Saddle Set-back, Pros and Use of Smaller Frames
03-25-12, 05:05 PM
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Saddle Set-back, Pros and Use of Smaller Frames
I'm confused...
I've been playing with my bike set-up of late, mostly trying to get the right saddle height. I now seem to have it all dialled in and it feels pretty much spot on - I rode the same 50km course I've done about 100 times previously and managed to up my average speed by about 0.8km/h (which to me was a massive improvement).
But, something is still nagging away at me:
When I look at the pros riding what seem to be ridiculously small frames with massive setbacks and 140mm stems...it seems to fly in the face of KOPS... I.e. with such massive saddle let-back surely their knees are way behind the pedal spindle?
So how valid is KOPS?
I've been playing with my bike set-up of late, mostly trying to get the right saddle height. I now seem to have it all dialled in and it feels pretty much spot on - I rode the same 50km course I've done about 100 times previously and managed to up my average speed by about 0.8km/h (which to me was a massive improvement).
But, something is still nagging away at me:
When I look at the pros riding what seem to be ridiculously small frames with massive setbacks and 140mm stems...it seems to fly in the face of KOPS... I.e. with such massive saddle let-back surely their knees are way behind the pedal spindle?
So how valid is KOPS?
Last edited by Lexi01; 03-25-12 at 05:10 PM.
03-25-12, 06:05 PM
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https://www.peterwhitecycles.com/fitting.htm
...
Notice that in most of this there is no mention of measuring body parts. And nowhere do I have you dropping plumb lines from knees, positioning handlebars so they block views of front hubs, comparing the length of your forearm to the distance between the front of your saddle to your handlebar, etc. My methodology is quite different from what most people are doing in bike shops. The Fit Kit and other marketed fitting systems are based on the measurements of lots of different riders and their bikes. It assumes that the averages of those measurements are somehow going to result in a good fit for you.
...
Notice that in most of this there is no mention of measuring body parts. And nowhere do I have you dropping plumb lines from knees, positioning handlebars so they block views of front hubs, comparing the length of your forearm to the distance between the front of your saddle to your handlebar, etc. My methodology is quite different from what most people are doing in bike shops. The Fit Kit and other marketed fitting systems are based on the measurements of lots of different riders and their bikes. It assumes that the averages of those measurements are somehow going to result in a good fit for you.
...
03-26-12, 09:55 AM
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I just moved from a 56cm frame to a 54, went back to an offset seatpost, and went to a 120mm stem (could probably go 130mm easily). Although, my last stem was a 110 with -10 degree, new one is 120mm with -6. So in the end, the reach is nearly identical due to the less negative angle.
I really like the smaller frame with offset and longer stem with 15mm spacer under the stem. I have a much better stretched out, lower slung type feeling/more aero setup than previously. Probably gain nearly 1mph with this setup over the old just due to the body position. I race, so this is important. I will sacrifice some comfort if necessary, but I actually don't feel less comfortable at all like this.
KOPS...don't care about that. I've had two "pro" fittings, both people had me all over the place using KOPS, or other ideas/theories that felt like garbage and I ultimately moved my setup around to a better setup that generates more power and less fatigue. Never getting a "pro" fitting again. They are only as good as their "theory." Which pretty much isn't based at all on power/aero and better performance. Retul doesn't even talk about how they determine a proper setup and what proven methods they use to generate more power and better performance while maintaining some comfort level. Unless someone can show me proven power gains with a different setup and I still feel comfortable...no thanks.
I really like the smaller frame with offset and longer stem with 15mm spacer under the stem. I have a much better stretched out, lower slung type feeling/more aero setup than previously. Probably gain nearly 1mph with this setup over the old just due to the body position. I race, so this is important. I will sacrifice some comfort if necessary, but I actually don't feel less comfortable at all like this.
KOPS...don't care about that. I've had two "pro" fittings, both people had me all over the place using KOPS, or other ideas/theories that felt like garbage and I ultimately moved my setup around to a better setup that generates more power and less fatigue. Never getting a "pro" fitting again. They are only as good as their "theory." Which pretty much isn't based at all on power/aero and better performance. Retul doesn't even talk about how they determine a proper setup and what proven methods they use to generate more power and better performance while maintaining some comfort level. Unless someone can show me proven power gains with a different setup and I still feel comfortable...no thanks.
Last edited by zigmeister; 03-26-12 at 10:02 AM.
03-26-12, 10:18 AM
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zigmeister, help me out here.
I am pretty certain your saddle height is the same. That should be a given. You mention that your reach is near identical and you talk about stems, but not about the effective top tube length, head tube height, or any other frame geometry.
Why do you have a lower slung position now? I think the answer is somewhat obvious, your bars are lower and you have more bar-to-saddle drop. Couldn't you have done this on the previous size 56 frame with the right combination of stem and spacers? (Should be a "yes" unless running a slammed -17 stem on the 54.)
I am pretty certain your saddle height is the same. That should be a given. You mention that your reach is near identical and you talk about stems, but not about the effective top tube length, head tube height, or any other frame geometry.
Why do you have a lower slung position now? I think the answer is somewhat obvious, your bars are lower and you have more bar-to-saddle drop. Couldn't you have done this on the previous size 56 frame with the right combination of stem and spacers? (Should be a "yes" unless running a slammed -17 stem on the 54.)
03-26-12, 10:24 AM
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zigmeister, help me out here.
I am pretty certain your saddle height is the same. That should be a given. You mention that your reach is near identical and you talk about stems, but not about the effective top tube length, head tube height, or any other frame geometry.
Why do you have a lower slung position now? I think the answer is somewhat obvious, your bars are lower and you have more bar-to-saddle drop. Couldn't you have done this on the previous size 56 frame with the right combination of stem and spacers? (Should be a "yes" unless running a slammed -17 stem on the 54.)
I am pretty certain your saddle height is the same. That should be a given. You mention that your reach is near identical and you talk about stems, but not about the effective top tube length, head tube height, or any other frame geometry.
Why do you have a lower slung position now? I think the answer is somewhat obvious, your bars are lower and you have more bar-to-saddle drop. Couldn't you have done this on the previous size 56 frame with the right combination of stem and spacers? (Should be a "yes" unless running a slammed -17 stem on the 54.)
03-26-12, 10:30 AM
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if the old and new frame are very similar then setting up the original one for his desired fit would have removed the need to purchase the new one.
