Top Gear Size and its Influence on Average Touring Speeds

[Mick F]

And of course on twisty descents you are constantly turning the cranks to ensure the inner one is pointing up as you corner.

Depends on your pedals.
I don't think you could lean over enough to ground my pedals.

Old days with rat-raps I agree.

[reohn2]

having a higher top gear has a virtually negligible effect on average touring speeds. So does having closer ratio gears, in the absence of a burning urge to ride as fast as possible.

In simplistic terms if you are happy to pedal at 90-100 rpm (say) and you have a 100" gear you will use it between 27 and 30mph, and freewheel at speeds above that. If you only have a 90" gear you will pedal up to 27mph and then freewheel. So you will go 0% to 10% slower for a tiny fraction of the time when you would otherwise be pedalling at 27mph to 30 mph. Since (with a lower gear) you will be resting more of the time, you may go faster at other times and your average speed may be the same or faster.

NB pedalling when you are already going fast (eg down hill) merely increases your net work done against air resistance, over a day's ride. If you have effort to spare, you are almost invariably better off using it in uphill sections.

BTW comparing historic advice for gear ratios should be undertaken with some caution; commonly used crank lengths have occasionally varied. Even so, the suggestions for gears of 55, 72, and 86" if you are only going to have three gears might make more sense if the cranks are longer, but even so are not a long way away from those I would choose in the UK; walking up the odd hill that is too steep for the lowest gear isn't the end of the world.

cheers

This,with a couple of personal adendums.
I like two tooth steps in the most used gears with one tooth steps in the top couple of gears,and wider at the bottom end,my 9sp(custom)cassettes are 14-15-17-19-21-23-25-28-32,with a 46,34,24 chainset on 700C x 40mm tyres it wouldn't bother me a bit if the big ring was a 44t,top gear would still be big enough as pedalling at over 25mph is a pointless waste of energy IMHO.
As an alternative for really hilly or heavy touring the bottom three ratios on the cassette would be 26-30-34 and an MTB c/set with 44,32,22t rings.
Average speeds aren't determined by top gear ratios but by efficiency in the most used gears

[reohn2]

Depends on your pedals.
I don't think you could lean over enough to ground my pedals.......

It depends more on BB drop and crank length.

[meic]

as pedalling at over 25mph is a pointless waste of energy IMHO

You could argue that any cycling is a pointless waste of energy.
Pedaling at over 25mph will burn calories, help to improve fitness and be great fun.

[reohn2]

as pedalling at over 25mph is a pointless waste of energy IMHO

You could argue that any cycling is a pointless waste of energy.
Pedaling at over 25mph will burn calories, help to improve fitness and be great fun.

But not as much fun as pedalling uphill

[Trebor]

Thanks for all the replies. I'm interested in cycling history, the gearing used and its evolution over time, so perhaps a trainee nerd?
The results, so far, seem to indicate that the ideal top gear for touring is either 80.74 or 172 inches but quite possibly something in-between?

Historic and current recommendations regarding the best bottom gear, for touring, differ by an even greater multiple! In 1939 F.W Evans, the touring specialist, were suggesting a bottom gear of 50 inches, on a Sturmey-Archer AW hub as being "suitable for very hard touring work", although some ignored this advice and went 'ultra-low' by gearing at the AW hub at 2:1 with a bottom gear of 39 inches a middle of 52 inches and a top (cruising) gear of 69.33 - on a 26 inch wheel (or 72 54 40.5, on a 27 inch wheel).

http://www.purelyaloveofthebike.co.uk/e ... catp04.jpg

The special alpine tourer mentioned in the same link above, built in 1938 for "Hodites" (Neville Whall) the foreign touring expert, appears well ahead of its time, with a bottom gear of 26 inches and a top of 76.3 inches.

I think there is a typo and the 45.5 gear inch figure given should be actually be 48.5, because the 26 inch wheel tourer used a double chainwheel of 44/28 and a 4 speed freewheel 15,17,20,28T. This bike has a certain elegant simplicity: A cruising gear then a Rohloff-like step of 13.33% to top gear plus multiple climbing gears - the 40% step at the bottom is a bit of a stretch but less than that of the Shimano Mega 7, with its 24-34 tooth jump.

In a Pathe documentary (nostalgia alert) featuring a CTC guided tour, from 1955, the narrator (at 1:33) mentions the specifications of one of the touring bikes – having gear inches from 29 to 82. This gearing range is not much different (slightly less) than the “Hodites” tourer of 1938, just shifted upwards but now a 10 speed rather than an 8. If the "Hodites" cycle was upgraded to 5 speed then would you go for a higher top gear or reduce the gap at the bottom by adding a 23T?

https://www.youtube.com/watch?v=QPkT0paGEnQ

So some tentative conclusions: high top gears beyond the mid 80s don't seem to offer much of an advantage, regarding average touring speeds (assume most are in the range 12-15 mph?) but can be fun for downhill blasts. Never had it so good, regarding choices but perhaps 9 speed cassettes were good enough for many?

[Mick F]

Depends on your pedals.
I don't think you could lean over enough to ground my pedals.......

It depends more on BB drop and crank length.

I'm sure BB height comes into it, but old pedals would catch if you weren't careful, and I have the habit of lifting the inside pedal up like I always used to have to.

These days ............... same bike ................ there is no way at all that my Mercian would scrape the inner pedal any more like it used to. It has Campag Pro Fit pedals nowadays.
The Moulton - same BB height - would go even further over due to Speedplay Frog pedals.

Tell you what, I'm not doing much this afternoon, I'll go and measure.
Back later!

[Tigerbiten]

I, however, was singing on a traditional steel-framed, 27 x 1 1/4" wheeled tourer

Mine was a "racer" +30 years ago. 53/14 top gear and as low as possible with a triple.
So I know where you're coming from.

It was only after my accident with a Tiger that I got a bent trike.
My first trike had fairly standard gears, a 9 speed triple with a range of 12.5"-100" and I used it for 2 summer tours, ~4k miles each.
But I got bored of spinning out at ~30 mph.
So with this trike, I've gone for the maximum range of gears starting sub 10", without going silly with something like an extra mid drive.
I did think of a triple with a 9 speed dual drive.
But with only one hand after my accident, I thought there would be too many controls under my one hand.
So ended up with a Schlumpf HSD and Rohloff as only one hand control.
I've ended up with twin chainrings for a final tweak, but they just make the whole system better.

With my ultra high gears, I now find it more relaxing because I don't spin out until the hill gets silly steep.
While we're probably using a similar amount of energy dropping down a hill ~25 mph.
As you get faster you either have to work harder by upping your cadence or start to free wheel.
I just click up a gear or two/three/four as needed and just keep the legs turning over.
So I don't work any harder than you do if you're coming down a hill at around 20-25 mph, it's just that I'm doing 35-45 mph.
I doubt that I raise my speed by very much, if any, but it's "FUN".

Ps:- I don't credit card tour.
Me + trike + trailer + full camping kit is probably getting close to 150 kg.
Why do you think I have a 9.5" first gear.
It's only hills steeper than 20% that are hard work with the full load, without the load I can spin up anything I keep traction on ......

[Roadster]

You misquote me, Tiger: I said the wheels on my Mistral Tourer are 1" in width, not 1-1/4" which was then considered ludicrously wide and fit only for... well, Roadsters. How times, touring bikes and touring cyclists have changed over the last 30-odd years!

[Mick F]

Measured the lean-overs of the two bikes where the pedal touches the floor.

Moulton handlebar drop to floor is 32"
Mercian handlebar drop to floor is 31"
Both bikes are set up identically, but because the Moulton has suspension, the front end height is statically higher, but both BBs are basically the same height.

I leant both bikes over one at a time and measured the 'bar hight vertically to the floor from the same place on the 'bars.
Moulton 20"
Mercian 23"

Rudimentary geometry with paper and pencil and ruler and compass and protractor ................ I can't remember my trig.
............... gives an angle lean from the vertical of 43deg for Mercian and a whopping 53deg for Moulton.

The tyres wouldn't grip the road at those angles.

[reohn2]

Mick,measure the height of the BB with the the bikes plumb and compare crank length.

[PH]

In a Pathe documentary (nostalgia alert) featuring a CTC guided tour, from 1955, the narrator (at 1:33) mentions the specifications of one of the touring bikes – having gear inches from 29 to 82. This gearing range is not much different (slightly less) than the “Hodites” tourer of 1938, just shifted upwards but now a 10 speed rather than an 8. If the "Hodites" cycle was upgraded to 5 speed then would you go for a higher top gear or reduce the gap at the bottom by adding a 23T?

https://www.youtube.com/watch?v=QPkT0paGEnQ

That's a lovely bit of film which I've watched several times, I know most of the roads and it's surprising how much of it remains the same.
As the film shows and the narrator says - These are cycle tourists and not ashamed to get off and walk.
I'm more interested in when this attitude changed than the "improvements" in gearing. On anything the UK has to offer, walking up the steepest hills won't have much effect on overall average speed. Yet to many it's now seen as some sort of failure. That's also true for many other parts of the World, though there's also plenty of exceptions, it's not called Alpine gearing for nothing!
I like a gear range of around 20" - 100" but still spend so much time in the 50 - 80 part of it that loosing the rest wouldn't affect my average by much at all. But that speed isn't very high on my list of priorities when I'm touring (Or most of my other cycling either) and having the gear range I like increases the enjoyment.

[reohn2]

........... But that speed isn't very high on my list of priorities when I'm touring (Or most of my other cycling either) and having the gear range I like increases the enjoyment.

Agreed, though I'd add that efficiency is included in that enjoyment for me,so not only range but good gear progression is also part of that enjoyment too

[axel_knutt]

In 2006 I had a gear lever fail mid-tour, so that I could no longer access the top 3 sprockets. Comparing the first 500 miles with the last 500, the end of the tour was 1mph faster, but doing the same with other rides I get that much variation at random, without the gear failure.

[geocycle]

In a Pathe documentary (nostalgia alert) featuring a CTC guided tour, from 1955, the narrator (at 1:33) mentions the specifications of one of the touring bikes – having gear inches from 29 to 82. This gearing range is not much different (slightly less) than the “Hodites” tourer of 1938, just shifted upwards but now a 10 speed rather than an 8. If the "Hodites" cycle was upgraded to 5 speed then would you go for a higher top gear or reduce the gap at the bottom by adding a 23T?

https://www.youtube.com/watch?v=QPkT0paGEnQ

That's a lovely bit of film which I've watched several times, I know most of the roads and it's surprising how much of it remains the same.
As the film shows and the narrator says - These are cycle tourists and not ashamed to get off and walk.
I'm more interested in when this attitude changed than the "improvements" in gearing. On anything the UK has to offer, walking up the steepest hills won't have much effect on overall average speed. Yet to many it's now seen as some sort of failure. That's also true for many other parts of the World, though there's also plenty of exceptions, it's not called Alpine gearing for nothing!
I like a gear range of around 20" - 100" but still spend so much time in the 50 - 80 part of it that loosing the rest wouldn't affect my average by much at all. But that speed isn't very high on my list of priorities when I'm touring (Or most of my other cycling either) and having the gear range I like increases the enjoyment.

It is a great bit of film isn't it. I suspect the get off and walk attitude changed with the balance between 'touring' and 'sport', or cotton shorts as displayed on the film and lycra performance gear. My gear range is 18-95 on the rohloff and losing the top wouldn't be a problem. I do like my gear 1 though!