Jockey wheels upgrade

[tim-b]

Hi

IME spidery design means fiddly cleaning, which takes much longer. I prefer a solid jockey wheel, quick wipe and job done.

I fitted Ultegra jockey wheels to my 105 mech. Better quality but not straightforward to install because somewhere a dimension is different which meant that I couldn't tighten the 105 pulley bolts without the jockey wheels binding. Maybe you need Ultegra bolts as well, 6Nm threadlock became my new best friend.

EDIT: Just checked, Ultegra bolts seem to have several different part numbers

Regards
tim-b

[BigG]

There is IMO no practical benefit from "upgrading" jockey wheels. The difference in friction is miniscule when clean and totally negligible when dirty (as normally ridden). Brucey''s point about the number of teeth is valid although twice the life from an odd number is a considerable exaggeration. Wear is not only (or even mainly) on the sides. Most is from the rollers on my gears. Brucey's point about chain wrap and capacity is also valid. I have added 5 tooth capacity to an old Duopar gear by simply replacing the original 10 tooth tension sprocket with a 15 tooth Shimano one. The only mod needed was to extend the chain guide round this using 0.5 mm aluminium sheet (cut like a pair of large washers) to prevent possible derailing during rough treatment. It works fine.

[Brucey]

most keen cyclists remove the rear wheel regularly or clean the chain or something; this unships the chain from the jockey pulleys and tends to even out the side wear. I regularly see bikes where the chain has never been unshipped from the jockey pulleys and those with even teeth can be very worn indeed.

Years ago the shimano crane mkIII came with solid steel jockey pulleys, with 9T. These were pretty indestructible, but also noisy and slightly inefficient.

Anytime the pulleys are smaller the chain sees a greater chordal action and this makes the efficiency lower. On small jockey pulleys the chain absorbs energy simply by flapping up and down more than it would otherwise.

These losses are not large in the grand scheme of things but they were well known even when derailleurs were still a fairly new idea; many old derailleur systems had ball bearing pulleys, and/or various methods of reducing the chain tension on the slack run, so as to reduce the losses to a minimum.

cheers