Drilling out the soles of SPD shoes

[Globalti]

Late to the thread as usual but I can tell the OP with certainty that it's not possible to move those cleats back 15-20 mm, which is why nobody in the world has ever done it. The steel backing plate inside the shoe won't slide that far back as it sits in a recess in the sole.

 

[Milkfloat]

Late to the thread as usual but I can tell the OP with certainty that it's not possible to move those cleats back 15-20 mm, which is why nobody in the world has ever done it. The steel backing plate inside the shoe won't slide that far back as it sits in a recess in the sole.

It is fairly trivial to do by creating a new recess / new plate. Plenty of people have done this. Will I be doing it? - no.

 

[T.M.H.N.E.T]

OP: Have you considered trying or comparing to different shoes? There's no direct correlation between brands as to the cleat adjustment area so another brand may well allow the cleat to be further rearward without modification.

 

[Twilkes]

Do you work on your calf length? Stretching ?
(speaking as someone with crazy tight calves, abnormally so, but I don't get cramp cycling, more likely to be hamstrings)

Sorry, I missed this first time round - I don't stretch particularly (or, like, at all) but I think it was down to an excessively high saddle and trying to scrape back on the pedals which meant I was pointing my toes down a lot, meaning my calf was contracted most of the time so it never rested. It's pretty much gone since I lowered my saddle and moved my feet forwards.

 

[Twilkes]

OP: Have you considered trying or comparing to different shoes? There's no direct correlation between brands as to the cleat adjustment area so another brand may well allow the cleat to be further rearward without modification.

I was limited to budget shoes, and in size 12/13 that were available online and in stock, so pretty much the only option were the Shimano ME2s (and Muddy Fox, but wanted to avoid those). If I ever spent more on shoes I'd want to try them on and would check for cleat positioning.

 

[Twilkes]

In case anyone finds this thread in the future, I extended the slots by using a 6mm drill bit, it was the biggest metal bit I had but a 7mm or 8mm would have made things less snug, and then smoothed off the edges with a Stanley knife. I’d intended to use a jigsaw to get a straight line but although the surface of the sole is very hard once you get a few mm down it’s like going through rubber so the jigsaw would have been overkill (possibly literally, it’s a beast).

I tried cutting the end off of the 4-hole plate to enable it to stay in the recess inside the shoe, but the saw really struggled with it and I found it difficult to clamp as it was so small. Luckily I discovered and bought the smaller 2-hole plates which sat on top of the internal structure without sticking up into the inner sole much at all. I ordered some 16mm bolts instead of the original 12mm ones, to make sure they would reach, but I probably could have got away with the shorter ones, they would have just been a bit more difficult to initially screw into the thread.

On the outside, the back of the cleat where it is positioned now actually sits on top of the extra thin layer of sole, so I didn’t need to cut or trim that at all. If I move them forward a few mm I might need to but they’re fine as they stand.

So this gives me an extra 20mm range for the cleat, which is what I was looking for. When I measure the new pedal spindle position in relation to the ball of my big toe it’s around 22mm behind it, which isn’t that much more than some bike fitters would end up with, especially for people with larger feet (and big toes, which move the ball of your foot further back than someone with smaller toes but the same size feet). A true mid-foot position would have been 50mm behind, much more than I had expected and on my shoe would actually have been closer to the heel than the tip!

Anyway, job done, thanks for the pointers.