Hi, can I swap my current 105 cassette for a xt one, are the spacings the same? I need a lower gear and have a xt spare. I have 105 shifters and medium cage mech so what’s the max teeth (32)? I could use?

My 105 mech copes with 32t fine, give it a go

I THINK that you’d be OK if both were 10 speed and not OK if both are 11 speed

Regardless of whether or not I’m right, meausre across the cassette for both. If it’s the same (and they’re both the same number of sprockets) then you should be right

No idea about max cog – shimano should spec that for a given model number though

It’s all 10speed with 32 teeth, I tried it earlier but couldn’t get it to sync properly, I could get it right at the top or at the bottom but not both, any advice?

I think there are two versions of the rear mech 5700 won’t work but 5701 does.

Have you fiddled with your b tension? I think you may need to

Is chain long enough to cope with the extra sprockets?

Are the cassettes the same width ?

10spd XT cassette is 1mm wider than a 10spd 105 cassette. In most cases it will work fine though.

I have a 10sp Tiagra sti unit that operates on an xt 10sp cassette, but to get it to work you have to use an XT 9 sp rear mech.

I had 3500 Sora on my X when I bought it, running a standard road compact and 11-32 cassette.

Usually it’s capacity that matters most if trying to fit a bigger cassette : ((big ring -little ring)+(big cog -little cog)). If that gives you a number lower than the T capacity rating of the mech you’re using, the limits are correct and the B tension right then you should be OK, although as Simon says above, due to the slight spacing difference of road and mtb cassettes you may find you’re more sensitive to flex or bent hangers etc than normal.