A question of gearing

[Ti Designs]

In coaching riders I find that the hardest part is explaining things in terms the rider can understand or relate to. I happen to work with Scott Fader (at some large bike shop in Belmont MA) who should have been a school teacher had he not turned bike bum. We started talking about gearing and how most riders shift way too often. When he starts a coaching session on the bike the first thing he asks is "what gear are we using today?". The rider has no idea what he's talking about, there are 9 or 10 gears back there, all controlled by these things on the handlebars - there's even a set of gears on the cranks! he goes on to explain that it's like training a dog, gotta show it that you're the boss, not the other way around. If every time it gets harder or easier to pedal your legs tell your brain to shift, the dog is taking you for a walk. If on the other hand your brain says "OK, more resistance, tell the legs to work harder", then your brain is in control - and you shift only when your brain tells you that you need to.

I had this in mind when I started looking at some of the threads about compact cranks or triples. My goal in setting up gearing is much like my goal in setting up a custom bike - everything near the center of the adjustments to start with, that way there's room to move in any direction. In gearing that means the gear I use the most is somewhere in the center of the cassette, in the little ring. That way I have at least 3 gears higher or lower without a front shift, and if I want to go faster I can jump up into the large ring or just hold onto Scott's seatpost. I run a 42 inner ring most of the time because my normal cruising gear is a 42/17, I switch out to the 39 for hillier rides which still puts my average gear in the center.

So I looked at some of the compact cranks running 36's and 34's. Yeh, that gets you a low gear, but where does that put the cruising gear for flat roads? The 50 puts you most of the way to the left of the cluster, it's an ugly chain line and needing a smaller gear means a front shift and a whole lotta rear shifts. The 34 puts you in the smallest cogs and probably has the chain hitting the side of the large ring as it goes by. The triple makes a little more sense to me in that it's a double with an added range should you need it.

So why run what you run? And if you say it's for the weight savings I expect you to be below 8% body fat...

[Matt Barkley]

Yep Compacts suk' for the flats. Cross-chain hell. :beer:

Boston area 42 inner 52 or 53 outer 12x21or23.
Hillier area 39 inner 52 or 53 outer 11x23/24/25 (allows better crosschaining in the 39 on flats - you are "up" one gear without being "over" one more gear) - Get it? :beer: - Matt

[davids]

Ed,

When I buy my next bike, you're the guy I want to work with! :beer:

[Too Tall]

Honestly, it was an experiment to see if this gave me more higher gears in a close ratio to shift. It seemed pretty useful at first for very hilly terrain and than I got critical and actually paid attention to my hill repeat times / ratios used etc. and found that if I had an easier gear I USED it and guess what? I went slower. For race oriented training it's a dog. For racing...it's a dog largely because I'm in a different gear than everyone else which is a little not alot vexing in a tight pack. No big whoop. It was wonderful for a mtn' TT I did last yr. Way sweet to have more than one or two gears to work with on the steep pitches.

I have little interest in more Q and changing Brifters to accomodate a triple...it's not about weight.

For cruising it is just as you say, I'm always looking for a front ring shift or have a bad chain line. It's a PITA.

My compact crank got yanked and awaits a new steed. Luckily it's 110 bcd :cool: so it's still a super useful crank.

[Vancouverdave]

Why run what I run? Front 48/38/26, rear 12-25 8 speed, because I'm slow enough uphill that slugs (real ones, the ones that leave trails on the pavement) pass me climbing. I run a triple because of using a bike with 44cm chainstays that minimizes sharp chain angles--with a short bike I'd be using something like 12-34, 38/48.

[zap]

TT, not to mention it was hard riding behind you when you were using your compact. Interesting experience when riding with someone for years, then they switch to compact and the ratio's don't match up. :eek:

[Carpe Diem]

If I can´t get to the top of a hill using my standard 39/53 - 11/23, then I keep coming back until I can.
If the hill is not viable on a racer, I´ll come back on my mountain bike.

[Birddog]

I've been running a compact 50/34, 12/25 for several months now. Initially I liked it when I was using it out in NM in the mtns. Back in the flatlands, I've grown to dislike it for all the reasons others have given. It's like my father used to say about manual transmissions after he switched to an automatic. "I hate playing a tune with the stick on the tranny" You have to make too many double shifts for me. I'd maybe use it in the mtns again, but really a custom 12/28 or 29 would probably be as good or better for me.

Birddog

[Dave]

If your terrain is easy enough and/or you have the power to carry only a 42/23 low (same as 39/21). There would be no reason to switch to a compact crank, other than possible weight savings. In that case, a rider would need 49/36 with an 11-21 instead of a 53/39 with a 12-23.

It also makes no sense to me to alternate between a 42 and 39 inner rings for different rides, since the 39 has all the same ratios, just using one cog smaller. Unless there's something magic about a 42/13 (87 inch gear) that's not available with a 39T (unless you're using a 11-23 cassette), a 39 makes more sense to me. Why give up gearing range if you don't have to?

I also don't agree with the idea that you should not shift often, unless you're on a training ride, intentionally performing a workout intended to overstress that leg muscles and build strength. If you're on a long ride, stretching the limit of your endurance or in a race, the goal should be maximum efficiency to minimize fatigue and that will occur in a narrow range of torque and cadence. Frequent shifting as the terrain changes will keep the rider in the most efficient range. Ignoring the need to apply heavy torque and a slowing cadence or the opposite, spinning like crazy and getting nowhere, isn't efficient.

All that said, I carry a range of gears that is sufficient to handle anything I might encounter, while remaining seated. If I chose to stand on a steep section, I want it to be MY choice, not the bike's (due to a lack of low gears). I also don't want big jumps between cogs (no MTB cassette for me) and I don't want 4-cog shifts after changing chain rings, which requires a double pump of the shift lever (no wide chainring spacing). The 53/39 was designed to limit cog shifting to a maximum of three, which either STI or ergo levers can accomplish with a single sweep of the shift lever. Ergo levers can also shift 3 cogs smaller (and more) with a single push of the thumb button. To meet all these requirements, a 53/39/28 triple with a 12-25 (10 speed) does the trick for me.

[Ray]

I ride what I ride because:

I'm not racing and, while I like to go hard on some rides, speed isn't the emphasis. And I live in a very hilly area. Not mountainous, but lots of steep little buggers.

Therefore, I like having low gears.

I agree that it's easy to get into the habit of shifting too often, but I'm comfortable at a fairly wide range of cadences (I ride fixed a lot, which contributes to this).

So, I frequently use an mtb rear cassette with big jumps - when I finally do get around to shifting, I want to KNOW I'm in a higher or lower gear. And I use a compact with 48-34 rings.

I rode a 53-39 with a 13-26 my first year and I got up all of the hills I get up today with my compact. But I worked like a dog and didn't enjoy the riding that much, because I lived in something approaching fear of the climbs. I got stronger, but not enough to actually make it fun.

With a 34-48 and a 12-27 I use every gear on the bike. With a 12-34, I almost never use the 30 or 34 cogs in daily riding, but I spend a good deal of time in the 34x26 on the steeper climbs. I don't mind having the 30 as a bailout. And having those two big cogs brings everything up to a 26 into the range of the big ring. So I spend a LOT of my time in the big ring, with very few crossover problems. My cruising range is comfortably in there and with a useable 48x26, I do a lot of climbing without changing chainrings also. But when the climbs get steeper, I have all sorts of low gears to bail out to in the little ring. On tough centuries and week long tours, I even the use the 30 and 34 on occasion.

This setup works great for the kind of riding I do in the terrain I ride in. If I lived in the flats, I can't imagine I'd have more than one chainring, but I'd probably ride my fixed most of the time anyway except on really windy days.

All of this would be out the window if I raced, but I don't think racers are the market that the compact crank makers are trying to appeal to for the most part anyway.

-Ray

[Ti Designs]

If your terrain is easy enough and/or you have the power to carry only a 42/23 low (same as 39/21). There would be no reason to switch to a compact crank, other than possible weight savings. In that case, a rider would need 49/36 with an 11-21 instead of a 53/39 with a 12-23.

While the compact crank with the 11-21 looks like the same range as the standard double with a 12-23, the gear chart isn't telling the whole story. The smaller the cogs get the larger the percentage of change gets. While I've used an 11 on the way down a few mountains, I've never been able to use one in a sprint, the step up in gear is just a bit too large for me.

It also makes no sense to me to alternate between a 42 and 39 inner rings for different rides, since the 39 has all the same ratios, just using one cog smaller.

That's simple to explain. I live near Boston, the hills around here don't require anything wider in gearing for me, so I run a 42/53 with a 12-23. When I go somewhere that has bigger hills (dare I say mountains?) I want more spread to the two chainrings - what goes up must come down!!! Going up with the 39 means my chainline is still somewhat straight, going down my cassette goes to 11...

I don't have any personal favorite gears, to be honest I don't really care about the numbers. I ride a fixed gear half the year, people ask me what gear I'm in, I say "this one".

I also don't agree with the idea that you should not shift often, unless you're on a training ride, intentionally performing a workout intended to overstress that leg muscles and build strength.

The basis for having people shift less often and gain a greater torque range is mostly group riding. In working with groups I've always noticed that the people who have a wide usable RPM range and more power to deal with have an easy time of it while the ones who shift a lot get dropped. Once my riders have learned how to put the power to the pedals instead of shifting all the time I have to teach them to spin for the first part of any race or ride, saving their power for the end. There's no down side to having more power.


I have little interest in more Q and changing Brifters to accomodate a triple...it's not about weight.

Hmmm, the Q factor is a good point. In doing fittings and checking knee alignment I have noticed narrow people with triples do seem a bit outboard. I guess in some cases a compact double would make some sense - thanks for pointing that out.

[BarryG]

I run a 42 inner ring most of the time because my normal cruising gear is a 42/17

I'm going through the decision of whether to equip a new bike with compact or triple. My proposed compact gearing would initially be 48/34 13-29 (will put on a 12 later if I decide I really need the high gear). The 48/19 comes in near your 42/17 in terms of gear inches and central location, with ample gears above and below.

The compact will have a wider range cassette than the triple but cover about the same range on its single big ring as the 52/42, by having slightly wider spaced cogs. If you need closely spaced gears on the flats, this setup wouldn't work for you. But I find it an attractive setup (on paper anyway) to cover a wide range with a double.

Barry

[jeffg]

what the cross-chain difference is between a 48/34, 11-23 and a 53/39, 12-27. I ask because I notice no difference between my 48/34 and 53/39 setups when theyare running equivalent gear ranges. A 16 tooth jump will necessitate more shifts, but that is another matter.

My own view is that a tightly spaced cassette and standard gearing is great for those of us that can do it, but that a compact offers some great options. I got a PMP crank for my Legend and am very pleased. The swap was much cheaper than a triple upgrade for DA at the time (almost $800 versus the $350 I spent -- strong dollar then), and I can get relatively standard gearing for the flats by just swapping cassettes.

The downsides of the large jumps is why I still have a 53/39, 13-29 on my Campy bike. My solution will be to get two sets of rings. 50/36 for normal and 50/34 for the Dolomites and Cal Triple Crown events.

Triples mean wider Qs, new FD/RD, crank/BB, etc. For a Campy switch it would just be crank and perhaps FD. It's not necessarily the best or the only option, but it's a good one ...

[Dave]

"While the compact crank with the 11-21 looks like the same range as the standard double with a 12-23, the gear chart isn't telling the whole story. The smaller the cogs get the larger the percentage of change gets. While I've used an 11 on the way down a few mountains, I've never been able to use one in a sprint, the step up in gear is just a bit too large for me."

I think you're confusing the 49/11 that I referred to with a 53/11. The 49/11 is less than 1% different than a 53/12. For all practical purposes, it's the same gear. You are right that with a compact crank, every gear ratio will use a smaller cog and the percentage difference between an 11 and 12 is larger than a 12 to 13 shift, but it's only .7%. Even at a high cadence, we're talking less than 1 rpm.

I agree that the idea of "favorite gears" is silly. Even if you rode the same route on every ride, the differences in wind speed and direction can easily change the required cog by one or more, at the exact same point in the ride. A 42/17 might be great one day and way too high or low the next.

"The basis for having people shift less often and gain a greater torque range is mostly group riding. In working with groups I've always noticed that the people who have a wide usable RPM range and more power to deal with have an easy time of it while the ones who shift a lot get dropped. Once my riders have learned how to put the power to the pedals instead of shifting all the time I have to teach them to spin for the first part of any race or ride, saving their power for the end. There's no down side to having more power."

Remember that power is simply torque times cadence. From my personal experience in group rides, those shifting a lot may not always lack a reasonably wide torque range, they may simply lack the power to maintain the speed being ridden (by more powerful riders) and are merely searching for a gear combination that will allow them to keep up. They may also be smart enough to know that riding with excessively high torque will burn out their legs quickly. Obviously, more powerful riders can ride faster and perhaps shift less, since they aren't being taxed as heavily.

Everyone's not the same either. There are those who can get my mashing big gears, while other's can't. I see a lot of folks trying to climb the Colorado mountains who apparently don't understand the difference between power and torque. While they can make it up a mountain pedaling a 39/23 at 60 rpm, they often get passed by a rider using a lower gear at a more efficient 85 rpm. If you don't carry a gear that's low enough to maintain a high level of efficiency, you won't complete a climb as quickly.

[mad_mark]

But, I'm a child of the 70's, when my then coach would have me doing LSD on the flats in a 42 x 16t. Call it ingrained, but even today I have trouble with a 39t, even though a gear chart tells me 39 x 15t is the same, the gear chart can't seem to tell my legs that. So I use a 12-25t 10s with 42/53t rings and sit happily in the 42 x 16t most of the time. I have noticed though that I'll put it in the 53 x 17t and go a couple of mph faster (so alone I'm doing average 18-19mph in 42 x 16t, with others, 53 x 17t and 22mph) when riding with others, who all have a 39t, and just sit in the 53t on the flats (normally in the 17t as well). Why that became the "norm" (it is around here - SoCal) I don't know, but I suspect it has to do with the 39t. I'd even bet that if you fitted all those bikes with a 42t, they'd be in the 42 x 16t on the flats (I'm thinking of PCH). If I ride a hilly event (a Century or Double), then I do fit a 39t, but I'm always riding with others (so in the 53t on the flats), and the drop to a 39 x 25t allows me to get up anything pretty much. I'm lucky enough to have a couple of bikes, so the light "toy" has a 39t permanently, and the regular two bikes have 42's.

I was looking at my regular bike late last night, the 17, 16, 15t all show black teeth, the others are all clean still (after a month of use), which bears out my mainly flat riding. Any climbs I have done, it's been in a 42 x 17t as the lowest gear.

If I only had one bike, I'd change chainrings for when I wanted a 39t, the normal ring would be a 42t. That's how ingrained it is.

Mark.

[Matt Barkley]

I'm with Mark on this one. Something about that even gearing..... 42 is so nice! - so is 52. When everything went 39x53 a few years ago (I think around 1994) things have never felt the same... Cheers to all! :beer: - Matt

[JohnS]

My problem has never been with the small ring. Being a spinner, I never used the 53. Since I went to a 48t Stronglight, I use my big gear a lot more.

[Peter]

I run a 39x48 with a 12x21 on my road bike.

I run a 42x50 with a 13x25 on my commuter.

I pick my low gear on either bike by going one gear lower than I know I'll use on a regular basis. It's a bail out gear/bonk gear, whatever. On my commuter, it's available if I'm hauling a 15lb. load.

For high gear, I go one gear higher than the gear I'm capable of sprinting in. While I may spin out sooner on downhills, I've never been dropped due to lack of gearing on the descents.

On an average ride, if I weren't utilizing ALL the cogs on my cassette, less the bail out gear, then my gearing is wrong. I think most cyclists have no business with this 53x12 stuff and if they think they need this, then why aren't they all signing pro contracts?

[jerk]

the jerk has talked about this before....but the slow jerk likes having a 42 tooth chainring and a 50 tooth chainring with his 11-21 or 11-23 cassette....he's a stupid rouler with long cranks and lives in the flatish rolly eastern new england area....and pretty much rides alone so it works fine...the jerk tried the 50/36 for a while....with disasterous results....never shifted out of the 50 except twice...once the guy drafting the jerk crashed into him due to the rapid decrease in speed and the other time.....well, it was a little better but still stupid....50/11 is still way big for this fat slow jerk.

jerk

[Climb01742]

for me, smaller than a 39 (particularly a 34) on the flats leaves me under-geared too often and spinning like a fool. and a 53 leaves this wuss over-geared too often and cranking my biomechanically challenged legs way too much. for me, a 50 is pretty sweet and i'd be curious to try a 48, 'cause i like a pretty high cadence. but i'm pretty clueless about gearing. i just ride what feels right...which means it's probably wrong.

however, scott fader told me about his fewer-shifts thinking this past fall...and so far it's helped my training rides a lot.

finally, ray from phillie--your post made a ton of sense. plus, it was a gearing post my tiny mind actually understood! :rolleyes: i am curious about a 48.

[Ray]

finally, ray from phillie--your post made a ton of sense. plus, it was a gearing post my tiny mind actually understood! :rolleyes: i am curious about a 48.
It's worth a try, but keep in mind that for the combination I talked about to work for you, you can't mind fairly large gaps between gears and it helps a lot to be slow! :cool:

If it doesn't work, just fast for about 5 more days!

-Ray