Let's talk about jockey wheels

[Tom B]

I have access to a fleet of bikes whose maintenance peaks at a few drops of weekly oil and a 6monthly jet wash.

Jockywheels get pointy. Knackered pointy stars cause shifting and chain noise issues.

 

[Blue Hills]

Old and new side by side for comparison - SRAM Apex , somewhere around 10k miles on an all weather commuter bike with Tacx replacements View attachment 485634

I wouldn't have replaced those.
In just over 20 years of serious cycling have replaced two sets when they got to the star shape.
First set I replaced where on a cheapo shimano mech which was a pig to open and close as didn't use normal hex fittings. Would have made more sense to replace the entire mech.
Second more recently on a nice 105 rear mech. Far easier. Job well done. Hopeful of getting another 10 to 15 years out of that mech to push it beyond its quarter century. By the time it's shot we may well be on 19 speed, not that I care.

 

[Blue Hills]

Size matters - or does it?

I've seen oversize jockey/pulley wheels on pro team bikes.

No idea if they make any difference.

The likes of Ceramic Speed will tell you big wheels is the way to go.

But as a manufacturer, they would say that wouldn't they?

https://www.sigmasports.com/item/Ce...heel-System-for-Shimano-Ultegra-Dura-Ace/DTH8

No, i too have often wondered about this.
Oddly, some pretty cheap rear mechs have this feature as well. Am currently on a trip with an alivio which has big jockey wheels and I have another big wheel cheapo mech in the spares box. These days I tend to standardise on small, as it makes replacement more straightforward.
But yes, excellent question - does size matter?
And my additional one - why do you seem to find the big ones at the top and bottom end but not in between? Can we look forward to seeing cav run on alivio?

 

[Nigelnightmare]

Further, metal jockey wheels are noisy.

I can't say that I've noticed and I've been using them on my recumbent trike for the past 2 years & my head is only 18"-24" away from the rear derailleur.
Sealed bearings in both with no float & it indexes fine. (A little more precise/fiddly to set up).