I know I am twenty years behind the times, but I am about to switch from clips to Shimano 105 clipless. The pedals have two cleat options - fixed and 3 degrees of float each direction. What are the advantages and disadvantages of float? I am an older rider, but ride almost every day. Thanks

Float is better for the knees and ankles. More is better.

float allows your foot to twist side to side a bit without popping you cleat out. this is good if your leg doesn't move in a perfectly straight motion. for example, if when you pull up your heel goes out and when you push your heel goes back in, then float is good because it allows for this. if you have no float, your knee will compensate for your foots desire to pivot.

now if you have awesomely straight knees or you had an awesome bike fit, then no float is nice because it won't let your feet twist you out of your fit.

it's really a preference in the end. do you want your feet pretty much stationary or do you want them to have a little give from side to side.

It's up to you but I vote for float.

edit: my current pedals float about 7 degrees which I think may be a bit much, but 3 should be fine

I love my float, I think my knees would never forgive me if I went to zero float.

OK, educate me, how do I adjust the float in my SPDs?

Standard SPD have 9 degree float, multi-release SPD have 6 degree float and have a big M marked on them.

https://www.cambriabike.com/Images/pr...lti_rel_cl.jpg

my look pedals came with 0 degree float cleats and they nearly destroyed my right knee.

Float it.

The Shimano 105 pedals the OP is talking about are SPD-SL pedals. I do not know anything about SPDs, but with SPD-SLs to adjust float involves buying different cleats. For SPD-SLs you can tell by the color of the plastic "bumpers" (I don't remember the correct term, but they are the plastic parts on the cleat that protect against wear on the metal parts). The yellow ones have 6 degrees(I think) of float, whereas the red ones are fixed and have no float.

I myself have the same pedals as what the OP is looking at (PD-5610), and use the yellow cleats that came with them. They work very nicely

Mel likely float.

one of the reasons i love speedplay is the adjustable float. and more is NOT necessarily better. i can not stand 15 deg. float. and happen to love the feel of no float, especially when climbing, that being said, if i know i am going to do a longer ride, with speedplays, i have the option to "open" the float to 3-5 degrees for some movement. I do not understand why other companies do not give you that option with out having to buy other cleats.

at the same time speedplay has its cons. you will most likely loose cleat bolts, even with locktite, and the cleats cost about $30-40.

Not necessarily. However having no float makes the cleat positioning, q-factor, etc. More critical. If everything is correct no float can work very well. Float can also be worse for some people if they are really sloppy and have a lot of movement as they pedal.

I used to think the same thing. Then I got a professional fit and found that with the bike properly adjusted to fit me, I could get by with minimal float...