Frustrating issue with rear gears

[crot4lus]

Hi guys

I currently ride a Giant Revolt 2, 2014 model Cyclocross bike.

Last week during my commute to work I lost a spacer from my rear cassette so had it repaired by a local guy who is a friend of mine.

He managed to get every gear sweet bar the highest (small cog) on the rear cassette, it shifts nicely from the second smallest cog down to the smallest cog but it won't go back up - only on that one lowest gear.

He took it to his workshop over night and fit a new cassette and removed a link from the chain as the chain was still slack but that one gear still persists, to get off of the smallest cog I need to jump up 2.

He also tried with a new derailleur, to no avail.

Have any of you guys heard anything similar? And if so, any idea what would fix it short of replacing the shifters which is the last thing to try... Albeit an expensive try.

It's a Shimano Claris system.

Really appreciate any help/advice you can give me.

[RBurrelli]

Did you try a different chain? Or are you using the original one.

[crot4lus]

Original chain, just removed one link mate

[cny-man]

If the entire cassette cluster was really replaced then either the new cluster has the wrong spacing between the two smallest cogs or there is a shifter problem.

[crot4lus]

Hi mate

Thanks for the reply, he did initially attempt to rebuild the old cassette which just did the exact same thing.

I've ridden in to work on it this morning, all the gears are fine bar the one mentioned..

Although there is a tiny, tiny bit of hesitation between a couple of gears when shifting down (to a larger cog) - do I just presume this is normal?