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 Post subject: Bikeposition
PostPosted: Mon Dec 12, 2005 9:23 pm 
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Joined: Wed Oct 19, 2005 8:16 am
Posts: 279
Location: Copenhagen, Denmark
Just wanted to hear some opinions on front /aft saddle placement. I have recently totally adjusted my setup on my bike after reading some of Steve Hoggs answers on bikefit in the Q and A of cyclingnews. I am 192 cm with a 91 cm inseam. I used to be way up front on the bike with a 14 cm stem and the saddle almost as far forward as possible on a 73,5 degrees seattube with a 2,5 cm setback seatpost. I have now changed my style completely with the saddle all the way back and a 12 cm stem (contemplating 11 cm). The result is a much more comfortable position on the bike. On the trainer I get 15 extra watt at threshold (!) and generally I feel I´m using my gluteus and hamstring more with less quad pain. Surprisingly I don´t feel less aero on the bike and can still have a flat back.
Now this has got me thinking. It seems that old school bike manufacturers (italians pinarell, de rosa etc and Mercxx as well as Trek) goes for this laid back geometry, whereas a lot of newer bike makers go for the more steep saddle tube geometry. Where has this trend appeared from?
Has any of you done any experiments in fitting your bike like this and what has your results been?

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 Post subject: Bikeposition
Posted: Mon Dec 12, 2005 9:23 pm 


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 Post subject:
PostPosted: Mon Dec 12, 2005 9:46 pm 
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Joined: Wed Oct 06, 2004 6:55 pm
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Location: Vienna, AUT
I can't speak to the origins of the aggressive forward positioning, but the first time I saw a differentiation between laid back (Euro) geometry and something more agressive was with Cannondale - who back in the day had models that were "Criterium" oriented. I never saw the advantage and was more than happy with the standard slack angles and low BB in crits, but some North Easterners were excited about the aggro CDales back then.


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 Post subject:
PostPosted: Mon Dec 12, 2005 11:46 pm 
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Joined: Thu Sep 25, 2003 9:11 pm
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Location: SC, USA
hey... that's a really fun question. I wonder if there are any bike historians out there who can answer this question.

For what it's worth, to me, it makes sense to shift to a more forward position for TTs and Crits. I'm not sure I can satisfactorily explain bio-mechanically why this is, but I can tell (using a broad generality) that getting your legs over the pedals is easier when your saddle is forward. A steeper seat tube begins to mimic the bodies more upright walking/running position, but in turn is less efficient/comfortable (even though you can generate more power at a steeper angle). I think part of the reason is that you're involving more of your back and shoulder muscles with a steeper angle, but that's just my limited BS theory. I'd sure like to hear what others think about this.

As for stems, that's a totally different issue. Stems do effect performance, but not in a direct power output way like your saddle position does. The stem provides a point for your upper body to balance itself with. If your stem is too far forward your (shoulder) muscle are likely over extended. If your muscles are over extended, then they can't engage correctly to counter act the forces of your legs. Your upper body will spend a lot more energy using smaller muscles, cause a drain on your power output. Sooo many people use stems that are too long, and they end up with losses in power, saddle sores (and back problems!). I once had an adjustable stem... and I mapped out my HR as a function of stem length, and believe it or not, the longer stem, the harder my body had to work, and my HR changed by 10 bpm from the optimum point to 6cm over extended. I didn't have a power meter back then, so I couldn't gauge it's effect on power.

I think generally, for shorter duration events, such as crits, steep seat tube angles make sense. But I'm not sure I'd want to do a long training ride on one.

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 Post subject:
PostPosted: Tue Dec 13, 2005 1:30 am 
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Location: Sydney, Australia
You move towards the front to get more power from your quads which are more powerful (for most) than your hamstrings but don't have the endurance which is important for time trialing.

It depends on your anatomy and your riding style as to what's best for you, but I know people that lower their saddle to use their quads more (they have massive quads).

Not sure about the history of the road bike, but a look at the track bike might be more representative of set-up schools of thought.


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 Post subject:
PostPosted: Tue Dec 13, 2005 9:13 am 
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Location: Copenhagen, Denmark
I agree with the fact that you can get a higher peak of power from your quads, hence you go forward out of the saddle when sprinting, but I find that for anything over 1-2 minutes I experience severe lactate aciod built up in the quads compared to a similar power output in the laid back position. But on the other hand I feel sort of silly with my big a.. hovering around over the back wheel compared to the more fashionally "almost tilting forward position" :( A thing I´ve noticed is also that the lower down I push my upper body - like on descents - the more rearward on the saddle I go, which is also somewhat contrary to the idea of getting forward for aerodynamics?

Another subject of some concern is that my present position although feeling a lot more ergonomically correct gets my knees about 1.5-2cm behind the pedal axis, where they in theory isn´t supposed to be. Now I am currrently using 175 cranks but strongly considering a move to 180 (I started on 170, and 175 definately felt better). The question is will the longer cranks put my knees even further behind the pedals or will it make me comfortable with pushing my saddle 0.5 cm further forward :?:

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 Post subject:
PostPosted: Tue Dec 13, 2005 8:05 pm 
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Joined: Sun Oct 09, 2005 10:30 am
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Location: North of Scotland,Uk
My saddle sits as far forward as it can go.I find it nice and comfy and as my races as a juvenile are only about an hour long i can sprint the whole way.

http://www.flickr.com/photos/magnusdavidson/43810562/

Theres the bike!Getting my new one in febuary though


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 Post subject:
PostPosted: Sat Dec 17, 2005 7:06 pm 
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Steve Hogg is the greatest, actually he published my problem on 'pronating feet' in cyclingnews.com recent fitness article. Anyways the new school of though seems to be pushing the seat as far forward without putting weight on your shoulders. To perform this test release the handle bars while seated in a 3 at 9 o clock position. The idea is if you are too far forward you will fall forward, this indicates the kind of weight your shoulders are bearing. Remember your arms are for steering and nothing else. Of course I am referring to Road riding geometry.

Steve also believes your body adapts. As for stem I assume that once you find your seat fore/aft position the next easy thing would be stem length. With some experience you would know what feels right and riders should always try to achieve a 'straight back'.


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 Post subject:
PostPosted: Sun Dec 18, 2005 5:36 pm 
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Joined: Wed Oct 19, 2005 8:16 am
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Location: Copenhagen, Denmark
My position is actually a little back from this point (although I find it an excellent test) since I procuce more power (15 watts more at HR 160). It´s very interesting that Steve Hoogs goes directly against the whole trend in bikepositioning that has people stting way forward with all their weight on their arms.

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 Post subject:
PostPosted: Mon Dec 19, 2005 1:05 am 
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Sparta wrote:
My position is actually a little back from this point (although I find it an excellent test) since I procuce more power (15 watts more at HR 160). It´s very interesting that Steve Hoogs goes directly against the whole trend in bikepositioning that has people stting way forward with all their weight on their arms.


Didnt Keith Bontrager also denounce the KOPS in pretty famous artice 'myth of KOPS'.


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 Post subject:
PostPosted: Mon Dec 19, 2005 1:59 pm 
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Location: Copenhagen, Denmark
Yes I read that too. Actually i think lot of people are adjusting their saddle around their preferred (read fashionable) stem length rather than the other way round.

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 Post subject:
PostPosted: Tue Dec 20, 2005 2:17 am 
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Shouldn't the position of the cranks be more important? That was the Q implied by the original post.

I was taught to measure the distance from the knee to the pedal axle and move the seat accordingly. I've found that getting this position wrong results in knee pain though at the other end of the scale as per Hogg's position perhaps this isn't the case.


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 Post subject:
PostPosted: Tue Dec 20, 2005 4:35 am 
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Joined: Tue Jun 22, 2004 11:42 pm
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Location: lat 38.9677 lon 77.3366
A forward position tends to favor high rpm, farther back gives more power. Lymond bikes used to set the rider to the rear and as others have posted Cdale moved them up. Some riders wil have a preference for one or the other but most will be better served with a center position IMO
FYI after riding for 20 plus years I still fiddle with my saddle position depending on my flexability and fitness. I also tend to set the seat futher back when I spend lots of time in the mtns, forward when I am at the beach (flat) but thats just me


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 Post subject:
PostPosted: Tue Dec 20, 2005 10:22 am 
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Joined: Wed Oct 19, 2005 8:16 am
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Location: Copenhagen, Denmark
Quote:
I was taught to measure the distance from the knee to the pedal axle and move the seat accordingly. I've found that getting this position wrong results in knee pain though at the other end of the scale as per Hogg's position perhaps this isn't the case.


Try reading this http://www.bsn.com/Cycling/articles/kops.html

And this http://www.peterwhitecycles.com/fitting.htm

What I was unsure about was if any of you have experience with incresing crank length, does it change your balance on the bike so that you have to change your saddle position.

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 Post subject:
PostPosted: Tue Dec 20, 2005 10:29 am 
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Location: Sydney, Australia
It changes your leg angle, saddle height and seat position in one move.


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 Post subject:
Posted: Tue Dec 20, 2005 10:29 am 


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 Post subject:
PostPosted: Tue Dec 20, 2005 4:10 pm 
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Joined: Mon Dec 08, 2003 11:33 pm
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Location: Sweden
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Susanne has adopted a diffrent style for her pedaling and it seems to work for her (Markus Ljungkvist fourth at mens worlds also uses this style)


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