Annoying cassette size question

jonny_trousers

I'm having some new wheels built that I intend to use solely for training rides/sportives and am wondering whether to duplicate my current setup that works perfectly well for commuting (53/39 up front with 12/25 at the back) or to go for something that will offer me slightly higher gearing. I don't think I've ever had to go into 39/25 given the routes I ride, but have felt like I'm spinning out on 53/12 on a few occasions on long, not desperately steep descents. Is there a more suitable cassette for me to consider, bearing in mind that I am still a newbie, or should I just stick to the standard?

Your advice is appreciated.

Wheelspinner

The tallest cassette gear you can get is an 11 tooth, as any smaller cogs than that and (most) frames and derailleurs don't have the clearance at the chain and seatstays to cope. So, you can get 11/25, or 11/23 as the two most common variations. Of the two, if you really never need the 25, then the 11/23 will keep the gaps between ratios smaller which is always a nice thing.

BUT.. I'm surprised you are "spinning out" on a 53/12??? At 110 rpm cadence, (reasonably quick spin) on a standard roadie, that gearing will give you about 38 MILES per hour. A 53/11 at the same spin will give you 41.5 mph.

If you really can drive that gear that hard, even downhill for more than a few seconds, then give Brailsford a shout. Your country needs you!

Monty Dog

It's a common question and the answer is to learn to pedal faster - most noobs struggle to get above 80-90rpm whilst an experienced cyclist should be able to cope with 120rpm plus whilst expert track and fixed gear riders can exceed 200rpm.

Pross

Monty Dog wrote:

It's a common question and the answer is to learn to pedal faster - most noobs struggle to get above 80-90rpm whilst an experienced cyclist should be able to cope with 120rpm plus whilst expert track and fixed gear riders can exceed 200rpm.

This. It may sound glib to say pedal faster but it is definately an art worth perfecting. I raced for years on nothing bigger than a 52 x 13 and never felt undergeared. I can't remember ever coming close to spinning out on a 53 x 12, the only time I hit those sorts of speeds are on descents where it's far more efficient to get aero and freewheel.

jonny_trousers

Thanks guys! That all makes sense, and it's true what you say about the 'spinning out' thing: It's maybe the feeling that you could shift into a higher gear rather than that you actually need to. Thanks for the advice! 12/25 it is then!

styxd

You mention entering some sportives?

I guess it depends which ones really, but it could be worth considering a cassette with a 27 or 28 tooth cog on the rear (for the steep hills!)

Or go with the 25/12 and swap your chainset to a compact if/when you need to.

jonny_trousers

styxd wrote:

You mention entering some sportives?

I guess it depends which ones really, but it could be worth considering a cassette with a 27 or 28 tooth cog on the rear (for the steep hills!)

Or go with the 25/12 and swap your chainset to a compact if/when you need to.

Thanks! I think I'll stick to the less hilly sportives while I'm getting going.

sherer

I thought this when I went from standard to compact that I was spinning out. Spoke to some people that were more clued up than me and basically I was the problem

Not got a cadence sensor but based on the data I just don't turn the pedals fast enough, as stated it's a fine art and increasing the cadence seems to be a longer process than I realised