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riding position when climbing
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I have been thinking about this for a while and would like to see what some of think.

I have a bike with tri geometry adn 650c wheels, I haven't measured the actual seat angle, but I'm pretty sure it's around 78. I also have my aero bar pads about 4 inches lower than my seat, so it's a relatively low position.

I also have a Surly Steamroller, set up as a fixed(46 x 17) that I use mostly for commuting but also for some training. This bike I have set up with a much different position from my tri bike. I have the seat much more rearward and lower.

Here are some measurement comparisons although I don't know how relavelant they are. Tri bike: seat height-30", setback-1/4" behind BB, basebar to seat nose-21". Fixed: sh-28.5", setback-2",basebar to sn-22".

Anyway, there is a short climb(2km maybe 5-6%) that I do fairly often(If you live in the Phoenix area, it is 5th Ave from Chandler Blvd to Telegraph Pass in Awatukee). Usually on my tri bike, riding in the aero position I can ride up at about 14mph without pushing too hard, the best that I've averaged with my tri bike was 18mph with a little tailwind. But on my fixed gear I can usually do 19-20mph up this hill in similar wind conditions. In general I've noticed that I climb better on my fixed than on my tri bike.

One thing that I did notice doing on my fixed was that I put my hands on the back side of the bar near the stem and push back. I can't do this on my tri bike because there isn't room on the base-bar with the aerobars mounted.

Also, the fixed feels like it actually weighs more and I'm using velocity aerohead wheels on the tri bike and a Campy Scirocco front(around 30mm deep, 20 spokes) with a 32h box section rear on the fixed.

I would like to get your opinions/ideas on this. Do you think it is simply the lower frictional losses in the drivetrain of the fixed that is letting me climb better on shallow climbs?



thanks,

Ed


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Re: riding position when climbing [edwinj] [ In reply to ]
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Just my own opinions: no I don't think the drive train friction is much of a factor. Unless your fixed gear bike is a lot lighter than the tri-bike, I would say that it is mostly due to your own pedaling power in the two different positions. You are much more 'opened' up if holding the back of the bars, which usually helps. Some people think being further behind the bottom bracket will emphasize the 'glut' muscles as opposed to the 'quads' when more forward. Personally, I climb a bit better in the lower position - why I don't know. Also, aero wheels will not climb as well due to more weight toward the rim and usually more weight overall too.





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Re: riding position when climbing [hoehler] [ In reply to ]
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I'd be willing to be a whole dollar that it's positioning, not weight, especially not drivetrain friction or aerodynamics or anything else that is significantly causing the difference in speeds you are seeing.

Being further back will allow you to activate those Gluteal muscles more...that's lots of potential power there. Also, being further back lets you drop your heels more...again, allowing earlier and greater gluteal involvement. It's no surprise at all. I don't climb worth a darn on a 78 degree bike, but do much better on a 76 degree one. I climb even better at 73 degrees, but not as much of an increase from 76 to 73 as I get from 78 to 76. Everyone may be a little different as to where their big jump in power occurs, due to anatomy, training, musculature, etc....mine occurs somewhere between 76 and 78 degrees.

Now, all that being said, it doesn't necessarily mean that you should bag the 78 degree bike. Especially if you are doing triathlons....because there is that nasty little run that follows the bike leg. You may find you climb better on a 73 degree rig, but can't run the first few miles as fast as your grandmother....BOOM...you just gave up your time gained on the climb. You may be much more efficient on the steeper bike, and more comfortable, and more calf and thigh muscle glycogen-sparing. After all, those gluteal muscles have to transmit their power via the quads, hamstrings, and calves, so these muscles have to work somewhat harder when the glutes work harder...come to think of it, your core muscles are also needed more to stabilize the body as the glutes work more, maybe your back and arms work more, too. You may be less stiff in the lower back/hamstrings coming off of the 78, so maybe it's better to lose a little climbing speed for the other benefits.

You just have to experiment to make an educated guess. But, it is positioning that makes the difference you are seeing.



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(That which is said in Latin sounds profound)
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Re: riding position when climbing [yaquicarbo] [ In reply to ]
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I concur. I realized this at Alcatraz. I rode my tri bike exclusively to about 2 weeks before Alcatraz. Switched to my road bike for the hills and according to my PT, I am giving out (on avg) 5-20 more watts. Faster on the climbs, etc..I'm still gonna race on my tri bike for the rest of the year though.
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Re: riding position when climbing [edwinj] [ In reply to ]
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I agree that it is probably a function of position as well, but also consider the gears.

46x17 seems like a pretty tall gear to me, even for a 5-6% grade hill. You've probably got up to a 39x21 on the tri bike or maybe a 42 instead. Either way, you're going to have to be down in the 14 or 15 to get similar gearing. So, maybe on the fixed gear, you have to go a certain speed. I've ridden behind guys on fixed gear mountain bikes and there are sections where they are just faster because they have to muscle it up the hills more, and trust me, I'm pretty sure it's not a fitness thing.

Just another opinion.


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Re: riding position when climbing [edwinj] [ In reply to ]
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I agree with -Tex. I think gearing may have something to do with it. There's a really steep climb I do that takes me about 18-19 minutes when I spin up in a 25 and only takes me 15- 16 minutes when done in a 19(for strength training).

Before you assume it's all the position, do a test: Put your tri-bike in an equivalent gear ratio to your fixed gear and then do the climb.

Also, the fact that you're doing the climb in your aerobars may have something to do with it. I climb much better out of the aerobars. In fact, I climb just as well on my 78 degree tri bike as I do on my 73 degree road bike given the same gearing.
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