Cassette Upgrade and Sprocket Ratios

pprendeville

Can someone advise which is the better sprocket ratio on a cassette to go for for racing?
11-23
12-23
12-25
11-25
11-28

First year racing (club). Just purchased a turbo and using existing sprocket on training wheel so buying a new sprocket.

Existing sprocket is 23-11. Thinking of going with Shimano Ultegra CS-6700 10 speed cassette. Existing groupset is 6600, 10 speed cassette. This wouldn't be an issue to move up, would it? €46.90 on Bike24 (http://www.bike24.com/1.php?content=8;navigation=1;menu=1000,4,27;product=11672). Anyone know any better deals.

Also need a turbo training tyre also. Any recommendations? Do these last long? Believe they're silicone based so don't heat up as much as standard road tyre, hence wear less?

Finally, I believe I'll need a new chain as well. Read it on bike radar. This true? Again, what's good to go for? Existing chain is definitely stretched. Had it checked while on bike maintenance with handy little tool.

Beasty

Are you riding the Swords League, and how good are you on the hills? What size are your chainrings?

For example last year I had an 11-23 for a flat course like Bog of the Ring, but would have changed it for an 11-25 for most of the other courses (11-21 for the Batterstown 25mTT), and had 52/39 on the front

I would personally suggest 11-25 to give you most flexibility if you are proposing to ride the Swords League to cover all circumstances (you could always put the 11-23 back on for the Bog if you like)

For turbo tyre I've done many hours (around 50 or so in the last year) on the Continental without any problems

pprendeville

Beasty wrote: »

Are you riding the Swords League, and how good are you on the hills? What size are your chainrings?

For example last year I had an 11-23 for a flat course like Bog of the Ring, but would have changed it for an 11-25 for most of the other courses (11-21 for the Batterstown 25mTT), and had 52/39 on the front

I would personally suggest 11-25 to give you most flexibility if you are proposing to ride the Swords League to cover all circumstances (you could always put the 11-23 back on for the Bog if you like)

For turbo tyre I've done many hours (around 50 or so in the last year) on the Continental without any problems

Ya Swords league. Good on hills. 53-39 chainrings.

Thanks for advice.

Is that a turbo training tyre you're using?

Beasty

pprendeville wrote: »

Is that a turbo training tyre you're using?

Yes

We've had a few threads on the topic, but normal tyres overheat and wear out very quickly on the turbo

I've also used a Tacx one, which was fine

Beasty

You could probably get away with a 23 if you are good on the hills - none of them are very steep, maybe up to 8% or so on Ardcath (12% for a short spell on the Ardgillan hill climb - didn't stop Mr Skeffington going up on the big ring last year though), but by the 3rd time round I tend to be suffering....

funkyjebus

I like the conti training tyre personally.

I went up sally gap last weekend for the first time on an 12-23 (53-39) and it nearly killed me (head wind:(), so just picked up a 12-26 and getting a 12-27 on my new bike so can swop when heading up again. But unless I'm tackling any major hills, I'll still stick with my 12-23.

Also there is no problem using 6700 with 6600, in fact any 10 speed shimano cassettes will work, even 105 if you want something cheaper. I think sram cassettes work as well, althought I'm open to correction on that, but I know they are the same for 8 speed.

Lumen

For racing 11-23 and 53-39 is fine.

If you're going slow enough for the 23 to be a problem you've been dropped anyway.

SRAM chains are good. I picked up a couple of SRAM Red PC1090 10 Speed Chains from ShinyBikes a while back for £23.27 each. They're currently £27.10.