[tmorefi]

This is the exact bike I have with the compact crank and 11-26 9-sp cassette.

TrekBikes.com Bike Archive | 2008 2.1

I have been climbing more lately and always feel like I need another gear but don't want a triple. I recently changed the wheels to Velocity Deep-V's and just purchased a Shimano Ultegra 6700 11x28 10-sp cassette. Will I have any issues with derailluer, shifter, chain, etc? I was thinking I could just drop in this cassette but now I'm thinking I have bigger changes required. Thanks for the help.

 

[drussell]

Your rear shifter is almost certainly only a 9-speed. If I remember correctly, the 10 speed cassettes fit onto the same free hub because the rings are closer together (ie a 9 and 10 speed cassette are the same width), and may require a narrower chain? So, your shifts may be off.

 

[brianmcg]

Now all you need is a rear derailer, new shifters and a chain.

Or a cheaper and more practical option is to get a 13-30 nine speed cassette from Harris Cyclery.

 

[Randy99CL]

Edit: Let me explain. Shifters and cassette have to match. Derailleurs will work because shifters control how far RD moves. Your probably need a new chain.

Tiagra 10-speed shifters are around $200 on amazon last time I looked.

Nashbar has MicroShift 10-speed shifters for $119. Nashbar Microshift 10-Speed Dual Control Levers - Road Bike Shifters

But that seems like a lot of money for one more cog, I'd just buy a different 9-speed cassette. How about $23.31 for an 11-28? Amazon.com: SRAM PG950 9-Speed Cassette: Sports & Outdoors

 

[tarwheel2]

Keep your 9-speed. The extra cog will make no difference at all in climbing because 10-speed cassettes do not have larger cogs, just closer spacing between the cogs. A significant disadvantage is that 10-speed chains will wear out much quicker than 9-speed, adding to the considerable costs of changing out your derailleurs, cassette, shifters, etc.

 

[tlg]

just purchased a Shimano Ultegra 6700 11x28 10-sp cassette.

Return the cassette. You just started down a very expensive path with no real benefit.

Will I have any issues with derailluer, shifter, chain, etc? I was thinking I could just drop in this cassette but now I'm thinking I have bigger changes required.

You'll have lots of issues. Even if it were to run smoothly (which it won't) your shifters are 9sp so you can't you all 10 sprockets.
All your shifts will be off. Your chain will likely rub and cause issues with the cassette. At a minimum you'll need new shifters and a new chain.

9sp cassettes have a 4.34 mm spacing.
10sp cassettes have a 3.95 mm spacing.
That's a .39mm difference. Every shift would be off .39mm cumulative. Over a 9 sprocket span your derailleur would be off 3.51mm (.138"). Sprocket thickness is 1.6mm. Your derailler wouldn't even line up.

9sp chain is 6.57 mm wide.
10sp chain is 5.88mm wide

 

[tmorefi]

thanks for all of the help. Returning the 10-sp cassette and will just buy a 9-sp with a larger cog. You guys more then asnwered my question and I learned a lot about future projects.

 

[JasonLopez]

Now all you need is a rear derailer, new shifters and a chain.

Or a cheaper and more practical option is to get a 13-30 nine speed cassette from Harris Cyclery.

This this this. Just get a wider cassette or one with a bigger bottom end. I still run 9spd, pretty soon they will be 11, 12, 13, yawn. Too many gears.

 

[Randy99CL]

thanks for all of the help. Returning the 10-sp cassette and will just buy a 9-sp with a larger cog. You guys more than answered my question and I learned a lot about future projects.

Thank you for coming back to finish out your thread! :thumbsup:

Lots of people just take the info they receive and never bother to tell us what they've decided to do. I often wonder.

Thanks, I for one am glad I could help.