Shimano/SRAM incompatible now?

[peetee]

I’ve just serviced a Specialized Allez and included a new chain, cassette and full gear cable.
It’s the sort of job I have done countless times to different bikes. I could probably do it with my eyes shut but, well, it’s not my bike so…
The bike has Tiagra 4700 which, apart from normal wear and tear, is in good order.
I discovered a problem with the rear shift so checked rear mech alignment, cable action and seating but all was well. The chain would shift concisely up the whole cassette, gear by gear but would only do the same down the cassette with a bit of cable adjustment. None of this made sense to me so having eliminated all the poor set-up and geometry options I double-checked I was using 10 speed chain and cassette.
On very close inspection of the chain (a SRAM 1031) I wasn’t altogether happy with the look of it; the finish seemed a bit poor in places. A Shimano 6700 chain was substituted and, thankfully, accurate up and down shifts followed.
I’ve never seen this problem before when mixing Shimano and SRAM gear. The parts I have used should be genuine; I never buy from open trading sources such as eBay or Amazon, so I’m a bit stumped as to what was to blame.

[Jdsk]

...
The parts I have used should be genuine; I never buy from open trading sources such as eBay or Amazon, so I’m a bit stumped as to what was to blame.

In the previous discussions of fakes there were some interesting observations about logos and packaging...

Jonathan

[peetee]

I only buy from the likes of Wiggle, Merlin and Tredz so if they are fakes it raises a pretty major issue, I would say.

[slowster]

There appears to be some variation in specification and/or presumably manufacturing tolerances for 10 speed chains based on the link below.

https://bike.bikegremlin.com/3555/bicyc ... ndards/#t1

I don't know if it is related, but Shimano 6700 is Ultegra, and Rene Herse state that their 5-9 speed chainsets can be used for 10 speed, providing an Ultegra chain is used (https://www.renehersecycles.com/shop/co ... ble-crank/), which suggests that the Ultegra chain is significantly better than others, possibly especially compared with the cheapest models of some other brands.

[hamster]

Sounds to me like a sticky cable, as it's the mech spring that initiates the shift.
I would lube the cabling.

[peetee]

Sounds to me like a sticky cable, as it's the mech spring that initiates the shift.
I would lube the cabling.

Nothing wrong with the cable. Inner and outer replaced at the start and all outer ends were trimmed and finished correctly.
The gear change with the Ultegra chain fitted shows the cable is fine.

[Brucey]

SRAM use fractionally larger rollers in some of their chains, but I have not heard of it causing this specific issue before. My suspicion is that it would be worth checking the guide pulley very carefully, and perhaps upgrading it.

[peetee]

Sorry, didn’t mention that I had checked the guide pulley wasn’t unduly worn or exhibiting excessive side-to-side float.

[mattsccm]

From experience, cheaper SRAM chains are not overly nice to use. Noisy and don't shift well. Even cheap Chinese stuff seems better.

[Brucey]

....I had checked the guide pulley wasn’t .......exhibiting excessive side-to-side float.

Maybe not, for a shimano chain, but SRAM chain is a different kettle of fish entirely. I probably would look to fit a different guide pulley, with taller teeth and reduced float. What cassette are you using?

[peetee]

....I had checked the guide pulley wasn’t .......exhibiting excessive side-to-side float.

Maybe not, for a shimano chain, but SRAM chain is a different kettle of fish entirely. I probably would look to fit a different guide pulley, with taller teeth and reduced float. What cassette are you using?

Shimano Tiagra 12-28
To be fair, Shimano do say you should use a Shimano chain within this groupset. Normally I treat such self-interest with scepticism but looks like there is some truth to it after all.

[JohnR]

Shimano Tiagra 12-28
To be fair, Shimano do say you should use a Shimano chain within this groupset. Normally I treat such self-interest with scepticism but looks like there is some truth to it after all.

I've had good experience, so far, with the KMC X series chains.

[Cyclothesist]

Shimano Tiagra 12-28
To be fair, Shimano do say you should use a Shimano chain within this groupset. Normally I treat such self-interest with scepticism but looks like there is some truth to it after all.

I've had good experience, so far, with the KMC X series chains.

+1

[peetee]

That would be my first choice but at the time of ordering certain items was hard to find.

[NickJP]

I have one bike with 10s Shimano shifters, derailleurs, and cassette that is using a Campagnolo 10s chain. No problems there. The cranks are Middleburn RS7 with their Duo chainrings, which I think date from 9s days.

With 11s, I haven't encountered any incompatibilities - I have one bike using SRAM shifters/derailleurs with Shimano chain/cassette, and another using SRAM shifters/derailleurs with ZTTO cassette and KMC chain. I remember Leonard Zinn, who used to write the tech columns in Velonews, commenting that with 11s all three manufacturers (Shimano, SRAM, Campagnolo) had made the spacing close enough that you could slot any manufacturers wheel/cassette into a bike with another manufacturers components and it still shifted fine.

With 12s, I have a bike using SRAM AXS shifters/derailleurs with Shimano chain and cassette, and that shifts fine as well.

On none of these bikes am I using a chainset that says it's intended for the particular speed of chain/cassette in use, and that appears to have no ill effect on the front shifting. My bike with otherwise 12s components is using Deore XT M737 cranks, from the mid-90s when 8s was the latest and greatest. My opinion is that warnings from manufacturers that you need to match the speed of cranks/chainrings to everything else is designed to extract more money from the credulous.