Hello all, I want to upgrade my trek 1.5 from 9 (11-26) to 10 (11-28) because I was told (nashbar tech) that I would not have to replace any other components. When i called back to place the order spoke to a different person who said that I would have to change all the components to do that. Who's mistaken?
And if I do have to switch all the components to match I might as well go to the 11's no?

Going from 9-speed to 10-speed requires new shifters (the most expensive part), a new cassette and a new chain and possibly a new front derailleur. About all you can retain are your wheels, crank and rear derailleur.

I have no idea how the first "tech" at Nashbar could have given you such bad information.

Edit: I just noticed your 11-speed question. Yes, along with the the shifters, cassette chain and front derailleur you will need a new rear wheel to accept the wider 11-speed cassette and probably brakes to match the different cable pull. I'm not even sure the older Shimano 7/8/9/10-speed compatible rear derailleurs work with 11-speed. This is going to be a costly update, even if you do the work your self and a lot worse if you pay the shop to do it.

At a minimum, you'd need to replace the cassette, chain, and shifters (and road bike shifters aren't cheap). If you go to 11, possibly the hub on the rear wheel, or at least the freehub body. Maybe the brakes as well since Shimano has changed the cable pull ratio of their newest sets.

What is your goal? If you just want new stuff, it may be a better deal to replace the bike. You can sell the old one, or keep it as a backup (N+1).

You've got "upgradeitis". It's highly likely that it'll cost you more to do all this than to just sell what you have and buy a new bike that is on sale due to all the parts that need replacing.

And other than the two additional gear teeth on the big cog what's it going to get you? If you want an easier bail out ratio just get a suitable 9 speed cassette. There's quite a few folks that feel that once we got up to around 8 to 9 speeds on the rear that it became more of a case of bragging rights when the 10's and higher came out. You can just pretend that you're one of us old curmudgeons....

replace the (worn?) chain and cassette with the same 'speeds count' but get a 11 to 28t range if you need a tiny bit lower gear.

sucked in by marketing and want the one that goes to 11, buy a new bike..

Other than what? What components did the first tech say to replace? At what cost?

Still, one whole gear for the money and effort could be a great bargain. [/s]

Plus, if you mismatch something or don't set it up correctly, you'll end up with a bike that doesn't shift right... then it won't matter how many gears you have!

Seriously, don't mess it up... just stick with the 9 speed.

10 speed is a big/stupid/expensive change, 11 speed is bigger/stoopider/more expensive. It is NOT just a cassette change.

Find a 9 speed 12-28 cassette and replace the chain while you're at it. Enjoy the slightly lower gear and realize you never used that 11T anyway. Done. This will give you exactly what you'd get with a 10 speed 11-28 cassette but without the useless 11T.

Wow!!!!
Thanks all for the quick replies, the upgrades he mentioned were chain, front and rear derailleurs. I think FastJake came closest to resolving my concerns. I don't consider myself a power cyclist yet so I find it strange that some find the 12T adequate enough. I have wished for a lower gear countless times while riding and wished for a higher gear even more often and all I do is road work. So i will get a good 9 11-28. Any recommendations for one?

Thank you all

Nubian, I know what you mean. On my bikes the only time the chain rests on the smallest rear cog is when I dial it there to test the shifting or to allow me to take the wheel off for transport or servicing....

Something to consider when picking your gearing is the little added efficiency and longer chain life you'll get if your chainline is "flatter". I tend to pick my gearing to keep the chain as aligned as possible and practical for the most often used gearing combo. This means that I long ago came to realize that 53T road rings are just not for me. My front gearing setups are all either MTB cranksets or in one case I'm using a 48T cylclocross ring on a road crank.

Reality bites, but it's still reality.

If you want even more chain life, go for bigger gears. I have a 53T ring on a couple bikes but no 11T cogs. I get cassettes like 13-26 or 12-23. I also have a couple cassettes that start with a 14T cog but those have to be purchased separately and cassettes have to be "custom" made.

You simply need to get more comfortable spinning at a more appropriate RPM. A 53/12 ratio will put you at 34 MPH at 100 RPM. If you're wishing for a higher gear there you're probably a sponsored professional.