I am Spartacus
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roadjunkie said:
what gear were you in when it got its steepest?
Triple to Double!
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what gear were you in when it got its steepest?
Tell him about power output Jimbo and how it links to gears.
This question in the context of, well nothing really, is always impossible to answer. To give advice we need to know what gears you use, what speed you travel at, what riding you do etc... Otherwise you might as well ask, 'cheese, red or white?'
This question in the context of, well nothing really, is always impossible to answer. To give advice we need to know what gears you use, what speed you travel at, what riding you do etc... Otherwise you might as well ask, 'cheese, red or white?'
Crackle said:
My pleasure....
You can cycle up any hill at the same power output you give to ride at 30kmh on the flat.
Mine is 185 Watts. Yours will be different because your bike is different to mine.
You just have to gear the bike to achieve it.
At 30 kmh, I use an 81" gear at 79 ish rpm cadence.
To ride up a 10% gradient for any length of time, it will be ridden on a 39" gear ( 30 x 21, Yes, it’s a triple ) at 80 cadence at 14ish kmh. The bike's 'dead weight' is 25 lb. (1/25)x1000 = 40. The 39" gear is close enough.
In reality, the 10% hills around Warwickshire are so short, I ride them at 40 rpm on a 67" gear using both halves of my legs.
If you are a 'Spinner' you immediately give yourself a disadvantage because you want to 'Spin' up the hill, requiring a lower gear than us slow revving lads.
The media has prescribed 'Spinning' for several years. I would advise 'mixing it up a bit' to build the muscle fibres for those hills where you run out of gears.
You have the choice. Either 'Spin' up the hill and buy standard fit trousers, or use higher gears and have to buy tailored trousers.
The latter costs more, but looks better.
According to Jimbo's encyclopaedia of cycling, to ride up a 45 Deg slope, 1:1 or 100% gradient, your bike needs a 10" gear.
What you do is get your hands on a 48 tooth chainset. The type where the ring is swaged to the crank arm ( cottered ). Cut off the swaging until the ring falls off. Put the chainring on a lathe and cut it until it fits on a SS freewheel. Jig it and weld the chainring to the freewheel.
Set the crank arm up on a faceplate so the BB hole is central, and then centrally clamp an 18 tooth sprocket to the crankarm. Weld the 18 tooth sprocket to the crankarm.
Assemble these onto a stripped down bike and you have a 10" SS freewheel bike.
Now take the bike to a 45 Degree slope and with the help of your school chums holding you upright, ride up the slope.
This is, of course, is an extreme, but if the bike weighs 25 lb, to get up a 25% gradient for half an hour, you need a 24 inch gear.
Something like a 30 tooth ring to a megadrive 34 tooth sprocket.
What you do is get your hands on a 48 tooth chainset. The type where the ring is swaged to the crank arm ( cottered ). Cut off the swaging until the ring falls off. Put the chainring on a lathe and cut it until it fits on a SS freewheel. Jig it and weld the chainring to the freewheel.
Set the crank arm up on a faceplate so the BB hole is central, and then centrally clamp an 18 tooth sprocket to the crankarm. Weld the 18 tooth sprocket to the crankarm.
Assemble these onto a stripped down bike and you have a 10" SS freewheel bike.
Now take the bike to a 45 Degree slope and with the help of your school chums holding you upright, ride up the slope.
This is, of course, is an extreme, but if the bike weighs 25 lb, to get up a 25% gradient for half an hour, you need a 24 inch gear.
Something like a 30 tooth ring to a megadrive 34 tooth sprocket.
jimboalee said:What you are describing here is an "Alpine" chainset. 55/37 where 55 x 21 was the same as 37 x 14. 37 x 25 was 40" and 55 x 14 was 106".
Tom used to ride with 'Bar end shifters', which made it a bit tricky to change both mechs at the same time with one hand like it was with 'downtube levers'. he would have needed to put both hands on the drops to change both mechs.
A 50 x 14 was only 96". He would have been really pedalling it on the descents
Are you saying he didn't ride a 50 then? If so I beg to differ. There's reference made to this in plenty of articles and books on cycling written at the time Simpson was riding. Simpson himself said he rode Stronglight chainsets as they were the only ones at the time that could provide a 50 tooth chainring.
When you've got a bunch of top level pros it's the climb not the descent that makes the difference. Especially when, as in the sixties, the passes were badly surfaced so it was far harder to go blazing down the descents as the riders do today. Equally the difference between the riders (especially in the era before physiologically altering drugs) is often psychology. Mountain stages are usually decided on the final climb so this is where the edge is needed. Hence Simpson's reason for using a 50 was psychological and for little else.
