My new bike has Aeffecr R cinch cranks.
I removed them to fit an oval chain ring. No problems, I put everything back on in the order it was fired, with the instructions on their product page

Now mine seem to have an extra nds spacer (it is a wider superboost chain line and a 143.5mm spindle, so I’m told) and what appears to be a self extracting style bolt under a cap to pull off the drive side when uninstalling. All fine I guess, but slightly different to what’s shown on the link above.

What puzzles me is that it appears that you just tighten them up against the bearing. There’s no preload collar, just whack them on and do then up pretty tight. Surely this is going to put excess binding on the bearings.

Older cinch, SRAM dub, Shimano all have some way of adjusting preload during installation. I can’t help feeling what I’ve got is going to either accelerate BB wear or run the risk of excess play if I try and don’t tighten them so tight.

Any experience with these?

My raceface crank tightens down onto a shoulder on the spindle giving zero end float. The bearings are not preloaded

Cinch is how the chain ring fits to the crank rather than how the crank fits to the bottom bracket.

The “adjustment” on the Aefect crank is with washers. You’re right, get it wrong and you will put too much preload on the bearings. It’s better to be ever so slightly too loose than too tight.

In fact, this is why Hope recommend their bottom bracket not be used with RaceFace cranks.

The fact that the crank arm tightens down to a shoulder only gives repeatability on the end position, it doesn’t control preload. You need to get the spacers right. The elastomer spacer is supposed to compensate for any slight inaccuracy but it’s not really a quality engineering solution.

I really like the system. Much more robust than shimano and foolproof I thought. there is no preload with mine. You use the spacers to control endfloat.

Cinch is the whole system used on the higher priced cranks (turbines, SixC, nextr, Atlas). Aeffect have the cinch chainring direct mount but not cinch axle or preload system. Iirc the Aeffect axle is the Exi design. If you use a torque wrench and tighten to the correct value with the correct spacers then there should be no worries excess bearing load. Iirc one of the spacers (maybe buried in one of the arms) is an elastomer which gives the correct bearing preload.

Let me know if you decide to change cranks as I could do with the longer axle but can’t find them for sale seperately.

Cool, thanks. I’ll see how I get on with them then. The elastomer spacer explains it. I can see the pros and cons. It is what it is.
No reason to change them now, they do the job and fit the bike.

Edit: 61Nm on the bolt – still sounds a lot!

tjagain
Subscriber
I really like the system. Much more robust than shimano and foolproof I thought. there is no preload with mine. You use the spacers to control endfloat.

TJ, the spacers are the preload. The distance between the crank inner faces is fixed. The distance between the bottom bracket outer faces is fixed. The difference is made up with spacers rather than a threaded collar but they both do the same thing. There’s nothing special about the collar other than you only fit the crank once whereas it can involve repeated fittings with the spacer/washer system to get it optimised. As said above, I’d rather have too much play in a bottom bracket (with radial bearings, ACBs are a slightly different story) than too much preload. With the elastomer, it’s easy to put too much faith in that, compress it about 50% and add too much preload to the bearings. I got some wheels manufacturing spacers to set mine up as accurately as possible so there’s maybe 1mm of compression on that elastomer.