Anyone else having problems with the 16t cog that comes with the 40/42t oneup?
New chain/ring/cassette. works perfect in every gear but the 16.
Changes up and down into it fine but skips over the top of the teeth when a crank really hard on it.

I had an issue when I installed mine, was a bit slow to shift… Re-read the OneUp set up guide and didn’t realise it went on a certain way guided by printings on the 16t itself. Reinstalled it after reading this and been good since.

I just purchased an actual shimano one from Rose Bikes UK, seems to work fine and cost about £3.

I’ve had a similar problem when I’ve installed a loose sprocket for a casette in slightly the wrong orientation.

Take the cassette off, make sure the 16t cog is installed the right way.

Is your chain worn? Might not be an issue on the giant sprocket, but on a smaller one it could

I just did what scud did and bought one from Rose Bikes – when were OneUp giving them away, I didn’t get one 😥

OneUp include one now, if you didn’t get one then they’ll sell you one for a few quid but I decided to spend a couple of quid more and get a proper Shimano one. (it was mostly postage, because obviously Rose had to send it in a box the size of a fridge)

Fitted the correct way according to the instructions.
Though when you look at the steps on it they don’t line up with the steps on the rest of the cassette.

I should have a shimano one from Rose waiting for me whe i return home so i’ll just fit that and throw the oneup in the bin.

Fitted the shimano 16t and made no other adjustments and everything is working fine now.
The tooth profile on the Oneup looks totally different to shimano.