Upgrading Derailleurs

[cleavesf]

Hi,

I have a Trek 4300, with the stock deraillers and shifters. I wanted to upgrade to the Deore XT or XTR, but those are 24 and 27 speeds respectively.

I have XT hubs on Mavic wheels. I can clearly see that my rear tire certainly has room for one more cassette ring, so I'm pretty sure 24 would work.

Is there any chance I can go up to 27?

Also which version should I buy? I'm very confused with the top and bottom pull and angle. I looked at my front derailleur and I see it's 66-69 degrees. I can't tell if it's bottom or top pull though, because it seems to get pulled from the side. I'm baffled.

If I upgrade to more speeds, that would mean I would only have to buy a cassette, rear derail, and new shifter for my rear derailleur right? I assume the front derailleur I buy is gonna be compatible anyways since 3 rings is maxed out right?

 

[artmichalek]

I have XT hubs on Mavic wheels. I can clearly see that my rear tire certainly has room for one more cassette ring, so I'm pretty sure 24 would work.

Is there any chance I can go up to 27?

So I take it you have a 7 speed cassette now? If this is the stock setup it's unlikely that it's on a 8-9 speed freehub, even if it looks like you have more room. It's possible to break a 9 speed cassette down to an 8 speed and put it on a 7 speed freehub, but getting all 9 is out of the question without a new hub.

If I upgrade to more speeds, that would mean I would only have to buy a cassette, rear derail, and new shifter for my rear derailleur right? I assume the front derailleur I buy is gonna be compatible anyways since 3 rings is maxed out right?

Both derailleurs will work, but if you want more gears you will need a new rear shifter.