Bike Forums - View Single Post - Compact Double - Grip Shift Triple Comparison
Old 04-23-08, 05:08 PM
  #7  
BarracksSi
Bike ≠ Car ≠ Ped.
 
BarracksSi's Avatar
 
Join Date: Jul 2007
Location: Washington, DC
Posts: 13,854

Bikes: Some bikes. Hell, they're all the same, ain't they?

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Adding on --

Here's a page about the 7500, which includes the chainring sizes and the range of the rear cassette:
http://www.bikepedia.com/QuickBike/B...7500&Type=bike

The 1-4 that you mention is likely to be a 28-21 or 28-18 combo. The ratios for those combinations are 2.7 and 3.1, respectively.

The lowest gear on the Roubaix, the 34-28 combo, gives you a ratio of 2.5.

You'll actually have a lower gear on the Roubaix than you've been using on your Trek. It's at the bottom of its total range, but if you never need the bottom three gears on the Trek anyway, you won't miss them.
BarracksSi is offline