Changing the ratio of a cassette

SWL

Hi Guys,

Need some training advice

Presently using Shimano 105 think it’s the 5700, 50/34 front crank and a 32-11 cassette, when I cycle I spin at a min of 90 – 110 rpm and regularly spin out in the lower gears 12, 13, 14 (ratios may be incorrect as I can’t remember them right now).

Usually I would put into the big ring and work away, but I am following advice from various sources to spin in lower gears to develop some muscle endurance and eventually more speed. my speed is usually 26-28kph in the lower ratios (12 – 14) so not very fast and I always spin out, I often get passed by people using lower gears, less rpm and going just as fast, I can easily use the big ring and about half way up the cassette – this is my sweet spot a bit of bite in the pedals but still able to spin at over 100 rpm and get some speed so do I need to change my cassette for a 12- 27 – 12-25?

Chips Lovell

Not sure I understand.

You have an 11-32 cassette and want to change to 12-25 or 12-27 because you're spinning out? Both of those will give you a smaller top gear.

You shouldn't be spinning out with a 50/11 combo anyway.

SWL

Vladimir Kurtains wrote: »

Not sure I understand.

You have an 11-32 cassette and want to change to 12-25 or 12-27 because you're spinning out? Both of those will give you a smaller top gear.

You shouldn't be spinning out with a 50/11 combo anyway.

I was thinking if I changed the ratio in the middle it might give me more options, I cycle often in the 120rpm and the speed is pretty low, I don't know if I should revert to 90-100 rpm in the big ring or try to develop more leg endurance to increase my leg speed using the existing cassette. I must be doing something wrong and shouldn't be spinning out half way up the cassette ??

niceonetom

Eh, use the big ring?

Lumen

You don't need a new cassette. Use whatever gear combination allows you to achieve the desired combination of cadence and speed.

SWL

niceonetom wrote: »

Eh, use the big ring?

Lumen wrote: »

You don't need a new cassette. Use whatever gear combination allows you to achieve the desired combination of cadence and speed.

I was under the impression that spinning in lower gears was better, than using the same rpm in a higher gear, might need to go back and re-read what I was reading:D

Lumen

SWL wrote: »

I was under the impression that spinning in lower gears was better, than using the same rpm in a higher gear, might need to go back and re-read what I was reading:D

"spinning in lower gears" means "spinning in lower gear ratios". Which sprockets are in use makes no difference, aside from cross-chaining issues.

NeedMoreGears

What is your training objective here - cadence or simple speed? If you're focusing on cadence, then it may not matter that others are going past you. From what you're saying you can hold similar cadences in the big ring so why not do so? It would increase speed and you seem to be pretty handy ( to me anyway) at maintaining cadence already so maybe you're at the "eventually more speed" stage.

In any event, it probably isn't a great idea to sit in the 34/12 due to cross-chaining (I assume 11 is your smallest cog from the description in your post).

I'm not sure what 12-25 would do for you as compared to 11-32 if you want to focus on high cadence - other than it being easier to maintain higher cadence on a hill when the largest cog at the back is 32 rather than 25.

tunney

I got a hack saw and cut off four of the teeth on my 34 cassette - now I have a 30. Problem solved and didn't cost a penny.

Idleater

tunney wrote: »

I got a hack saw and cut off four of the teeth on my 34 cassette - now I have a 30. Problem solved and didn't cost a penny.

Engineering solution to an engineering problem