Fitting Shimano Cues U 4010 40/ 26 Chainset

[Reece]

Hello, at the moment I am using Shimano Sora double STI 9 speed with a Sora 46 / 33 chainset. I need lower gears in my old age and was thinking could I fit the Cues 40 / 26 chainset, has anyone done something similar or have any thoughts or ideas about this.
Thanks.

[cyclop]

This sounds familiar to me as an aging rider.The main issue you may come across is lowering the front mech to the best location for smooth shifting i.e.a few mm above the large chainring.Two issues.....a band on mech may foul the frame tube or the mech is mounted via a brazed on fitting with slots which may not allow you to mount the mech low enough for smooth changing.Note that I said smooth changing....it may change ok ,suck it and see,there may be a greater chance of the chain unshipping outwards.I,m sure there mast be front mechs with shorter arms out there,yours may already be one.You may have to shorten the chain a few links.

[531colin]

Spa cycles do a range of super compact doubles.
(Basically square taper triples with a chain guard instead of a big chainring)
The stock ratios all have 16 teeth difference between the rings, which should match Shimano road double front mechs. tooth difference. ( eg. 34/50T) Smallest stock chainset is 24/40.
Previous comments about lowering the front mech. apply

[ANTONISH]

I converted a triple chainset to an alpine double - something like 42/24.
My main difficulty was finding a suitable front derailleur.
I found an old dura ace mech which worked - some chain rub on small/small but I didn't need that combination.
It was ok when I got used to it but I find a triple set up works better for my needs.

[Valbrona]

I thought the Cues chainset was single only ... but there are a number of compact doubles out there now.

You coud also switch to triple, but at greater financial outlay.

[rareposter]

I thought the Cues chainset was single only ... but there are a number of compact doubles out there now.

You coud also switch to triple, but at greater financial outlay.

CUES comes in 2x and 1x versions.
It'll almost certainly need it's own front mech and I have no idea what the cable pull is on it - whether it'll work with a Sora front shifter. Certainly off the peg, the groupset only comes with flat bar shifters at the moment; drop bar options are apparently in the pipeline.

Going triple will be a complete drivetrain replacement inc new shifters, it's far and away the least efficient option for getting lower gears.

[TheBomber]

The stock ratios all have 16 teeth difference between the rings, which should match Shimano road double front mechs. tooth difference. ( eg. 34/50T)

It had never occurred to me to match the tooth difference spec for a double - a triple for sure, but why on a double? Not that I’m going to change my setup as I find such large jumps break rhythm too much.

[531colin]

The stock ratios all have 16 teeth difference between the rings, which should match Shimano road double front mechs. tooth difference. ( eg. 34/50T)

It had never occurred to me to match the tooth difference spec for a double - a triple for sure, but why on a double? …….

I don’t know if it’s important or not; it’s just what Spa do.
Last double I had was cotter pins.
Triple F. mechs. have grooves and bumps to correspond with the placement of the chainrings, I assumed double mechs. are similar? Maybe not?

[Brucey]

I think even double mechs from some manufacturers (eg. shimano) are fussier now than they used to be, because of ridges, extra-deep inner plates etc. BITD if you were running a double and the FD had a capacity of 'n' teeth almost any interval up to and including 'n' would be quite workable. Now I'd have to check to be sure.

[531colin]

OP is running a “non-standard” chainring difference (46/33) at the moment, so maybe it’s not that important?

33T to 29T isn’t much of a difference, hardly worth the effort I’d say.

Probably worth talking to Spa, they fit more chainsets in a week than most will fit in a lifetime

[rareposter]

Thinking about it, I reckon the front mech is only going to be part of the problem.

CUES is designed to run one chain - across all 9, 10 and 11sp variants, of CUES, it runs the same 11sp chain.
And that's not going to work on a Sora 9sp cassette / rear mech!

And you can't run a 9sp chain on it, the teeth profile won't accommodate it. I do remember reading that CUES has extremely limited (if not actually zero) backwards compatibility so I suspect that a combination of the front mech not working with the Sora shifters and the 9sp Sora cassette & rear mech won't work with the 11sp chain you need for the chainset makes the whole idea a non-starter.

[TheBomber]

I think even double mechs from some manufacturers (eg. shimano) are fussier now than they used to be, because of ridges, extra-deep inner plates etc.

Thanks Colin and Brucey. I’ll have a look and see if there are ridges that aren’t lining up. In my case it’s a 10speed setup. It struggled with chain suck on the down shift when first fitted but since changing chain brand it’s been fine.

[Brucey]

.......
And you can't run a 9sp chain on it, the teeth profile won't accommodate it.....

explain please

[531colin]

I think even double mechs from some manufacturers (eg. shimano) are fussier now than they used to be, because of ridges, extra-deep inner plates etc.

Thanks Colin and Brucey. I’ll have a look and see if there are ridges that aren’t lining up. In my case it’s a 10speed setup. It struggled with chain suck on the down shift when first fitted but since changing chain brand it’s been fine.

I don’t think chainsuck can be down to the F. mech.
Isn’t it when the chain fails to release from the bottom of the chainwheel? …due to mis match between tooth profile and chain?

[TheBomber]

Sorry, I meant ‘when the chainrings were first fitted’ - they having significantly less than a 16T difference. You’re right that the f. mech is likely unrelated, though it does get associated in my mind as it’s when using it that the problem used to occur.