Berichten weergeven met het label Gear ratios. Alle berichten weergeven
Berichten weergeven met het label Gear ratios. Alle berichten weergeven

vrijdag 31 oktober 2008

Eccentric (?) plan for the long weekend…70rpm

Saturday:
With only 7 days left before the Giro de Hotaka, I am planning to go on an extra-long “toge-busting” ride tomorrow cresting some 9 mountain ridge and tracking a nicely-shaped loop like this: Sekidobashi -> ①WADA-> ②TAWA -> ③TSURU -> ④IMAGAWA -> ⑤YANAGISAWA -> Enzan -> Katsunuma -> ⑥SASAGO* -> ⑦SUZUGANE -> ⑧HINAZURU -> ⑨OTARUMI -> Sekidobashi...
View Interactive Map on MapMyRide.com
(*completion of old & haunted Sasago tunnel repair works slated for today!...sure hope it will be passable tomorrow!!)

Bike: Colnago / Wheels: Fulcrum R-3 / Gear ratio: F 50X34T B 11-23T


Sunday:
Morning ride with daughter to recuperate: OTARUMI -> MAKIME -> OTARUMI

Bike: Vlaams / Wheels: Shimano RS20 / Gear ratio: F 52X39T B 12-25T


Monday:
All-day Chichibu pilgrimage: Sekidobashi -> Ome -> SHOMARU -> KARIBAZAKA (the long pancake approach cutting KAOBURI) -> Green Line over SHIRAISHI & SADAMINE -> R11 + some Fudasho (possibly Shinpukuji) -> R299 -> YAMABUSHI -> Ome -> Sekidobashi

Bike: Vlaams / Wheels: Spinergy / Gear ratio: F 52X39T B 12-27T


To avoid getting burned out and to allow my body to recuperate in time for the Hotaka event, I plan to do the Sat and Mon rides at a leisurely but steady pace maintaining as much as possible a 70rpm cadence on the climbs. I am still undecided as to which bike, wheels and sprocket to take to Hotaka. In view of the variegated parcourse and the +22% slope on the Day 1 Hillclimb, I am leaning towards the Monday set-up with the wider gear ratio and the softer wheels.

…Or perhaps an even more forgiving and cushiony combination such as the springy 27T-sprocketed Spinergy wheels on the soothing Colnago CLX frame?? I might test for the first time the efficiency of this combination on Sunday afternoon.

Gear ratio memo to myself:

Supposing a cadence of 70rpm (the ideal number of revolutions for hillclimbs excluding +12% spikes), then:

a compact drive 34T (Colnago) combined with a 23T cog will produce a speed of 13.0 km/h
34T combined with a 25T cog → 12.0 km/h
34T + 27T 11.1 km/h

A normal drive 39T (VLAAMS) combined with a 23T cog will produce a speed of 14.9 km/h
39T combined with a 25T cog → 13.7 km/h
39T + 27T12.7 km/h

To climb hills with maximum efficiency, one must find the ideal gear ratio adapted to one’s engine (= heart, lungs and legs) so as to be able to maintain 70 revolutions per minute.