What is meant by a "Compact Crank"

[p38lightning]

I've seen this in catalogs, and also mentioned in articles. What do they mean?

 

[capwater]

I've seen this in catalogs, and also mentioned in articles. What do they mean?

50/34 vs. 53/39

 

[gclark8]

50/34 vs. 53/39

Wrong!

Compact Crank is one with a PCD of 114mm or less, today, 110mm!
They take smaller chainrings.

 

[caferacerwanabe]

110 BCD (or PCD) sometimes known as Maxy is a chainring type that allows for a lower gearing than the standard Shimano 130 BCD of 38 teeth . The 110 Maxy chainrings & cranks have been around for years but mostly used by tourist & bmx riders. A few years back FSA & Miche among others pushed the product into the road scene as a 50/34 or 50/36 , it was famously used by Tyler Hamilton in the TDF so he could climb the mountains with his injured shoulder. So now Maxy 110 is now commonly referred to as 'compact' , that is compact cranks as opposed to Giant's 'compact' geometry & Gios' 'compact' adjustable frame dropouts. These compact chainsets make a lot of sense but are often frowned upon by 'dinkum' racers basically because they are visually smaller rather than any performance losses.
Advantages:
Theoretically Lighter
Lower gear 34t as opposed to 38/39t
Highest gear 50x11 is higher than 53x12
Disadvantages
May not fit some frames due to the placement of the braze-on front derailleur.
Visually challenged ... bigger is better a bit like a 130mm stem & a 58cm frame.
Some riders do not a need 34t if they live in a flat area or they are racing criteriums.

 

[capwater]

Wrong!

Compact Crank is one with a PCD of 114mm or less, today, 110mm!
They take smaller chainrings.

Never said they were the same BCD so how can I be wrong? And it's BCD (bolt circle diameter) not PCD just for your edification (yeah, I know you just whacked the wrong key!)

Just wish some folks would use the search function more often so we don't have to rewrite the book each time .........

 

[1id10t]

Never said they were the same BCD so how can I be wrong? And it's BCD (bolt circle diameter) not PCD just for your edification (yeah, I know you just whacked the wrong key!)

Just wish some folks would use the search function more often so we don't have to rewrite the book each time .........

PCD = Pitch Circle Diameter. Measures the same thing. Just for your edification...

 

[gclark8]

Lets have a poll!

PCD or BCD?

Derailleur or Mech?

Campy or Shimano?

Sliced Chicken, Shaved or Plucked?

 

[hd reynolds]

I've seen this in catalogs, and also mentioned in articles. What do they mean?

A crank with BOLT CENTER DIAMETER of 110mm that usually takes chainrings in the 50/34-36 combination.

 

[1id10t]

hd reynolds....that avatar of yours is obscene; I mean, how on earth could you wrap your mouth around those!!!!

 

[LeDomestique]

hd reynolds....that avatar of yours is obscene; I mean, how on earth could you wrap your mouth around those!!!!

Well....those are definitely NOT compact !!

;-)

 

[capwater]

PCD = Pitch Circle Diameter. Measures the same thing. Just for your edification...

Cool! Keep forgetting this is a global forum, that's the beauty of it! Different terms in different parts of the world.

 

[jhuskey]

Cool! Keep forgetting this is a global forum, that's the beauty of it! Different terms in different parts of the world.

So your saying that the things in the avatar are not called "Big Boobs" in Oz?

 

[hd reynolds]

So your saying that the things in the avatar are not called "Big Boobs" in Oz?

I think they're called OVERSIZED.

 

[capwater]

Wow! I was too pre-occupied talking about bikes to check out the avatar!!! Who cares about a compact cranks anymore???? Nothing compact about that rack.

 

[gfspencer]

Wrong!

Compact Crank is one with a PCD of 114mm or less, today, 110mm!
They take smaller chainrings.

The important information for those of us who are not technically inclined is relative the size of the chain rings (50/34 vs. 53/39). Compact cranks take smaller chainrings and give us lover gearing.