cadenceblur Posted September 26, 2011 Share Hi Guys Does anyone have the formula for determining km/h based on one's cadence?I am doing some training on the indoor bicycles found at the gym, but they don't provide a reading on speed, only cadence? Link to comment Share on other sites More sharing options...
Zac.A Posted September 26, 2011 Share Not completely sure but i dont think its possible.If you are rolling at 70r/pm in a massive gear then you'll probably be going around 35/40km/h, but if your struggling in an easy gear at 70r/pm then you could be going at 25km/h. You'd need a power meter or some other things to do that.I think. Link to comment Share on other sites More sharing options...
gogo@ Posted September 26, 2011 Share Would depend on gearing - what sprocket you're in and then what speed you're turning at (cadence). But I'm not sure how that works on fixed-wheel spinning bikes where you're using resistance to control your speed?? Don't see how you can work it out 'cos there's no clear relationship between this resistance and cadence that you can use... But gym bikes with speedos are making a calculation, based on what?? I'd like to know as I've wondered how 30km/hr compares on one of those with the real thing... Link to comment Share on other sites More sharing options...
gogo@ Posted September 26, 2011 Share gym bikes with speedos are making a calculation, based on what?? How fast the wheel spins. Duh. Link to comment Share on other sites More sharing options...
Minion Posted September 26, 2011 Share Speed [km/h] = cadence [rpm] x Gear ratio x wheel rollout [mm] x 60 / 1,000,000 Gear ratio = No. of teeth on front chainring x no. of teeth on rear sprocket.Wheel rollout [mm] ≈ π x wheel diameter [mm] The problem with comparing a spinning bike to normal riding is choosing the right gear ratio and wheel rollout estimates.On a road bike, rollout is about 2096mm. On a spinning bike, it's a meaningless number. Edited September 26, 2011 by Edman Link to comment Share on other sites More sharing options...
Tankman Posted September 26, 2011 Share Are you having an uitkak session with yourself there gogo? Link to comment Share on other sites More sharing options...
tunariaan Posted September 26, 2011 Share ..lol Link to comment Share on other sites More sharing options...
Tankman Posted September 26, 2011 Share SportTracks has a cadence plug-in that can estimate you ave cadence based on speed and gearing (there is a gearing plug-in that can guess what gears you are using) As Edman says ... doesn't mean anything on a spin bike, how do they determine resistance from one spin bike to the next? Not a consistent value. Link to comment Share on other sites More sharing options...
Guest agteros Posted September 26, 2011 Share SportTracks has a cadence plug-in that can estimate you ave cadence based on speed and gearing (there is a gearing plug-in that can guess what gears you are using) As Edman says ... doesn't mean anything on a spin bike, how do they determine resistance from one spin bike to the next? Not a consistent value. The ST3 gear plugin I've got guess gears based on cadence, speed and info you provide w.r.t. gears on the bike. Doubt it can do a double guess based on nothing though Resistance does not affect gearing, but rather incline, or a head wind If the speed for a cadence is known, then, armed with the correct calculations the gearing meters development can be calculated, and then a set of gears can be picked which will approximate the meters development? However, wind resistance an other outside factors are still not taken in account, so there is no real purpose to compare an indoor cycling session to an outdoor session, other than curiosity? Link to comment Share on other sites More sharing options...
Tiny K Posted September 27, 2011 Share here is an idea - how about just skipping the IDT and actually going for a ride Then your speed, cadence, and gearing will all be relevant Link to comment Share on other sites More sharing options...
gogo@ Posted September 27, 2011 Share Are you having an uitkak session with yourself there gogo?More fun than editing your own post, don't you think?? *~) Link to comment Share on other sites More sharing options...
Tankman Posted September 27, 2011 Share More fun than editing your own post, don't you think?? *~) Absolutely, very entertaining, please continue! Link to comment Share on other sites More sharing options...
NotSoBigBen Posted September 27, 2011 Share Just wondering what wheel size you would use when you do these 'calculations' 26' for the 'big bmxr's' and 29' for the 'clowns' Link to comment Share on other sites More sharing options...
gogo@ Posted September 27, 2011 Share How fast the wheel spins. Duh.Sharp. Took you 4 minutes to figure that out. Past your bed time?? Link to comment Share on other sites More sharing options...
X-Man Posted September 27, 2011 Share ..lol Nice rottie there TunaRiaan. Beautiful dogs in the hands of right owners! Link to comment Share on other sites More sharing options...
Tankman Posted September 27, 2011 Share Nice rottie there TunaRiaan. Beautiful dogs in the hands of right owners! Wrong fred dude! Link to comment Share on other sites More sharing options...
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