Single speed bikes.

[hubgearfreak]

Says who? It's just more noticeable when climbing.

not if you use the same bike, once with a fixed sprocket and once with a freewheel sprocket, it isn't. as brodie (&I) have stated, you can't compare a single speed to a geared bike.

unless you wish to simply keep repeating yourself & ignore the facts i suppose

 

[MartinC]

no i don't. but if you told me that people can levitate, i wouldn't believe you, regardless of my lack of biomedical knowledge. it's fairly simple Newtonian physics...all you (or I) need is to have studied it at GSCE or O level

This is the nub of the argument. It's not simple Newtonian physics. The bike and load will require the same input of energy to climb the hill whether it's fixed or free - no-one sensible disputes that. The power output of the engine is governed by many physiological factors and the idea that features of the transmission can affect this is perfectly rational and doesn't conflict with Newtons's laws.

The only way to prove this would be an experiment with a very large sample of riders performing identical climbs with fixed and free bikes with identical efficiencies measuring the oxygen used. Pretty near impossible. Many riders, but not all, report that their perception of the effort is that it's less. If it's not your experience then fine but nothing you've said is evidence that this effect can't exist for some riders.

 

[ASC1951]

so the question is - has anyone tried the same bike on the same day on the same hill, but with a fixed sprocket one time and a freewheel sprocket the other? i know i have

Call that scientific? You didn't do it at the same time; and how did you correct on the second run for your subjective feelings of what happened on the first run?

I've never ridden a singlespeed. To me, the whole point of riding fixed is to use your muscles downhill as well as up.

 

[RedBike]

I think most of us who have tried fixed have at some point done the 'hill test'. Ride up a hill on the fixie and compare the time taken to that of a gears / single speed bike.

For what it's worth, here's my effort.
http://redbikes.blogspot.com/2009/09/hill-climbing-fixed-wheel-vs-single.html

The fixie was quicker than the single speed; but the geared bike was quicker overall. This test wasn't in any way scientific but it does show that there is something about having the bike fixed wheel that aids climbing. Just a shame fixed wheel doesn't aid going back down the hills!

 

[swee'pea99]

What's with all the handbags? Fixie's make you well'ard, so you go faster up hills. Simples.

 

[PpPete]

ROFL