Tuesday, April 27, 2010
Sidi shoe and SPD-SL compatibility issue
Ran into a problem with newer model Sidi road shoes (the last few pairs I've had this issue with are the Sidi Genius 5) and SPD-SL pedal/cleat system.
I need to research this further, but my guess is that Sidi, in an effort to continue to reduce the shoe weight and especially to decrease the stack height of the sole, has begun making the sole of the shoes thinner.
I do believe that this is more of an issue with Shimano than Sidi -- I don't have this problem with the Sidi shoes when I use Look pedals or Speedplays.
With the SPD-SLs it's even a challenge to get the screws to "bite", when you try the first-time installation of the cleat -- they just don't seem long enough. When I tried a 12 mm screw, however, it bottomed out before it could ever tighten down on the cleat and washer. Once you do get them fastened with the 10 mm screws it turns out you get only about two (2) turns on the fasteners until they are "tight" -- definitely not very confidence inspiring. Once you do get them fastened, if you need to remove and refasten for any reason, it's much easier the second time as it seems that the threads, which are pressed into the sole of the shoe, "pull out" slightly and seat themselves further toward the cleat side of the sole, which is a fairly common occurance with many shoe threads.
I have heard that there are 11 mm fasteners available to fix the problem -- apparently they "bite" easily when you first put them on, but, based on how early the 10 mm screws bottom out, I can't imagine that the screws that are 1 mm longer are going to tighten very well on the cleat either. Both the 10 and 11 mm should hold initially, but cleat fasteners have a way of unwinding -- anyone who has had a cleat come off mid-ride can attest to this.
I don't have this problem with the Look Keo system at all -- the rectangular washers are thicker, and the entire setup seems to have more leeway built into it, as I am able to shim and wedge the Looks, and I can always find a proper fastener length that works. When I tried to place a varus wedge under one of the SPD-SL cleats, I could not find a length of fastener from my whole trove that was a workable length.
I thought about using a thicker rectangular washer (possibly just substitute in the Looks) and a longer fastener to see if that alows for a bit more thread overlap, but I'm not sure that the fasteners won't protrude below the cleat and 1. contact the ground first when you walk and 2. it may interfere with the engagement on the pedal.
If anyone else has some experience with this combination and has a different, successful solution, I'd appreciate any feedback.