Cassette change

nick67

Currently have a Supersix 105 2012, which has a 10 spd 12-27 cassette. I am finding myself spinning out so wondered whether to chop it out for a 11-28 cassette.

Will I see any downside to doing this, was going to keep with the 10 spd 105.

Trying to get out in the week most days to do circa 20 miles mix of flat and hills and longer rides at the weekend, should really get myself a bike computer but that's another dilema

Should I consider something else?

shirley_basso

It's surprising you're spinning out.

Generally speaking once your legs are spinning at 120rpm in the hardest gear, you're better off tucking up and getting aero for descents.

But to answer your question, yes, 11T is a bigger gear than 12T and will be an easy swap.

No downsides.

drlodge

Changing a 12-27 for a 11-28 will have the benefit of:
- slightly lower low gear (good for when your legs are tired and lots of hills but its only 1 tooth so marginal)
- high top gear (helps stop spinning out)

with the disadvantage of
- some larger steps between some gears. Where as now you might have say 12-13-14-15-17-19-21-23-25-27 and moving to 11-12-13-14-15-17-19-22-25-28 will give you some 3 tooth jumps rather than 2T. What you want to watch for is bigger tooth jumps in the middle of the cassette which is used the most.

nick67

Thanks to both of you for quick reply, should I stick with the 105?

drlodge

I'm not clued up about Shimano, but I would expect cheaper Tiagra not to be much different to 105 and upper Ultegra will only save a bit of weight. Just look for a 10 speed compatible cassette that seems reasonably priced, probably 105.

fenix

What cadence are you spinning out at ?

Maybe you just need to learn to pedal faster ?

keef66

Must admit I've never been remotely close to spinning out in 50x12; maybe you've got some long / steep descents with good sight lines where you ride?

Anyhoo, just get the cheapest Shimano or SRAM 10 speed road cassette with the range you're looking for.

Dearer stuff may have a more durable finish and be a tad lighter, but it will all perform the same

nick67

Fenix wrote:

What cadence are you spinning out at ?

Maybe you just need to learn to pedal faster ?

You might be right, since I don't have a bike computer simple answer is I don't know, speed wise is showing as 35mph if that helps, before the spin out.

Not the fittest or slimmest!!!!!

maddog 2

50-12 @ 100rpm is 33mph

50-11 @ 100rpm is 36

maddog 2

[this does not assume that 'spinning out' occurs at 100rpm]

nick67

Thanks for that info maddog 2

So looks like a cassette swap and computer for cadence might be a good investment

trekvet

Or much cheaper is the ability to spin to 120, which would raise your max. and make every gear more flexible.

nick67

TrekVet wrote:

Or much cheaper is the ability to spin to 120, which would raise your max. and make every gear more flexible.

I shall give it a go, but easier to track with a computer, just need to decide on either the Edge 520 or Wahoo Bolt

paul2718

Why is the reaction whenever anybody asks about taller gears 'learn to pedal faster'? It's an equally apposite reaction when inverted to people asking about lower gears, yet the advice to 'learn to pedal at lower cadence' never comes.

Inconsistent and somewhat narrow minded.

It's perfectly reasonable to feel you are 'spinning out' at 95 or 100rpm when power levels are low, as they could be when pedalling down a shallow gradient, or with a tail wind, or in a fast group. If your usage includes pedalling when travelling at 30mph and you're in your biggest gear and would like another then a good answer could be '52/36'

nick67

paul2718 wrote:

Why is the reaction whenever anybody asks about taller gears 'learn to pedal faster'? It's an equally apposite reaction when inverted to people asking about lower gears, yet the advice to 'learn to pedal at lower cadence' never comes.

Inconsistent and somewhat narrow minded.

It's perfectly reasonable to feel you are 'spinning out' at 95 or 100rpm when power levels are low, as they could be when pedalling down a shallow gradient, or with a tail wind, or in a fast group. If your usage includes pedalling when travelling at 30mph and you're in your biggest gear and would like another then a good answer could be '52/36'

Thanks for this, I did consider the 52/36 but was concerned about the impact on climbing hills

keef66

To be fair, not everybody just said pedal faster. Some were pointing out that the move to an 11t sprocket would mean a gap elsewhere.

Pedalling faster is the cheapest option, then a smaller cassette, then a bigger chainset, then both (or all 3)

I have no idea at what cadence I'd feel I could use a bigger gear and start to bounce a bit on the saddle because I have no way of measuring it. It's academic anyway, because that's the point I'd be sitting up and taking a breather.

paul2718

I think the maximum cadence you are comfortable with is dependent on the effort you are making. So a gentle 120rpm is uncomfortable, but at high effort completely natural. I think this is because of the overhead of the leg flapping which is more or less independent of the effort and dependent on the cadence.

Anyway if you pedal on the slight downs then a bigger gear can be worth it, one tooth may be enough, so 11-28, and I find the 52/36 combination ideal on most terrain. Until you get into serious climbing. Some riders don't pedal on the slight downs, so have a different personal experience.

I cannot find data on a 12-27 105 cassette but 11-25 and 11-28 look like,

11 / 12 / 13 / 14 / 15 / 17 / 19 / 21 / 23 / 25
11 / 12 / 13 / 14 / 15 / 17 / 19 / 21 / 24 / 28

You can feel the difference between 23 and 25, but I'm not sure you could tell them from a 24 without direct back to back comparison. The 28 is obviously a significant jump. I switch between these cassettes (nowadays in 11 speed) according to where I'm riding and how gung-ho I'm feeling.