonight whereupon a bunch of blokes proffered their thoughts and pronounced my handiwork shite.

What started out as replacing a shot freehub with wasted bearing faces has turned into an introspective should-I -give-up-bike-repairing-forever funnel of despair.

Thoughts very much appreciated.

Topic

[KiwiMike]

Fish_n_Chips wrote:I think

Fish_n_Chips wrote:

I think you’ve given a warning to all of us who want to help out.

Let us know what it was in the end!

Will do – and yup, if the chain’s gone beyond 0.4-0.5% wear then the likely bill in time/materials is going be ‘large’.

[Fish_n_Chips]

I think you’ve given a
I think you’ve given a warning to all of us who want to help out.

Let us know what it was in the end!

[KiwiMike]

Thanks all for the advice –
Thanks all for the advice – I’m clearly not going mad (well, in this respect anyway).

She’s now taken it to a ‘proper shop’ where (I hope) they will find the same as I have.

One thing is sure as hell: next time someone brings me a bike with a chain that knackered, my opening gambit is ‘ This will cost you £115 in parts’ and go from there, not to do things bit-by-bit to hopefully save them some cash and end up being blamed for someone else’s malfeasance.

[barbarus]

I would also be surprised if
I would also be surprised if the chainrings aren’t knackered after turning a chain that worn…

[shutuplegz]

Is the rear mech
Is the rear mech ‘b-adjustment’ screw (think 105 mech has one?) set okay?

Also, I had similar issues (not 105 but Shimano Deore IIRC) where after changing rear cassette and chain, with good chainrings, still had a jumping chain in some gears – definitely from the rear.

Rear mech adjustment was perfect and gears would shift nicely when spinning the pedals by hand with the rear wheel off the ground, i.e. unloaded. When loaded however it jumped some but not not all of the time.

In the end I decided that although it ‘looked’ and shifted fine, the rear mech bushings were probably quite worn due to its age so bit the bullet and replaced that too. In my case that did the trick and it was only when I had the old and new mech’s next to each other that I realised just how much the angular alignment had moved on the old one. The rear derailleur is obviously not loaded under pedalling forces but the interaction between it and the partially loaded chain must be different enough when compared to an unloaded shift test to subtly change how it is tensioned.

Hope you get it sorted. The bike too.

[AJ101]

No comment on the chain wear
No comment on the chain wear rate

but

GET YOURSELF SAFELY OUT OF FRIENDZONE BRO B-) !

[Anonymous]

The lift test is really to
The lift test is really to test if a chain is worn for those that don’t have a chain checker tool.

I check for chain ring wear by pulling the chain at the bottom of the ring as it heads back towards the cassette, you will notice if the chain sits neatly into each tooth profile, or if you can see increasing amounts of daylight where the chain rollers sit in profiles as it wraps around the ring. As you know your chain is new and thus the correct pitch, it should sit in each profile all the way round the ring with no daylight when you pull back hard on the chain with your hand.

I also try lifting the chain away from the ring with just the top part still engaged on the top part of the ring, then whilst pulling on the chain, slowly wrap it back onto the ring. It should just drop neatly into the profiles, but if it starts to foul and catch on the teeth points or near the front edges of the tooth,as it wraps further around then the ring is showing wear.

[KiwiMike]

CXR94Di2 wrote:If you have

CXR94Di2 wrote:

If you have changed the chain, cassette, and free hub for new parts, then its either there isn’t enough chain tension(look at chain length then derailleur tension) or the front crank teeth are worn. Need to work out if its front or rear jumping. Why don’t you ride the bike and see if you can provoke the condition.

Chain length is correct (both big-big full-link overlap outside of mech, and 12T-50T with pulleys 90º to chainstays. Mech moves freely across range – it’s a new 105. Skipping happens even in largest cog, so I’m pretty sure that rules out tension as the culprit.

[CXR94Di2]

If you have changed the
If you have changed the chain, cassette, and free hub for new parts, then its either there isn’t enough chain tension(look at chain length then derailleur tension) or the front crank teeth are worn. Need to work out if its front or rear jumping. Why don’t you ride the bike and see if you can provoke the condition.

[KiwiMike]

DaSy wrote:First thing is to

DaSy wrote:

First thing is to establish where the chain is skipping. I usually put it in a heavy gear and give it a hard push from stationary, and watch the chain on the chain rings to see if it skips over those teeth. If it skips but not on the front, then repeat whilst watching the chain on the cassette. I sometimes get the owner to ride it whilst I ride alongside watching the drivetrain to see where the fault is.

From what you have said, it does sound like chainrings, some of the lower end Shimano original rings are made of butter, and do wear quickly if the chain gets badly worn.

You need to establish where the problem is before buying new parts.

Thanks DaSy – thing is it was skipping off of both. Now I think it’s just the front, so was specifically interested in thoughts on whether a chainring that passed the historic ‘lift-test’ and wasn’t visibly hooked/shark-toothed could still skip.

[Anonymous]

First thing is to establish
First thing is to establish where the chain is skipping. I usually put it in a heavy gear and give it a hard push from stationary, and watch the chain on the chain rings to see if it skips over those teeth. If it skips but not on the front, then repeat whilst watching the chain on the cassette. I sometimes get the owner to ride it whilst I ride alongside watching the drivetrain to see where the fault is.

From what you have said, it does sound like chainrings, some of the lower end Shimano original rings are made of butter, and do wear quickly if the chain gets badly worn.

You need to establish where the problem is before buying new parts.

[KiwiMike]

Colin Peyresourde wrote:Did

Colin Peyresourde wrote:

Did you check the chain length on the new chain/chain set? That can cause skipping on all gears.

Yup, single link’s worth of overlap in big/big, sans mech.

[Colin Peyresourde]

Did you check the chain
Did you check the chain length on the new chain/chain set? That can cause skipping on all gears.

[Fish_n_Chips]

Well it’s up to you if you
Well it’s up to you if you want to keep on trying or give up.

Personally you’ve come this far you might as well keep trying.
Chainrings next!

Does it slip/happen in all the chainrings?

My theory: She is sabotaging the equipment so it keeps you visiting or she generates 1000 Watts and wears the parts out very quickly.

[KiwiMike]

Fish_n_Chips wrote:One way to

Fish_n_Chips wrote:

One way to do this is to use a donor bike.

Swap the wheels, is the fault gone? Yes? Sorted it’s the cassette or freebhub.

No? Then could be chainrings or chain or front mech.

I’d swap parts rather than buy but not everyone has a donor or compatible parts to try.

Check the chainrings or frame and if no luck then get a 3rd opinion.

Thanks for the thoughts F’n’C, yep went down this path with a donor 105 10spd machine. The thing is, chain skipping can be caused by a bunch of factors – and they were *all* present – knackered chain, cogs, rings, bent mech (straightened), crapped-out freehub (replaced) – so you see that swapping in-out donor bits was a mug’s game – I thought I had it a number of times by ruling stuff out that transplanted with no issue or 100% issue, but then – nope. As the donor bike was worn to a far lesser degree (but was still worn) it wasn’t a genuine pass-fail test.

Swapping stuff in/out only works if just one component is shagged :-/

[Author]

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