Mid-compact gearing

[kgreene10]

I'm sure that this has been discussed to death, but I can't seem to find useful threads with a web search.

I have always used standard 53-39 rings. I train with a 12-27 and do most of my racing in Austin on that cassette or an 11-25. But I also travel sometimes for hilly races and my cadence gets pretty low on serious climbs in my 39-27.

Now I'm thinking of making the move to DA 9000 (seems like 11sp is all but inevitable for many of us, so why not sooner rather than later?). I'm intrigued by the ability to get a 52-38 or a 52-36 on their new crankset. But I haven't worked out the gear-inches across the three sets (lazy, I guess) or thought through the other plusses and minuses.

Has anyone gone from a standard to a mid-compact and can comment?

[John H.]

What kind of cadence do you ride?
I find that riders who tend to spin like the compact or mid compact- riders who tend to ride bigger gears tend to not like the compact.
They feel weird when they are in a smaller than usual gear on the small ring.
Seems to me a 36/52 with an 11-25 would give you the best of both worlds in terms of the low gears that you need sometimes and a cluster with pretty small jumps. 11-25 goes 11,12,13,14,15,16,17,19,21,23,25.

[kgreene10]

Good question -- the computer shows 91 rpm avg after almost every race unless it's really hilly and then cadence drops.

[John H.]

91 is reasonably high- I think 36/52 would suit you.
Beauty of that new Shimano crank is that you can run any of those gear combos. 53/39, 52/38, 52/36, or even 50/34.

[kgreene10]

91 is reasonably high- I think 36/52 would suit you.
Beauty of that new Shimano crank is that you can run any of those gear combos. 53/39, 52/38, 52/36, or even 50/34.

Yeah, that's what I find appealing about the 9000 crank too, though the absence of aftermarket rings (for the time-being) means that switching sets is a costly endeavor.

[John H.]

True, right now I have a GXP compact SRAM crank where I run Praxis 34/50 and sometimes 35/52- Their rings are nice and way less expensive.
But I am also eyeing a 9000 crankset.

[Chance]

Yeah, that's what I find appealing about the 9000 crank too, though the absence of aftermarket rings (for the time-being) means that switching sets is a costly endeavor.

Of the four available chainring sizes available (excluding the even larger ones for TT or small wheel bikes), only two could be considered “mid compact” – the 52/36 and 52/38. Obviously the 53/39 would be considered standard and 50/34 compact by most people. Will assume you are asking about 52/36 and 52/38 only.

You mention that cost could be high to convert, but if only between these two, wouldn’t buying an extra relatively inexpensive inner ring be all you need to switch back and forth? Not sure how they did it (without looking up part number) but it seems logical that Shimano would have kept the same 52T outer ring and then matched two different inner rings to it. Doesn't seem like that in itself would be "that" costly.

[Chance]

My two cents on this particular gearing issue: Not sure either mid-compact does much for you. May help a little based on your data and criteria, but not much.

The most important crankset variable (assuming you can get the right gearing range you need) is the gear ratio between small and large ring. In my opinion that’s what differentiates standard from compact more than anything else. Percent wise it’s a big jump between 34 and 50 when compared to 39 and 53.

In that light, 52/38 is very similar to the standard 53/39. Personally see them as nearly interchangeable. On the other hand, a 52/36 is closer to a 50/34 when it comes to the wider ratio going from small to big ring. It’s slightly closer, but not by much (more or less the equivalent of theoretical 49/34 shifts). Bottom line is that it would be a bigger jump than you are used to with standard 53/39 gearing; and that’s one of the reasons many don’t like compact gearing.

If you decide to go with 52/36 and 11-25 cassette as recommended by John, your low gear of 36/25 would be essentially the same as your present 39/27. It would therefore not help you at all with low cadence on big climbs. The new 11-25 Shimano 11-speed cassette has nice tight mid-range ratios but you’d be paying for it with much wider ratio at the front than you are used to. Personally, that would not be my first choice.

Would have suggested you look at an 11-28 cassette instead to meet your climbing needs but Shimano screwed that up royally in my opinion. They seem to have removed the 16T cog in order to keep gearing closer at the very extreme of the large-cog range which doesn’t get used as often. Very disappointing. The idea of an 11-speed cassette without a 16T cog seems crazy to me at a personal level.

And if you consider a 12-28 cassette (which puts the 16T back in) to improve cassette gearing then you’d have to go back to standard 53/39 rings, or at least 52-38 which is fairly close. Either way it’s not going to improve your total gearing range very much. Not saying a 38/28 isn’t better than your present 39/27 for climbing, but it’s not a quantum leap if you are spinning too slowly at present.

You could always consider a true “compact” with 50/34 rings and an 11-25 cassette. In your case the numbers work out better than if you go with a 52/36 which is nearly as wide anyway. There may be other combinations, but in your case it seems to come down to whether you’d value a 16T cog in the cassette more or less than wider ring ratios. Based on your general requirements it doesn’t seem like you can have both.

• 11-23: 11-12-13-14-15-16-17-18-19-21-23
• 11-25: 11-12-13-14-15-16-17-19-21-23-25
• 11-28: 11-12-13-14-15-17-19-21-23-25-28
• 12-25: 12-13-14-15-16-17-18-19-21-23-25
• 12-28: 12-13-14-15-16-17-19-21-23-25-28

[kgreene10]

Thanks for your well-reasoned suggestions. Really helpful!

[oliver1850]

Sounds like Chance is ready for 12 speed. :)

I know lots of people really miss a 16 cog in cassettes that don't have one, but I don't think it's as important in rolling country, as the pack is going to spend less time at that comfortable cruising speed as the terrain changes. Lacking a 16 would make you pedal about 6 rpm slower in the 52/15 combo or 6 rpm faster in the 52/17, compared with the current 53/16. I'd think one or the other would still be in your range of cadence, at least for short periods of time.

I would think the 52/36 with the 11-25 would work well for you everywhere but where the real hills are. When you go to the hills, use the 11-28, or perhaps you could run the 34 ring successfully with the 52. Perhaps the 9000 crank will explode with a non standard ring combo, has anyone risked this experiment?

[Louis]

Whenever I have this sort of question I create an Excel spreadsheet and see what the numbers say. Combine that with a list of the available options and knowledge of the gear combinations where you tend to spend most of your time, and you ought to be able to figure out what will work best for your type of riding.

[Ralph]

I use a triple for extreme hilly areas, or long climbs, but most of my riding is done on a double....a Campagnolo 39-52. It's so easy to change cassettes for any extreme riding you might do, I don't see why you wouldn't use whatever works for most of your riding, and do a cassette change for something special. Set it up right, with some lattitude for bigger cassette change, and cassette change is simple. I mostly ride a 13-26, but can switch in a 12-30 in just a couple minutes. Put bike on repair stand, slide old cassette off, slide new one on, put wheel in, check if pulleys line up and cable tension right, and away I go. You are a strong rider, and change you are talking about isn't very much, so don't see the big deal. Just stay with the 39-53 if you wish. Or a 38-52. Get some extra cassettes. Gear the bike for each race (just like a race car).That's all you need to do. That's what I would do if I rode as good as you.

[Chance]

Sounds like Chance is ready for 12 speed. :)

.......cut..........

Nah. A 3X9 already mirrors a future 2X12 when used with tightly geared cassette, and it’s been available for years.;)

Also, my preference is towards Ultegra over Dura-Ace. Previously purchased a 10-speed Dura-Ace group but didn’t think it was different enough to warrant the added cost. So for now Ultegra will do nicely. The trickle down technology has a lot of value.

Having said that, and knowing that new 11-speed Ultegra now offers 11-32 cassette, my choice would be to go with the 52-38 and 11-25 cassette for everyday close ratios, and then have an extra wheel ready with an 11-32 cassette for demanding climbing days. When the road goes vertical the 16T cog isn’t all that important to me anyways.

[majl]

Anyone know the BCD on the Campy semi-compact 52/36 cranks? Are the rings interchangeable with their standard or compact cranks or neither?

[kramnnim]

Anyone know the BCD on the Campy semi-compact 52/36 cranks? Are the rings interchangeable with their standard or compact cranks or neither?

Should be the Campy version of 110 BCD, compatible with Campy 50/34?

[marques]

One question I have about mid compact rings is if there is any flex?

I need new rings and have a 110BCB Force compact crank. I'm thinking of 52/36 though a few riders I know say that mid compact rings can flex and its not a good idea.

I would be leaning towards Praxis rings...

[oldpotatoe]

Should be the Campy version of 110 BCD, compatible with Campy 50/34?

Same cranks, just different rings..110/112 BCD, compatible with all Campagnolo carbon compact cranks..all with a hidden arm, all now.

[josephr]

I'm used to riding a 52/39 with a 12-25 in the the back. New bike this spring came with a compact crank with the standard 50/34 and a 12-28 in the back. After 100 miles, I switched the back out to a 12-25 and changed the front small ring to a 38. Haven't looked back. I don't know how hilly it is in Austin, but I'm in Birmingham and we've got some decent climbs around here. The only time I wish I had something lower is on one hill where I'd probably need a triple anyway.
Joe

[rice rocket]

One question I have about mid compact rings is if there is any flex?

I need new rings and have a 110BCB Force compact crank. I'm thinking of 52/36 though a few riders I know say that mid compact rings can flex and its not a good idea.

I would be leaning towards Praxis rings...

People say a lot of things.

50T ring is 25" circumference, or 3.97" radius.

Subtract the BCD / 2 = the distance from chainring bolt to edge, which is 1.81" from chainring bolt to the inner edge.

That distance on a 52T chainring is 1.97".


You think you're really going to feel the .16 inches (4mm) in extra radius as flexy?

If so, I've got a bridge to sell you.

[Uncle Jam's Army]

One question I have about mid compact rings is if there is any flex?

I need new rings and have a 110BCB Force compact crank. I'm thinking of 52/36 though a few riders I know say that mid compact rings can flex and its not a good idea.

I would be leaning towards Praxis rings...

I run 52/36 rings on my Red 110bcd crank and zero flex.

[Lovetoclimb]

Who is using Campy 11s rings in a 52/36 110BCD set-up? If so what rings have you had good experience with?

[firerescuefin]

Who is using Campy 11s rings in a 52/36 110BCD set-up? If so what rings have you had good experience with?

Praxis....done.:)

[PaMtbRider]

Who is using Campy 11s rings in a 52/36 110BCD set-up? If so what rings have you had good experience with?

I'm using a stock 2013 Chorus 52/36 crankset. I have noticed zero flex. FWIW I weigh 175

[Lovetoclimb]

I'm using a stock 2013 Chorus 52/36 crankset. I have noticed zero flex. FWIW I weigh 175

I can not find Campy rings for sale individually in the 52/36 combo. Seen a Super Record 52 ring, but I can't believe SR rings are spec'd on a Chorus crankset . . .

[thirdgenbird]

91 is reasonably high- I think 36/52 would suit you.
Beauty of that new Shimano crank is that you can run any of those gear combos. 53/39, 52/38, 52/36, or even 50/34.

Yeah, that's what I find appealing about the 9000 crank too, though the absence of aftermarket rings (for the time-being) means that switching sets is a costly endeavor.

Agreed. So far this is only an advantage in theory. I just looked, and some vendors are selling a 9000 big ring for $250. In today's market it would be cheaper to buy a used record compact crankset than it would be to swap rings on a dura ace 9000 crankset.

I can not find Campy rings for sale individually in the 52/36 combo. Seen a Super Record 52 ring, but I can't believe SR rings are spec'd on a Chorus crankset . . .

I am pretty sure the rings are the same

[SpokeValley]

Should be the Campy version of 110 BCD, compatible with Campy 50/34?

According to their charts, yes.

https://docs.google.com/viewer?url=http%3A%2F%2Fwww.campagnolo.com%2Frepos itory%2Fdocumenti%2Fen%2FUltra_torque_crankset_UK_ 06_12.pdf

[nathanong87]

You think you're really going to feel the .16 inches (4mm) in extra radius as flexy?

If so, I've got a bridge to sell you.

u obviously dont know the wattz i dump.

but btw what bridge?

[SpokeValley]

I'm using a stock 2013 Chorus 52/36 crankset. I have noticed zero flex. FWIW I weigh 175

Ditto here...stock Chorus 11s, 52/36. I weigh 195.