Ive always used SPD’s when riding and have also suffered from cramp on 40k plus rides. For the last 6 months ive been running flatties and the cramp is for less severe and infrequent.

I have decided that i prefer the SPD’s so i put them back on yestarday and done a lap of W2 at Afan. 35k in and i got massive cramp in my hamstrings which hurt like a bastard (funny if you were watching me).

Why do my hamstrings feel so tight and cramp easily with the SPD’s? does this mean that my cleats are poorly positioned? too far forward maybe. At current they are 2-3mm in front of ball of my foot.

does sound like a set-up issue. Current trend is to have the spindle sightly behind the ball of yer foot.

moving back to the SPD’s from flats did first feel like the cleats were unnaturally too far forward. gonna try them back 1cm.

How is your saddle height?

You do stretch after riding?

my saddle height is ok, i think thats the one thing that i have correct. My saddle is fully back on the rails. So i may be able to lower the saddle to match pulling back the cleats on the pedals. Not sure if i need to bring the saddle forward too.

Will having the seat to high and cleats too far forward give your hamstrings jip? Got a big ride planned sunday and need to put new cleats on shoes. Dont want to get problems again this weekend.

tight hamstrings suggests saddle too low…stretching, diet and hydration matter also.

cleat position is more associated with calf issues IME.

Sounds like you may be relying on the attatchment to the pedals to provide a mechanical pull on the pedals. (not a bad thing) if you think that your hamstrings are there to flex your knee and will be working to pull the pedals up towards you while the other leg is applying the push/downward stoke. Can make you more efficient, particulary on the climbs.
This would also explain the difference between no cramps using flats as you havent got the same amount of upwards pull on the upstroke as your feet would come off the pedals.

did you move the saddle (forward) when you changed to flats? I find i need to.

do you stretch?

i dont stretch enough, have done this week though.

I moved the cleats back and dropped the saddle a bit today, ride wasnt long enough for cramp but it felt more natural.

flats let you subtly re-position your feet as you ride, I reckon this goes a long way to help prevent cramps – on a long spd ride I make a conscious effort to flex my toes every so often and unclip to give my feet a waggle, I find this helps.

My saddle is fully back on the rails.

Maybe you’ve too small a frame, and its just ‘showing’ in your hamstrings?

I concur with ianm3409, being attached to the pedal enables you to pull on the upstroke more so than when riding with flat pedals. You will be utilising your Hamstrings during this part of the pedal cycle hence the reason you are experiencing problems when using SPD’s.

Pulling up is very much a learnt thing, op will know if if is doing it….very few do, mostly those who have ridden fixed!

Success. A bit of tweaking my cleats, saddle height and position. I didnt get any cramp after 37k in the cold. Think ive cracked it. I hope.

Cool.

saddle height up?

Saddle forward. Cleats back a cm or and saddle hieght about the same. Made it feel like i wasnt doing hamstring stretching on every stroke.