gear ratios and hill climbs

[asterix]

With a 36 inch inside leg measurement, I suspect I might not be average! Nevertheless, I am unaware of any difference between 170 and 175mm cranks.

WRT the OP, I find that ergonomics and frame stiffness are more important than minor weight differences. The bike built for me by Roberts transformed my hill-climbing abilities. They used 170mm cranks.

 

[bleakanddivine]

Meanwhile having established that the hill in question certainly exceeds my 15% guessestimate and may be close to 20% I will establish another thread to see what views others have of appropriate ratios

The LHCCC (London and Home Counties Cycle Chat) group ride in November took in the main circuit in Richmond Park, some of it in both directions. I don't see anything over 15% in the GPS log.

 

[gbs]

to bleakanddivine: I do not argue with mapmyride. Check it out for the section from RHG towards KG. Their data suggests that the short pitch up to the carpark exceeds 20% - I had previously guessed at 15% or so (based on skiing experience - I am an aged but novice biker) . I think the difference in average gradient reading is a function of the length of the measured sector. Regardless of the precise facts of the gradient perhaps you could tell us:
(1) of the gear ratios used by yr mates on that more difficult part of the stretch and (2) let me know how you deal with cleats when you are at yr personal limit.

 

[bleakanddivine]

to bleakanddivine: I do not argue with mapmyride. Check it out for the section from RHG towards KG. Their data suggests that the short pitch up to the carpark exceeds 20% - I had previously guessed at 15% or so (based on skiing experience - I am an aged but novice biker) . I think the difference in average gradient reading is a function of the length of the measured sector. Regardless of the precise facts of the gradient perhaps you could tell us:
(1) of the gear ratios used by yr mates on that more difficult part of the stretch and (2) let me know how you deal with cleats when you are at yr personal limit.

Hi gbs
Yeah I guess the figures will vary depending on the source. I'm not that familiar with the area myself so we could even be talking about a different stretch!

(1) Don't know what others were using, there was at least one fixed, but I would have used my lowest 36/30. This is the standard equipt on my 1981 tourer. (2) Never used cleats, still have the old toe clips. At 50, I actually prefer sitting rather than pedal dancing, I think it puts less strain on the legs and back, and less disastrous if the chain jumps. I can still get up most things, but the length would eventually take its toll now on anything over say 20%.

Jonathan

 

[gbs]

Jonathon, thanks for gear ratio info - makes me feel less embarassed that I failed on 39/23!
BRs GBS

 

[gbs]

Hi gbs
Yeah I guess the figures will vary depending on the source. I'm not that familiar with the area myself so we could even be talking about a different stretch!

(1) Don't know what others were using, there was at least one fixed, but I would have used my lowest 36/30. This is the standard equipt on my 1981 tourer. (2) Never used cleats, still have the old toe clips. At 50, I actually prefer sitting rather than pedal dancing, I think it puts less strain on the legs and back, and less disastrous if the chain jumps. I can still get up most things, but the length would eventually take its toll now on anything over say 20%.

Jonathan thanks for the ratio comment - makes me feel less embarassed that I failed with 39/23. As for the gradient, I doubt that we are confused; travelling from Robin Hood Gate towards Kingston there is only one climb. bikehike.co.uk suggests that the pitch is closer to yr GPS result. BRs GBS

 

[bleakanddivine]

I doubt that we are confused; travelling from Robin Hood Gate towards Kingston there is only one climb. bikehike.co.uk suggests that the pitch is closer to yr GPS result. BRs GBS

Ah, I wasn't sure whether RH was Robin Hood, Richmond Hill or RoeHampton but I see what you mean. On MapMyRide I played with the distances and got a small stretch of a few yards up the KG end to register as 18-20%, although this is downhill, and I think you are probably referring to the uphill Broomfield Hill section. Both these sections maxed at 14% when I rode them, both ways, Maybe using only the economy mode GPS sampling is why.

Anyway, good luck in resolving the gearing issue.

Jonathan

 

[DreamBig]

Today I came across a nice app called Bike Gear Calculator, www.BikeGearCalculator.com I had the same dilemma to get compact or not. this gear calculator gave me the answers I needed. Switching to compact now. As it turned out there are so many things to take into consideration. http://itunes.apple.com/app/bike-gear-calculator/id505985340?ls=1&mt=8