 Neil it's camny cool. So how are you mate? But you know how you told me to put my seat up last night. I didn't tell you I cut the chimney off my BMC yesterday as well Small dick syndrome. I'm a flamingo. I know Good. Yeah, no no there does seem weird A good way a good way Yeah So if you didn't watch last week's video I'll put it somewhere up there in case you want to check it out But in a nutshell last week I took my BMC team machine into my local bike shop trilogy cycles here on the Sunshine Coast to get new cranks Installed which are seven point five millimetres shorter at the same time We cut the top off my chimney on the BMC team machine Which essentially made the front end of the BMC shorter because we cut the steerer tube off and the back end So where the seat is taller had to go up and down because what I neglected at the time Was the crank length change meant that I had to put the seat up and I was worried Had I wrecked my BMC team machine for my purposes anyway So after I edited that video and published last week I quickly jumped back on a phone call with Neil Stambry to get the full lowdown on the change in seat height And how to manage that and while on the phone with Neil He was explaining to me after watching my video that he actually thinks the chimney chop will not be an issue Because of what the cranks are going to do to my overall body position So I said to Neil over the phone I said can you explain that to everyone for me and he kindly said yes So I barged into his house two days ago and he's got some pretty interesting Insights to share about this crank length change and the positive impact It's going to have to my position making the chimney cut a non-issue But before he talks about that I got Neil to briefly discuss the methods of moving the seat up when you change crank lengths Because there are a ton of questions about that in the last video. So let's get into it Basically the easiest way to explain it is is as the crank gets shorter Your leg has to reach less far to the bottom of the stroke So it's logical that the seat height would need to go up to maintain the same kind of Angle if you like at the bottom of the stroke and and I don't measure seat heights Or or dictate seat heights by based upon knee angles at all I set seat height based upon control of the leg extension But in general it will need to go up now There's this occasionally There's a really a really rare possibility that there'll be an exception to that rule And the seat height won't need to change if the the person's a really extreme heel dropper Or the crank length change makes some other major sort of Change to their to their to their motion of their leg But in general the seat will need to go up somewhere between five and 10 millimeters So the variation depends a lot upon what the person does when you raise Sorry when you shorten their cranks Basically the seat needs to go up by an amount that varies sometimes between five and and and 10 millimeters It seems to be about the right range, but sometimes up to 15 millimeters If the person's having a lot of trouble controlling the bottom of the stroke with like a 172.5 crank And you shorten the crank by you know by seven and a half millimeters And suddenly their leg starts to gain proper control of the bottom of the stroke Sometimes that that that will really raise this that they're necessary Raise of their seat height will go up a lot and you might need to raise their seat up to 15 millimeters It all depends upon the person and I haven't seen you writing this thing yet But I said yeah, I'll just raise it five millimeters to start with But you know until I can see you on the on the bike and check out what's happening with your leg extension And so the the idea is that your seat height needs to go up But then that person if their crank length was limiting Their pelvic rotation forwards By shortening the cranks you will increase the ability of that person to to anteriorly rotate their pelvis to to roll their pelvis forward And as you do that if you imagine your hip is a ball and socket joint operating like this It's going to go forward and down right as you roll your pelvis forward. So that Then brings the center of rotation of the hip Forward and down closer to the cranks again So that can that can be where the the seat height changes more than the crank length changed So as as the hip goes down and forward the hip the hips rotational center gets closer to the crank And so you may need to go up and back More than the seven and a half millimeters And it depends basically upon how much that individual rider Makes that change And if they do it a lot you might need to go up by 15 millimeters, you know And and so i'm hoping that in your case your hip impingement, which is reasonably severe if it becomes Significantly unloaded as a part, you know on the shorter cranks your hips are going to roll forward and down More so you you will need to raise and possibly move the seat back a little bit That that varies a lot depending upon The rotational angle of their pelvis How much that affects their hamstring engagement at the bottom of the stroke? Some people as you roll their pelvis forward their their hamstrings go from being completely useless and doing nothing To suddenly engaging across the bottom of the stroke a lot more and then they will they will need to move the seat back Or or sometimes forward And they may bear their weight differently on the saddle as well And as they roll their pelvis forward The the sit bones the isiopubic ramai they they curve in three dimensions And so as you roll your pelvis forward you might sit deeper into the saddle or more shallowly up on the saddle Which can change the effective seat hiding as well So our hope with you is that because you you previously had this very rounded C-shaped curve in your back due to due to a posterior rotation of your pelvis um on the on the seat My hope is that if you start rolling your pelvis further forward here Your effective torso length that the you know if we took an imaginary dimension between your hip and your shoulder It's actually going to get longer because your spine will straighten out So you you'll go from being hunched to hopefully more extended And that can that can be a significant significant change And so the front end will need to quite likely go out And possibly down or just down or just out It could be it depends upon the person as to how much their spinal posture changes But steve hogg uses this um reference on his website, and I like it as well He calls it effective torso length because obviously we're not really changing the length of your torso But we're changing the shape of it, which effectively changes the length of your torso You know if you look at me from the side with a hunched body my head goes down You know 30 millimeters if I straighten my spine out it goes up 30 millimeters So your effective torso length on the bike can change quite significantly with a crank length change up or down If the hip impingement Is causing an issue like like it was for you So my hope is that you'll roll further forward here Your front end will go out and down and we may end up having to run a 10 mil longer stem And having to drop it 10 to 15 millimeters as well as raising the seat So this is where the Yeah, it may need to drop down to be you know the the holy grail of road cycling the slam stem right And you know that that would be nice because of the aerodynamic advantages that it that it brings to to you as a as a racing cyclist But we're not doing it to make you more aerodynamic We're doing it to make you more comfortable because if if you roll your pelvis further forward And your torso gets longer suddenly those bars are going to be too high and too close to you And you're going to prop yourself on them and bear more weight on your hands Like we talked about in the in the balance section of that of the video that we did before And so you may find that you get some unintended consequences of shortening the cranks like you start getting Numb hands because you're bearing so much weight on your hands And suddenly you need to drop down the bars and lengthen them out to get to get the weight to come back off your hands So it changes the whole kind of effective balance of the rider by changing their pelvic rotation And that I should qualify that that only really occurs if there's hip impingement In play quite quite probably. Yeah. Yeah, I teach for serious cyclists who've got good bike handling skills I'll often tell them to sort of ride with their forearms on the bar for a while Just just for five minutes two or three times a ride to condition that anterior rotation because it kind of forces them into that forward rotation of the pelvis And also to ride on on what I call the the joystick position Which is to hold the hood there and drop there drop their elbow down horizontal You know, they're forearm horizontal to the ground and that again will start to condition that anterior rotation of the pelvis And if you've spent a lifetime riding your bike with a with a posteriorly rotated pelvis And we suddenly give you the ability to to not do that It does still take a bit of time to change that that ingrained motor technique, you know that ingrained patterning So um You'll need to think about it briefly, but it will very soon very soon become normal to you And how did you go noticing the cadence increase that usually comes with it? So what i'm going to do next week is share my initial first impressions on the crank length change It's too early for a comprehensive review yet But certainly there are some things that I have noted that I think it's worthwhile sharing at this point in time Some things that are positive and also some things that i'm a little bit concerned about Now I wanted to quickly mention that the chimney that I talked about last week in the video I focused very much on aesthetics and I neglected A very important safety item Which i'm not going to reinvent the wheel There's a very good video that ray all did from lucid technique Which i'll link to below if you want to check that out and i'll leave you with some scenes now of my wife On Zwift doing some training. I'll catch you all in the next video It's going on boy What are you doing Alice? Baking a cake for you guys. Yeah. Yeah, you're doing new training sessions on Zwift. How's that going? It's good. I like it. I mean i'm watching it, but what are you doing? I'm watching Netflix On your phone That's pretty cool. Yeah, what show are you watching? I'll let you get back to it. Thank you