Faster bike

terryduff12

Hi looking for some advice, have a 21 speed raleigh mountain bike i bought few years ago in England. Its very light, now when im cycling its in top gear and im not going very fast as that's all i can get with the gears. I guess i would need to drop it down to a 10 speed change out crankset and cassette, went in to bike shops before basically got no help on the matter. is it possible to do and if so were would i go from here.
Thanks

Lumen

How many teeth on the largest front ring and smallest rear sprockets?

terryduff12

At the front 42 and at the back 14

Lumen

I don't know about compatibility with your drivetrain, but something like this ought to help.

Shimano SLX HG80 9 Speed MTB Cassette
http://www.chainreactioncycles.com/ie/en/shimano-slx-hg80-9-speed-mtb-cassette/rp-prod27680

An 11 sprocket will give you another 27% top speed over your current 14, with 47kph at about 100rpm depending on tyre size (compared to, say, 37kph at the same cadence on the 14 sprocket).

rollingscone

terryduff12 wrote: »

Hi looking for some advice, have a 21 speed raleigh mountain bike i bought few years ago in England. Its very light, now when im cycling its in top gear and im not going very fast as that's all i can get with the gears. I guess i would need to drop it down to a 10 speed change out crankset and cassette, went in to bike shops before basically got no help on the matter. is it possible to do and if so were would i go from here.
Thanks

Do you mean that you're spinning out? As in you can't turn the pedals fast enough to keep generating power?

cdaly_

Lumen wrote: »

I don't know about compatibility with your drivetrain, but something like this ought to help.

Shimano SLX HG80 9 Speed MTB Cassette
http://www.chainreactioncycles.com/ie/en/shimano-slx-hg80-9-speed-mtb-cassette/rp-prod27680

An 11 sprocket will give you another 27% top speed over your current 14, with 47kph at about 100rpm depending on tyre size (compared to, say, 37kph at the same cadence on the 14 sprocket).

If it's 7-speed with a 14 sprocket, I'd say it's likely a freewheel rather than a cassette in which case, chainrings are the only option to change.

Lumen

cdaly_ wrote: »

If it's 7-speed with a 14 sprocket, I'd say it's likely a freewheel rather than a cassette in which case, chainrings are the only option to change.

Oh yeah. 21/3 !=9. Maths fail.

How much is a new rear wheel?

beauf

I get this when I use my MTB for commuting. Out of curiosity what are you doing when you are spinning out, and need to go faster.

terryduff12

basically if your going down a hill your going faster than pedals can do anything, just if im out for a cycle on a flat straight can't go any faster than I would like to.

terryduff12

Would I need to change crankset get a new chain or just take a link out or two

beauf

I wonder would it be a better idea to buy a higher geared hybrid more suitable for your use?