cassette advice

vespario

Currently have 12:25 cassete on my compact super six.

Getting some new wheels and was considering getting a different ratiod cassette.

I have notice that going down hill i could be pushing a bigger gear for longer as my legs are now much stronger but I don't understand the ratios.

What would you guys recommend?

I do club runs which take in a lot of the medics, ebor gorge etc and weekly time trailling as well as zipping across the somerset levels.

thanks

dnwhite88

If you are running out of gears coming down hill you could probably do with an 11t sprocket so something like a 11-25. If you need help going up as well shimano do an 11-28 which is the best of both worlds, but of course there are bigger jumps between gears then.

smoggysteve

dnwhite88 wrote:

If you are running out of gears coming down hill you could probably do with an 11t sprocket so something like a 11-25. If you need help going up as well shimano do an 11-28 which is the best of both worlds, but of course there are bigger jumps between gears then.

I would go for the 11-25 if you are comfortably climbing with a 25 or less. The bigger spread of an 11-28 as mentioned has a bigger gap between the middle gears which you are using a good 80-85% of the time. It is not very often you go into the extremes of the gears even on a hilly route. I find its better to have a good smoothly changing middle of the cassette which makes it easier to accelerate on the open flat and as you approach the top of a climb.That clunk when you change in a much different gear can really throw your rhythem. What you may gain in a wide range of gears on a 11-28 you lose that smooth natural change up.

arlowood

SmoggySteve wrote:

I would go for the 11-25 if you are comfortably climbing with a 25 or less. The bigger spread of an 11-28 as mentioned has a bigger gap between the middle gears which you are using a good 80-85% of the time.

Not quite true I'm afraid. The 11-25 and 11-28 have exactly the same sprockets for the top 8 gears ie 11,12,13,14,15,17,19,21 the only difference is the lower two sprockets 23,25 and 24,28

So for 80-85% of his riding he should experience no real difference as the middle gears are in fact the same. If he needs a bit of help with the hills then I would suggest the 11-28.

smoggysteve

But 24 to 28 is a big jump when you need to get some rhythem. I would prefer a more gradual change than that through the gears. And rhythem and cadence play a big part in climbing. BTW, depending on the make and group level they are somewhat different. SRAM are slightly different and so are Campagnolo. Considering you can get a super six in all 3 it could be a bit different ratio than just saying Shimano's standard

End of the day, If the OP is only after a bit more top end speed and not really after a lower climbing gear I would just get a 11-25 If he wants to try a few more steep climbs than he would normally attempt then go for the 28 but I still think the gap from 28 to 24 is maybe a bit big when wanting to change up on a steep climb.

dgstewart

Yes, the SRAM 11-28 goes 11,12,13,14,15,17,19,22,25,28, so more consistent steps at the bottom three cogs, but then you do have a jump from 19 to 22. That said, I've run both Shimano and SRAM 11-28s and had no issues with either, they give a good spread of gears for climbing and descending. The gaps never bother me (just learn to pedal at a wider range of cadences in my opinion) but I accept it seems to bother some people more. Horses for courses.

SRAM also do an 11-26 if you don't need much more at the bottom end.

vespario

Cheers guys.

I run Shimano 105. I should have said.

Definately will go with the 11 and do ok on the 25 but may try a 28.

smoggysteve

If you want to try SRAM it will work with shimano

dgstewart

Just beaten to it! What he said ^ .

SRAM and Shimano cassettes are compatible, you can choose whichever you want, obviously as long as it's 10 speed to match the 105 set-up.