gearing from Poly de Chanteloup, 1949

[djconnel]

From Jan Heine's truly excellent book: "René Herse":
"A single chainring (for the winning tandem) was sufficient for the 14% of the climb of Chanteloup, which hd to be climbed eight times. In 1950 a report listed the gearing of their tandem: a single chainring with 46 teeth and a 5-speed freewheel with 13-15-18-21-22 teeth. They never used the 22-tooth cog, and they made their attack with the 46-18."

I figured 14%? Sure, typical French hyperbole. Probably the inside of a switchback. But I checked Strava. Here's the Chanteloup climb. Here's the same segment on VeloViewer. No kidding!

I like running a 46 big ring on my racing bike, my races being mostly hillclimbs these days. But I don't do 14% climbs in it.... for those I have my 34-27.

[tymon_tm]

lots of training and hard work and you'll simply fly over 14% ascents with such gearing. seriously, just ask any pro

[HillRPete]

Wow, quite the feat.
[...]

[ultimobici]

The piece mentions gearing for a tandem nota solo machine.

[djconnel]

Right -- which makes it even more remarkable. Tandem riders need to be synchronized making it harder to honk up a steel climb.

The 21-22 jump seems way out of place in that progression. But they didn't use the 22 anyway. Concerns about overshifting to the biggest cog? It can't be a chainline thing since the tandem had the rear wheel driven from the front rather than rear bottom bracket, to allow the captain to shift the front (when there were multiple chainrings installed) using a rod-and-pivot front shifter.

BTW, I don't think it was a hillclimb, as the text claims they did 8 laps. But I believe a hillclimb was run in addition to the circuit race. The single ring makes sense for that, although perhaps with the race being all up and down front shifting was considered too cumbersome.

[stella-azzurra]

The answer could be that we are turning into wimps as newer technology makes the work easier. Man/Woman will evolve into a lump of fat as muscles are not used to their full capacity.

[tymon_tm]

wassertreter, i tried to be ironic, refering to pro's capabilities that seem to exceed natural, human abilities. guess that did not work out well..

[djconnel]

[Antoine]

it's not that steep, the hardest part must be around 12 %.

[HillRPete]

I've been thinking that Strava was very "generous" on the max gradient percentages, but blamed it on my mediocre GPS until now.

[djconnel]

I agree: when I looked at altitude data from other riders it wasn't that severe. I wonder if the segment was defined from iPhone data, which uses map look-up for altitude.

I was talking to the guys from Wahoo fitness at Interbike and was told altitude profile data on Strava segments tends to be of very mixed quality. Better, I suggested, was instead of using the reference profile data, for using data from activities on the KOM list which specifically came from riders with barometric altimeters + GPS. I should have taken my own advice here!

I'll update my profile.

[djconnel]

Much better... I used the data from the KOM instead of the defining segment data: