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show them the contents of this thread and they won't let you have your liberty either - sectioned on the basis of a danger to yourself or others...
You're quite welcome to try and turn a wheel backwards while I try and ride it forwards
That's a much more illustrative example than guess-work about crank lengths, wheel size and gear ratios. Bike in turbo with no resistance, person holding outside of wheel. Pedal away. I'd have my money on the rider every time unless the gear was massive and the tyre was grippy.
That's a much more illustrative example than guess-work about crank lengths, wheel size and gear ratios. Bike in turbo with no resistance, person holding outside of wheel. Pedal away. I'd have my money on the rider every time unless the gear was massive and the tyre was grippy.
Yeah probably so. If that is the case, then it's an interesting demonstration that the bike allows you to put more than 4 times as much power through your legs than just using your arms alone. Although it does depend a lot on the gearing, and these track bikes do tend to have very high gears no?
Thinking about it, you could modify the wheel turning method by putting the bike on the ground and pushing it forwards. I imagine you could put quite a large amount of force on then - if someone stands and pushes backwards on your handlebars as hard as possible, can you make the bike move forwards, or do you get moved backwards? That'd be a kind of fair comparison, I've never tried that either.
Joe
Your cranks are 170mm, compared to a 311mm radius wheel, which is 1.8 times the leverage. Then you're going through a gearing system, say if you're using a 70 inch gear, that's another 2.5 times the leverage. Using the wheel as a lever, you'd have a total of 4.6 times the amount of force. Are your legs really capable of applying 4 and a half times as much force as your arms? That may be true, although I'm not 100% sure of it. Using your arms would have a bonus in that it would be a nice smooth application of force, so you're much less likely to break things either - like when you use a scaffold pipe to remove stuck cranks, it always seems much less bad for them than using a hammer on the allen key.
I think the 70 inch gear = 2.5 times the leverage bit is wrong. You need a smaller chainring to get more torque. A bigger gear amplifies distance travelled, not force.
I'm pretty sure that the rider on rollers on a fixie would not be able to turn the wheel if someone is holding it. But the rider will be able to stand on the pedal and get his whole weight on it, so will have more force than you can get through your arms. Someone needs to test it!
I don't run a lock ring. Just used a chain and a bit of wood to tighten the sproket on to the hub and away. Been running ok around town for the last year ok.
I reckon I could hold a wheel quite easily on a roller while sam tried to pedal away from a standing start.
and I have successfully pushed someone backwards down the road while they were trying to ride forwards.
Does this mean I will or won't die when I ride the flaming bike?
It is getting late and at this rate I will be using the cock ring before the lock ring.
😉
[i]
I don't run a lock ring. Just used a chain and a bit of wood to tighten the sproket on to the hub and away. Been running ok around town for the last year ok. [/i]
But how do you ride?
Skip stops, skids, slowing with back pressure etc or do you mostly use the back brake?
Offroad is a totally different kettle of frogs with the far lower gear, steeper downs and varying grip.
I've undone cogs that have been on my fixed for a thousand miles by taking the lockring off and riding round the road and slowing down rapidly with my legs.
Tom - I am not planning to skid by pedalling backwards or anything clever like that. I reckon speeding up and gently slowing down will all the pedals will be used for. The occasional unexpected down hilly bit I guess but it is the south of England, Swinley will be as severe as it gets.
Are you saying off road without lock ring is okay?
I happily[1] ran fixed offroad for a few rides without a lockring.
[1]OK, that's a lie, it was shit.
It adds interest to the New Forest, just don't want to wreck a Phil Woods hub
As I said before JDI.
I'm sure it'll be fine as there are no downhills in the south anyway.
get some loctite - strong stuff.
he clearly just wants us to back him up .... hes not gettting a lockring is he ...
let him do it , then wait for the thread " ****ed my hub "
You WILL want to do skips 'n skidz 'n stuff & then it WILL come undone, trust me.
[i]But the rider will be able to stand on the pedal and get his whole weight on it[/i]
And the rider will be able to pull on the bars, dunno how much extra force that adds. The person standing in front of the bike is an entirely different proposition. There's all the additional factors of that persons's weight and the friction of their feet on the ground.
take the advice of some very experienced fixie riders WCA, at best you'll undo the cog and die, at worst you'll knacker your hub.