Compact vs Double - explain please!

[Lurpak]

I find with my compact I have to change back and forth to the outer ring at around about 14 mph which is mighty annoying because that's the speed I usually hover around. Think my old double was about 18mph which was rarely achieved unless I was late for something.

 

[Citius]

The English language is full of expressions that are logically fallacious, but nevertheless understood by practically everyone.

Either they are both doubles, or they aren't.

 

[Dogtrousers]

@Yellow Saddle is right that the units "gear inches" don't mean anything to us. How many of us have ever ridden an Ordinary? Not many. But the thing is that once you have become used to a system of measurement, no matter how silly or illogical, it tends to stick (witness the continued use of imperial units). So I personally now think in terms of "gear inches" just because that's what I do. I don't think in ratios, but perhaps I should. It would be neater.

As an aside I do think it would be helpful if bike advertisers gave the gearing range of a bike as part of its spec. I don't care what units they use, as long as they are consistent. So many bikes are sold with racy close-range relatively high gears, that people often find they do not like. Witness the number of threads on here saying "can I fit a 32T cassette to my bike"? IMO this is a more important part of the spec than the number of gears. But not as cool.

 

[w00hoo_kent]

Either they are both doubles, or they aren't.

Does it really matter for this conversation?

 

[Citius]

Does it really matter for this conversation?

It matters generally. This conversation is evidence of how fcked up the general understanding (of what should be a relatively straightforward topic) actually is.

 

[youngoldbloke]

While we are being pedantic .... Compact Chainset please, not Compact Crank. Crank (or crank-arm if you're from the USA) refers to the long straight part to which the pedal is attached, not the whole assembly of cranks,(spider) and chain-rings. All chainsets I've ever known are double crank. Rant over!

 

[Yellow Saddle]

While we are being pedantic .... Compact Chainset please, not Compact Crank. Crank (or crank-arm if you're from the USA) refers to the long straight part to which the pedal is attached, not the whole assembly of cranks,(spider) and chain-rings. All chainsets I've ever known are double crank. Rant over!

Rant on.
What is a set of chains?
Crankset is the term that should be used either side of the Atlantic, Pacific, Indian Ocean, Baltic sea and pond down the road.
Rant over.

 

[youngoldbloke]

OK - 'Crankset' - I can understand might be just about excusable (especially if you are from USA), but NOT 'Compact CRANK'. What does that mean? A short Crank?
'Chainset' (one word) - nothing to do with a 'set of chains' -as you well know - this is a nice, simple, explanation - http://www.tredz.co.uk/bikeguides/chainsets

 

[mjr]

Anyone like a half-step double?

 

[Ness]

Either they are both doubles, or they aren't.

A compact double 50/34 is referred to as a compact. A semi-compact double 52/36 is referred to as a semi-compact. A standard double 53/39 is referred to as a double as it was once the only double there was and, therefore, no need to specify what type of double.

Simple enough really.

 

[Poacher]

I'm old enough to remember when a standard double was 52/42, and 42 was the smallest ring which would fit on the spider!!!!!

 

[Ness]

I'm old enough to remember when a standard double was 52/42, and 42 was the smallest ring which would fit on the spider!!!!!

Back when there were only 6 speed blocks? How are your knees?

 

[Citius]

A compact double 50/34 is referred to as a compact. A semi-compact double 52/36 is referred to as a semi-compact. A standard double 53/39 is referred to as a double as it was once the only double there was and, therefore, no need to specify what type of double.

Simple enough really.

Congrats on perpetuating the general confusion on this issue. Like I said before on another thread, a double chainset is defined by its BCD, not by the tooth-count of the chainrings fitted to it. Remove the rings from a compact double chainset and it would still be a compact double chainset. Remove the rings from a standard double and it would still be a standard double. The definition would not change simply because it had no rings.

One of my bikes has 50/38 - does that make it a three-quarter compact double, or maybe a six-eighths double? Or maybe it's just a compact double with a 50 and a 38 on it.

 

[Poacher]

Back when there were only 6 speed blocks? How are your knees?

Back when there were only 5 speed blocks, and knackered, respectively!

 

[Smokin Joe]

Back when there were only 6 speed blocks? How are your knees?

It is a myth that high gearing damages the knees. If the gear you are using is too high your thighs will refuse to push the pedals round long before your knees give up. Walking up stairs - which most of us do many times a day - puts far more strain on the knees than riding a bike where your body weight is supported. Runners, footballers, rugby players and dancers put far more strain on the knees and all the other joints than cyclists do and they seem to manage ok. All my racing was done in the days when 42x23 was the lowest you got and my knees are ok.