How much should I drop my seat height for a 1cm change in cleat position (moved cleat rwd i.e. mid foot)?
I have thought about this , but concluded it depends how much you ‘ankle’. If you imagine where the cleat goes and bend your ankle up and down your effective leg length changes, as does the effect of moving the cleat.
I know when I am fresh that I ‘ankle’ more than when I am knackered, which led me to wander if optimum bike fit was different when fresh and when tired. I’ve not heard of bike fits happening when tired out. I also think I vary the amount of ankling I do with cadence and with % of FTP. When I’ve had fittings I’ve not had resistence to pedaling and can’t remember my cadence. I suspect it was slow.
I suspect the answer is that there is not one specific fit that it’s perfect for every situation, but a range and you possess some ability to adapt (unless it is widely wrong).
You could just video yourself before moving the cleat, measured the degree of maximum pointing of toes, and then calculate the amount using trigonometry, but that wouldn’t account for any chances that can occur with fatigue and cadence.
I will be interested to read if you get any advice based on evidence and not just guess work.
Incidentally, I didn’t move my cleats in the end. Are you doing it for running after? I thought about the calf muscles and of the two big ones; Gastrocnemius crosses 2 joints, whilst Soleus crosses just one, so they already do two different things. I’d want a bit better evidence that it helped, before I’d actively change something.
My goal is mostly to put less stress on the calves to have a better run off the bike. I noticed that I tend to engage the calf quite a bit and that my cleats are set pretty far forward.
Probably not an issue for the shorter races but I noticed my calves was quite fatigued at the end of my bike leg last weekend (70.3), not to the point of cramping but close… Had an OK run but I wonder if I could have had fresher legs off the bike. Now it could be anything that causes cramping but I thought about giving this a try here.
I have Shimano shoes with Look cleats so there isn’t a ton of room to move fore-aft and 1 cm is the most I was able to move them back. I’m thinking it’s not a huge change and a 3-4mm seat drop should compensate for it but I wanted to see if there are more qualified opinions on this.
If you imagine your foot is at angle Y degrees (relative to BB to saddle line) then I think it is a triangle with
Angle = Y degrees
Hypoteneus = distance of ankle joint to cleat = X
Adjacent (what you want) = X Cos Y
You could calculate the amount with both cleat positions and see how much has changed, but you need to know or guess what the angle is and measure the ankle-cleat distance.
If you look up the muscles yourself. I’m sure there are online versions of anatomy books. Grey’s Anatomy (book not TV show) is so old I expect it is out of copyright and out there somewhere. The calf isn’t just one muscle.
For example gastrocnemius plays a bigger role in toe off whilst running than it does in cycling, as it bends the knee and you are straightening your knee whilst pointing the toes in the cycle stroke. It might work and maybe there is evidence I didn’t find out there, but I didn’t read an exponent of cleat movement who seemed aware that there were muscles with different functions in the calf. I did read of people drilling holes for even further back cleats though & that because of the thin width in the true midfoot they used standards SPD pedals. I thought it sounded like a lot of faff. I can’t remember having read about changing seat height though, which suggests to me it is probably not a huge issue.
I guess we shall see if anyone on the forum has tried it and what they did.
I guess this is not a mod lots of people have actually tried. Maybe it is the faff
what is your crankarm length?
165
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Perhaps a middle ground starting point for guesswork would be to move the seat down 2 mm and forward 7 mm for every 1 cm “rearword” cleat placement. It’s not exactly precise, because it is going to depend on the amount of ankling (toe down riding style like Lance vs heel down like Lemond). But I think this would serve as a decent starting point for trial and error. I would not move seat forward the entire amount and I feel you do have to lower it a bit due to the overall “reach” being affected.
Anne, how would crank arm length come into play in terms of how much fore-aft to move saddle, and how much to change the seat height?. I think I am missing something
I’m definitely more of a toe down type.
My guestimate, not looking at you, but going by the geometry posted above, is that if you ride toe down (vs flat foot), then you loose some height and some fore due to your foot being angled down. I’d drop saddle a bit and go forward almost the same distance as the cleat placement back and see how it “feels”
Cool, I’ll give it a try.
Here’s a video I took this morning. This is with the cleats moved back and 4mm seat drop.
I was just curious as to what his entire system was. If he was running 172.5 and having calf issues, playing around with cleat placement and saddle position is moot.
Agree that getting that cleat back as far as possible is best in most situations. Trying to sync up the two levers (foot length and crankarm) while ankle is pivoting is the aim. Reducing dorsiflexion can occur more quickly with a crankarm length change instead of messing around with the foot lever length by changing cleat placement. But perhaps his spindle center is currently at or in front of his first metatarsal head - moving back 1cm shouldn’t necessarily need a change in saddle height or fore aft.
I’ve not seen any need to change saddle placement after cranklength change either; it’s not that the crank is shorter ‘at the bottom’, it shorter ‘at the top’, ie, the TDS. Ankle flexion may increase at BDC slightly, but the heel doesn’t drop as much at the TDC, where gastroc/soleous get eccentric contraction.
There are many cycling shoes out there that simply drill the holes too far forward; extender plates certainly help but those shoes with just single holes (no fore/aft adjustment) should be placed predicated on having the spindle center 1cm behind the first met head.
Cool, I’ll give it a try.
Here’s a video I took this morning. This is with the cleats moved back and 4mm seat drop.
I’m not a fitter by any stretch of the imagination, but it looks to me like you’re really pointing your toes to be able to maintain your knee angle and keep stable hips. I bet if you lowered your saddle a bit, the knee angle would stay the same but your ankle wouldn’t have to extend so much, which I suspect would help you run stronger off the bike.
I am going to hope that Anne comments on this because she seems much better qualified. I just wanted to say that you did everything right for an ST position video…race wheels —> check, aero helmet —> check, skinsuit —> check, nothing controversial in the background —> check. Well done! Seat definitely does not look “too high” so you escaped the “seat’s too high” mafia commentary too!
Seat definitely does not look “too high” so you escaped the “seat’s too high” mafia commentary too!
Hmmmmmmmm, I’d vote for a bit too high. Stop the video at the bottom of Spike’s pedal stroke and take a look a how much he points his toe to preserve an appropriate knee angle.
Hugh
I suppose I could drop the seat a tiny bit but it’s just the nature of any TT position that you “look” toe down because you are rotated forward. I think it would be impossible to have a flat ankle at the bottom. I’ll see how it feels if I allow the foot - leg angle come closer to 90 degrees.
Seat definitely does not look “too high” so you escaped the “seat’s too high” mafia commentary too!
Hmmmmmmmm, I’d vote for a bit too high. Stop the video at the bottom of Spike’s pedal stroke and take a look a how much he points his toe to preserve an appropriate knee angle.
Hugh
Fitter advice to you. Seek out a qualified fit Specialist and schedule a fit session with them. If you have already had a fit performed then ask your fitter.