The Bike Fitting Mega-Thread

For those that want to try and match the saddle position from your road to your MTB or vice versa, I have found that by pulling the saddle down into sag with a parachord rope.
Even on my Epic Evo, that only has 110 of rear travel, it does effect:

  1. Saddle tilt: Not sagged, nose down 4 degrees. At sag, front of saddle (ergon smPro) is level.
  2. Nose of saddle moves back behind the BB about 20mm
  3. If measuring the saddle height from BB, it drops about 5mm.

I’m sure with more suspension, this all gets even more exaggerated.


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Are you also sagging (manually compressing) the front at the same time?

No, haven’t done that. Good point.

I’m having a lot of trouble with fittings lately.
Everyone wants to slam the saddle back, to the point where some MTBs can’t go back far enough, but I always feel like I’m trying to get over the pedal.

I’m tinkering with running it forward and it seems to be getting closer.

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OK, just wanted to mention it because if you sag the front along with the rear, the angle delta’s you mention between unweighted and sagged will level out a bit. On par with the sketch geo I ran for you (and others?) a while ago.

As far as saddle setup, unless you are having serious problems with that forward position, I don’t know a reason to push rearward. Droppers and modern geo almost demand a more forward position vs what may have been common just 5-10 years ago.

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I’m going to keep trying it to see if it makes a big difference.

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I found this video really helpful for evaluating if you have a good fitter. If you ask questions before signing up for a fit, it could help weed out a bad fitter.

Related, I tried My Velo Fit and I really didn’t like it.

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Years ago I was told by an old hand that ideal stem length (or at least a starting point) is when riding if you look down the front axle shouldn’t be visible.

Essentially if the axle is visible in front of the bars it’s too short.

Old wives tale or good starting point?

It is a reasonable starting point, but there is more than just stem length that factors into it. Raising or lowering your stem will affect where the front hub sits in your view, even if you keep the stem length the same.

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Not horrible, but the realities of modern components kills it to a degree. Consider that the horizontal part ot the bat (tops) is the reference and what happens to rider reach after.

  1. Handlebar reach can vary from 65mm op to 100mm or more. This alone will impact the final location of the roder on the hoods.

  2. Functional reach of the hoods is not a single value either. It’s not easily measured, but even hoods within the same brand have different lengths. Even if yku match bar reach, this can move a rider 10mm or more either direction depending on the hoods compared.

All that to say that there’s far more to this than a simple summary like tray.

Thanks both!

I moved to a -17 100mm this time last year, I’ve since pushed cleats to a much further back position and lowered saddle by a bit to solve a recurring saddle sore hotspot (successfully I should add).
Now wondering if having moved hips down and forward a bit if I need to add some reach.

Food for thought.

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It’s meaningless as a fit rule these days (and probably always), but it’s also weird how often it works. Maybe it’s more of an optical trick.

Sounds stupid, but where exactly on the saddle should one be sitting? It seems logical to be on the widest part to spread weight more evenly but i always find myself comfiest on the skinner bit of the saddle, even across a selection of bikes. Is this indicating a saddle type preference or something else? I’ve tried adjusting fore and aft as well and kind of feel the same regardless. I wonder then if it puts quite a lot of load on my triceps as im trying to get more aero, and if i sat further back i would unweight my hands and arms more?

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You should sit where the saddle supports whatever part of your pelvic bones are “down” based on your pelvic rotation. The idea that you sit on your “sit bones” isn’t really right unless your back angle is quite upright. If you go down the Google/Youtube rabbit hole of SMP saddles you’ll see lots of examples of pelvic bones being matched to saddles forwards of the sit bones.

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Per the above, we typically want the wider parts of our pelvis bones sitting on the wider parts of the saddle. This can be the sit bones (ischial tuberosities) in some cases, but usually blends into the pubic rami with anterior pelvis tilt.

One basic check I mention to people is to look at where the end of your bottom is over the saddle.
Reach back with your hand while seated, hold it vertically along the back of your bottom and see where the saddle is in relation to your hand.

  • If your hand hangs well beyond the saddle back, you have a very rearward position that might indicate you could benefit from a wider saddle.
  • If your hand bumps into the top of the saddle, and you have more than maybe 5mm of saddle top visible, you may be too forward and might benefit from a narrower saddle.

In essence, the typical “good” position should “shadow” your bottom over the saddle without excessive overhang or underhang.