I have a nine-speed Shimano Ultegra with a standard chainwheel. I want to swap it for a compact chainwheel for hilly events. Can you tell me what is available to do this?

Dean Marshall, email

The Ultegra nine-speed set-up will have an Octalink bottom bracket, so the simplest option is to use a chainset compatible with this, although this limits your choices considerably. Ritchey makes Octalink chainsets.

Perhaps a better alternative is to take this opportunity to upgrade to the latest technology, which uses external bottom bracket bearings and hollow oversized axles. Shimano FCR700, at £135, with an additional £20-£25 for the bottom bracket, would be the most obvious choice given your current set-up.

If you are concerned about the compatibility of the 10-speed rings then use nine-speed chainrings from a company such as TA, which produces very high quality replacement chainrings of all types. Some manufacturers recommend the use of a dedicated front derailleur to improve shifting with compact chainsets, but in practice it is worth trying to adjust your standard one first.

Stu Bowers

Bike fitter and mechanic: Stuart is an expert in biomechanics and bike mechanics