What's your favourite gear ratio?

Sheldon agrees...1/8" x 4 = 1/2". Theoretically I've enough for 6 tooth difference.

Tried the 19 tonight, no slower, no faster. Which is a good start.

Hornsey, commuting to Mayfair via Crouch End and Kings Cross. Currently, 69.9GI (28 tyres), doesn't give me anything to sprint with on flats and is too spinny on any decline.

I agree that does sound a bit short for the flat lands.

Sounds like you need to work on your spinning.

Not everyone is a high cadence spinner. And some people are more adept to sprints than endurance. We might be physically quite difference so I wouldn't be so quick to assume it's solely technique.

too spinny on any decline.

It is a fixed wheel drivetrain after all, I'm on 45/18, and that was just about spinny enough on the descent in Surreys (66GI).

Stick to the 17t you originally selected, 1t is quite a big jump on the rear.

I thought I could only push big gears and was on 53/18 daily then found out I could get used to spinning and now I'm around 65GI.

pretty much anyone can spin if they can be bothered.

It is a fixed wheel drivetrain after all, I'm on 45/18, and that was just about spinny enough on the descent in Surreys (66GI)

Are you touching the brake(s) on the descents and do you know what sort of top speeds you're hitting?

I thought I could only push big gears and was on 53/18 daily then found out I could get used to spinning and now I'm around 65GI

Well, I'm not far off that now and am already having to spin.

N.B. What's the general consensus on cadence RPM thresholds for spinning?

I can't recall but have a feeling it's around 25mph judging by the speed sign I pass before the descent, I feather the brake mostly to slow me down enough to resist the pedals a bit.

Cadence are personal, generally aim for 90rpm would be a good start.

Well, 25mph is going to be about 120rpm for me and it seems wasteful to use the brakes on a decent. 90 rpm currently gives me 18.7mph which isn't quite enough to flow with the traffic for the most part.

The 90rpm thing is a good guide - maybe - but it's a huge generalization for the highest common denominator, is it not?

It's not possible to say what average cadence people ride at. It just covers too much variety in cycling.

It is possible to have a good idea what cadence humans should ride at... and it's around 90 - 100. Most regular/keen/trained cyclists probably average 85 - 95. Mountain bikers, racers and the talented often average a bit higher I reckon.

Poloists are obviously even better.

Late poloists are off the chain.

Does the sprinter and the endurance athlete require the same cadence?

@Lémonsqueezer buy/borrow a garmin with a cadence sensor for a while and reep the datas.

This linked ride is on a freewheel 46/18 and commuting in the wet+dark so my speed is up down up down as I stop for lights and stuff but it gives you exact numbers with a map and everything once you shove it into garmin connect/strava/whatever, especially with cadence it's all just guessing until you use magnets. Seems I averaged 74 and apart from the sensor mess up peaked at 140ish for a few bits but most of it seems to be in the 90s when you hover over it until I got back over the river on the way home and was chilling.

http://www.strava.com/activities/217902246/analysis

@Lemonsqueezer Even a track sprinter rides for more than 90 seconds. So all cyclists are endurance athletes. Even @Skülly.

You don't need magnets.

If you're riding fg/ss then you can calculate it from your speed.

If you're riding geared you can count a foot against 30s on a watch (then double it obvs). Do this for a few weeks and it becomes pretty easy to judge within 5rpm.

#badscience

I've used them before.

You don't need magnets.

If you're riding fg/ss then you can calculate it from your speed

This

Even a track sprinter rides for more than 90 seconds. So all cyclists are endurance athletes

So after 90 seconds only one energy pathway is used?

No: under 90s the effort is anaerobic.

No.

under 90s the effort is anaerobic.

As a general guide it may be the dominant pathway but all pathways are utilized in varying degrees regardless of the activity.

And I'm pretty sure anaerobic isn't the most dominant energy pathway in most circumstances with a sub 90rpm cadence.

@miro_o @Lémonsqueezer if you are watching your speed on some cheapo cycle computer or better yet guessing your speed while using a stopwatch or cycling one handed with a pocketwatch or just guessing how long 30 seconds is then your numbers will get out of wack fast.

You also get a very isolated section of your ride that you are all pumped up for recording so the result you get is higher(as you want to be the best lol) or you feel distracted by all the counting, riding one handed and junk and ride slower to be safer as you still need to pay attention to the road somewhat and results are lower.

You could get another rider on a group ride to count a few times cycling behind you without warning, after a while when you forget and are riding like normal they just go "hey I did the count on that last bit, 18mph and 40/30sec".

tl:dr #badscience