Racing with a compact crankset

colm_gti · 31-01-2013 10:10am #1

Raced at A4 last year with a 50/34, got on grand, but don't recall ever using the 34 in any races I done.

Upgraded to A3 for this year, am I likely to get dropped descending in the 50-11? Or is there THAT much of a difference between a 50-11 and a 53-11?

I.E. Should I buy a 53/39 asap or will I manage with a 50/34 for a couple of months?

Plastik · 31-01-2013 10:15am

50x11 is a bigger gear than 53x12, so at the top end you only gain a single gear. Like yourself though, I effectively raced all last year on a maximum of 10 gears - start of the race, big ring and it never left. I've gone 53/39 because it was handy to pick one up a few weeks back, but it wouldn't have particularly bothered me to stay until I found a deal.

I think I might have used the 34 once last year - club league race that ended at the top of the Shay Elliott.

Morrisseeee · 31-01-2013 10:16am

The 50-11 is bigger than the 53-12 and unless you're on a long downhill descent than I wouldn't worry about it.

Actually what I did was a get a different cassette, ie. a 11-21, and this gave me a good range to work with.

colm_gti · 31-01-2013 10:19am

Cheers lads, been eyeballing a brand new ultegra 6600 53/39 crankset for ~€65, but if I'll manage ok with a 50-11 then I'll hang onto my money for now

Morrisseeee · 31-01-2013 10:33am

colm_gti wrote: »

Cheers lads, been eyeballing a brand new ultegra 6600 53/39 crankset for ~€65, but if I'll manage ok with a 50-11 then I'll hang onto my money for now

Don't let us put you off :pac:

There is a nice difference in the gears, 50-11 < 53-11
eg: @ 90rpm > 50-11 = 52.9km/h, 53-11 = 56.1km/h, 53-12 = 51.4km/h
but.........I'd imagine the only time it would count is on a long (not so steep) descent and you're struggling to gain contact with the group, once in the group you'd be drafting anyway. The other time is sprinting, are you a Mark Cavendish in surprise ??

I definitely used my 34 last year, the Tommy Sheehan springs to mind, a right bitch of a circuit :eek:

colm_gti · 31-01-2013 12:26pm

Morrisseeee wrote: »

Don't let us put you off :pac:

There is a nice difference in the gears, 50-11 < 53-11
eg: @ 90rpm > 50-11 = 52.9km/h, 53-11 = 56.1km/h, 53-12 = 51.4km/h
but.........I'd imagine the only time it would count is on a long (not so steep) descent and you're struggling to gain contact with the group, once in the group you'd be drafting anyway. The other time is sprinting, are you a Mark Cavendish in surprise ??

I definitely used my 34 last year, the Tommy Sheehan springs to mind, a right bitch of a circuit :eek:

Bear in mind I only started racing in July, so the only race I done with a notable 'climb' was that one in Gorey near the end of the season where I would have been better off in a canoe thanks to the rain....but even on that hill I'm pretty sure I was in the big ring (I prefer to grind than spin).

Wish I could sprint....so no, not Cav in surprise

FrankGrimes · 31-01-2013 12:32pm

Morrisseeee wrote: »

Don't let us put you off :pac:

There is a nice difference in the gears, 50-11 < 53-11
eg: @ 90rpm > 50-11 = 52.9km/h, 53-11 = 56.1km/h, 53-12 = 51.4km/h
but.........I'd imagine the only time it would count is on a long (not so steep) descent and you're struggling to gain contact with the group, once in the group you'd be drafting anyway. The other time is sprinting, are you a Mark Cavendish in surprise ??

I definitely used my 34 last year, the Tommy Sheehan springs to mind, a right bitch of a circuit :eek:

Thanks for posting that, particularly the bit in bold is really interesting. Is there a site that you used to calculate it? Might be handy as I'm also thinking about what chainset to use for racing.

ford2600 · 31-01-2013 12:35pm

If you have a smart phonr just download a gear calculator app

Morrisseeee · 31-01-2013 12:55pm

FrankGrimes wrote: »

. Is there a site that you used to calculate it? .

I think I got it from here.
Here's another interesting site: try the MP test for various climbs.

RobFowl · 31-01-2013 12:58pm

It's nice to have the extra gears but TBH in 27 years racing used the 53/11 once (on the boot inn circuit with a howling tailwind).

feck sake lads · 31-01-2013 1:23pm

the ultegra chainset might be better as you can change the rings to suit.. you cant on a compact well you could get a 36 instead of the 34 .

check out TA rings or stronglight to use with bigger chainset (110Arms );)

Dubba · 31-01-2013 3:32pm

Nothing to do with racing but I tried a 39-25 lately and could barley push the bike up steep hills and as I live on top of a steep fecker, I've changed back to a 39-28. As far as I know 39-28 is equal to 34-23, anyone know what a 39-25 equates to on a compact?

feck sake lads · 31-01-2013 3:38pm

now to be honest would you be one bit worried about gear ratios if you were struggling to get up a hill:P

Dubba · 31-01-2013 3:40pm

Hell no!

Plastik · 31-01-2013 3:46pm

Dubba wrote: »

Nothing to do with racing but I tried a 39-25 lately and could barley push the bike up steep hills and as I live on top of a steep fecker, I've changed back to a 39-28. As far as I know 39-28 is equal to 34-23, anyone know what a 39-25 equates to on a compact?

34/23 would be very close to 39/26, 39/25 close to 34/22 ... if such gears were available.

feck sake lads · 31-01-2013 3:49pm

they are shimano xt up to 36 on rear 22 up front

Morrisseeee · 31-01-2013 3:50pm

From below you can see that a 34-23 is very similar to a 39-26

50 47.10% 34
11 122.7 83.5
9.10%
12 112.5 76.5
8.30%
13 103.8 70.6
15.40%
15 90 61.2
13.30%
17 79.4 54
11.80%
19 71.1 48.3
10.50%
21 64.3 43.7
9.50%
23 58.7 39.9
13.00%
26 51.9 35.3
53 35.90% 39
11 130.1 95.7
9.10%
12 119.3 87.8
8.30%
13 110.1 81
15.40%
15 95.4 70.2
13.30%
17 84.2 61.9
11.80%
19 75.3 55.4
10.50%
21 68.1 50.1
9.50%
23 62.2 45.8
13.00%
26 55 40.5

granda · 31-01-2013 4:07pm

i had the same dilema colm and ended up buying a bbb 52 chainring and a 36 small chainring which are both for 110 diameter which if i find i dont like its just a case of swapping back to the full compact with no real hassle or messing with different chainsets

CaoimH_in · 31-01-2013 6:02pm

Yeah, I really don't have the legs for a 53 x 11, I've tried 'um before and it's just too heavy to push. I can't sprint, and I'd only fancy myself as a rouleur that can climb a bit, so a compact suits me fine. I'd pretty sure I'm gonna go from a 34 to a 36 and I might go for a 52 though I'm pretty comfortable with my 50. I'm training on a 12-26 cassette, but I'm pretty sure an 11-23 or 25 would be better again.

I think the important thing to remember is you won't be in flat lab-like conditions, I really never used my 53-11 all too much when I had it. You should probably look for the gears that suit your ability/style over choosing on more arbitrary notions of what everyone else is doing. What are you best at? Can you push big gears comfortably? Are you a sprinter? Will you be targeting flat courses? Is there nothing you like more than getting in the break on a flat section and drilling it all the way to the line? Like descending at Cunego, or Cancellara like speeds? Are you a man for the TTs? Sounds like you? I'd say you should get yourself a standard crank.

Or, are you fond of climbs, hills, and, drags? Do you like a war of attrition over difficult terrain? Are you clearly not built to sprint? Do you like the feeling of having a nippy, punchy gearset? Do you feel comfortable with your hardest gear over 10-20k and do you think you could handle much more? Do you hope just not to lose that much time when you descend (are you rubbish)? Should help you decide if you want a compact.

Racing with a compact crankset

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