12-27 cassatte, what next?

strodey

Hi,

searched forum but didnt get exactly what i needed!!!!
Bought a new set of wheels ready for spring (dura ace cl 7850 at a bargain)

I currently run a 12 - 27 casstette on my defy advanced, and never use the lowest gearing even on the stupid gradients, what would be a sensible move to give a noticeable difference on the downs without suddenly killing me on the ups? Will i notice a small change?

Will keep my old wheels for winter so this is for good weather blasters!

advice appreciated!

cheers

Anonymous

Not really sure what you are asking, matey.

hopper1

The lowest amount of teeth you can have, is a 11/23, in the middle there is 12/25.
Changing to the 11/23 would be like losing the top (large cog) gear off your present cassette, whilst giving one gear at the other end.

See here to work it out for yourself.

acidstrato

if you truely never use the 27t cog and you want abit more top end then picking up an 11-25 would be beneficial to you. an 11-23 would in all likelyhood be great until you hit a long tough climb.

if you have a compact chainset then it might not be so bad but if you have a double and you want to do even a little climbing i wouldnt get an 11-23

Infamous

hopper1 wrote:

The lowest amount of teeth you can have, is a 11/23:

What about 11-21 ?

Strodey: sounds like you want a 12-25

bigal.

Keep the 12-27 and find steeper hills to train on.

ScottieP

bigal. wrote:

Keep the 12-27 and find steeper hills to train on.

+1 - Longer and steeper hills are the way forward.....

John.T

strodey wrote:

Hi,
I currently run a 12 - 27 casstette on my defy advanced, and never use the lowest gearing even on the stupid gradients, what would be a sensible move to give a noticeable difference on the downs without suddenly killing me on the ups? Will i notice a small change?

Unless you want to pay for Dura-ace the only cassette with an 11 sprocket is an 11/23. SRAM do a larger range with an 11. This will give one higher gear but with the loss of lower ones. If you are using a 53/39 standard chainset then the 53/11 is huge. Not many pros can really handle it for long. If using a compact 50/11 is still a very big gear and I have never found use for one that big. With the compact you could always fit larger chainrings. Stronglight and TA both do a range. I use Stronglight 52/38 on Ultegra compact cranks on my Madone for some events.

strodey

Keep the 12-27 and find steeper hills to train on.

This is my regualr short ride;

http://connect.garmin.com/activity/15127788

if you go down the bottom and click the elevation tab it'll show you the elavation profile!

i cant find any steeper hills near that are close and on good routes, (i do it lots quicker than the time on link now)

Thanks for the advice, looks like ill go for a 12 -25 (its a 10 speed so will get ultegra)

John.T

http://www.bikehike.co.uk/mapview.php?id=4618
This is one of mine. Click the elevation and gradient buttons. My average speed is much the same on this but I often ride it without going off the 34 ring. Looking at your cadence I would say you need to practice spinning a bit more.
Changing to a 12/25 from a 12/27 only changes the bottom 2 gears bringing them closer together which is just what you do not need in the lower gears.
12/27 is 12,13,14,15,16,17,19,21,24,27.
12/25 is the same except 23,25.
I would save your money and stay with what you have got. I use a 12/23 for racing and flatter events as it has an 18 sprocket which is more useful than a 27 for these.

strodey

cheers, my spinning has got much better since this but as i'm a regulat mtb'er the whole cadence thing is a bit messy when on the road bike!

ScottieP

12-25 should be good. I bought a SRAM 11-26, but as John.T said - I didn't find I used the 11 much it was too big for where I live. Once you try the 12-25 you can always get more "aggressive" and go for an 11-23 or something like that if you still find it too easy with the 12-25.

GavH

strodey wrote:

Hi,

searched forum but didnt get exactly what i needed!!!!
Bought a new set of wheels ready for spring (dura ace cl 7850 at a bargain)

I currently run a 12 - 27 casstette on my defy advanced, and never use the lowest gearing even on the stupid gradients, what would be a sensible move to give a noticeable difference on the downs without suddenly killing me on the ups? Will i notice a small change?

Will keep my old wheels for winter so this is for good weather blasters!

advice appreciated!

cheers

Are you using a compact or standard double up front? As has already been said, the next cassette 'down' be it a 12-26 from SRAM or a Shimano 12-25 or even 12-23 won't give you anything extra in terms of speed on the flats and downhills, you'll need a 11-23 for that. If however you're on a 50/34 compact chainset, moving to a 53/39 or suchlike and keeping the 12-27 might be a better option? You might even find you'll actually use that 27t cog! That said, without knowing what mechs you are running, I can't say what compatibility issues that may throw up.

markos1963

John.T wrote:

strodey wrote:

Hi,
I currently run a 12 - 27 casstette on my defy advanced, and never use the lowest gearing even on the stupid gradients, what would be a sensible move to give a noticeable difference on the downs without suddenly killing me on the ups? Will i notice a small change?

Unless you want to pay for Dura-ace the only cassette with an 11 sprocket is an 11/23. SRAM do a larger range with an 11. This will give one higher gear but with the loss of lower ones. If you are using a 53/39 standard chainset then the 53/11 is huge. Not many pros can really handle it for long. If using a compact 50/11 is still a very big gear and I have never found use for one that big. With the compact you could always fit larger chainrings. Stronglight and TA both do a range. I use Stronglight 52/38 on Ultegra compact cranks on my Madone for some events.

I think you'll find that you can get a 105 cassette in 11-25 and quite cheaply to. Look here:-
http://www.chainreactioncycles.com/Mode ... elID=13593

John.T

I think you'll find that you can get a 105 cassette in 11-25 and quite cheaply to. Look here:-
http://www.chainreactioncycles.com/Mode ... elID=13593

I only looked at Ultegra SL. I would never use that cassette as it has no 16 tooth cog. Far more use than an 11.

bigal.

Strodey- I am not familiar with your area or obviously your ability etc but if you were to attempt your 25 mile loop say 3 times you would probably be very thankful of having a 12-27.

You may also just be a very strong rider so it really depends on what feels right for you. I have changed all my bikes over the years onto 12-27 mainly because my rides are generally no shorter that 50 - 60 miles and we look for the steepest and most hilly routes possible.

Yep, you guessed it. I am a glutton for punishment and daft.

Hagrid

The answer to the question seems to me to be fairly straightforward. To make any difference on the downs, you need an 11. As for the upper limit, look at the number of teeth on the lowest gear that you do use. Then go out and get an 11 toothed cassette that matches that. SRAM have a number of ratios you might find useful if Shimano doesn't get it done for you.

strodey

Thanks for all the good advice!

Gone for an ultegra 11-25 lets hope the legs don't burn too much after the bigger hills!

oldwelshman

Infamous wrote:

hopper1 wrote:

The lowest amount of teeth you can have, is a 11/23:

What about 11-21 ?

Strodey: sounds like you want a 12-25

+1
Why arew people obsessed with a 11 tooth? You should never need it.
If in a race going that fast yopu think you need it just draft some one, you sure won't need it on the flat.
Better to keep closer ratios and go for 12 25 or 12 23.
I rarely use a 12 to be honest.

oldwelshman

Hagrid wrote:

The answer to the question seems to me to be fairly straightforward. To make any difference on the downs, you need an 11. As for the upper limit, look at the number of teeth on the lowest gear that you do use. Then go out and get an 11 toothed cassette that matches that. SRAM have a number of ratios you might find useful if Shimano doesn't get it done for you.

On the downs you get more benefit getting more aero and it is better to keep the larger sprockets because you will notice loosing them far more than you will notice any gain in having an eleven.
If you want to go faster downhill practise getting more aero and go on a track to learn to pedal faster.
50mph should be fast enough surely?

oldwelshman

strodey wrote:

Thanks for all the good advice!

Gone for an ultegra 11-25 lets hope the legs don't burn too much after the bigger hills!

Think you may end up jumping up and down the gears on the steeper climbs

pianoman

Think you may end up jumping up and down the gears on the steeper climbs

If that's with a 39 inner ring then invest in some superlight wheels, tyres and tubes, to give you all the help you'll need or you'll never get to the top of some climbs :shock:

34-25 is a lot more manageable though, and you can still have 50-11 for bombing it on straight descents. At least that's all good for me

roger_merriman

PianoMan wrote:

Think you may end up jumping up and down the gears on the steeper climbs

If that's with a 39 inner ring then invest in some superlight wheels, tyres and tubes, to give you all the help you'll need or you'll never get to the top of some climbs :shock:

34-25 is a lot more manageable though, and you can still have 50-11 for bombing it on straight descents. At least that's all good for me

or just be heavy! works for me at best part of 14stone I with ease roll away from racing snakes on the down parts.

strodey

I'm 6 foot 2 and weigh 10 and half stone so should be fine! just bought some dura ace cl 7850 wheels to replace the mavic cxp22's too so i dont see myself having too many issues!

John.T

You are only averaging 14.3mph round that route. You need to climb faster, that is where the time is lost and saved. Descending makes little difference and is best used as recovery. The route I showed is similar but I can usually get over 15mph on it when fit and I am 5'11", 12 stone and 67 years old. Don't waste money on new cassettes, just do more training. (Says he, looking out of the window at 10" of snow.)

strodey

You are only averaging 14.3mph round that route. You need to climb faster, that is where the time is lost and saved. Descending makes little difference and is best used as recovery. The route I showed is similar but I can usually get over 15mph on it when fit and I am 5'11", 12 stone and 67 years old. Don't waste money on new cassettes, just do more training. (Says he, looking out of the window at 10" of snow.)

Not any more, average always over 15 now, that was the first day out on the road bike! hence trying to get used to drop bars, thin tyres and was dressed for mtbing so over heating!
I do climb faster but dont use the 27 so whats the point in having it! as its a compact i dont always have enough on the downs hence the 11 would be more useful, my spinning is not that good from mtb habits so cadence is low and i prefer this, tried upping the average and it didnt feel comfortable!

amaferanga

If you learned to spin faster than 80rpm you wouldn't need the 11....

balthazar

I ride in terrain with constant very steep, but generally short, hills. For example:

www.bikehike.co.uk/mapview.php?id=29724

I've always used a bottom gear of either 39/23 or 39/25. I'm not going much (if at all) faster than you, but I don't want lower gears, even for 20-25% hills. I'm quite happy pedalling a low cadence at 10mph or even below.

At the other end, I enjoy my top gear of 53/12 or even 53/11. It's certainly not necessary, but I like to keep pedalling at 50+mph, even if I'd go faster by stopping pedalling and tucking. My bike is configured to serve my enjoyment firstly, not my speed.

strodey

Hi,

searched forum but didnt get exactly what i needed!!!!
Bought a new set of wheels ready for spring (dura ace cl 7850 at a bargain)

I currently run a 12 - 27 casstette on my defy advanced, and never use the lowest gearing even on the stupid gradients, what would be a sensible move to give a noticeable difference on the downs without suddenly killing me on the ups? Will i notice a small change?

Will keep my old wheels for winter so this is for good weather blasters!

advice appreciated!

cheers

Horses for courses, looks like we all like something different!

Thanks for all the help!

Pross

Why do people think of 39 x 25 as being a high gear? It is the lowest gear on my new bike and is by far the lowest gear I've ever had on a road bike. I'm grateful for it due to my lack of fitness but don't feel I need anything easier even living in a hilly part of the country. When fit (and a similar height / weight to the OP) my lowest gear was 42 x 21 and that was pretty much the standard low gear for anyone - there were a few with 39t chainrings and / or 23t sprockets but that was it we only had 12 or 14 gears at the time anyway. OK, we were club level cyclists but I can't recall anyone having to get off and push at any time. Obviously having the additional gears available gives the chance to have lower gears without the bigger jumps which is a good thing but comments such as

If that's with a 39 inner ring then invest in some superlight wheels, tyres and tubes, to give you all the help you'll need or you'll never get to the top of some climbs

are plain ridiculous if someone as unfit / heavy as I am now can get up 1 mile long 10 - 12% grades in relative comfort on 39 x 23 / 25!

oldwelshman

Pross wrote:

Why do people think of 39 x 25 as being a high gear? It is the lowest gear on my new bike and is by far the lowest gear I've ever had on a road bike. I'm grateful for it due to my lack of fitness but don't feel I need anything easier even living in a hilly part of the country. When fit (and a similar height / weight to the OP) my lowest gear was 42 x 21 and that was pretty much the standard low gear for anyone - there were a few with 39t chainrings and / or 23t sprockets but that was it we only had 12 or 14 gears at the time anyway. OK, we were club level cyclists but I can't recall anyone having to get off and push at any time. Obviously having the additional gears available gives the chance to have lower gears without the bigger jumps which is a good thing but comments such as

If that's with a 39 inner ring then invest in some superlight wheels, tyres and tubes, to give you all the help you'll need or you'll never get to the top of some climbs

are plain ridiculous if someone as unfit / heavy as I am now can get up 1 mile long 10 - 12% grades in relative comfort on 39 x 23 / 25!

funny pross
Yopu sound like me I used to ride on a 42 x 21 and even did the five valleys and came second when it was a top event and only used 42 19 and 17 over the Bwlch and Rhigos.
That was then, now I am older, also it was only 75 miles race and not very steep.
If you tried to do the MArmotte with a 42 x 21 or even 39 x 25 you would struggle like hell to get around. I could have plodded ropund on 39 x 21 but would have died, I used a compact with 12 x 27 on the back and for racing in uk use compact with 12 x 21.