Compact VS Triple VS Double

jdog

Shop: Halter's Cycles
Shop Keep
A request was posted about triple vs double gearing. I just built a cross bike with a compact crank so I have an opinion now. I do like the compact better than a triple but I still prefer the standard double since the jump between the 50 to the 34 feels like a huge jump.

Out on the road I see these as advantages over a triple or standard double.

-Lighter overall weight (smaller rings and shorter chain)
-Better shifting than a triple (but no better than double)
-Better chainline
-Smaller gear jumps in the cass but still nearly as wide a range

..most everyone would like a compact if they gave it a shot. The missing top end 40mph+ gear might be a bummer to a select few.



I have a bit more to say but I stole this from the FSA website since they were among the 1st to bring this idea to the masses:




COMPACT GEARING

-What are compact cranks?

Compact cranks are characterized by a 110 mm bolt circle diameter instead of a 130 mm bcd (as in standard cranks). This smaller bolt circle allows one to mount smaller gears on the low end – its now possible to mount a 34 tooth ring instead of the 39 tooth ring which comes with a standard crankset.

-Are compact cranks right for me?

f you spend a lot of time riding in the mountains, your riding style dictates more spinning than pushing higher gears , or you’d like lower gearing but don’t want the added weight/complexity of a triple crankset, compact cranks may be right for you.


-What change in gearing can I expect?


If you keep the same cassette, you’ll lose the equivalent of one gear on the high end, but gain two gears on the low end. Check the downloads page of our website to compare gearing.



Can I convert my 130 bcd (standard) cranks to compact (50/34)?


With a standard 130 bcd crankset, the smallest chainring you can mount is a 38 tooth. On a 130 bcd crankset one can run a 38/50 or 38/48 (a gearing commonly used for cyclocross). It is possible to do the reverse – convert your compact cranks to standard. 39/52 chainrings are available for 110 spacing.



Is it possible to run 52-34 or other gearing?



Not advisable. A normal Shimano or Campagnolo front derailleur is designed to handle a 14 t difference. However, a standard road front derailleur works well for compact gearing (a 16t difference) because the rings are smaller and the physical gap between the two rings is roughly equivalent. Going to an 18 tooth or greater difference will adversely affect your shifting. That's why, when you see a crank offered with a 52 big ring, it comes with a 36 to go along with it.




I want to buy compact cranks. What do I need to do to set this up on my new bike?



You’ll need to lower the front derailleur by 10 mm and readjust the shifting. It’s also recommended to shorten the chain so you’ll have less chain slack with the smaller gearing. Otherwise, if you’re currently running a road double, there’s nothing new you’ll need to buy.




I am having trouble adjusting shifting on my compact cranks.



While a standard road front derailleur is designed around the 53/39 gear combination, we’ve had plenty of luck using Campagnolo or Shimano front derailleurs on compact setups. One suggestion that works for us is: instead of running the derailleur as close to the rings as possible, raise it up by a millimeter or two. This makes the gear change happen not quite as abruptly and reduces the chance of the chain derailing to the inside.




Will my FSA cranks work with my Campagnolo or Dura-Ace 9/10 speed?



Yes, they are compatible with all of the above. The primary difference between the various standards is the chainring spacing. In fact, this difference is so minute that Campagnolo and Shimano’s tolerances for 9 and 10 speed actually overlap each other. We’ve chosen a spacing that is an average of all four standards and which easily falls within the tolerances for Campy or Shimano – 9 or 10 speed.
 

jdog

Shop: Halter's Cycles
Shop Keep
This years 10 speed triple has a 52-39-30. Run that with a 12-25 and you should have all bases covered.

Sram has a 10 speed cass in an 11-26. Run that with a 34-50 and you should also have all bases covered.


In my mind the smaller big ring just feels less powerful. I know that the equivalent gearing can be achieved but somehow it feels different.


To really mess this up I just got a ton of rotor rings in today which can make a 50 compact feel more like a 52..

It never ends.


j
 
Last edited:

ChrisG

Unapologetic Lifer for Rock and Roll
In my mind the smaller big ring just feels less powerful. I know that the equivalent gearing can be achieved but somehow it feels different.
This is a real thing. It's a function of chain wrap and the attendant efficiency differences.

I think it's hard to argue against compacts for most riders, particularly those who ride the hills a lot.
 

anrothar

entirely thrilled
why not just concentrate on the genius of this design: http://www.whiteind.com/VBC.html compact and standard double all in one. this should be the new industry standard, and tulio and shozaburo should be resurected to slap all of their descendants upside the head for not thinking of it first.
 

Space Heater

Shop Owner / Employee
Shop Keep
I am running a 50/36T as well. It originally had a 34T on the inner ring and I was sacrificing wattage while my heartrate skyrocketed. Probably could have solved this by putting a 11-23 cassette on, but I went the route of a 36T with a 12-25 and I love it. I do miss screaming down the hills at 50 miles and hour but I have a wife and dog who depend on me.
 

jdog

Shop: Halter's Cycles
Shop Keep
i may be confusing compact and SS crank sets..

My compact are 172.5 and my SS are 167.5.

what are standard 39/53?

Your ss Cranks are 167's??:hmmm:

I have one SS with 175's and the other with 180's.


167 is mega short. Good for kids but that is about it.

j
 
Last edited:

Norm

Mayor McCheese
Team MTBNJ Halter's
I'm in my 52/12 combo quite a bit. I'd hate to drop to a 50. I agree that the triple is overkill though. As it is, I never drop below the middle ring (42) and I tend to wonder about the chain line when I'm climbing. I used the small ring when my chain broke last week and when I went up Schoolhouse Rd a month or so ago. Other than that, never.

It seems like the argument for compact, "If you're in the hills" is actually an argument for a triple.

But if I wanted to go double, are 38/50 and 38/48 my only choices for the 130 mm bolt? I assume the triple is a 130? Is it not worth the trouble? What of doughnuts?
 

ChrisG

Unapologetic Lifer for Rock and Roll
I'm in my 52/12 combo quite a bit. I'd hate to drop to a 50. I agree that the triple is overkill though. As it is, I never drop below the middle ring (42) and I tend to wonder about the chain line when I'm climbing. I used the small ring when my chain broke last week and when I went up Schoolhouse Rd a month or so ago. Other than that, never.

It seems like the argument for compact, "If you're in the hills" is actually an argument for a triple.

But if I wanted to go double, are 38/50 and 38/48 my only choices for the 130 mm bolt? I assume the triple is a 130? Is it not worth the trouble? What of doughnuts?
What gearing do you run on the back?

A triple is 130 for middle and big rings. The granny is smaller, not sure what it is off the top of my head. The triple needs a wider BB spindle to make room for the third ring, thus widening the Q factor.

A big bonus of the compact is that it allows a tighter gear spread on the rear. Steps of more than one tooth on the rear are much more significant on the road than in the woods when you're trying to maintain an optimum cadence.

I am a fan of the doughnut, btw.
 
Last edited:

Norm

Mayor McCheese
Team MTBNJ Halter's
I think it's a 12-25, maybe a 26 but I think I dropped the 26 when I picked up a cassette last time. I don't know that I'm at the point I notice the 1 versus 2 tooth difference, though this year shifting efficiency is much more prevalent than ever before.
 

PedalPaddles

New Member
I switched to compact with 50/34. I found myself switching back and forth between the two rings too often. I changed the 34 to a 36 and that solved the problem. I run a 12/23 for the Hopewell area (hilly) and a 12/21 for most flat riding. I have never run out of gears on the downhills. (this can be a function of being able to spin well at 150rpm cadence) Having one tooth increments in the back is a big plus on the road.

As a side note, I put a 12/27 cassette on my mtn bike and love it. The increments are closer and it's lighter.
 

jimvreeland

Endurance Guy: Tolerates most of us.
FYI...If you run a 11-21T cassette on a typical 50/34 crank...you end up with 1 higher and 1 lower gear than if you ran a traditional 12-23T and a 53/39...(low ends up as 1.619 compact-1.695 standard, high is 4.545 compact-4.416 standard)...I personally run a slightly different set-up with an 11-23T and a 53/38 up front, it ends up being just low enough to keep my wattage down on recovery days (I do commute over Washington Rock every day;))
 

monkey boy

Self-Imposed Exile
Just to chime in...
I live and road ride up in west milford. as well as dig around in JH
See skyline drive, westbrook road, otterhole, macopin, sterling forest, mt peter, ect,ect. all big a&$ hills. I have seen teams from all over the state training on the hills up here.
I have always rode standard gearing and never really had an issue. for the normal day to day rider a mile or two climb there isn't really a difference.

This compact trend came from the pro tour where you have alps type climbs that go on and on for miles and miles. that is where the compact makes a difference. over alot of time
Triple is to heavy, roadies are 10x the weight weenies that mtb riders are.

but ultimately as long as you are having a good time on whatever bike who cares?
 

jdog

Shop: Halter's Cycles
Shop Keep
Triples on roadbikes suck.

SRAM saw this and didn't even bother making their road groups in triple at all.

The only downside to triple is that with less teeth spinning in on the cass yo may wear out cogs faster.

This may be less of an issue with the new sram cass. The new cass is machined out of a block of steel that weighs 12 lbs before cnc work is done.

I had a clinic on the new RED group the other day and I was mighty impressed.
 

jimvreeland

Endurance Guy: Tolerates most of us.
AGREED!!

We also got the Red demo...Stuff is pretty sick, not enough to make me switch out my Dura-Ace just yet...Even though it's a LOT lighter!!
 

Norm

Mayor McCheese
Team MTBNJ Halter's
I have a triple on my road bike and I could give a rat's butt what it weighs because it's a training bike not a race bike. To that end, I'm filling my frame with lead next week.
 

jdog

Shop: Halter's Cycles
Shop Keep
AGREED!!

We also got the Red demo...Stuff is pretty sick, not enough to make me switch out my Dura-Ace just yet...Even though it's a LOT lighter!!
I am going to do it .. I think.

I had the Force for a bit and I sold it whe i had a chance. As much as they say you don't need it i do think the 3rd trim position on the Red shifters will make a difference.

I would say for most folks a full Red Group is silly. mix and match is the way to go.
 

monkey boy

Self-Imposed Exile
SRAAM is the schizznit! I have a Force / rival mix on my road bike and the stuff is so much nicer than DA. crisp shifting, clean look, and tough as nails.
They really bridged the gap between campy & shimano.

If anyone wants one of those sweet new red casetts test ridden I would be glad to accept:D
 
Top