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-   -   Gearing Curiosities - Standard vs Compact vs Cassette (http://www.bikeforums.net/long-distance-competition-ultracycling-randonneuring-endurance-cycling/949340-gearing-curiosities-standard-vs-compact-vs-cassette.html)

eithr 05-21-14 08:53 AM

Gearing Curiosities - Standard vs Compact vs Cassette
 
I recently pieced together a bike. My main goal was to build something comfortable for longer rides. The only organized cycling event I participate in (for two years now) is TOSRV, a two day double century ride in Ohio. I've been riding, seriously, for a decade, but just don't get into organized events.

The issue - For the past 6-7 years I've been riding a modified 1987 Bianchi Trofeo, fitted with a 10-speed Campy mix. Compact crankset and I believe a 13-26 rear cluster.

The new bike is a standard, 53/39, with an 11-23 rear cluster. I used to ride a fixed gear and be able to mash, but my knees are getting upset more and more these days, so I find myself spinning more and more. I also am a short dude, so the old bike had 170mm cranks, the new bike has 165mm cranks... to encourage more spin, less mash.

Should I just stick with this set-up and wait for my legs to catch up to the gear ratios? Or am I better replacing something? If I replace something, what is more efficient? Swap the crank for a compact? Or swap the rear for a more forgiving spread?

LWaB 05-21-14 12:42 PM

You've just gone to higher gears, shorter cranks and to spinning more? I'd swap the cassette to something more forgiving.

hamster 05-21-14 01:51 PM

With 53-39 / 11-23, you have no choice but to mash whenever the grade gets above ~4.5 ... 5% unless you're very lean and powerful. I don't think there will be much catching up going on. I'm not sure what kind of terrain you have in Ohio, but it would be a pretty safe recommendation to upgrade the gears.
Cassettes are cheaper and they tend to wear faster, so, unless you have other reasons to replace the crank, I'd go with the cassette.

Weatherby 05-21-14 02:53 PM

both

Donnie Johnson 05-21-14 03:22 PM

Eithr,

Why not consider a mountain cassette on the rear. You could go for something like an 11-36 if you have 10 speed or and 11-34 is the largest 9 speed. This would mean that you would need to upgrade you read derailleur to long cage model (if your bike doesn't already have one fitted witch is unlikely considering the gears you described ). If you were to consider this option, there are some comparability issues mixing 10 speed road and Dyna-shift mountain components. e.g 105/Utlegra/etc 10 speed shifters wont work with an XT rear derailleur, (something to do with lever pull ratios). The solution to this 10 speed problem is to use a 9 speed mountain derailleur as they are compatible. e.g. 10 speed 105/Utlegra/etc 10 speed shifters and a 9 speed XT derailleur. 9 speed components are compatible and mixing and matching parts doesn't cause any major problems.

While this option may look a little odd; it is very practical as you will have a very large range of gears, offering both very high and log gears, although the gear ratios will be further apart especially towards the 34 end.

I run this system on my bike and it works a treat, especially after riding 250 km fighting headwind and climbing up long/steeper hills as it sometimes works out.

Good luck

Donnie

unterhausen 05-21-14 03:44 PM

I use a compact 50/34 crank and an 11-32 cassette with a road derailleur. Shimano now sells road 32 cassettes. A few years ago, I was using higher gears and mashing, but then I realized that mashing means you have to refuel sooner. One of the hardest 125 miles I have ever ridden was in Ohio, monster rollers with steep grades. I don't think that your current gearing makes much sense under those conditions.

Bandera 05-21-14 04:19 PM

Quote:

Originally Posted by eithr (Post 16778516)
The new bike is a standard, 53/39, with an 11-23 rear cluster. I used to ride a fixed gear and be able to mash, but my knees are getting upset more and more these days, so I find myself spinning more and more.

That's pretty stiff gearing, perfectly suitable for serious paceline work in rolling terrain but not what I'd want for a long solo slog in serious hills.
As others have noted a wider range cassette (and fresh chain of suitable length) would be the ticket. Having an 11X53 top cog is a fantasy unless down-mountain time trials are your thing. Look up the max your rear derail will handle and select another couple of cassettes to match terrain/distance. 11-23 for flat/wind, 12-25 for moderate hills and 12-28/30/32 or whatever your kit will handle for the big lumps and long days. Easy to change, inexpensive and optimal gearing for all conditions.

This isn't like trying to calculate a Mars launch. Find a nice great big nasty hill in your locality, go for a good very long solo ride on a windy day and climb it after, twice would be good. Note your gear ratios, adjust as necessary up/down and there you are.

This may help to quantify: http://sheldonbrown.com/gears/

-Bandera

Bacciagalupe 05-21-14 06:34 PM

Yeah, I don't think even a lot of pros these days climb with a 50/39 and a 12-23.

I'd get a wider cassette and a mid- or long-cage RD. If you are mechanically inclined, you can easily swap cassettes as needed.

Coluber42 05-21-14 07:01 PM

If the choice is between a compact crank and a larger cassette, go with the larger cassette. All else being equal, between two drivetrains with the same resulting gear inches, a larger combination (i.e, large cog and chainring) will have lower friction and take longer to wear out than a smaller combination.

OldsCOOL 05-22-14 03:57 PM

Quote:

Originally Posted by LWaB (Post 16779342)
You've just gone to higher gears, shorter cranks and to spinning more? I'd swap the cassette to something more forgiving.

+100

I run a road double 53/39 with 12/28 cassette. I have 2 hills that I cant ride up and have been tempted to throw a compact 50/34 on. Otherwise that 28 works ok on the other hills....and I live in hill country. The 53/12 gives me a good run on the descents in the elusive 50mph mark. :)

delcrossv 05-23-14 08:48 AM

Quote:

Originally Posted by LWaB (Post 16779342)
You've just gone to higher gears, shorter cranks and to spinning more? I'd swap the cassette to something more forgiving.

Add another +100. Put an 11-36 on the back and save the knees.


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