Longer bolts for MTB spd cleats

[greenmeansgo]

Having seen a physio I'm about to experiment with spacing out one of my cleats. For this I will obviously need longer clear bolts. I know the thread is M5, and I guess the counter sink is standard. The existing ones use a 4mm Allen key. I can only find ones that use a 3mm Allen key, or a screwdriver.

I'm sure that a 3mm will round off too easily, and that a 4mm Allen key would be better than a screwdriver.

Anyone know if what I'm looking for exists?

[Sergeant Pluck]

You might find that the existing bolts will cope fine with the 1 or 2 mm difference involved.

What model are the cleats and what length are the existing bolts?

You could achieve the same effect with an internal wedge within the shoe under the insole. That depends on how much room you have in the shoe, and whether you find the difference in room between your feet to be tolerable.

[Biggsy]

I can't find countersunk M5 screws with 4mm AK heads yet, but plain-slot screwdriver can be more than good enough, depending on what tools you carry on rides (if you like to be prepared for anything).

I get my Look cleats extremely tight with a T-handled screwdriver at home.  I carry (but have never needed) a suitable bit for my Ratchet Rocket.

[LittleWheelsandBig]

HK has a 5mm spacer under her Keo cleat. We tried spacing out a SPD cleat but it protruded from the sole too much and was extremely difficult to get into the pedal. She ended up using a 5mm shorter crank instead with her SPD bikes and the cleat spacer with her Keo bikes.

Slot head screws work a lot better than 3mm Allen bolts.

[greenmeansgo]

Great replies so far - thanks! I'm looking to space the cleat out about 5mm so I would need new bolts. I guess walking anywhere like that would become a pain like in road shoes.

What was the clipping in difficulty you had, LittleWheelsandBig?

I like the crank length solution, and might steal that idea if this experiment solves the leg pain problem!

[LittleWheelsandBig]

The pads on a MTB shoe help guide the cleat into position. Lift the cleat out of that and it is much more difficult.

If you want to make a SPD spacer, make it just about fill the recess. Any gaps between the spacer and the walking pads will tend to catch the pedal's cleat mechanism.

[Sergeant Pluck]

5mm is quite a bit of additional height for your foot to be above the pedal axle, but I’m no physio.

If you can reveal the length of your existing bolts, it would make it easier for us to find ones that are 5mm longer.

[LittleWheelsandBig]

Biomechanically the height of the foot above the pedal axle is only a marginal effect. Plenty of folk (including Shimano!) have invented pedals with reduced or negative height. They don't show noticeable improvements in performance.

[greenmeansgo]

Thanks for the ideas. For now I'm trying spacers underneath the footbed. Today's ride in indicates this might have improved things slightly already.

The cleats and bolts are just whatever comes with M520 pedals. However the posts above discourage me from messing with the cleat right away. Spacing out the footbed is quicker and easier. If I need to try spacing the cleat out, I'll just get some flat-head bolts.

[Brucey]

presumably you have uneven length legs?  As I understand it (for cycling purposes) most folk seem happy with a packing/spacer/crank length difference that is about half the difference between the leg lengths.  A few experiments (inside the shoe is easiest if you can manage it) will soon tell you if you are on the right track or not.

I too would hesitate to pack out SPD cleats on an SPD shoe, for the reasons LWaB suggests.  What might work easier/better is to use a different pedal system or a road shoe with an SPD converter on it. The converter can be packed out, which preserves the geometry of the cleat and the surrounds.

If you do experiment with packing of an SPD cleat, bear in mind that many shoe/pedal combinations rely on the shoe sole (each side of the cleat recess) bearing against the pedal to help stabilise the cleat against tipping laterally.

BTW 4mm AK CSK M5 screws are not standard items.  You might find ones with torx key fittings though.  Slotted screws work well but the slot isn't that deep; prolonged use in an SPD cleat could easily wear the slot away entirely.

cheers

[greenmeansgo]

Yep, leg length discrepancy is being blamed for the leg pain which has plagued me on and off for years now. 5mm is about half the discrepancy, and I tried a 3mm footbed spacer today and it appears to have helped.

Torx head is a good shout. If I try messing around with the cleat itself that's what I'll get.

[Biggsy]

For the bolts, Torx head is another option - eg. eBay

[andrew_s]

The pads on a MTB shoe help guide the cleat into position. Lift the cleat out of that and it is much more difficult

Some of the more expensive MTB shoes come with replaceable tread (eg Sidi SRS models). If you spaced that out to match, you reasonably should be OK walking

[LittleWheelsandBig]

HK has 5mm compensation in cleat spacer or crank length and another 5mm via cycling-specific orthotics. Her walking orthotics have 10mm compensation.

[greenmeansgo]

Thanks for your help - I got some Torx bolts and the shim has dispensed with the leg pain. Awesome.

However, as indicated up thread, it's really difficult to clip in. I can't figure out the detail of why this is. Anyone have any ideas?




I'm on the look out for new cranks so I can have 170mm one side and 175mm the other. But in the mean time ...

[Brucey]

I think that clipping in will be difficult unless you extend the packing shim past the nose of the cleat; I think that the front claw needs to be pushed down (usually by the shoe sole) so that the rear claw is able to be engaged.

 As it is, I would expect the rear claw to be pushed down and the front claw to go up and then the cleat won't snap into the rear jaw.

Good result that your packing works OK though, leg-wise.

cheers

[greenmeansgo]

Thanks for that Brucey. I might try a new spacer shape as a temporary arrangement.