Road Bike, Cycling Forums banner

1 - 20 of 25 Posts

·
Registered
Joined
·
174 Posts
Discussion Starter #1
Hey All,

The concept of compact gearing (generally 50/34 chainrings with a tighter cassette) is, to me, genius and a no-brainer. For those of you who already use it, what's the crossover situation? Are you happy with the gearing in general and with the number of shifts to get an equivalent gear in the other ring?

In other words, when increasing your gearing in the small ring to where you're in need of big-ring gears, does it require an inordinate amount of shifting to get a slightly larger equivalent gear on the big ring?

I'm sure everyone will/can get used to it in short order and that it's not so terrible or anything, but I'm just curious as to whether or not it requires lots of extra shifting initially.

Any help/experience/advice is greatly appreciated. Big thanks!
Nige
 

·
Registered
Joined
·
10,160 Posts
an OLD topic...

Try a search, this topic has been covered extensively.

A 50/34 takes 6% from the top gear ratio and increases the low by 13%, for a net increase in range of 7%, which is slightly less than an average 9% 1-cog change. In other words, you can get almost 1 cog’s worth of extra range, but NOT without some expense. More cog shifting is required after every chainring shift, when wide-spaced chainrings are used. Most often, it requires a one additional cog to be shifted compared to a 53/39.

Using a compact rarely permits the use of a "tighter" cassette, except in the case of a 12-23 9 speed being used instead of a 12-25 or 12-27. Then you get a 16T cog that's missing from the other cassettes. 10 speed users don't have this problem becasue all stock cassettes have a 16T cog. Some of the most recent advertising from FSA suggests that an 11-23 is a tighter cassette than a 12-25. They need a math lesson, since the percentage jumps are larger, not smaller.

With shimano 10 speed, about the only reason to use one is if a 12-27 cassette does not provide a low enough gear. Campy users can just put on a 13-29.
 

·
Registered
Joined
·
376 Posts
I'll chime in

I ride a 50/36 on two bikes. Love it. IMHO, the 50 is the best reason to get the compact. I find I ride the 50 a lot, and only ride the 36 for true climbing. In the old days I almost never rode in the 53.

Unless you are doing a LOT of climbing, the 34 is too small. That is why I swapped out for the 36. Never had any shifting problems with the 50/34, but the 50/36 is spot on.

Not scientific, but it works for me (and a lot of people). Nothing against triples, but for where I live (north Georgia) the compact is the right range of gearing for this semi-old clydesdale. If I ever move back to Iowa I'll probably go back to standard gearing as I lose the hills. Until then I am a shameless schill for compact gearing. (Sorry C-40)
 

·
Registered
Joined
·
1,085 Posts
GiantNigel said:
The concept of compact gearing (generally 50/34 chainrings with a tighter cassette) is, to me, genius and a no-brainer.
Does anyone remember MicroDrive? I think it was a Suntour concept in the early 1980s. Whoooweee....it was real crap.
 

·
Registered
Joined
·
95 Posts
A little off topic but when switching to a compact crank from a triple and/or standard double, do you need a new derailleur? I am installing a new compact crankset and using a spare triple derailleur.....is this a no no?
 

·
Registered
Joined
·
482 Posts
All my rides are climbs. Usually 4000' avg.
The compact suits me for both ascending & decending.
My 50x11 is bigger at 122.72 than a 53x12 which is 119.25
At the other end which is strictly a bail out gear I get 39.91 out of a 34x23
My pal suffers along in a 39x25 which is 42.12
You would need a 39x27 to get a 39inch gear or 39x26 for a 40 inch

Even on a rolling flats ride a 50 chainring with a 11x23 cassette yields higher gears in the 1st seven or eight gears than a comparable 53 with a 12/25 cassette

So I like it ;)
I also think a 11x23 cassette is the perfect match for a 34/50 compact.
It has great range & shifts extremely well.

Your milage may vary ;)
 

·
Registered
Joined
·
10,160 Posts
close spaced cmpact..

As you've noted, a compact does not have to be wide spaced. A 50/36 or 48/34 will not add the extra cog shifting that the 50/34 does.

People get some unusual ideas about the advantages of the 50T gear. It's less than a full cog lower than a 53. When you had a 53, you could get basically the same gear ratio, just using one cog larger than you do with the 50. Why this would suddenly make the big ring so much more useable is beyond me. Changing the cassette to one starting with a 13 instead of a 12 would have a greater effect.

As for the 34 being too low, that depends on you choice of cassette. As I noted earlier, compacts are more useful for those using 9 seed who are willing to give up some top gear to get a midrange gear (the 16T and/or an 18). Then 12-21 or 12-23 cassettes become attractive.
 

·
gastarbeiter
Joined
·
1,513 Posts
also sort of OT

i'm thinking of buying the ultegra compact for a couple of gran fondos i'm doing this summer.

the idea is to switch from my DA (double) cranks to compact just for a few weeks (it works ouyt as only a little more expensive than buying a new chain/casette).

the question (a stupid one, i'm fully aware) - do i aslo have to change the BB?

thanks in advance
 

·
Registered
Joined
·
1,859 Posts
Hyperglide-C is Microdrive under a different name

SDizzle said:
Does anyone remember MicroDrive? I think it was a Suntour concept in the early 1980s. Whoooweee....it was real crap.
Is that why everybody copied them? Previous to Microdrive, MTB cranks used a 110mm/74mm BCD (same as today's road "compact" cranks). The smallest inner chainring that would fit was 24 tooth. Most manufacturers paired this with a 12-32 8spd cassette. That changed when Suntour introduced Microdrive, with a 94/56mm BCD and 20 tooth inner chainring and an 11-28 8spd cassette. Shimano soon followed with Hyperglide-C, with a 94/58 BCD crank which also allowed inner chainrings as small as 20 tooth, and they modified their freehubs for 11 tooth rear sprockets. And of course, SRAM followed Shimano. Microdrive/Hyperglide-C has become the new standard for MTBs

Microdrive may or may not have been crap, but Shimano decided to redesign their cranks, chainrings, freehubs and cassettes to achieve the same thing just the same.
 

·
Banned
Joined
·
6,360 Posts
Had it 30+ years ago, glad it's coming back.

For me (aging Clydesdale in big mountains), it's the second-best thing that's happened to bicycles, right after triple cranks. I had a Peugeot in college with what was then called "alpine gearing," 50-36 with a 13-26 five-speed freewheel. It covered everything I needed in those days, but with my next bike the standard had moved to 52-42, and then to 53-39. I don't think 2 percent of cyclists need anywhere near a 53-tooth big ring.
I'm running 46-36-26 triples on my two main road bikes now, and I like it. If I ever replace a crank, though, I'll probably go with a compact double on the Rambouillet.
 

·
merckxman
Joined
·
2,116 Posts
Which granfondos are you planning to do?

Which granfondos are you planning to do?
botto said:
also sort of OT

i'm thinking of buying the ultegra compact for a couple of gran fondos i'm doing this summer.

the idea is to switch from my DA (double) cranks to compact just for a few weeks (it works ouyt as only a little more expensive than buying a new chain/casette).

the question (a stupid one, i'm fully aware) - do i aslo have to change the BB?

thanks in advance
 

·
gastarbeiter
Joined
·
1,513 Posts
maratona dles dolomites and possibly the etappe de tour a week later.

did the maratona last year, and definitely needed the 39x26 i had. this year i'll be using a new bike and moving from 8spd ultegra to 10spd DA where my biggest gear will be a 39x25, hence the idea to just switch the cranks instead of casette and chain.


merckxman said:
Which granfondos are you planning to do?
 

·
Old Skool
Joined
·
719 Posts
It is all in the spin...

I don't think 2 percent of cyclists need anywhere near a 53-tooth big ring.
IMHO Cory has the right idea. Most people do not need a 53 tooth big ring. If you learn how to spin properly you are doing 90-100 rpm on a consistent basis. A 50x11 at 100 rpm equates to about 35 mph. I don’t know about you, but I almost never need anything more than this even on descents. Even if you mash along at 80 rpm, you still get over 28 mph with a 50x11. How many of us are really in good enough shape to need more than this.

As a point of reference, the first year I raced as a junior back in the 70s the gear limit was a 47x15. We went plenty fast, but you had to spin like crazy. The next year they increased the limit to a 52x15 and you still had to spin.
 

·
Windrider (Stubborn)
Joined
·
22,021 Posts
It works for some cadences.......

and in others it creates a situitation where the majority of your riding is in crossover gears....it's a real PIA.

There are two issues with a compact that are being adressed in this thread.

1.) The benefit of a 50 tooth Chainring. I couldn't agree more that for most non-racers, (and even many racers) a 50 is a much more usable large chainring. The only exception is if you like to keep pedaling on very long fast descents. You don't need a compact to achieve this though. Just switch out the 53 for a 50. I have a 50 on all my doubles and triples.

2.) The benefit of the 34 in terms of climbing. It certainly gives you lower gears than a 39, but at the expense of (depending on your cadence) crossover gearing. Me, I have triples set up as 50/39/28's on my climbing bikes. For most riding I have a "Normal" 50/39 double......but when I get in the mountains I have very low gears. For flatland riding, I use a 12/23 cassette....for the mountains, I just put a 12/27 on and I never run out of gears no matter how tired I am.

I'll probably get flamed, but I suspect that the atteraction for some people of the compact is that it is a double and only "Freds" use a triple.

Use whatever works for your terrain, your cadence, and your enjoyment....it's all good.

Len
 

·
Registered
Joined
·
267 Posts
For the same reason that C-40 pointed out (extra cog shifting) I decided not to go compact. I have campy and went with a 13-29 when I upgraded to 10spd. The other reason I didn't go compact was that I didn't like the compact crank choices out there. They were either too expensive or used an old or proprietary BB design.
 

·
Registered
Joined
·
205 Posts
I have the big three, and more...

I think about this stuff too much, but I'm coming from "back in the day" of 6 speed Campy Nuovo Record, 42/52 cranks, 13-23 cobs (or whatever- I forget, I went as big as 42x27T and felt like I realy needed to get back in to shape to get that huge cog off my tubular wheelset) And... then I got married, had a kid, lost perspective and stopped riding for about 10 years.

Fast forward.... Wow- 9 and 10 speed deraileurs are a huge factor to consider! Add 39/53 cranks... another huge factor. The biggest factor of all was me remembering myself as a 27 year-old that had the legs and wind to hammer my hot criterium bike just behind the big dogs, but really being a fat, out of shape 46 year old. Reality sucks.

I wonder what the bike guy was thinking when I stepped in to the shop for a full fitting with all this ancient gear last July. He set me up perfectly. The key in my mind was the FSA Energy 34/50 compact crank. It uses a standard ISIS bottom bracket, it's aluminum, really stiff, really good, and it's a real value bike part. I bought an Energy 39/53 for another bike for less than $50; the compacts go for less than $110 and it is not out of place on my Serotta- it's almost like FSA sells these by mistake- I think if people saw these cranks they would never buy the carbon fiber crap they sell. I digress. I digress a lot, in fact.

So this fat and out of shape guy plunks down a frickin wad of cash for a very hot bike. I LIVED in the 34 ring the entire summer. It got me through a tough Century. It got me up some major climbs. It got me around my favorite 58 mile training loop every other day- except when we went out for distance or I tried a sprint loop that I used to fly through, back in the day. By the end of summer, I didn't even need 34x27T to climb the big 350 foot vertical, 10% grade hill. I was feeling good, and I was determined to keep it up and skate my butt off in the winter, and hit the trainer hard. Then I got rollers... good move.

Then I got a cyclocross bike- EVEN BETTER move! I put a 39x47T FSA Energy crank on the thing with 8 speed 13-27 cassette and big nobby tires on it. Now I'm out in January until now in snow, sand, salt, mud... whatever. I'm on the road, bike path, gravel paths, anything I can roll on. 39x27 is not low enough to double as a mountain bike- but I hope to race 'cross this fall, and I think it's geared right for that, and where I hope my legs will be.

39x27T is doable on the 350' 10% climb, now that I've been working hard for 7 months. Well, it's doable because it's 25 miles frome home. If it was 50 miles from home over a moderately hilly ride, I'd be deep in the redzone on that climb.

I've been riding the hell out of that 'cross bike. Big nobby tires go "RRRrrrRRRRrrrrRRRR" like a Cessna trying to take off all the way down the road. As the weather gets nicer, there are more people on the road- you gotta be kinda hardcore to be out in Feb/March in Wisconsin, but there are beautiful days in the high 40s and 50s once and a while. Um... I'm rolling over all kinds of people. I'm spinning along comfy with some racing team guys, most all of us on 'cross bikes, passing riders like it ain't no thang. Yeah, I know they are not out to drop me, but I'm not busting butt to play with 'em, neither. I'm happy with my progress, to say the least. 39x27T is probably enough gear for most rides, but compared t the average rec rider, I'm getting very strong. Compared to the serious riders, I can hang on until they want to drop me.

Now, my tandem has 35/42/53 with 11-32 on the back... me and my kid are hitting the road now, too. For a tandem, it's good... except we've dropped the chain, gotten chainsuck on the crank side (THAT SUCKS!!!!) and generally worry every time we try to use the granny. Hauling a 9 year old... I need that granny gear. Problem is, I can't rely on it to happen without being ready to pull over to the side of the road 1 of ten times. Well, I'm not counting, but it sucks when it doesn't work. That's over 200 miles, this 'spring'. The Compact has dropped it's chain 3 times in about 4,000 miles. Two of those times were totally abusive bonehead both ring shifts down-OOPS! Down!-UP! I meant up! DAMN! shift moves... just wrong- wronger than aerobars on the bike path. The third was bad but I was too braindead to help it.

While I'm on this ramble- it really has to do with the bike industry. If the goal was to get people on top quality bikes with good handling and gears they can use every day that are reliable and sporty- Compact should be standard. 99 out of 100 people I see or more would be better served. When the legs and lungs can do it, some will go the racing route (towards 39/53), and some will go the distance or touring route (triple- when you are going a seriously long hilly way, you need a bail-out gear option- that's cool too- not many ride over 100 miles a day.)

What I see, living near a major college campus, is thousands of kids riding mountain bikes with front and rear suspensions and triple rings with MTB cassettes and giant knobby tires 4 miles on the flat pavement to campus. Obviously, the goal is not to get people on the right bike. That's why Cyclocross is so cool, for me. You can't even buy a mountain bike without some sort of suspension on it. Don't even get me started. But a 'cross bike- out of the box, geared for the average flabby person doing the average pathetic little ride (or a powerful rider flying over some really crappy surfaces.)

Shimano now has compact; if enough people go that way, it will get cheaper and more common, and people will like riding their bikes more- and maybe get fired up and get in shape and then move up as their legs do. Thanks Tyler Hamilton. Even though he's probably a VAMPIRE (or something... how would I really know) he did popularize the Compact by running it successfully in a TdF stage.

Wow, I have way too much time on my hands.

'meat
definately not ready to give up Compact!
 

·
Registered
Joined
·
133 Posts
How about for 'touring'

I am spec'ing out a 'touring' setup based on the Surly LHT. I am in a quandry about what to do for the crankset....go triple or go compact. I am thinking of putting an 11-32 with the appropriate rear derailleur if that will help the assessment.

In both cases, I am looking at the Sugino cranksets. Seem to be a good value for the buck.
 

·
Registered
Joined
·
21,504 Posts
Your gearing

fracisco said:
I am spec'ing out a 'touring' setup based on the Surly LHT. I am in a quandry about what to do for the crankset....go triple or go compact. I am thinking of putting an 11-32 with the appropriate rear derailleur if that will help the assessment.
No one who doesn't know you well can recommend your gearing. People have ridden across the country, fully loaded, with a 55 inch low gear. Others can't seem to get up a 3% grade without a triple. YOU have to know what low gear you need and what high gear you want. From there, you can determine what setup will get you where you want to be.
 

·
NeoRetroGrouch
Joined
·
6,491 Posts
C-40 said:
As you've noted, a compact does not have to be wide spaced. A 50/36 or 48/34 will not add the extra cog shifting that the 50/34 does.

People get some unusual ideas about the advantages of the 50T gear. It's less than a full cog lower than a 53. When you had a 53, you could get basically the same gear ratio, just using one cog larger than you do with the 50. Why this would suddenly make the big ring so much more useable is beyond me. Changing the cassette to one starting with a 13 instead of a 12 would have a greater effect.

As for the 34 being too low, that depends on you choice of cassette. As I noted earlier, compacts are more useful for those using 9 seed who are willing to give up some top gear to get a midrange gear (the 16T and/or an 18). Then 12-21 or 12-23 cassettes become attractive.
50t chainring - Until recently, the 13/x Shimano 9-speed cassettes were more than 2x the price that you could pick up a 12/x for. A 50 with a 12/21 works perfect for the fast rides I do. Now that 13/x are more available, I am putting the 53 back on. There can be a reason. - TF
 
1 - 20 of 25 Posts
Top