Dear Editor, first of all I congratulate you and thank you for the website that I find very interesting and full of useful information. I contact you for advice on a change I would make my race bike.

I am a rider with great passion but little time available. I love going uphill, I can also take away some satisfaction but I have a hard time so I'd like to have have a more agile. My bike is fitted with Ultegra SL compact crankset and 12-27 sprockets, and I'd like a sprocket that it reaches 28 or 29. But I am very confused about compatibility issues, I do not know if I have to search only in the Shimano catalogue (but which product? Are all compatible?), Or if I can consider other producers (which?). So if you were me what sprocket would you buy? The cost in this case is not a problem. In the end we are not talking about a whole bunch of sprockets... Thank you in advance for any advice you can give me.

Signed letter

Dear Reader, thanks for the compliments. The group you have already adopted the currently installed configuration with the gears as short as possible. Certainly could find in the catalog Shimano, Sram, Miche or Marchisio alternative solutions, but all have a claim against: its rear derailleur accepts up to 27 sprockets. So, for the future, I suggest you go to a bike with triple crankset or with the group Sram Force, Rival, or Apex, which can adopt the new sprocket Sram 11-32 or 12-32. However, it can take a sprocket Shimano Ultegra 6700 11-28 or if you prefer another sprocket Shimano 10-speed road. Alternatively the products compatible with Shimano, Sram cassette as the PG1050 11-28 or 12-28, PG1070 12-28 Sram cassette, or a tape to be assembled with specific Marchisio sprockets or Miche for Shimano. The best solution is that your mechanic takes a cassette Shimano Ultegra 670011-28 or SRAM 12-28 (does not matter whether 1050 or 1070) by verifying the correct operation of the exchange rate and avoid to cross 50-28. I advise not to go beyond 28, although Marchisio, Sram and Miche propose solutions to the 30, 32 and 29, respectively, Marchisio, Sram and Miche. Too bad for you will find a small difference, but the only other possibility which is to update the group switching to a triple crankset, which is very expensive, so convenient, almost, to change bikes.