Going down in frame size?

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topflightpro
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by topflightpro

11.4 wrote:It's not quite as simple as some are portraying it here, and you may have more position improvement than some see here.

Consider what's happening here. You drop your front end and end up more aerodynamic. But in the process, you are changing both two critical measures, the angle of your hips to your thighs and your weight distribution. On the angle of your hips, this change will in practical measures change the power you deliver, for better or worse. Because it will demand a bit more flexibility in your hamstrings and glutes and lower back muscles, you may not see the improvement right away but be able to find significant improvement as you adapt to the position. That new position will change your saddle height (rotating your hips does that), potentially change your cleat position, and likely change your foot angle at the pedal. For what it's worth, you'll also change your rib cage position with regard to your diaphragm (which changes your lung capacity), and you'll change your shoulder angle (which can improve or worsen shoulder discomfort and also affect how you transition from seated to standing position).



This is really good info., but it neglects one other potential issue: changing the angle of the hips could also lead to injury if you lack the necessary flexibility in your hamstrings, glutes and lower back muscles. And there is a chance that you take months or years to adapt to that position.

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11.4
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by 11.4

topflightpro wrote:This is really good info., but it neglects one other potential issue: changing the angle of the hips could also lead to injury if you lack the necessary flexibility in your hamstrings, glutes and lower back muscles. And there is a chance that you take months or years to adapt to that position.


I think I made the specific point that one might accimatize slowly to the different position, and also that it might not actually result in better performance. Not changing position because one worries about flexibility-induced injury is like not racing faster because one is worried about overtaxing one's system or about bike handling skills. That's what training is for. I specifically said that only the individual could determine whether the position change was an improvement. If one doesn't look for ways to improve performance on the bike, it's time to hang up the bike. What we do, and what this forum in particular is about, is finding ways to improve our performance.

I actually pointed out to the OP that there were many more positional changes involved than simply lowering the front end of the rider. Some can be compensated for, some have to be adapted to, some don't work. It's the rider's judgment as to what works for him. And it's not just flexibility. Extra weight or large thighs or barrel chest can cut off your diaphragm long before you run out of flexibility. Curvature in your upper back can limit how well you can look up and forward when you're in a lower position (or at least be comfortable with it). And in small sizes, every fixed dimension such as the size of bars or the size of brifters has greater effect on position that it does on some on, say, a 58 cm frame. Frankly there's not much one can do to alter dimensions in a 50 or 52 cm frame compared to what that 58 cm can achieve, simply because one has to maintain clearances for the same wheels and basic rideability. I ride a 50 and can certainly attest to that. Big riders have more opportunity to dial in position than smaller riders do. But in this case, I simply said that the OP should consider more issues than just aero position, which is actually what everyone else is saying too. I simply listed some of the specific issues and how to address some of them.

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WMW
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by WMW

I had a major realization while trying to cope with a back injury during rides. If I relax my lower back, and extend and relax my lower abdomen (the opposite of sucking in your gut), I can get as low as I want without problems. The limit is the quads hitting my rib cage. No loss of power at all, with extreme drop. The muscle utilization and posture was very different from what I was accustomed to, but it didn't take long to adapt. I had previously held constant and unnecessary core tension.
formerly rruff...

AGW
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by AGW

@WMW, basically rolling your hips forward/sticking your tail out a little? This was a huge "aha" moment for me as well. Diaphragm clearance, more neutral (rather than lordosed) lumbar spine, and easy reach to the drops and invisible aero bars.
Last edited by AGW on Fri Nov 30, 2012 6:00 am, edited 1 time in total.

11.4
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by 11.4

WMW wrote:I had a major realization while trying to cope with a back injury during rides. If I relax my lower back, and extend and relax my lower abdomen (the opposite of sucking in your gut), I can get as low as I want without problems. The limit is the quads hitting my rib cage. No loss of power at all, with extreme drop. The muscle utilization and posture was very different from what I was accustomed to, but it didn't take long to adapt. I had previously held constant and unnecessary core tension.



It's called hip rotation and it's what good fitting is all about. Hip rotation drives your saddle position (height, angle, fore-and-aft), changes your saddle choice, and does a dozen other things to your riding position. Determining your hip rotation is where I start when fitting a rider, and I get them to adjust hip rotation if it's a meaningful handicap to his/her performance. For some reason I don't see it discussed much by domestic fitters, though the top pro fitters and many European fitters are much more conversant in it. I rather suspect that many don't understand it. I also suspect that when they encounter so many riders with no flexibility and bad hip rotation, they just don't focus on it and work with what they have -- instant gratification, as it were. It's sad how badly riders get fitted, especially when riders are often willing to work on their position and can achieve so much improvement.

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WMW
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by WMW

11.4 wrote:I rather suspect that many don't understand it.


In my case I'd spent decades with a very different posture and muscle engagement. I held a lot of tension in my lower back and core which I "braced against" to pedal. It is not so easy to change a habit like that. I mean, I didn't even realize there might be a different way to do it. I happened on it quite by accident one day, and though I felt that I was really onto something, I had to concentrate and relearn how to pedal with that posture.

The best way I know how to describe it is to completely relax the lower back and stomach muscles. Release all tension in that area, and try to pedal. If you aren't used to it, it will feel very weird at first and you will lose power, but it doesn't take that long to adapt. A lower torso feels very natural and comfortable when you do this.

I'd heard people talk about "tilting the pelvis forward" but when I tried that it didn't work at all. That's because I was still engaging the muscles in the same way as before and it caused even more discomfort.

A lot of people in this thread are talking about "flexibility", but IMO that has very little to do with it. You don't need to be flexible to have a low position. You just need to relax the core and pedal with that posture.
formerly rruff...

Don
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by Don

I agree with WMW about "flexibility". In my case, I have not become more flexible although my preference in position on the bike has become lower. If anything, I think that I have become more "agile".

basicuser
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by basicuser

I joined the board just to talk about the benefits of this thread. [Thank you to the contributors, btw].

I had a 53cm TT with a 13 HT/12cm stem with 42cm bars. Been riding this setup for 3 years.
I went to a 51.8 TT with a 10.5 HT/12cm stem with 40cm bars.

Wow. What a difference - it took me about a week to dial in. I try and ride as aggressively as I can. So this path of reducing drag coefficient may not be for everyone.
Couple points of feedback:

My saddle to crank length had to drop ~1/2 inch from first setup to accomodate the lower front end, because I found keeping my old saddle height created too much stretch for the hamstrings. It makes perfect sense though, if your drop dropped - you would suddenly find your quads ramming into your chest, the hamstring angle would be extreme, and difficulty getting blood to the legs because all your body parts near the saddle are now being squeezed by your upper body coming down. Saddle height and fore-aft are coupled, so I had to move the saddle back a little, down a little, front a little, etc - to get a really good position for my hips/quads. Not sure what the exact procedure is, but I found I spent a lot of time fiddling with these two positions until I got it just so. The result is, a good powerful stroke, more hip rotation from previous position, stretched flat back, and lots of room between my quads and lungs/rib cage [almost triathlon position like].

The benefit to dropping the front end - massive aero benefits. My bib straps form a nice horizontal ellipse in the mirror [while on the hoods!]. Very nice. Very comfy too, because I shortened the top tube. How comfy? When I'm in the drops, my shoulders are almost vertical and relax, allowing me to get even lower without tension or hold the position for an extended period of time.

I will never go back to 42cm bars. 40 is where it's at. Small chested/shouldered riders should really consider trying 40cm bars. I spent 8 years on 42's. Call me ignorant of change.

Power: I didn't really notice a big difference. It didn't drop and it's gone up maybe 10W for both 1hr and 5min, but that could just be from regular training, so it's hard to say.

The biggest difference for me is creating more space for the lungs and general comfort. The old setup was longer, higher, and wider - I was quite stretched out on the hoods. Maybe too stretched, because now, I feel like I am not straining to breathe during hard efforts [but it is hard to actually determine whether it was the effort or the position which creates discomfort]. I feel it is a very aggressive position, almost too much [?], because in any hand position - wrists on bars/holding bars/hoods/drops - my back is between 20 - 0 degrees to parallel. I haven't gotten a chance to do a 4 hour jaunt on this setup, so the long-term ride report will reveal itself in the spring.

Thanks again - we'll see what happens in 2013...

ichobi
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by ichobi

This is by far one of the most useful thread on this forum. Made me rethinks how I fit into the bike and various positions that could be improved. Thank you all.

Btw to the above poster: I assume you were riding a handlebar too width (42), i thought a smaller handle bar generally restrict your breathing? How should correct arms position in relation to the handlebar looks from our point of view? The width should be about our shoulder width right?

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SolidSnake03
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by SolidSnake03

So after reading through this thread I figured I would give the relaxed core/pelvic rotation thing a shot while I'm bored and snowed in. Turns out :unbelievable: :shock: WOW!

I'm currently running a 120mm Deda stem flipped with no spacers but on a "tall" bearing cover and that actually felt too high! I could bend my arms all the way to 90degrees at the elbow and my back didn't feel I thing. I kind of stuck my stomach out/forward a bit and rolled my pelvis forward and my back just sort of folded in half. It felt like my back just released or something and everything relaxed allowing me to bend as much as I wanted. The feeling was amazing! I seemed so loose and relaxed, also my legs had a ton more clearance and my body went much more horizontal.

I'm going to assume this is what a few of you were talking about? It was such a weird feeling, I think all my body weight/tension just got transferred to my arms. The only down side was that it felt like I was doing a push-up with my arms/forearms to hold my body in that position. Is this normal? Is that part of getting acclimated to that type of position?

Also, I do have my saddle slightly forward, straight post and about middle on the rails on a 54cm Spec Allez. This previously felt ok however that was with my back/core tense, now might it be too far forward? Maybe that is putting additional pressure on my arms?

*edit*
Forgot one thing, I previously have always had trouble reaching the hoods compared to the drops unless I ran a very short stem *100mm* which significantly altered steering/handling to my disappointment. When I rolled my pelvis a bit forward and my back released I had NO TROUBLE reaching the hoods anymore, felt fine aside from the arm pressure/weight.
Looks like I made a new 90 Proof friend

AGW
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by AGW

Sorry this has gone slightly OT, but here's a great article: Cycling Posture Part I

Edit: And another - Pelvic Tilt, quote below.

In this case, pelvic tilt refers to how we address the saddle or position our rear ends on the seat. Most of us spend a good deal of our days sitting at a desk or driving the car, and our seated position during those activities has influenced how we sit on the saddle: in short, we sit on our saddles the same way we sit on a chair. Our pelvis is rotated backwards, hips pointed to the sky, and our spine rounded forward to allow us to reach the handlebars.

The main problem is that last part: the center of our rounded spine becomes the focal point for a lot of energy and pressure. Think about bending a stick; at a certain point, that stick will break at the center where all the pressure is focused. Why not relieve that stress and allow your spine to be in a neutral position by rotating your hips forward?

Here's a quick drill I do with clients to help them find this position and feel what a neutral spine feels like:
1) Put your bike in a trainer - do NOT attempt this while riding;
2) Stand out of the saddle with your hands out wide and the handlebars (on the hoods/brakes for road bikes), bring your crank arms to be parallel with the ground, pedals at 3 and 9 o'clock;
3) While keeping your behind off the saddle, bring your nose down to the handlebars (a nice hamstring stretch as well);
4) Keep your nose down and then slowly lower your behind to the saddle and move it forward and backwards until you find the most comforting and conforming place to sit;
5) Then keep your hips still and slowly raise your head and shoulders (your pelvis should now be rotated forward);
6) Now think about stretching your spine along the axis that goes from the bottom of your spine to the top of your head, elongating your spine and further putting it in a neutral position (do not arch your back forward or back, but engage your core to help stabilize this position);
7) Lastly, relax your shoulder and arms. Let your arms be your shock absorbers and not translate impacts to your shoulders and back.


You should now feel like your handlebars are closer than they ever have. Try pedaling now. In addition to creating a better position for your back, you should be able to better engage your hamstring, hip flexors and quads.

Note: This is primarily for flat, seated riding. There are many situations that may change the position of your pelvis, back, etc; but a little efficiency here and there can make a big difference on your overall riding experience. Enjoying our sport means staying injury free and this should help prevent some pain in the back.

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SolidSnake03
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by SolidSnake03

Sorry about contributing to the off-topicness as well but it is a very interesting subject!

Also, one last thing than I'm done, have any of you experienced a relationship between some soft tissue/squish stuff discomfort as a result of forward pelvic tilt? I have found that the Arione I previously had on my bike became VERY uncomfortable to certain parts when rolling my pelvis forward while when I more "flex my back" it feels fine.
Looks like I made a new 90 Proof friend

AGW
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by AGW

I have noticed it with some saddles as well and have resigned to the idea that learning to sit properly on a bike might change your saddle preferences. I think a lot of saddles are designed to (try to) accommodate a population of riders sitting improperly on their bikes. The saddles of yore all have some sort of profile to them compared to many of the board-flat saddles of today (Toupe and Arione are probably the most ubiquitous examples).

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WMW
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by WMW

SolidSnake03 wrote: I have found that the Arione I previously had on my bike became VERY uncomfortable to certain parts when rolling my pelvis forward while when I more "flex my back" it feels fine.


From what I can tell, when I tilt my pelvis forward, the sit bones are closer together where they contact the saddle, and the effective saddle height drops.
formerly rruff...

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