clipless pedal problem

[Craig]

Hi all...wonder if anyone has had this problem. I have a set of Shimano PD-M520 pedals on my mtb and on my road bike. I have two pairs of the same shoe, FLR F-55. One pair has SM-SH51 cleats and the others have SM-SH56(M) cleats. My issue is both style cleat is difficult to clip in ( I have the pedals at the least tension setting). It appears that the hard tread part that you would walk on is almost too thick and is preventing the cleat from engaging fully. My feet actually flew off the pedals on rough ground the other day when wearing the multi release cleat. Not what you expect when clipped in is it?

[Hardi]

I had same problem with my first clipless mtb shoes that I had.. the cleat was recessed too deep into sole.. Good that it did not scratch the floor when walking, but difficult to clip in and out..  Because cleat did not reach the binding mechanism too well.. It reached, but very, very parely. Maybe, it was because I tightened the bolts of cleats too much, when installing them to shoe.  Shoes were some cheapest specialized shoes.. with naylon soles.

I now use only SM-SH56 cleats,  I don't dare to ride with them on PD-M520 pedals with these, because it can so easily unclip.. slip off to side, even when the spring tension isn't weakest. It seems that it can happen when foot tilt a bit outward.. Weight to out side of feet too much. But they worked very well with my M530 pedals and also work  with T8000.. I use T8000 pedals now, (because need to have flat side when riding at shared bike road with pedestrians and kids.. I feel safer this way.) T8000 actually did come with sh56, so I guess they really must work with them... But I think that with M530 they had even better match.
With M520 and lowest spring tension I slipped off from pedal even with SH51 cleats, and with shoes that had well constructed soles(cleat not recessed too deep)

[SickBiker]

On 8/12/2018 at 1:38 PM, Craig said:

both style cleat is difficult to clip in ( I have the pedals at the least tension setting)

I totally agree with @Hardi. It is the sole of your shoe, that creates the tension and not the cleats, which are compatible with the pedals. The M520 pedals are one of the easiest for mounting and dismounting.