mooder

What's the best way to figure out the ideal length?

I adjusted the height of my seat post and my saddle position to respect the 145-155 knee angle & alignment with the pedal axle. I was at 125 degrees and now at 145. I feel more comfortable but now I start to get very hard to handle neck pain and discomfort around the deltoid area. I guess my neck is a bit too compressed but I don't see how I can change that. Any tip?

Campag4life

Hi,
Would help if you snap a pic with you on the bike leaning up against a wall...or on a trainer.
Neck pain has always been my Achilles heel. Would say most have something. Some guys have wrists, others have knees, some guys it their back. I don't have much of those other things but my neck lets me know if my posture is off.

So how to fix your neck. Truth? Watch the way an 80 year old rides a bike. Most are bolt upright. Neck is straight up and down. A head weighs the same as a bowling ball. Bend your torso over and hold up your head for 1-2 hours doing anything and many people will have some level of discomfort

So, you probably need to get between the position you are now and 80 year old upright guy riding his cruiser without neck pain with high handlebar

Only way to determine this is trial and error. Each of us are 'vastly' different in this regard..depending on your musculature, neck length, nerve structure, flexibility...any arthritis...etc. Some guys can ride flat backed all day. I have asked many of my riding buddies who are no faster than me. Many ride with 4 inches of drop and never have an ounce of neck pain. I am the opposite. I need to be more upright so my head is more supported by having my neck more vertical.

A last note and quite nuanced. The height of your shoulders matters. Shoulders too high impinges on the nerves that run behind the neck. Sometimes a more close in and lower handlebar helps this posture taking pressure off the neck. Too much reach can pinch the nerves at the back of the neck.

Good luck

mooder

Thanks, I will take the time for a snap but I don't know when! I will try an adjustable stem. Can be had for ~20$. I wonder if I should aim for a shorter one? Current is ~95mm, don't know the angle but probably around 6...

Campag4life

stem length depends on your choice of frame size relative to your body proportions including how aggressively you can ride in comfort. Latter varies greatly from rider to rider depending on fitness and flexibility. Most can't ride in a racer position without pain. This is an 'acquired position' thru miles of hard training.

79pmooney

How long have you been riding? As mentioned above, heads are heavy. But our bodies have pretty amazing ability to adopt. If this amount of forward lean is new to you, stick with it. Observe whether the discomfort you feel is muscle or something else. Observe whether it gets better or worse as the rest of our conditioning improves.

Edited for spelling

Ben

Campag4life

Here is a deeper dive into stem length not taught in bike fit 101. See below pic marked up by bicycle guru Dave Moulton.
Dave believes a common mistake is to position the handlebars too far away from the rider and too high. What this does as mentioned earlier is rotate the shoulder blades up which puts more pressure on the base of the neck when the neck is extended viewing the road ahead which leads to fatigue and pinching off the blood supply

Based upon his thousands of fittings, he believes the hands on the hoods should parallel the line intersecting the pedal spindle at 3 o'clock and the the hip bone. As a result, his critique is this rider needs a shorter stem with less rise.

See below:

mooder

I think a snap is definitively a good idea. It is indeed a new position for me... I added around 3 cm to the total saddle height.

Dean V

If you were to do that the pictured rider would need a zero reach stem set lower as well. That would be crazy.

OldTryGuy

Old rule of thumb......Hands on hoods, front axle hidden by bars when looking down. Ride it and go from there.

Another take.....John Cobb's Advanced Positioning System

Campag4life

You don't get it. The rider shown isn't necessarily on the correct size frame according to Dave Moulton. He may suggest a shorter top tube.

ckindt

The rider in the pic is riding a frame that is too small already.

fietsbob

Shermer's neck syndrome Shermer's Neck: Cycling's Most Bizarre Injury | ACTIVE


https://en.wikipedia.org/wiki/Michael_Shermer

Campag4life

Think so? Why don't you prove your point by photoshopping the rider in a better position on a larger bike.
If you can't produce proof, your speculation goes unsubstantiated.

ckindt

I don't think so. I know so.
The burden of proof is yours.

Campag4life

No silly. Its on your hollow conjecture. It isn't about me. You are criticizing a guy who is famous...a rule of thumb he used for thousands of fittings.
So the burden is on you. I am pretty open minded to fit because even racers past their prime and into retirement often ride up to 3 stem sizes shorter and higher, no longer able to sustain a stretched out position at the peak of their racing days. Same size guy...different fit based upon a change in weight, strength and flexibility. There is no absolute correct when it comes to bike fit.

ckindt

ok.

Fiery

For starters, the lines should be drawn correctly. The one for the arm angle starts way behind the actual shoulder, almost as far back as he suggests the hands should be moved.

Campag4life

More pot shots. You know better? Draw the lines in how you believe they should be to make your point. Basic computer skills. Repost the picture with what you believe the geometry should be.
If you don't, then you believe the rider is in a good position on the bike. Dave Moulton, a frame builder and professional fitter with a long career who marked up that picture disagrees.

Bike Gremlin

General starting tips on fitting:

bike fitting


Setting up road bars (after saddle has been set correctly):

Setting up road bike bars - Cycle Gremlin

Fiery

Oh noes, somebody dared to question your source. Don't embarrass yourself, use your eyes next time. You are smarter than this.

wphamilton

I was also wondering where you're supposed to draw the line to the shoulder, but this position looks wrong to me regardless.

For drawing parallel lines I suspect that Moulton has a few more qualifiers. If this guy un-hunched his back he might have parallel lines. Leaning forward more he might.

Wested

Fiery

"This position" - you mean the position of his shoulder as I've marked it, or the rider's position on the bike?

wphamilton

The reach does look wrong, but it could be the way he's sitting.

Fiery

Agreed, it looks like he could definitely do with a bit more drop and maybe a bit less reach. Obviously, judging a position by looks alone doesn't really work though, and the guy could be just fine the way he is.