Using a 50x11 I need to be doing at least 40mph

[Username]

Anyone here use a 53 chainring? I imagine the gearing would be way too high for me, I'd need hydraulic legs or something. Even switching up from the 34 to the 50 I need to be doing at least 20 mph or so.

*Im actually a slug of a cyclist, the 40mph thing is downhill

[foxyrider]

My 'race' bike runs a 52x11 and I reckon it gets used on most rides I use the bike for. It's not about actively trying to use what is quite a high gear but rather just changing gear based on feel. I often get home with a max speed @ 60kph but I couldn't be certain that i've used the top gear to get that. The highest on road speed i've ever recorded was 98kmh coming off an alpine pass but I was some way off pedalling at that point

Back before all this aero stuff and double digit gear sets I used to time trial with a 57x12 solo and 62x12 on the tandem (there were no 11 sprockets!)

[chris_suffolk]

Even switching up from the 34 to the 50 I need to be doing at least 20 mph or so.

How do you work that out? I rarely get above 20mph except down hill, but in 75 miles at the weekend never once dropped off the 50 front ring. Mainly used 50 - 21 /18 / 16 occasionally 24 and rarely 28. Plenty of range there to cope with speeds from below 10 to about 22mph -cadence about 80rpm

[whoof]

This site is handy for working out gear inches but also does what speed you will do for a given cadence or what cadence for a given speed.

http://www.bikecalc.com/speed_at_cadence


I have a bike with a top gear of 53/12 and at cadences of 80,90 & 100 would travel at 27.7, 31.1 and 34.6 mph. None of which are unusually fast. To go at 40 mph I would need to spin my legs at 116 mph.

My tourer has a slightly lower top 48/11 and I used this on the descents of a recent tour.

[Mick F]

Anyone here use a 53 chainring? I imagine the gearing would be way too high for me, I'd need hydraulic legs or something. Even switching up from the 34 to the 50 I need to be doing at least 20 mph or so.

*Im actually a slug of a cyclist, the 40mph thing is downhill

I have a 53t big ring on Mercian.
Campag Chorus Triple 53/42/30
Recently swapped the 30t inner for a 28t.
12-30 Campag Centaur cassette.

Bottom gear 24.45"
Top gear 115.72"

I would maybe like a 26t inner, and a 54t outer which would be probably 120" top and 22" bottom.
I like a wide range of gearing.

There were many times yesterday in Somerset/Wellington area I was riding along on the flat turning the pedals at maybe 15mph in top gear.
Cadence mid 40s rpm for miles.

[reohn2]

I never need such a high gear as 50x11 these days.
My range is 20in to 90in with top being 46x14,which is high enough for me,but I do like to spin,turning a slow cadence is purgatory for me and I find no pleasure or efficiency in it.
That's not to say a slow cadence won't suit someone else, gearing and cadence are both very personal preferences.

[Tigerbiten]

40 mph is about the speed my top gear starts becoming usefull.
But I do need ~10% down on good tarmac to use it.

But I tend to use my ultra high gears (+130") to keep my legs turning over on downhill runs rather than adding more power.
Nothing beats pedaling slowly downhill at 40 mph .........

[Username]

Even switching up from the 34 to the 50 I need to be doing at least 20 mph or so.

How do you work that out? I rarely get above 20mph except down hill, but in 75 miles at the weekend never once dropped off the 50 front ring. Mainly used 50 - 21 /18 / 16 occasionally 24 and rarely 28. Plenty of range there to cope with speeds from below 10 to about 22mph -cadence about 80rpm

Absolutely no idea what cadence I am doing, I pedal at a cadence that feels most efficient. How do I work that out? I have got a speedo and at about 20 or so I tend to change up to the bigger ring. Its not a "change up at XX speed" decision. Dont know how or why, but low cadence at high speed doesnt seem to suit me.

40 mph is about the speed my top gear starts becoming usefull.
But I do need ~10% down on good tarmac to use it.

But I tend to use my ultra high gears (+130") to keep my legs turning over on downhill runs rather than adding more power.
Nothing beats pedaling slowly downhill at 40 mph .........

If I were pedalling slowly at 40 mph I would not be able to push the pedals hard enough to add any meaningful power. At 40mph I cant do that anyway, but pedalling slowly is definitely worse for me.

[Mick F]

I was riding with six others yesterday for 60odd miles.

A few times, I was playing tail-end charlie and took a great deal of interest watching the others - all of us doing the same speed in a line - and how all the cadences were different.
Some slower than others, some higher than others, but all of them visibly different.

We're all different in so many many ways. What suits one, won't suit all .............. by any means.

[andrew_s]

I have a 46T large chainring, and use the 11 sprocket virtually never, and the 13 very rarely.
It's partly that I'm a spinner, and don't feel the need to change up until the rpm gets northward of 100, and partly that if a hill's steep enough
to freewheel down at 25 mph, that's what I do.

Anyway, once speeds get up to around 40 mph, aerodynamics are such that you've got to work quite hard to go faster in a pedalling position than you would by crouching down in an aero position (as well as having a suitable gear).

[whoof]

Absolutely no idea what cadence I am doing, I pedal at a cadence that feels most efficient. How do I work that out?

[/quote]

As before use this. Put in the speed you are going and the gear you're in and it will tell you your cadence.

http://www.bikecalc.com/cadence_at_speed

Using this riding to work on the flat and I have a cadence of about 90 which feels like if you put and Aftereight mint in each shoe I wouldn't crack it.

[Mick F]

Cadence in RPM = Speed x 336 divided by Gear in inches.

For instance ............ 20mph x 336 divided by 100 inches = 67.2 rpm

[Tigerbiten]

The easy one to remember is ....

If you can spin a 100" gear at 100 rpm then you will doing 30 mph.

[The utility cyclist]

50x11 @ 90rpm is only 32.5mph I do 10% more than that on my way to Tesco and it's only 1.7 miles away.

52x12 is just as good and leaves you the 11 for 40mph cruising on a longer/faster downhill. I go on the A505 (from Luton to Hitchin) and mid 40s doesn't take much but I prefer pedalling than coasting.

[foxyrider]

50x11 @ 90rpm is only 32.5mph I do 10% more than that on my way to Tesco and it's only 1.7 miles away.

52x12 is just as good and leaves you the 11 for 40mph cruising on a longer/faster downhill. I go on the A505 (from Luton to Hitchin) and mid 40s doesn't take much but I prefer pedalling than coasting.

Why aren't you world champion? You sure your comp isn't set in KMH, even on long Pennine descents I rarely see much over 30mph!