changing from 12-25 to 13-29 cassette

cookiemonster

Good point - I can descend reasonably quickly (think years of motorbikes help here - braking in the right place and taking lines through corners and stuff) and, yep, really wouldnt want bigger as 50x12 as minimum. 50x11 would be nice, but again i'm no doubt into dodgy territory.

I'd guess that somthing like a 54/33 front would actually be the way to go (12/25 rear), but i really dont want to take the chance of turning up with some radically different gearing and finding that I just cant get used to it

wildmoustache wrote:

cookiemonster - you should try and avoid having 50x13 as your biggest gear for the marmotte at least. from the lauteret down to the base of alpe d'huez is an exceptionally long, fast, relatively shallow descent where you'd benefit from a bigger gear (assuming you are comfortable descending at speeds of around 40mph).

I wouldn't want to go into that one with anything smaller than 50x12, and i'm actually planning on doing it with an 11-25 cassette but we are all different. 12-27 with 50-34 sounds like a good option if you can build it.

Ken Night

Unless you are exceptionally athletic, you won't need more than 50/13 on the Lauteret descent....find a big Dutchman to hide behind......and if you have to make a compromise, make it at this end of the gear range, not the low end

nick hanson

wildmoustache wrote:

cookiemonster - you should try and avoid having 50x13 as your biggest gear for the marmotte at least. from the lauteret down to the base of alpe d'huez is an exceptionally long, fast, relatively shallow descent where you'd benefit from a bigger gear (assuming you are comfortable descending at speeds of around 40mph).

I wouldn't want to go into that one with anything smaller than 50x12, and i'm actually planning on doing it with an 11-25 cassette but we are all different. 12-27 with 50-34 sounds like a good option if you can build it.

Might have to disagree with you on that.I've descended the lauteret on a 48x 13 at @ 40 mph,which gets the legs spinning nicely.
A mate of mine did the Marmotte last year @ was aiming for gold going over the Galibier.
He trammed down the Lauteret on some daft (V.large) top gear rather than trying to get a bit of recovery.
Sure,he descended maybe 5 mins quicker than i would have,then he hit the Alp......
3 hours later he gets to the top
maybe he learnt his lesson,who knows? :shock:

Ken Night

nick hanson wrote:

wildmoustache wrote:

cookiemonster - you should try and avoid having 50x13 as your biggest gear for the marmotte at least. .........
I wouldn't want to go into that one with anything smaller than 50x12, and i'm actually planning on doing it with an 11-25 cassette but we are all different. 12-27 with 50-34 sounds like a good option if you can build it.

Might have to disagree with you on that.I've descended the lauteret on a 48x 13 at @ 40 mph,which gets the legs spinning nicely.
A mate of mine did the Marmotte last year @ was aiming for gold going over the Galibier.
He trammed down the Lauteret on some daft (V.large) top gear rather than trying to get a bit of recovery.
Sure,he descended maybe 5 mins quicker than i would have,then he hit the Alp......
3 hours later he gets to the top
maybe he learnt his lesson,who knows? :shock:

Spot on Nick
I was well inside the gold time.

I've never been dropped on a sportive for the lack of a high gear

If it helps, I use 50/36, and either 13--26 or 13-29, having the latter for the Marmotte, using the 29 on both the top of the Galibier and Alpe

(I can't get on with 50/34, so have bikes with 53/39, 50/36 and 48/34..... 48-12 is a nice high gear)

rickhotrod wrote:

Marchisio cassettes allow you to choose what size sprockets to use. Something like 12-28 made up from one of the following combinations:

12,13,14,15,16,18,20,22,25,28

12,13,14,16,18,20,22,24,26,28

12,13,14,15,17,19,21,23,25,28

With a maximum sprocket of 28, this might allow you to use the short Campagnolo rear derailleur. Just don't use anything smaller than 15t when on the 34 chainring!

With the made up cassette from Marchisio, which will allow you to run 12-28 on 48/34.....you have lots of flexibility. You only need to change sprockets as they wear out, and can ditch the big sprocket when you don't need it, subsituting another in the middle of the block..

As a Campag user, you should be able to get away with using the (short cage?) mech you already have. It even used to say so on the Campag site-Centaur only for some reason, and I confirm I did so with an 03 Centaur short cage mech

-a med cage mech is pretty cheap anyway

jpembroke

Ken Night wrote:

Spot on Nick
I was well inside the gold time.

I've never been dropped on a sportive for the lack of a high gear

If it helps, I use 50/36, and either 13--26 or 13-29, having the latter for the Marmotte, using the 29 on both the top of the Galibier and Alpe

(I can't get on with 50/34, so have bikes with 53/39, 50/36 and 48/34..... 48-12 is a nice high gear)

You can get a made up cassette from Marchisio, which will allow you to run 12-28 on 48/34 and as a Campag user, you might be able to get away with using the (short cage?) mech you already have-a med cage mech is pretty cheap anyway

Have to agree with your thoughts regarding gearing. I've never understood why 50/34 is the common setup for compact chainsets. I had one on an old winter bike and hated it; I just couldn't get the hang of having such a large drop from big to small ring. I ended up putting the 53/39 back on. 50/36 seems to make much more sense - just wish it was offered by more manufacturers. Like you, I also have 48/34 (with 12-25 or 11-28 ) on my cross bike and really like it - prefect for 'cross racing and winter training.

nickwill

I rode the Raid Pyrenean on a 50/34, 13-29 set up. I was able to out- descend many of the other riders and was regularly descending at 40+ MPH. The trick was to carry more speed through the corners. People were recording higher max speeds than I was, but I was still dropping them, by, I presume, taking a better line. I was certainly glad to have the ultra low gears by the time I got to the top of the Tourmalet, and on the steep sections of the Portet d' Aspet!
The only time I missed a higher gear this year, was on the Southern Uplands Sportive where there were some long ultra shallow descents in the first half.
On balance, I would prefer a 12-27 cassette, but that is not an option with Campag 10 speed. I've looked into the idea of Marchisio cassettes, but have been advised that they wear quickly, and don't change as smoothly.

mercsport

Nickwill wrote:

I rode the Raid Pyrenean on a 50/34, 13-29 set up. I was able to out- descend many of the other riders and was regularly descending at 40+ MPH. The trick was to carry more speed through the corners. People were recording higher max speeds than I was, but I was still dropping them, by, I presume, taking a better line. I was certainly glad to have the ultra low gears by the time I got to the top of the Tourmalet, and on the steep sections of the Portet d' Aspet!
The only time I missed a higher gear this year, was on the Southern Uplands Sportive where there were some long ultra shallow descents in the first half.
On balance, I would prefer a 12-27 cassette, but that is not an option with Campag 10 speed. I've looked into the idea of Marchisio cassettes, but have been advised that they wear quickly, and don't change as smoothly.

As a user of Marchisio I must leap in and declare that the wear rate of the Aviotek system is bloody good . Easily the equal , or better than the Record blocks I previously used , whose teeth had an uncanny knack of splintering on me ( two blocks in a row . Maybe as a result of poor hardening - I don't know ) .

As for the 'smooth change' phenomena , ... well , I'd suggest that maybe subjective to some degree . I may be insensitive but , how can you tell ? In use I certainly cannot tell apart a Campag sprocketed wheel to a Marchisio one .

Having said all that I just put a cheapo 13-29 Campag block on my winter bike after I couldn't bring myself to fork out a ton for another Marchisio jobby which had given me good service for several years . I already miss that 11 sprocket !

I still have a Marchisio 11-27 on my summer steed though .

P.S. My aid to 'out-descend' everyone else , on a proper hill , I've discovered , is to become a great big - three stone overweight - 'tub o' lard ' .
But , an 11 sprocket is still the best thing to have on moderate steepnesses I feel .

Ken Night

Nickwill wrote:

I
On balance, I would prefer a 12-27 cassette, but that is not an option with Campag 10 speed. I've looked into the idea of Marchisio cassettes, but have been advised that they wear quickly, and don't change as smoothly.

Another Marchisio user here. The wear rate is better than Record, and of course you only change one sprocket at a time-the 17/18/19

nickwill

Oh dear, I can feel some more expenditure coming on!

Ken Night

Don't torture yourself-it's an expensive indulgence.....

FWIW, I mostly use Centaur cassettes with my Record setup.....you can tell if I ever manage to get in front of you. There is a blue spacer in the middle of the block

redddraggon

Ken Night wrote:

There is a blue spacer in the middle of the block

My Centaur cassette doesn't :?

Ken Night

cookiemonster wrote:

I'm down for the marmotte and the dave lloyd challenge this year (maybe the fred too if i get a place) and i'm toying with the idea of sticking a 13-29 on the back for somewhere to go after 100 miles - a safety net really...............

As an aside - my preference would be 12-27 as anything lower than 34/27 and you're faster walking, but i'm on campag and dont have the option of that size cassette - very annoying and the only thing I prefer about my old ultegra to the current chorus. And, I cant be bothered fitting a triple for the possibility, rather than certainty, that I'll use it for a couple of events over the whole year.
Cheers

Jon

You can cycle most hills faster than you can walk, with a low enough gear

As a Campag user if you want a really wide range of gears cheaply......and you still have that ultegra wheel

Buy a 11-32 MtB 8speed cassette, and a Shimano long arm mech-with a new chain, you should be able to get all this for less than £50. 50/11 is a huge gear, and 34/32 should get you up a wall

.............................runs perfectly on Campag 10speed, though you might have a mental block about how it looks

Actually, I think the XT mech looks quite nice, tho' you might have to pay a bit more for that.....thoughts?