Cassete choice

StanwaySteve62

ok, running a standard double with a 12-25 and find myself often with nowhere to go, I'm in bottom gear only doing 10mph on some of the local slopes.
Dont really wanna go compact because I like the 53 in the middle of the cassette for the flats.
Do you think this could be a good option?

http://www.evanscycles.com/products/shi ... e-ec020554

rake

it depeds if you like bigger jumps between gears. compact is better i feel.

alfablue

If you ar in the middle of the cassette for the flats then this shows the gearing could be a bit high; I know we like to think we would max out on the descents, but tbh I tend not to pedal when downhill speeds get scary.

A cassette change will obviously be cheaper than a chainset change though, but which one are you looking at? The 32 or 34 will most likely require a new mech, but it is fine to fit an mtb long cage mech if you want to do this, indeed, I fitted an 11-34 cassette with a (£10 secondhand) XT rear mech on my g/f's trek road bike - mind you, that has a triple as well! :roll:

cougie

Whats your cadence like ? I suspect you're turning the 53 over quite slowly on the flat - most beginners tend to pedal about 60rpm. You need to learn to spin the gears more - so you're doing more like 80rpm.

A 53 ring is probably overkill for most beginners,

StanwaySteve62

Was actually only looking at the 11-28 so guess no need to change anything else.?
Would hope the changes would still be smooth as it is with my 12-25
As for the 53 I like it and dont really want a 50.
Was also thinking about a 38t ring.

Buckled_Rims

StanwaySteve62 wrote:

Was also thinking about a 38t ring.

I think the usual technical reason not to go down to 38t is that means over a 14 tooth drop which I believe Shimano doesn't recommend. That's why it's usually 53/39 and 50/34.

I think a short cage RD can just accept a 28t.

StanwaySteve62

Thanks, good point but where is the 14 tooth drop?

rake

on the gears. :arrow:

Weejie54

Thanks, good point but where is the 14 tooth drop?

53 - 38 = 15

John.T

Most Shimano front mechs now recomend a max difference between chain rings of 16 teeth. 50/34 is 16 teeth and to my personal knowledge works fine with Sora, Ultegra 9sp and Ultegra SL 10sp.
You could change to a 12/27 cassette, only the 2 largest cogs are different to your current one. This would lower your bottom gear by 3" (4" if you also fitted a 38 ring). If you go to a wider range cassette you will find that the jumps between gears may be too much, also going above a 28 will probably mean fitting a MTB rear mech. A better option would probably be a compact chainset. This would drop your bottom gear by 5.5" (8" if you go to a 12/27).
All this information and more is on the sticky at the top of this forum section.

ireland57

I've recently changed 2 roadies over due to climbing difficulties and because cassettes were cheaper then a compact.
Both bikes are 53/39 chainrings.

Mine went from 12/23 to 12/27 and made a huge difference to my climbing (and I'm an older fella and have some knee troubles).

The mate's bike went from 12/25 to 11/28 (mtn bike cassette).
He hasn't ridden it yet to comment on hill ability but will asap.
Only hiccup with the 11/28 is while he has a 28t low gear he's lost the 25 for 2nd gear (it's a 24t on new cassette).

I only just thought of the following.
They may be changeable i.e. swap a couple of lower gears off the 12/25 to the 11/28.
E.g. swap 2nd, 3rd & 5th (19, 23, 25) to the 11/28.

End result being 11, 12, 13, 14, 16, 19, 23, 25, 28. (4t change in the middle of cassette)
Current 11/28 is 11, 12, 13, 14, 16, 18, 21, 24, 28.

If you do a lot of hills it maybe worth looking at.

I haven't tried it but will shortly.

The 11/28 bike is Ultegra short cage derailleur and shifts fine.

rozzer32

SRAM blocks will fit as well. Worth looking at them. Think they do a 12-27 of the top of my head so although not as big as the 28 there will be smaller jumps between the cogs.