The Rise of the Compact Crank (aka "The Death of the Triple")
May 19, 2008 · 07:00 AM · permalink
In the road bike market, you may have noticed that nearly every manufacturer is offering bikes with compact double crankset, ie road cranks with a 110mm chainring bolt-circle typically mounting a 50 and 34 tooth chainring combination. Bike companies have toted the compact double as the ideal way to gain most of the benefits of a triple crank (namely better low range gearing) while having a better chainline and lower weight. This is mainly true, but before you decide that the compact double crank is right for you, you should understand its real advantages for you as a user as well as the motivations bike companies have for selling it to you.
Ultegra SL standard double (top) and compact double cranksets. Notice the size difference between the compact double’s rings.
First, let’s back up a few decades to the days when Campagnolo Nuevo Record was the king of component groups. Back then crankset dimensions generally were 144mm bcd (bolt-circle diameter), and typical chainrings were a 52/42 tooth combo. On the other hand, freewheels of that era were usually 6-speed units. A tight ratio for flatland racing and criteriums might be a 13-19 straight block, meaning single tooth jumps between gears, while a touring cluster might be 14-28. Racers would always prefer freewheels that offered the smallest jumps between gears while still offering the lowest gear necessary for a given race course. The small jumps allow racers to stay at their most efficient pedal cadence as much as possible. Non-competition riders would generally prefer wider range clusters, since they wouldn’t have the luxury of a team mechanic setting up their bike specifically each day. Having a broader gear range gives those riders more flexibility for widely varying terrain.
You’ll notice that with a 6-speed freewheel, to have close jumps between the gears (“close ratio”) you must accept a narrow overall range. That’s why the 52/42 chain combination made sense: the ten-tooth jump between the rings creates a useable overlap between the gearing combinations. This would change over time, and when 7-speed became firmly established, most manufacturers moved to a crank with a 130mm bcd (or 135mm for Campagnolo) that allowed a 39 tooth inner chainring (though racers stil preferred a 42 tooth ring). Combined with a 53 outer ring, every rider could take better advantage of the extra cog in the cluster.
Seen above: Regina America six-speed freewheel 13-19 and a Shimano Dura Ace 11-23 ten-speed cassette.
Later still the industry moved to 8, 9, and today’s 10-speed cassette style cog clusters. A cassette construction, wherein the cog clusters slide onto a ratcheting body integral to the rear hub, also allows an 11-tooth cog, which was not an option with freewheels. Now a racer’s cassette choice might be an 11-23 or 12-25, and a touring rider can have a 12-27 or 13-29 while still having plenty of single-tooth jumps within that range. Thus, even today’s narrowest overall range ten-speed cassette is still significantly broader than a six-speed straight block of 13-19 while still maintaining mainly single-tooth jumps.
Right about the time that nine-speed drivetrains were becoming the standard for road bikes, road bikes enjoyed renewed sales presence, particularly at the high-end. Call it the Lance Effect or whatever, people were willing to shell out cash for high-quality stuff. And it wasn’t just young racers who wanted the good stuff. Shimano and Campagnolo began offering triple cranksets in their top-of-the-line groups to tap into the disposable incomes of touring riders and older riders either new or returning to the sport.
Triple road cranksets were/are structurally akin to the existing double cranks. Usually the third chainring is a 74mm bcd mounting inboard of the other two chainrings. The right triple crankarm is often minimally different than a double with the left being identical; the width of the bottom bracket spindle is greater so that the 74mm innermost ring is far enough away from the from the seat tube to sit properly in the front derailleur’s arc. Triple cranks require special derailleurs and often front shifters. A matching rear derailleur with longer pulley wheel cage accommodates the increased chain slack caused by the wide range between the chainrings. The front derailleur of course needs to deal with the increased swing across three chainrings as well as the innermost ring’s tiny diameter. Depending on the design, component manufacturers might choose to create a modified front integrated shift/brake unit specifically for triple (ex. Shimano Dura Ace). Initially the triple cranks had 52/42/32 chainring set that had almost become a standard combination choice, but eventually a 53/39/30 set became the preference. This combo is exactly a racing double’s 53/39 with an extra chainring (wags will call it a “granny gear”) thrown in.
So, the market had finally reached nirvana: he-man racers got doubles, and a triple crank solved every other problem. Simple, yes? But then on the heels of the new 10-speed drivetrains came the compact double crank featuring 50/34 tooth rings.
Though double cranks with 110mm bcd had existed in the past, they were never really common for road bikes nor did they have the 16-tooth jump between the rings typical of today. An important hurdle to overcome was chainring design that would allow smooth shifting with the chainring size difference, which is greater in the modern compact double than ever before. Sophisticated ramps and pick-up pins (and sometimes compact specific front derailleurs) were necessary to help lift and guide the chain during front upshifts. Shimano had been an industry leader in this technology going back a decade or more, but another company beat them to the punch in marketing similar techniques in a compact double.
Starting about 2002 or so, FSA made huge gains in the OEM market as well as the consumer aftermarket because of their innovative carbon cranksets, attractive pricing, and range of product. At the time of their compact double crank introduction, their modular chainring spider allowed them to easily adapt from existing standard double and triple production.
Seen here clockwise from top: Dura Ace 12-27 ten-speed, DA 11-23 ten-speed, and Regina America 13-19 six-speed.
Initially the compact double was considered a special application item, a tool for a hillclimb. This concept was cemented by Tyler Hamilton’s success with an early FSA compact crank during the 2003 Tour de France. A compact double had the chainline and narrower pedal stance of a standard double but almost the same low gearing of a triple crank because the compact’s 34 tooth inner ring split the difference between the two smaller rings of a triple. And a compact double could be lighter than either of the other two options. For racers, the compact double crank made great sense if the race was primarily uphill, but the uphill time trialist segment of the market is very narrow indeed, not enough to seize the OEM market. As much as anything else, the ease of marketing and producing complete bikes with compact doubles would be the reason these cranks are everywhere today.
It’s a two-fold reason. Component manufacturers would rather offer compact double cranksets instead of triples. Even if they could produce a triple version of a standard double with minimal changes to tooling (ex: Shimano Dura Ace 7700/7703 nine-speed and 7800/7803 ten-speed double/triple cranksets), the complexity of producing triple shifters and derailleurs to match far outweigh the cost developing the molds or dies for the compact crank. And for companies offering complete bikes, they know that they can often get away with offering road bikes only with compact cranks, particularly in the entry- to mid-level segments. Reduced variation means easier stocking, which leads to better profitability.
Three years ago, this was more disagreeable to me. At the time, cassette ranges for road bikes did not allow the compact double to properly shine. A compact double needs an 11 tooth start cog for most riders in not-so hilly areas, but in the past most cassettes with an 11 were narrow range with a 21 or 23 tooth bottom end. That didn’t really give much more low end than a 12-27 with a standard double. Now that 11-25 or 11-26 are more common, compact doubles are approaching the overall range of triple cranks. And in 2009, Shimano is introducing an 11-28 cassette in its Dura Ace line, bringing the gap down even more.
However, the downside is that the triple crank is being demoted from top of the line offerings. Shimano’s top-of-the-line Dura Ace 7900 next year gains a “DA” branded compact crank but drops the triple offering. Campagnolo has eliminated triple derailleurs branded to match their upper-end component groups. Even more telling, Campagnolo has yet to indicate that they will develop a triple version of their Ultra Torque style cranksets. And though only in the road market for two or three years, SRAM doesn’t even make a triple crankset at any price point.
Who suffers from this? With the newly expanded cassette ranges, compact cranks are more capable than ever, but I happen to wrench in a shop in a hilly area that caters to special niches in the high-end. Sometimes a 34 tooth inner ring just doesn’t offer a low enough gear even with a 28 tooth cog, particularly for touring riders. Not only are my customers looking for triple road cranks, they would like even more range on the cassettes. We’re putting mountainbike derailleurs on road triples for touring riders. I would like to offer both high-quality road triples and ten-speed cassettes with a 34 tooth bottom-end.
When I toured in Japan, my bike had a road triple with 28-tooth chainring and 27-tooth bottom cog. If a ten-speed 11-34 cassette had been available, it would have given me a comparable gearing range on a compact double, but the actual 12-27 cassette on a triple gave me closer ratios. I don’t think that bigger jumps between gears would have been favourable, but the closer pedal stance might have been kinder to my knees on the ride through Honshu, Japan. The hypothetical reduction in weight is meaningless on a touring bike that weighs 65 pounds loaded.
Seen here clockwise from top: Ultegra SL compact double crank, Ultegra SL standard double, and Ultegra triple.
Finally, the question: will the compact double completely replace the standard double as well? Not very likely. Racers in most cases will need standard doubles because they’ll need that 53-tooth ring to get a big enough gear. ProTour riders use a 53x11 top gear on flat stages and sometimes 55x11 or bigger for time trials. Cassette hubs can’t fit a cog with less than 11 teeth because of the size of the bearings and axle supporting the cassette body, so there is no way to approximate that kind of gearing with a 50-tooth big ring on a compact. Yes, you could just make a 53+tooth ring with a 110mm bcd to fit the compact crank, but such a ring would likely deflect more under power than would be acceptable without the larger 130mm bcd spider to support it. What about normal amateur racers who don’t need an 11-tooth cog with a 53 ring? A compact double’s 50x11 is very close to a 53x12, even a bit bigger. Arguably though, the standard double is better since the 53 tooth ring yields tighter ratios. For instance, upshifting from the 13-tooth cog into the 12 on a 53 ring is a smaller jump than a 12 to 11 shift on a 50 ring. And the racer’s desire for closer ratios was the reason for developing drivetrains with increasing numbers of cogs on the cluster.
So Campagnolo Record and Shimano Dura Ace will no longer be available in triple. On one hand, the traditionalist in me hates progress. On the other hand, before the turn of the century (as in the 21st) neither of those groups was traditionally available with triples.
So…yeah…um…compact doubles are good? Triples were mechanical abominations for weaklings who didn’t deserve top of the line racing components anyways, right?….
Well, those answers aren’t going to please everyone. But I suppose that as long as someone like Shimano at least offers triple cranks and shifting systems at the Ultegra level, the world will be okay.
Having just rode a triple on test, this post is well-timed. One thing is that with the “close” to your 53 x 39 based gear ratio, it’s gonna take a while to get used to the newness and finding that right gear. I’m experiencing that now riding a SRAM 11 x 26 on my double. Works great, but I’m just not in the right gear (yet). Also, triples just never have gained the acceptance with roadies. Sure you can show up with one … and someone’s gonna ask if your bike came with a purse and matching pumps.
@DL Byron — My life would be much easier if my triples came with a purse and matching pumps. Of course, my bikes aren’t multi-thousand-dollar road bikes.
I like my torelli w/its double, but crackly knees tell me to use my triple more often with a load (clothes, lunch, pumps… just kidding) even on a sunny morning like today (it’s my rain bike). I am interested in all this adjustable gearing; helps me understand how the cassette on my touring bike is actually geared. Now off to work with me!
I’m a CAT 2 racer and I’ve got a 53/39 + 11/23 on my race bike and a 50/34 + 11/28 on my non-race bike. I mostly ride the non-race bike when I go out because of the climbs here in Colorado and because I can still spin at around 35+mph. However, I’d never use a compact crank in a race when pedalling speeds will reach 40+mph regularly.
@Daphne — Ha, I think you could get a celeste Bianchi with matching pumps and purse and that’d look damn sexy!
See my related post here on actually riding a triple. And, Bill Davidson said, “yeah, just wait until your knees go.” Joking aside choices are good. For example, I’m a huge fan of internally geared drivetrains.
@ Huge — good point and cadence/speed is a def an issue in a crit/sprint. At our local tuesday night world championships, I’m regularly spun out in a 53 x 11.
Wow Mark - that was a brilliant article. Great history lesson as well!
I just got back from a weekend bike camping trip. We rode from Auburn through Black Diamond, across the Green River Gorge up into Ravensdale. It was only 30 miles each way, but with nearly 60lbs of gear, 32mm wide tires and a over 2000ft of climbing (each way), I had to hit the granny gear and the 32t on my 8spd cassette a few times.
Even on a ~20lbs road bike with a triple and a 12-27t cassette, that still seems a bit high gearing for long distance rides with lots of climbing.
Around here, once in a while you hit an 18% hill. Depending on your bike’s geometry, your size , etc. - standing isn’t always a good option.
Sean:
I spent a good deal of time out of the saddle while climbing the Japanese Alps, but I was pretty satisfied with my gearing choice. You didn’t mention the size of your granny gear, but I’m guessing that it’s probably a 32, maybe a 30. For my Japan trip, I used a Tiagra triple with stock 50/39/30 rings and then I swapped the original 30 with a 28. That works because front derailleur was designed to work with a 23 tooth difference, and the rear derailleur’s cage was long enough.
For loaded touring I am convinced that lowrider front mounts are the way to go. They get the weight down low, so the bike is more stable. My touring buddy had a rear rack, and my bike absolutely handled better.
Nuovo Record, sheesh. What’s wrong with Italian? Even the long dead King of Components deserves better.
Anyway… thanks for all the other words!
Another advantage of compact doubles over triples is that they’re easier to set up and get acceptable shifting, especially for lower-end components. Plus the trim-click function and cross-chaining on a triple can be confusing for a first-time rider(and I’m being generous -I know a lot of not-first-time riders who still don’t quite get it).
I commute on a 34/48 with 12-25 cassette. Only spin out going down hills. I’m absolutely convinced that compact doubles make sense for everyone but racers.
There are plenty of older chainsets with small BCDs and 52T or larger rings, a 52 on a 110 BCD is not an issue. Your historical perspective seems a bit focused on racers, find a retro-grouch to talk about randonneuring or touring and you’ll likely find a different perspective on appropriate cycling equipment.
One more thing- Santana makes a 10 speed “mountain” cassette for use on their tandems. Their may be others out there, especially if someone develops 10 speed flat-bar shifters.
Tai:
you know, I kept looking at “neuvo” thinking, “that’s not right.” Usually I just write “NR” for Nuovo Record, and thus “SR” for Super Record.
I also kept looking at the word “ten” thinking that I’d spelled it wrong. It still doesn’t look right to me, but that might be the cold medicine talking all along.
Jimmy:
the historical perspective is skewed towards racers because drivetrain development is skewed towards racers. Integrated shifting, indexed gears, shift pins on chainrings, Hyperglide, etc….the list goes on, and it was all developed and marketed towards racers first. Of course there are exceptions, but the market is very racer -first/trickle-down later. i’m not saying this is good, but it is reality.
I’ve done touring and I know retro…I speak half-step, Huret, Zeus, Suntour, etc. My shop does full-custom touring bikes all the time. However, the bulk of the market is “performance-oriented” road bikes, and not even Rivendell sells old French derailleurs anymore. Sad but true (well, it’s not really sad about the end of cheap French derailleurs).
Santana does market a ten-speed wide range cassettes, but you pay a LOT for substantially less quality than a Shimano. Word is Shimano isn’t really interested in developing those ten-speed wide-range cassettes. They just don’t feel the market for touring riders is big enough to return the investment, which again is another example how market caters preferentially to racers and wannabes.
Yes, the 52T rings on 110mm bcd cranks did exist, but the tolerances demanded by ten-speed drivetrains make 130mm bcd more desirable for rings that big or bigger. Maybe if super-duper carbon reinforced rings came became fashionable, there’d be a change to 110mm bcd for ProTour racers, but I don’t see it anytime soon.
Cyclingnews had a review of a Hampsten Cycles bike with some quotes from Andy Hampsten. It’s interesting to read his viewpoint on gearing old and new.
cyclingnews.com
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Ah, timely article, thanks for the link. Love those fat tires, too! With the articles on the bikes of Paris-Roubaix in all their fat-tired glory, I’m curious to see if any of that will trickle down, too. Specialized seems to have done Ok with their “Roubaix” model and related claims.
I hear ya about “performance-oriented” road bikes, I guess it’s just my wishful thinking that “performance” meant something else, or at least several types of something else. I’ve got my share of lightweight bikes, too.
How much is that Santana cassette? It’s got to be ungodly expensive. Anyhows, now everybody knows why I’m trying to keep the fleet all 9-speed, or figure out a way to use a 10s shifter with 9s cog spacing(haven’t looked into it much, you?).
Thanks for this site, just found it, not trying to come off as a know-it-all, jsut excited about bikes!
Jimmy Livengood Seattle, WA
Jimmy:
I can’t remember the retail price for the Santana cassette off the top of my head, but i do remember feeling bad about charging it to the customer last time.
the solution to the 9s mtb cassette with the 10s shifter, for my shop, has been the Jtek Shiftmate. it’s a cable-pull adapter that installs at the rear derailleur. it’s a little more gimmicky than i would prefer, and you absolutely have to trim rear derailleur cable housing right, but it seems to get good service from the customers who use it. we’ve got at least a dozen (probably more) customers out on it at the moment since about 10 month ago. once you install one correctly, it’s easy.
If you go back a bit more in history and look outside the racing scene a version of the compact double is easy to find with TA/Stronglight style cranks set up with a 48ish large and a 30ish small ring. Not a 110BCD compact, but functionally similar in that it offers the gear range of most triples.
Industry motivations for the phasing out of triples granted, the 110BCd makes sense for most riders. A 50-13 gear at 100rpm will move a 23-622 wheeled bike at 30.1 mph which is more than adequate for most, and the benefits at the low end are obvious.
I for one think compact doubles are great. The technology is better for commuters and other utilitarian riders than it is for racers… and that’s great. Cars are made that way, why shouldn’t bike be?
Just consider how many of the endless masses of old steel ‘ten-speeds’ can be made into hill-capable, friction shifting, beauties with a compact crank. Squeeze in a modern rear wheel with a 8,9 or 10 speed cassette, pick up a long-cage rear derailleur on it, and your running a capable, inexpensive, reliable, street machine.
I’ve got a compact crank on my 20+ year old Trek road frame and it has helped give it a new lease on life. Utilitarianism rocks!!
Hey Mark… FYI…Tai Po isn’t Tai Lee…you know I don’t know jack about campy.
Tai Lee
to summarize: there are two reasons for the rise of the compact.
A very timely article — it will have me looking for DuraAce triple closeouts while they are still around. Too bad, though, I’d hae liked the internal cable routing of the 7900 DA line that is coming.
I’ve never raced, never intend to, but am serious enough to have a powertap. In the last few years I’ve been through a 50/40/28, 53/39, 50/34, and now I’m using a 53/39/30 triple. I routinely climb hills where with the 30 inner and a 34 tooth mountain cog, it takes 240+ watts to turn 85rpm, and there are hills where 260 watts will have me going 54 rpm. I’d be happy with an even lower inner. A very well known racer acquaintance told me to believe the numbers, and not buy into the ego thing of bigger gearing. Only the watts count, and the closer to a decent cadence they are, the better off you will be.
I don’t think compacts are the only good answer, though it’s a nice idea, and I was happy with it until I got back to more serious climbing.
TBV
TBV,
Contador was riding a 34 x 27 on that hilly stage of the Giro and interestingly coaches are now saying that cadence is out now as a “doesn’t’ really matter” (post Lance era) It’s all wattage, whether you’re turning 85 or 105.
are you sure the new dura ace won’t have a triple version? My local bikeshop in Belgium told me the 7900 will come this summer and they just don’t know if there won’t be a triple.
Production versions of Dura Ace 7900 will reach the professional teams this summer, no doubt just in time for the Tour de France. But I wouldn’t expect DA to reach the retail market until at least fall. That is the general pattern with Shimano. In other words, I’d be really surprised if your bike shop has DA 7900 to sell this summer.
Officially, there is a media blackout from Shimano until June 1st, meaning that Shimano has no official news releases about DA 7900. I’m waiting to get some news release from my regional Shimano rep in a few days.
However, one of the worst kept secrets in the industry is that Shimano produces a huge book of production specs for up coming models. They’ve had this available since February or so for major OEM product managers to place orders for their 2009 complete bikes. Parts makers generally feed the OEM market first, then the aftermarket. Thus, I expect the aftermarket kits to be fall because bike manufacturers need their units ASAP so that their complete can ship.
Anyways, I’ve seen all the specs for Shimano, and they have zero mention of triples for 7900 over about 6 pages of detail specs. Furthermore, I’ve talked to industry insiders, and they’ve heard nothing about triples either. Just by reading the specs, I can tell you that not a single component is common between 7800 and 7900 even though they are both 10sp. As a matter of fact, you won’t be able to mix derailleurs or shifters. There is a compact planned (maybe slightly later delivery), and the crankarms are not carbon for either standard or compact. What I don’t know is what exactly they look like, since the pre-production units keep evolving cosmetically.
Still, there is nothing to stop Shimano from introducing a 7900 triple version in 2010. After all, there was a year delay between the introduction of 7800 and its 7803 triple companion. Yet, what is telling is that Shimano is all gung-ho for compact from the beginning of 7900. Pre-production plans call for DA 7900 to have a medium cage rear derailleur (to better work with wide-ratio cassettes on compact cranks) and apparently no short cage offering.
Time will tell though. Check back in a few days and I may have some more concrete information.
DL wrote, “Contador was riding a 34 x 27 on that hilly stage of the Giro and interestingly coaches are now saying that cadence is out now as a “doesn’t’ really matter” (post Lance era) It’s all wattage, whether you’re turning 85 or 105.”
I heard today Contador switched to a 34x30 for the time trial. I’ll take that as a hint.
I’m not concerned about the 85-105 rpm debate — but when it drops down to the 40s or 50s or even 60s at high wattage, like I was getting with the 34 ring on some hills, it just isn’t low enough. Run the numbers — I think most people can’t turn 280+ watts at 50 rpm for very long without problems.
For some reason, MTB riders are beyond the ego thing, and will cheerfully run triples with very low gears. And the makers produce them. The XTR triple is > $500, and is 44/32/22. If a 52/36 or 50/34 compact give reasonable shifting, then a 52/36/24 road triple ought to be workable, and would be useful for a lot of people.
Narrow gearing only works for people who can push 3-4 w/kg for a long time, or who live in Kansas. There aren’t that many of them in reality, but there are a lot of people who have egos that say they ought to, and buy equipment as if they do.
Anyway, I completely believe no DA triple for the 7900, at least for a while. It is further proof of The Conspiracy.
thanks, TBV
TBV:
recent custom bikes i’ve had to build up have brought something to my attention that is pertinent to the discussion. I have discovered that SGS mountain derailleurs don’t work so well on short chainstay bikes. What happens is that when the derailleur swings forward on big-big combinations, the chainline from the lower pulley to the chainring is really severe beause the cage wants to stay in the same vertical plane as the cog. it’s just a function of the long cage putting that pulley so close to the chainring. so in my recent experience, one should avoid cassettes with 34t bottom ends on bikes with chainstays less than 41.0 or 41.5cm.
Explicitly I am saying that compact cranks with 11-34 cassettes are a bad choice for a racing geometry bike. Even though on paper, a road triple with matching rear derailleur would have crappier chainline than a compact double with a mtb rear derailleur, in practice more ring-cog combinations are useable for the road. Additionally the triple would have closer ratios.
I suppose you could alleviate the chain problem by going with a smaller big ring (~46 teeth) but a lot of riders won’t like the loss on the top end.
My current favourite crank for touring riders is a Shimano 105 triple 50/39/30 with the stock 30t inner ring swapped for a 28t. Running that with a 12-27 cassette and triple rear derailleur works great. It still isn’t as low as I’d like to offer, but I personally hate spec’ing bikes with drivetrains that I don’t have absolute faith in…because experience tells me that the bike with crappy shifting will come back again and again for service. Modern 10sp systems don’t leave that much room for personal expression.
I favor the 50/34 crank and a 12/25 cog combination. I have another road bike equipped with 53/39 crank but I seldom use it because its not good for a long distance ride. I admit the 53/39 is fast but if your knees are not trained for a hard pedaling on hilly road, the 50/34 will easily beat and out run you. The reason for that is because it is more comfortable and lighter for your knees to cranked the pedals though your cadence is more faster than a 53/39. Your energy is not much spend and you can breath easily while on long ride. A 53/39 if you are not experience to use it can give you serious trouble along the way. I always had a “Cramp knees” before while using this 53/39 bike.
The Zipp Vuma uses a 110mm bolt cirlce for both its 53-39 and 50-34 chainring set ups. They seem to have worked out the deflection issues. Granted expensive, but it seems like a good trend. If it can trickle down to more affordable cranks it would help the mere mortal who doesn’t have a bike mechanic on call 24/7 with the ability to switch back and forth without having to switch out the entire crank.
I race (Cat 4, looking to upgrade to 3 this season.) I am currently running the 53-39 set up, but am thinking of trying a compact because I want to spin a bit more on the hills, especially in training.
Our coach has us doing a lot of work in specific heart rate zones, but wants us to always be spinning above 95. Gearing is particually an issue in heart rate/wattage zone training which requires sitting in various HR/wattage zones to effectivly train the different “slow twitch” “fast twitch” muscle groups.
On climbs with the standard 53-39 that means a low cadence in order to stay in an “endurance zone”.
For whatever its worth, it does not seem to be the accepted wisdom that lower cadence is “back in fashion” post Lance. Our coaches keep us in the 95+ range, with lots of trianing in the 100 to 120 rpm range. The science of spinning is well documented. Higher cadence helps to enlists the “slow twitch” longer lasting endurance muscles, while lower cadence, bigger efforts, enlist the “fast twitch” glycogen burning muscles, which don’t last as long.
I’m curious if any other racers have thoughts on this? Do any of you train on a compact cranks to help with cadence? And if so, do any of you race your compact cranks, or only use them for training?
nyc:
I suspect that Zipp choose to develop just one mould for both standard and compact. My prediction is not a lot of pro teams will be using those Zipp cranks, but a fair number of affluent individuals will. And that market segment is pretty hot for compact. So Zipp went were the money is.
As for defelection, I’d say that Zipp compromised for the sake of production costs. I doubt that they put as much into shifting development as Shimano or Campy. A friend of mine was telling me how in the early Nineties he saw Shimano’s lab for mtb chainring testing. It had an array of 14 naval gun cameras set to fire away hundreds of times per second to precisely analyze the path of the chain.
Seeing the new 7900 DA, Shimano obviously thinks more stiffness in the chainring is a good thing.
I doubt the 4-arm spider will influence the road crank market, but the 30mm spindle may. But that’s connected with frame design as well. It’s just another topic that I’d love to write about if I had more time.
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