Stone 12s Pulley Wheel Gear Guide Roller Jockey 11t 13t 15t 17t Bearing Road MTB Bike Bearings Rear Derailleur X4 Shimano M370
Material: POM high strength resin
Bearing: Japan NSK 689-2RS
Tooth: 11T/13/15T/17T
Weight: 9g/10g/12g/15g
Fit for most brand chain of 8 9 10 11 12 speed.
But not work for Sram brand road bike 12s chain axs flattop chain.
See below if you have for Shimano brand 12s road bike chain:
You have to remove the original chain quick link if you want work for shimano brand 12s road bike chain. change the quick link to any other brand quick link will works. Reason is, the original quick link for shimano 12s road bike chain is too narrow, but change to other brand 12s quick link will let it works and fit to this pulley.
Thickness: 8mm
Inner diameter: 6mm (compatible with 4/5mm)
Color: black wheel with black cover, black wheel with red cover
Advice and principle to customers who want to modification:
1. top pulley called guide pulley, size should be smaller then lower pulley, as if too big then it will hit the cassette flywheel. the max size you can buy is 1 tooth bigger than you current use.
2. Big size means more likely to round, but only recommend increase 1 tooth base on your current pulley size for the top guide wheel, if too big, the top guide wheel will hit the cassette flywheel.
the lower tension wheel, you can add 1-2 tooth base on the size you current using. as big size means more like to round, it will help riding.
3. If you are single chainring, recommend change to narrow wide tooth. Performance will better.
For example,
if your top guide wheel is 11T, the max you can change is 12T. 13T is too big for you.
the lower tension wheel you use is 11T, you can change it to 12T or 13T, any is fine.
Tooth OD(mm) Weight(g) Fit for
10T–44mm–8g– for some Campagnolo
11T–44.05mm–8g–95% Rear Derailleur
13T–52mm–10.5g– long arm down part
15T–59.6mm–12g– for sram down part
17T– 68mm–14g– need a special large size derailleur board frame
Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability.
POM is characterized by its high strength, hardness and rigidity to −40 °C.
Typical applications for POM include high-performance engineering components such as small gear wheels, eyeglass frames, ball bearings, ski bindings, fasteners, guns, knife handles, and lock systems. The material is widely used in the automotive and consumer electronics industry.
