Why are compact cranks called compact cranks?

[MattTuck]

Is it simply because compact cranks are more alliterative than compact chainrings?

All it refers to is the b.c.d. right?

I was trying to explain the concept to a casual cyclist thinking of getting into road biking and it really is a bit of a misnomer. Like trying to explain 'clipping in' to clipless pedals.

[parris]

I think you nailed it with the b.c.d. being smaller than traditional road cranks.

[eddief]

"The "compact" in compact gearing refers to the slightly smaller size of the two chain rings at the front. They usually have 50 teeth and 34 teeth instead of 53 and 39. This makes the gears lower ("easier"), all else being equal. But the gearing you get when you pedal is also determined by the sprockets at the back (this time, the more teeth they have the lower the gearing), so if you fit smaller sprockets you can get much the same gearing with compact as with a standard chainset. A compact chainset gives you more leeway if you want to have lower gears for steep hills, and most complete bikes sold with compacts are likely to have lower gearing than those with standard."

[josephr]

"The "compact" in compact gearing refers to the slightly smaller size of the two chain rings at the front. They usually have 50 teeth and 34 teeth instead of 53 and 39. This makes the gears lower ("easier"), all else being equal. But the gearing you get when you pedal is also determined by the sprockets at the back (this time, the more teeth they have the lower the gearing), so if you fit smaller sprockets you can get much the same gearing with compact as with a standard chainset. A compact chainset gives you more leeway if you want to have lower gears for steep hills, and most complete bikes sold with compacts are likely to have lower gearing than those with standard."

good description -- I always think of a 'compact' as being the merger of a triple and a standard 53/39. Especially now that some lines are doing away with triples all-together.
Joe

[R2D2]

I've read they were also used by Hamilton to save weight in TT setup. Smaller gears less weight.

[carpediemracing]

Is it simply because compact cranks are more alliterative than compact chainrings?

All it refers to is the b.c.d. right?

I was trying to explain the concept to a casual cyclist thinking of getting into road biking and it really is a bit of a misnomer. Like trying to explain 'clipping in' to clipless pedals.

Yes on BCD, 110mm vs 130/135/144. With Shimano's new cranks it's a bit of a misnomer since they support chainrings that reflect both compact and standard sizes. With the older Campy SRM double cranks they had a 110mm inner mount and a 135mm (or was it 130mm?) outer mount.

I tell people it's like having first gear in the car extra low and skipping the high gear. For people with automatics I tell them it's like not driving in D but driving in 3 (or 2 or 1 or 8 or whatever n-1 is for their transmission). If they look at me blankly I say that they give an easier gear for hills.

[MattTuck]

I think I misphrased the question. I'm not asking what they are, I'm asking who was the person (or marketing team) that came up with the name, and why did the industry accept it, why didn't someone come up with a name that was more logical than "compact cranks"... like, say, "BCD Compact", "Cadence chainrings".

[christian]

I call 'em redneck chainrings. 'cuz they're missing teef!

[Steve in SLO]

I think I misphrased the question. I'm not asking what they are, I'm asking who was the person (or marketing team) that came up with the name, and why did the industry accept it, why didn't someone come up with a name that was more logical than "compact cranks"... like, say, "BCD Compact", "Cadence chainrings".
Perhaps because the rings and crank were developed together as a unit?
Also, if you called it compact BCD or rings, the question of interchangeability might be less clear-cut.

[cachagua]

Perhaps it was felt that if you called them mountain-bike cranks you couldn't sell them to roadies?

But I mean -- in the end, who called *anything* whatever it's called was the marketing department. And those guy's minds don't work like ours -- their motivations and aims are impenetrable, and their methods are the deepest secrets. All we know about them is that they control us absolutely.

[Ken Robb]

I call 'em redneck chainrings. 'cuz they're missing teef!

That's FUNNY!!:banana:

[Rada]

Perhaps it was felt that if you called them mountain-bike cranks you couldn't sell them to roadies?

But I mean -- in the end, who called *anything* whatever it's called was the marketing department. And those guy's minds don't work like ours -- their motivations and aims are impenetrable, and their methods are the deepest secrets. All we know about them is that they control us absolutely.

Same could be said with mountain bike cranks as they were touring cranks previously.

[cachagua]

Good point! And everyone knows that conventional cranks have 42/52 rings, not no newfangled 39/53. . .

[enr1co]

I think I misphrased the question. I'm not asking what they are, I'm asking who was the person (or marketing team) that came up with the name, and why did the industry accept it, why didn't someone come up with a name that was more logical than "compact cranks"... like, say, "BCD Compact", "Cadence chainrings".



Siri says ;)

http://www.bikehugger.com/post/view/the-rise-of-the-compact-crank

There is mention of the Tyler Hamilton early use of an "FSA compact" version but anyones guess to whether it was their mkt folks who are credited with coming up w/ the "compact" term.


...now mid compact seems to be the flavor of the day marketed :rolleyes:

Since bio-pace was recently reincarnated as oval, q-ring, elliptical etc.
I 'll bet 52/42 will show up with some flashy term at interbike soon ;)

[merlincustom1]

I think because compact simply means smaller, but that's just me. As in "they're compact, smaller than 53/39."

[Mark McM]

Siri says ;)

http://www.bikehugger.com/post/view/the-rise-of-the-compact-crank

There is mention of the Tyler Hamilton early use of an "FSA compact" version but anyones guess to whether it was their mkt folks who are credited with coming up w/ the "compact" term.


...now mid compact seems to be the flavor of the day marketed :rolleyes:

Since bio-pace was recently reincarnated as oval, q-ring, elliptical etc.
I 'll bet 52/42 will show up with some flashy term at interbike soon ;)

As has been mentioned, 110mm BCD cranks have had several different names in the past, well before they were called 'compact road cranks. However, the name 'Compact' was first applied to MTB cranks by Shimano, although these cranks were not 110mm BCD.

While there have been many different BCDs used over the decades, of the most commonly used road BCDs today (110mm, 130mm, 135mm), the 110mm BCD is actually the oldest. It was introduced in the early '70s by Sugino, who mated it with a 74mm inner BCD to make a triple crank intended for touring bikes. Thus, 110mm BCD cranks were first called 'Touring cranks'

When the Mountain Bike was being developed in the late '70s & early '80s, it borrowed and adapted many existing bicycle components, such as cantilever brakes and 26" balloon tires. To fill the need of a wide range crank with low gearing, the 110/74 BCD triple crank was adopted as the standard crank for MTBs, so these cranks became known as 'MTB cranks'.

Around 1990, Suntour developed a new drivetrain that used reduced sized chainrings and rear sprockets, which they named 'Microdrive'. The new cranks needed smaller BCDs, so the new cranks had a 94mm outer BCD and 56mm inner BCD. Cranks with these BCD were called 'Micro cranks'. Shimano followed suit, but with a slight modification - they used the same 94mm outer BCD, but increase the inner BCD to 58mm inner BCD. To differentiate the smaller drivetrain components from their standard sized 'Hyperdrive' components, they named their version of the crank 'Hyperglide-Compact', or simply 'Hyperglide-C'. When 'Micro cranks' and 'Hyperglide-C' MTB cranks became the norm, the 110/74 cranks became to be know as 'Standard MTB cranks'.

When Shimano decided to apply the same down-sized drivetrain concept to their hybrid and cruiser (road) bikes in the mid-'90s, they downsized the by then standard 130mm BCD double road cranks to a 110mm BCD double crank. They applied the same 'Hyperglide-C' name to these cranks as well. Thus, the first use of the name 'Compact' to a 110mm BCD crank was for hybrid/cruiser bikes.

In the early 2000's, a few crank manufacturers (most notably FSA) noticed that the road racing bike had risen greatly in popularity, even amongst those cyclists that had absolutely no racing aspirations. Many of these cyclists were going back to their LBS after purchasing these bikes requesting that the racing-type gearing be modified to make them easier to ride up hills. In response, the manufacturers starting offering upscale 110mm BCD double cranks with smaller chainrings than the OEM 130mm cranks, which were now being dubbed 'Compact road racing cranks'.


*By the way, Tyler Hamilton didn't use quite the same chainring configuration as the 50/34 or 50/36 typically offered on contemporary 'Compact' cranks. After crashing and breaking his collarbone in the 2003 Tour de France, he elected to stay in the race. But due to the broken collarbone, he was unable to ride out of the saddle. To compensate, he elected to use a smaller 36 mm inner chainring, so he could sit and spin on the steep climbs. But he used a 'standard' 52mm outer chainring for speed on the flats and downhills. So what he used is more close to the 'Pro Compact' that has recently become popular.

[palincss]

Yes on BCD, 110mm vs 130/135/144. With Shimano's new cranks it's a bit of a misnomer since they support chainrings that reflect both compact and standard sizes. With the older Campy SRM double cranks they had a 110mm inner mount and a 135mm (or was it 130mm?) outer mount.

I tell people it's like having first gear in the car extra low and skipping the high gear. For people with automatics I tell them it's like not driving in D but driving in 3 (or 2 or 1 or 8 or whatever n-1 is for their transmission). If they look at me blankly I say that they give an easier gear for hills.

Except that the overall gearing is made up of both the chain ring and the rear sprocket. In the days of the 53T big ring the usual small sprocket had 12 teeth. Today, it's not uncommon to find an 11 tooth small sprocket mated up with a 50T chain ring. The 53x12 gives you a 116 inch gear; the 50x11 gives you a 119.5" -- in other words, a higher high gear for the compact.

(Though, in all honesty, I can't imagine what 90% of the riders who have them actually use those 119.5" gears for, unless they're riding a tandem.)

[fiamme red]

(Though, in all honesty, I can't imagine what 90% of the riders who have them actually use those 119.5" gears for, unless they're riding a tandem.)Maybe for trying to "win" Strava downhill segments? :eek:

[nicrump]

when we did it on the track in the late 80's we called it "micro" gearing. for example instead of a 50x15 you might run a 40x12 as the theory was less material, less contact, less friction. we were proven wrong soon enough.

[carpediemracing]

Except that the overall gearing is made up of both the chain ring and the rear sprocket. In the days of the 53T big ring the usual small sprocket had 12 teeth. Today, it's not uncommon to find an 11 tooth small sprocket mated up with a 50T chain ring. The 53x12 gives you a 116 inch gear; the 50x11 gives you a 119.5" -- in other words, a higher high gear for the compact.

(Though, in all honesty, I can't imagine what 90% of the riders who have them actually use those 119.5" gears for, unless they're riding a tandem.)

I understand the gearing thing. I also understand the two BCD thing - until recently a 110BCD 52T was going to be more flexible than a 130BCD 52T ring - you could make solid rings only so thick etc (obviously that's changed with the hollow Shimano rings). Having a 135 BCD outer meant being able to use a wide range of big rings (39T, if you really wanted, up to at least a 55T). The 110 BCD inner meant being able to use a variety of small rings normally not usable with the 135 outer, i.e. 34, 36, 38T.

I used to run a 51T outer, 39 or 42T inner, for better shifting and because, as you basically point out, a 51x11 is a pretty high gear.

I run (and use infrequently but I do use it) a top gear of 53x11. Last year, because I had worn my 130 BCD rings and didn't have any quickly at hand, I ran the rings I bought for the tandem, 55/44, and this was with an 11-25 since all but one cassette I have start off with an 11. I put the 53 on this spring but right now have kept the 44 for giggles.

The thing is that, okay, very infrequently I'll use the 11 on a flat road if riding solo. I'll use it on faster downhills (over 35 mph and maxing out at about 50 around here for me) or drafting things like trucks (over 35 mph and maxing out at about 50 for me). I'll use it when doing big efforts on the flat, usually for training. In the last 10 years I found that I'm really not able to turn over the 11 in a sprint; before I ran a 54x11 and I used it regularly when sprinting.

But the big reason I use the 11 is when things are already fast, like on a downhill or in a fast moving group. I don't have to over spin to move up or hold position, whatever my goal at that moment. I can roll to the front without frantically pedaling. It doesn't make much of a difference between me and someone with a 52x11, for example, but from smaller gears it starts getting significant. This is why I recommend even non-racers have a big gear available to them - you can pedal less frantically down a hill if you want to, or on a slight downgrade.

I found that if I can keep my cadence under control my heartrate doesn't skyrocket as quickly, meaning on descents or as I crest climbs. There was one descent where I remembered only as I started looking for the 11 that I was on the wheel where I only had a 12. I came close to blowing myself up following a guy who kept the speed high enough on the not-very-steep descent we were on. If I had the 11 I'd have been alternating pedaling-coasting and I would have felt a lot more comfortable.

[carpediemracing]

when we did it on the track in the late 80's we called it "micro" gearing. for example instead of a 50x15 you might run a 40x12 as the theory was less material, less contact, less friction. we were proven wrong soon enough.

As a Junior I figured I could run a 42x12 instead of a 53x15, the Junior gear limit at the time. I could run a shorter chain, use a Senior freewheel/cassette, and when I got old enough I'd just put the big ring on.

However I ran a 53x15 until I was a Senior and started using a 12T in the prior season.

In those days, the 80s mainly, TTT squads used huge big rings not as much for the gear but so that they could use bigger cogs in the back that were more in the middle of the cluster. Better chain line, better chain efficiency.

I think Suntour called their smaller mountain bike BCD (the stats escape me) Micro Drive.

Shimano had the 1 cm chain drive for track bikes, versus the 1/2" (1.25 cm) regular chain drive. I don't remember what that was called.