Clipless pedals - what does 'float' do?

I have Shimano SPD-sl pedals. They come with two types of cleats, a red one and a yellow one. I have no clue what either does but I'm told one has 'float' and this is easier on the knees.
Can someone explain the term 'float' what it is, does, it's benefits, who would need it? In both great detail and simplified terms so that I can better understand this please?
Thanks.
Can someone explain the term 'float' what it is, does, it's benefits, who would need it? In both great detail and simplified terms so that I can better understand this please?
Thanks.
Food Chain number = 4
A true scalp is not only overtaking someone but leaving them stopped at a set of lights. As you, who have clearly beaten the lights, pummels nothing but the open air ahead. ~ 'DondaddyD'. Player of the Unspoken Game
A true scalp is not only overtaking someone but leaving them stopped at a set of lights. As you, who have clearly beaten the lights, pummels nothing but the open air ahead. ~ 'DondaddyD'. Player of the Unspoken Game
0
Posts
It can be very handy if you have any kind of knee problem, or if you prefer a slightly toe-out or toe-in foot position.
I like it, which is why I have speedplays.
This is the extent of my knowledge about float!
EDIT: Ooooh wait, there's one other fact - some pedals allow float but are sprung to central - they pull your foot back to the central position. Others have what may or may not be called 'free' float - it's not sprung. Speedplays have the latter.
Viner Maxima, Tifosi CK7, Giant Bowery, Old commuter.
[/url]http://www.bikeradar.com/forums/viewtopic.php?t=12650240
They also had a debate on a Kharma, that you must have missed.
I've tried both yellow and red cleats on SPD SL's and would definately stick to the yellows. I barely noticed it until I'd changed, but the extra float in the yellow cleats does make a difference, having your foot fixed in one position with no rotation (red cleats) felt very odd to me. When you think about it the leg has a lot of very complex joints, so allowing for a bit of sideways movement during the pedal rotation makes sense. My LBS told me the red cleats would give me more power when I got them, but in reality they made no discernible difference other than feeling slightly odd and uncomfortable.
Revised FCN - 2
Planet-x Scott
Rides
Unless you leave the screws loose on your cleats, thats a misuse of the term "float", I'd say.
(On the part of manufacturers, JG has correctly used the incorrectly used terminology)
Interesting to read the above as I was thinking of getting a new set of road specific pedals and shoes for the road bike. This is as much to remove the need to constantly change pedals with my mtb, as well as for something a bit stiffer. Worried though about the float thing. Any recommendations?
Try the Time road pedals, they have angular and lateral float, which should be extremely kind to your knee
Revised FCN - 2
Thanks for the advice, will have a peruse. Of course, I have to get some pimpy shiny road shoes as well :-)
Good to hear you're on the mend Rich
Cheers dude, looking to get back on the fixie to commute in the next couple of weeks thank god. Not being able to ride is seriously sending me nuts. I still think being on the MTB is at least a month off though
Revised FCN - 2