11-speed Shimano cassette on Campagnolo drivetrain – a good idea?

We see an increasing number of Campagnolo groupset users opting for 11-speed Shimano cassettes, for a few different reasons – i.e. sometimes lower cost, or to avoid to use Campagnolo freehub bodied wheels (which are somewhat less widely available and, for some brands, absent), the famous ‘need’ of wide range setup in pre 2018 Campagnolo 11-sp setups.

11-speed Shimano Dura Ace & Campagnolo SuperRecord chainsets

But setting aside the obvious manufacturer’s T&Cs which are: it does not work and will invalidate your guarantee – does it really work and is it worth doing? With the assistance of Graeme Freestone King of Velotech Cycling Ltd – official Training & Service Centre for Campagnolo UK – we’ve tried to give an in-depth, technical view to anyone who is considering this particular mix & match.

Yes, you can make it work “sort of”, but it’ll never be 100%, quite apart from the official Campagnolo position.

Chain

To deal first with the chain – the outer link plates are not the same shape as Campagnolo and so don’t engage the lift ramps on the outer chainring properly – the chain, accordingly, does not lift cleanly when shifting small ring to big under pressure – it’s not so bad if the rider soft-cranks as they shift (as we used to have to in the old days) because then, essentially, the rider is making an old-school shift, the chain is being forced across and eventually it will snag a tooth and be dragged up to the big ring. That’s not what is intended by the design of the chainrings and we tend to see slow, inaccurate shifting coupled to higher rates of front mech wear and tear as well as higher failure rates in the left-hand lever as riders put more force on the lever to try and persuade the shift to happen and hold the lever “over” for longer waiting for the upshift to occur. It’s not great for the chain or the chainring wear either.

Shimano and Campagnolo Record chains

Cassette

On the cassettes, the problem is that people assume two things. First, they assume that the overall width of an 11-speed Shimano cassette and a 11-speed Campagnolo cassette are the same and second that the gaps between the sprockets are the same. Neither of these are strictly true.

It is true that back in about 2007 when Campagnolo were finalising the 11s systems and the first test systems were in use, Shimano approached Campagnolo and reached an agreement to place the centre-line of the teeth on the biggest and smallest sprockets the same distance apart on the at-the-time prevalent 12-up cassettes, so on a 12-23, 12-25, 12-27 or 12-29, the high and low limit screw settings would be the approximately same (some allowance having to be made for differences in cassette body placement and the thickness of rear drop-outs / hangers). This was done for some level of uniformity in the pro peloton, so that a wheel change would not carry a big risk of a chain jamming between the smallest sprocket and the frame or going “over the top” of the biggest and jamming the chain behind the cassette.

Shimano Dura Ace 11-speed cassette

However, Campagnolo vary the distance between the sprockets across the width of the cassette – Shimano don’t. One area of the cassette where this is really important is between the 12, 13 and 14, where the sprocket-to-sprocket gaps are different in Campagnolo but in a Shimano cassette remain constant.

In terms of the effect on cable tension, this is somewhat like having a mis-set high limit screw if you put a Shimano cassette into a Campagnolo system, as you will need less tension in the rear derailleur cable to go from the 12 to the 13 in Shimano, so the cable is less pre-loaded than Campagnolo’s designers intended it should be, almost as if the high limit screw was set around 0.5 mm or so too close inboard … and this will then have knock-on effects further down the gears, especially around the middle sprockets. We then need to add in the problem that between sprockets 6 & 7, Campagnolo change the spacing again (on all 11s cassettes) by 0.1mm, widening it, which will throw the cable-pull to movement / sprocket spacing relationship out further if a Shimano cassette is fitted, because they don’t do this.

Valerio Conti, fitted by Bio-mechanic Giuseppe, together with a Pink Valerio, at the Giro d’Italia 2019 – The maglia rosa was the ultimate reward for Giannecchini’s efforts.

If an 11-up cassette is fitted, the whole problem gets worse because a Campagnolo 11-up cassette is a fraction wider than a 12 up and the difference is in the 11->12 and the 12->13 tooth sprocket spacings, which are wider and not the same as each other. The Campagnolo rear derailleur is designed to work with this slightly wider spacing, which Shimano don’t have – the result is flaky shifting at the hard end of the cassette when a Shimano cassette is used – dial that out and you have noisy shifting and noisy transmission in the middle of the cassette and / or a laggy upshift as you go from the easier gears to the hard.

Some numbers

The differences on the Campagnolo cassettes are as follows. For clarity, sprocket 1 is the smallest, sprocket 11 is the biggest:

11-up 11->12, the spacing is greater than the 12->13 spacing, which is greater than the 13->14 spacing. 14->15 spacing is then constant until sprocket 5, where the space to sprocket 6 is slightly wider. From there to sprocket 11, the spacing is constant and is the same as from the 14->15.

12-up 12->13, the spacing is greater than the 13->14 spacing. From the 14, the spacing is constant until sprocket 5, where the space to sprocket 6 is slightly wider. From there to sprocket 11, the spacing is constant and is the same as from the 14->15.

The overall tolerance in the cassette across all 11 sprockets is +/- 0.1mm, so even with a Campagnolo cassette, when it is taken off the wheel for cleaning, you need to pay special attention that the spacers and the sprocket surfaces that meet the spacers are properly clean and that the locking ring is done up to the full 42nm. The spacers are plastic and are compressible – so they need the full tension on the lockring to maintain the correct sprocket spacings. Additionally, as the compression between the sprockets helps to prevent them from cracking, provided the mating surfaces are all clean, under-torquing should be avoided.

The ‘need’ of wide range cassettes

The need of a wider range cassette than Campagnolo originally produced, in pre 2018 groupsets – trying to replicate the Shimano wide range setups, perhaps even using longer cage Campagnolo rear derailleurs (those that were meant to be used for triple chainset transmissions) – has also been a common reason for riders to try and mix & match Shimano cassettes on Campagnolo groupsets. But this presents other technical issues: the cage length has very little to do with max sprocket size – it’s only really concerned with chain wrap. A lot of final users don’t really understand this. Typically, derailleurs for use with larger sprockets have longer cages, it’s true, because of the need to take up more slack chain as a result of the increased difference between biggest and smallest sprocket and / or chainrings – but the actual design of the whole rear derailleur is what influences maximum sprocket size.

Overall, a lot of cyclists are still struggling to get their heads around the fact that the things that you could do 20 years ago, which would more-or-less work, now won’t. Everything is, more than ever, designed to work as a system. What we all regarded as satisfactory function “back then” would not be regarded as acceptable these days. Ironically, it’s because consumers are asking for wider and wider range gears and the ability to make shifts that we all managed quite happily without in those days (for instance), that components have become that much more complex and sensitive.