Ratios ,

[dbeattie]

I'm sure crank length will have an impact on gearing. Don't know exactly how though.

 

[dbeattie]

Ok maybe not the gearing itself but it must influence how you experience it..

 

[Dogtrousers]

I'm sure crank length will have an impact on gearing. Don't know exactly how though.

You're right, it does. Not really sure how significantly. Anyway, Sheldon Brown's article discusses it.
http://www.sheldonbrown.com/gain.html

 

[Ajax Bay]

I do think the almost universal inclusion of an 11-tooth on cassettes is unhelpful

with a 48 on the front I don't have much use for the 12-ring either

I agree wholeheartedly. If I could get a cassette with 13-30 I would be pleased, but you can't sfaik. Campagnolo sprockets can be customised into a cassette but 13t smallest sprockets (with the serrations that the lockring tightens on) are expensive. With a 50 chainring, one has no need for an 11t and minimal need for a 12t. A 13-30 cassette allows closer ratios to be maintained for longer at the top end.

the pointless little 11T sprocket. No, I don't need it. But when it's there, I do use it quite a bit.

What for? A 50/11 gives you a length of gear that you will only use to waste energy on overcoming drag at 25+mph.

 

[Sharky]

One benefit of having an 11 on a TT bike is that the one you use most of the time, say 50-14 is in the middle of the cassette and therefore has a good chainline. The 11 comes in useful on those courses with a gift start or finish when you can exceed 40mph.

 

[Ajax Bay]

There's good science around to suggest that chainline angles make minimal difference to chain efficiency, within reason (which 52/11 will be). Start/finish of a TT is a bit of a special case, I suggest, and 'yes' go for that 11t but at the expense of closer ratios somewhere up the cassette.

 

[Dogtrousers]

What for? A 50/11 gives you a length of gear that you will only use to waste energy on overcoming drag at 25+mph.

For going along.

I'm not making any claims about efficiency (a subject I'm not qualified to comment on) or urging others to follow suit, just saying that I don't avoid it. I use it quite a lot seeing as it's there.

 

[ozboz]

You're right, it does. Not really sure how significantly. Anyway, Sheldon Brown's article discusses it.
http://www.sheldonbrown.com/gain.html

I saw something along this inquiry on the GCN youtube stuff

View: https://m.youtube.com/watch?v=eMAxH_Ud8YE

 

[Ajax Bay]

123 inch gear - just saying, or is this on a Brompton? 33mph at 90 cadence.

 

[smutchin]

I'm sure crank length will have an impact on gearing. Don't know exactly how though.

Think of the crank as a lever and apply everything you learnt about levers in GCSE physics.

You could even take it a step further and factor in leg length too.

 

[Dogtrousers]

Just as a couple of examples of when I like to use 50/11: Many of my rides end with about 10km of gentle downhill, twisty roads (the gentle side of the N Downs). I'm relaxing. The ride is all but over. I whack the bike into top gear. I freewheel a bit, and if I need a bit of speed a few hardish turns of the pedals do the job, then freewheel, brake for a corner, pedal, freewheel and so on. Alternately I quite like to use the slower cadence and bigger effort just for a change on a flat smooth road, going at, say 30 kmh. Probably with a tailwind. Neither is what a racing cyclist would do, but I'm not in any way a racing cyclist. Far from it. It just adds to the fun, it's a change. I wouldn't miss it if I lost it, but as it's there, I use it.