Thx for your reply.
Regarding to your link the attached pic should be the Ultegra pulleys from the AE shop. Could you (or someone else) explain to me the narrow-wide teeth profile, as I do not see any differences on the wheels. My understanding is that narrow-wide means an alternating teeth width and not longer/short teeth or gaps between teeths, is this correct?
EDIT: Could 11t narrow-wide pulleys exists at all due to the even tooth count?
Another thing I do not understand is why changing the lower (tension) pulley has effect on better performance with larger cassettes (>32t)?
My original lower pulley (12t) has a diameter of 51/52mm the lower ultegra one (11t) is 45/46mm...So how does this bring the RD's cage closer to the cassette?
Maybe someone can push me in the right direction here :-)
Thx :-)
It's more like the teeth are longer on the upper Shimano pulley wheel. From personal experience, the stock LTwoo pulley wheel will not retain the chain if over shifting without pedaling. The longer teeth is enough to retain the chain from coming off.
Regarding the lower LTwoo 12t lower pulley wheel. If trying to run a larger cassette like a 50-34t/11-34t combo, the stock LTwoo 11/12t pulley tooth combo will force you to run a longer chain, causing more chain whip, etc. With a Shimano 11/11t combo, you'll be right at the limitations of chain length.
Anyways, if you have the latest version of ER7/9/X, you can get the new LTwoo OSPW which should allow bigger cassette sizes or you can use the Cyclami 18t lower offset pulley wheel to increase cassette size without affecting shift performance (though I'd still use a Shimano upper wheel with this solution).
https://www.aliexpress.us/item/3256810474741039.html
