New pedals = adjust saddle height??

[Kingfisher]

This has to have been discussed somewhere, but I can't seem to find it.

Finally giving up my old school dura ace 7401's for some sleek, new dura ace 9000's. Is there a way to determine how different pedals affect saddle height? I imagine saddle height will change slightly.

Thanks

[MattTuck]

You need something like this stack height comparison. (http://www.cyclecycle.info/pedal-stack-heights)

[ldamelio]

Yep, find the stack height of the two systems from the mfr specs or google and raise or lower seat accordingly. Higher stack height = higher seat height generally by same amount. If you're really compulsive, this might affect your reach and saddle setback by a millimeter or so.

[AngryScientist]

if you can get the stack height measurements, fine - compensate saddle height accordingly. That said, there is probably no need to be that scientific about it. you know what your leg extension should be and how pedaling the bike should feel. swap the pedals and go for a ride and see how it feels, and adjust accordingly. my suspicion is that the stack height between old and new dura ace is going to be so similar that adjusting saddle height wont even be necessary; i personally feel that the body is remarkably adaptable and many people but too much effort into getting the numerical component of fit dialed in. if it works, it works.

[batman1425]

I was struggling with fit across multiple bikes due to injury and used this method:

1. Start with your preferred setup - shoes, pedals, and saddle height. For me, that was the most recent fit on my road bike.
2. Install shoe and orient cranks straight down. Measure from the floor of the shoe (on top of the insole you use in that shoe) at the approximate center of the pedal to BB center.
3. Change pedals/cleats/shoes/insoles etc. (whatever you plan on changing) and remeasure as in (2). The difference is the change in stack height between your new setup and old.

This was essential for me getting my cross and gravel bikes set up properly - different shoes (+ custom insoles for my cross/gravel shoes that didn't fit in my road shoes) SPD vs speedplay, etc.

Most shoe/pedal contact points are close regarding stack heights, but a combination of several different things (shoes, crank, pedals, insoles, etc.) can add up to almost a CM difference between bikes depending on the parts selection.

[GregL]

Yes, pedal stack height can definitely change the fit between otherwise identical bikes. I have two Cannondales that are identical in geometry and nearly identical in components that affect fit (saddle, seatpost, bar, stem, crank arm length). The only significant difference: pedals (Ultegra SPD-SL vs. Dura Ace SPD-SL). The difference was enough that I could definitely perceive it and I did adjust the fit accordingly (~1.5mm lower saddle height/headset spacers on the Dura Ace bike). I also agree that some (most?) riders would be hard pressed to notice such a small difference.

- Greg

[benb]

I feel like it can change things a lot and it's very hard to prescribe some kind of formula for some of this stuff so that you can repeatably get it right.

The stack height seems like it can effect where you want your cleats and a whole bunch of other variables and it might take a little some trial and error to get the last couple mm right.

Some of these things always make me scratch my head.. I've got the same pedals and shoes on my 2 bikes. My commuter/mixed terrain bike I have the bars higher. For some reason having the bars higher makes the saddle feel like it needs to go back a little bit. Odd stuff.

[tumbler]

I would just go for a ride and see how it feels. Your body isn't engineered to require exact tolerances down to the mm. It changes from day to day, week to week, cold weather to warm weather, beginning of ride to end of ride, etc. If the stack height changes so much that you feel a difference, you can investigate the change in more detail and adjust your saddle height. If not, go in peace and enjoy the ride :beer:.

[benb]

Your body isn't engineered to require exact tolerances down to the mm.

It's not, but your body is also not engineered to be bolted onto a machine that does have exact tolerances and doesn't respond to your movements. Even if you can't feel when something is off you're going to suffer in some way if you ride far enough with it wrong.

[sandyrs]

if you can get the stack height measurements, fine - compensate saddle height accordingly. That said, there is probably no need to be that scientific about it. you know what your leg extension should be and how pedaling the bike should feel. swap the pedals and go for a ride and see how it feels, and adjust accordingly. my suspicion is that the stack height between old and new dura ace is going to be so similar that adjusting saddle height wont even be necessary; i personally feel that the body is remarkably adaptable and many people but too much effort into getting the numerical component of fit dialed in. if it works, it works.

Could not have said this better myself.

[unterhausen]

when I switched pedals, I think the stack height changed quite a bit. 1/8" seems to be about where I can tell the difference. I would think that changing between to DA pedals would be a small fraction of that

[tumbler]

It's not, but your body is also not engineered to be bolted onto a machine that does have exact tolerances and doesn't respond to your movements. Even if you can't feel when something is off you're going to suffer in some way if you ride far enough with it wrong.

My point is that "wrong" is a poor choice of words in this situation where the human part of the equation is somewhat fluid and the change being made is very small. The human body changes by millimeters every day so you aren't going to find a static fit that is "right", down to the millimeter, every day of the week. Our bodies change by millimeters based on the time of day, the weather, what we ate, our choice of shorts, choice of socks, flexibility, etc. I agree that fit is key and the OP should be as comfortable as possible. I am only pointing out that he may not want to stress over a mm or two change unless he actually feels a difference on the bike. It's like counting the grams on a pair of skewers... just because the scale shows a difference, doesn't mean we will feel anything out on the road.

[John H.]

I would expect a saddle height change from 7401 to 9000 to be in the order of about 1cm.
Maybe more if you changed to more modern shoes.

[bart998]

clip a cleat (no shoe) into the old pedal. Measure from the top (where it contacts with shoe) surface of the cleat to a set point on the saddle (say, the center of the rail) at the bottom of the stroke, with the crank arm in-line with the seat tube. Install new pedal and do the same. Make any necessary saddle height adjustments. Obviously, different saddles have different stack heights as well, so you need different reference points for saddle changes.....

*** Now that I think about it, you could also use the whole shoe. Just measure up from the underside of the sole.

[Mark McM]

It's not, but your body is also not engineered to be bolted onto a machine that does have exact tolerances and doesn't respond to your movements. Even if you can't feel when something is off you're going to suffer in some way if you ride far enough with it wrong.

If it is far wrong, then yes, your body may suffer. But experience shows that small changes can be accommodated without issue. For example, if you slide forward or backward in the saddle, or if you rotate the pelvis (as when moving from between the bar tops and drops) you may change your leg extension by a few millimeters. The same if you switch between thick and thin socks, or between shorts with thick and thin chamois. Yet these changes are relatively transparent to the rider.

On MTBs, getting a precise fit (as in down to the millimeter) is often considered not vitally important, since one tends to move around on their MTBs far more than on their road bikes. So, while you may almost never be on the exact "sweet spot" for fit on the MTB, you spend so little time in any one position that it doesn't matter as much.

[batman1425]

If it is far wrong, then yes, your body may suffer. But experience shows that small changes can be accommodated without issue. For example, if you slide forward or backward in the saddle, or if you rotate the pelvis (as when moving from between the bar tops and drops) you may change your leg extension by a few millimeters. The same if you switch between thick and thin socks, or between shorts with thick and thin chamois. Yet these changes are relatively transparent to the rider.

On MTBs, getting a precise fit (as in down to the millimeter) is often considered not vitally important, since one tends to move around on their MTBs far more than on their road bikes. So, while you may almost never be on the exact "sweet spot" for fit on the MTB, you spend so little time in any one position that it doesn't matter as much.

Depends on the rider. The difference between chronic pain on the bike vs. comfort for me was a grand total of 8mm in saddle position. Forward 5 and up 3. Sometimes small changes can make a big difference, especially when you are doing the same motion in that position thousands and thousands of times.

[benb]

OP will know when it's right or wrong.

Personally I think the range of saddle height that works for me might be a window 2-3cm in size but once I pick a height within that window the setback better be appropriately correct within about 5mm or it's going to get annoying. Too much setback my shoulders start to feel stretched out/back might get sore/wrists might get sore. Too little and my legs are going to push back against the saddle and lead to saddle sores. (This is assuming the bars aren't being moved too.)

I find seat height much easier to measure and get correct. I find the setback trickier to get right.. It makes me wish I had an X/Y tool.

[Satellite]

clip a cleat (no shoe) into the old pedal. Measure from the top (where it contacts with shoe) surface of the cleat to a set point on the saddle (say, the center of the rail) at the bottom of the stroke, with the crank arm in-line with the seat tube. Install new pedal and do the same. Make any necessary saddle height adjustments. Obviously, different saddles have different stack heights as well, so you need different reference points for saddle changes.....

*** Now that I think about it, you could also use the whole shoe. Just measure up from the underside of the sole.

LOL, have you ever put a cleat in the pedal without the shoe? Believe me you redeemed yourself with your last sentence. Use your shoe you are only looking for a relative measurement. The cleat is damn near impossible to get out of the pedal I had to use a screw driver for leverage and I wouldn't want to do that with a D/A9000 carbon pedal mine were metal.

[eric01]

My two cents. Bring an Allen wrench and a sharpie on you next solo ride. Fiddle with your seat and cleats until it feels right. Then mark with sharpie

[Kingfisher]

OP here, installed new dura ace 9000's, took wrench, etc on initial ride.....didn't even notice a difference!! Only difference was the new blue cleats, they don't seem to have the float variation that the old red look cleats have, but it didn't bother me.

Thanks for all input.

[benb]

Heh.. I guess it shows SPD-SL really aren't for me. I mostly used the yellow cleats, the red ones were just about instant knee pain no matter what I did. And now they have blue ones which lock you in even more?

Mostly the only issue with them for me with the yellow would be finding shoes with the holes further back. I went through about 4 pairs of shoes in the time I was using SPD-SL and I'm now convinced none of them really had the holes far enough back for me.

[GregL]

To clarify any confusion:

Yellow cleats = 6 degrees float, center pivot point
Blue cleats = 2 degrees float, front pivot point
Red cleats = no float, fixed position

I've always liked the yellow cleats, and I'm trying the blue now. I have a 70 mile ride planned for the weekend, we'll see how the knees feel afterward.

- Greg

[BdaGhisallo]

To clarify any confusion:

Yellow cleats = 6 degrees float, center pivot point
Blue cleats = 2 degrees float, front pivot point
Red cleats = no float, fixed position

I've always liked the yellow cleats, and I'm trying the blue now. I have a 70 mile ride planned for the weekend, we'll see how the knees feel afterward.

- Greg

And, don't forget, the yellow cleats allow about 5mm of lateral movement independent of the 6 deg angular float.

[benb]

That makes a lot of sense.. my right foot likes to point out on the pedal, it's definitely easiest to get that right with the yellow cleat.

The reason I tried the red at one point is the lateral float kind of drove me nuts as my left foot would tend to float inward and rub the crank. A lot of that but not all of it had to do with bad fitting though.

[BdaGhisallo]

I have spent a lot of time on spd-sl pedals, first using them all the way back in Nov 2002 when the design was first released. I always used the yellow cleat and that lateral movement always irked me. In the last six months I have transferred over to the blue cleat and after spending more time focusing on getting the cleat position sorted, it is fantastic. I feel super locked in while still having a little movement to help out the knees and ligaments.