Hi folks. My neighbour bought a bike with one of these for the rear cogset:

https://bike.shimano.com/en-EU/produ...L-RS35-6R.html

No front derailleur. It has 7 gears, but only shifts 2-7. It won't go into first. The restriction is in the shifting unit.

Does anybody know why this has that restriction? I've downloaded the documentation and there's nothing in there. I can't see why this thing is not working. I thought somebody has some experience with these.

Any insight appreciated. Cheers