So, i was reading a recent write up where a guy got a retul fit, and they now try to produce a 110 degree angle at extension. Thats really a lot lower than im used to.
I always believed it be 135-145 degrees. If youre trying to emulate an angle closest to full extension, that would seem logical because your leg is strongest at full extension.
Albeit, retul believes that your should be engaging your quadriceps more, hence the lower angle. But wow, that would be a crunched hip angle!
Thoughts?
Are you asking about knee angle or hip angle ?
So, i was reading a recent write up where a guy got a retul fit, and they now try to produce a 110 degree angle at extension. Thats really a lot lower than im used to.
I always believed it be 135-145 degrees. If youre trying to emulate an angle closest to full extension, that would seem logical because your leg is strongest at full extension.
Albeit, retul believes that your should be engaging your quadriceps more, hence the lower angle. But wow, that would be a crunched hip angle!
Thoughts?
“they” as in retul or the bike fitter? In the end, it’s up to the bike fitter and person being fit to truly determine the right fit for the person. retul, from my understanding, is strictly a guidance tool. retul can’t ask you “how does that position feel?” I had a retul fit couple years and then one non-retul fit just recently. In my situation, the non-retul bike fitter seemed far more knowledgeable and I felt much more confident in the adjustments he made.
Knee
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I believe that’s the retul standard. Looking at the pro peleton, it has become more prevelant than i realized.
I have observed one thing about retul and seat height:
When you measure your seat angle statically and get a number, and then re-test with retul while pedaling, the knee angle will then measure more acute (than the static number) while pedaling via retul measurements. Conversely, if you try to get that same good knee angle with retul while pedaling, and then re-test while static, the knee angle will measure to be more obtuse (than the dynamic number). Your leg will also feel and appear more extended. And your seat will feel too high.
The bottom line: knee angles measured statically are not equivalent to knee angles measured dynamically via retul. Maybe the retul folks have finally realized this and are now compensating for this measurement artifact?
Stupid newbie observation so go easy on me … lol
If I look at Dan’s diagram and the diagram in my retul fit sheet they are measured differently.
Look at the smaller angle on the retul sheet (knee angle extension) and subtract it from 180 to compare it to Dan’s diagram.
In my case, 180 - 37 = 143
Is this more akin to what you were expecting ?
WD 
No worries.
Agreed, in addition to my observations above, you are correct, knee angles are even measured differently. Why? Who in the heck knows? Maybe to make us more confused.
That is why I use the terms ‘more acute knee angle’ and ‘more obtuse knee angle’, they focus on what the knees are actually doing vs how you measure the angle.
Sorry, that was aimed at the op - I have only just noticed that my reply quotes your user name in my title !
Stupid iPhone … lol
WD
I believe that’s the retul standard. Looking at the pro peleton, it has become more prevelant than i realized.
correct me if I’m wrong, I’m a newbie and certainly no bike fitting expert but the retul can have standards but I thought they are guiding standards to give the bike fit expert a good starting point? not just a “hear are the numbers. do this” but if their standard is a starting point and is working for many riders then maybe that’s why it’s showing up.
So, i was reading a recent write up where a guy got a retul fit, and they now try to produce a 110 degree angle at extension. Thats really a lot lower than im used to.
110 would be a common knee “flexion” (top of pedal stroke), not extension.
Yeah, that’s the other angle on my report - 109 and 112.
I am guessing I am a bit different side to side or the marker position was a bit off and / or moved.
WD
I have observed one thing about retul and seat height:
When you measure your seat angle statically and get a number, and then re-test with retul while pedaling, the knee angle will then measure more acute (than the static number) while pedaling via retul measurements. Conversely, if you try to get that same good knee angle with retul while pedaling, and then re-test while static, the knee angle will measure to be more obtuse (than the dynamic number). Your leg will also feel and appear more extended. And your seat will feel too high.
The bottom line: knee angles measured statically are not equivalent to knee angles measured dynamically via retul. Maybe the retul folks have finally realized this and are now compensating for this measurement artifact?
Ankling is a pain in butt, isn’t it?
I have observed one thing about retul and seat height:
When you measure your seat angle statically and get a number, and then re-test with retul while pedaling, the knee angle will then measure more acute (than the static number) while pedaling via retul measurements. Conversely, if you try to get that same good knee angle with retul while pedaling, and then re-test while static, the knee angle will measure to be more obtuse (than the dynamic number). Your leg will also feel and appear more extended. And your seat will feel too high.
The bottom line: knee angles measured statically are not equivalent to knee angles measured dynamically via retul. Maybe the retul folks have finally realized this and are now compensating for this measurement artifact?
Ankling is a pain in butt, isn’t it?
Not really. Because this measurement artifact seems to happen even if you put your leg in a static position at BDC with your ankle in the same position as you have when you pedal.
But, more relevant, is that most of the “knee angle at BDC” guidance out there (even if it is not evidence based) has typically been generated for static knee angle measurements. We need to use new guidance for retul dynamic measurements of seat height. Otherwise retul tends to set riders’ seats far too high.
The bottom line: knee angles measured statically are not equivalent to knee angles measured dynamically via retul.
This is fairly well known http://www.jsc-journal.com/ojs/index.php?journal=JSC&page=article&op=view&path[]=94
I find ~5deg difference between static and dynamic to be a decent rule of thumb
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The bottom line: knee angles measured statically are not equivalent to knee angles measured dynamically via retul.
This is fairly well known http://www.jsc-journal.com/...ew&path[]=94
I find ~5deg difference between static and dynamic to be a decent rule of thumb
Agreed, but this is nearly never mentioned among bike fitters and various fit discussions that I have read. And there are still lots of retul fitted riders out there with their seats way too high.
Agreed, but this is nearly never mentioned among bike fitters and various fit discussions that I have read. And there are still lots of retul fitted riders out there with their seats way too high.
It’s mentioned in the training and resources for my system…
I think the issue you’re seeing is fitters that can’t process all the information (both during the fit and as it was presented during the training) and ignoring hip motion and ankling metrics. Not a failing with the Retul guidelines as all those numbers are good.