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Seatpost with adjustable setback(10 posts)

Seatpost with adjustable setbackkilimanjaro
Jan 13, 2003 3:43 PM
I have seen posts from people inquiring about seatpost with more setback and I have seen replies suggesting from Campy Daytona/Centaur to Selcof.

Excluding seatposts like the Selcof CNC Bio Position or Look Ergopost which have a lot of setback adjustment, do "regular" seatposts like Centuar have any setback adjustment? If not then I assume the setback on these seatposts is accomplished with the seat rail clamp further back from the center of the post. Is this correct?

Thanks
no adjustment on the post...C-40
Jan 13, 2003 4:12 PM
Traditional road seatposts (like Campy and Shimano)have the front of the seat rail clamp located approximately at the centerline of the post.

The only posts that can be said to have "additional" setback are those that position the front of the clamp even further back. Selcof, ITM and Easton all make models that have additional setback, but they aren't adjustable. The new Easton carbon post has the most setback of those just listed.
Selcoftarwheel
Jan 14, 2003 11:56 AM
The Selcof Bio post is adjustable. I have one. You can set the clamp in one position that is comparable to most posts, such as Campy. Or you can move it to another position with about 2 cm more setback.

By the way, I bought a Selcof post because I was having trouble moving my saddle far enough back. About the same time, I bought a new Koobi saddle and found that I was able to position it correctly without the new post. The rails on the Koobi are positioned such that it allows more setback than most saddles. Fortunately, the Koobi saddle is also the most comfortable saddle that I have tried.
"excluding the bioposition"...C-40
Jan 14, 2003 12:17 PM
The question excluded the bioposition model. Selcof makes a number of other models. The two-bolt models have a bit of additional setback, but no adjustment.

http://www.selcof.com/Pages/start1.htm
you can tell I'm not a lawyertarwheel
Jan 15, 2003 5:11 AM
Missed the part about excluding Selcoff. But what's the point then? If you exclude seatposts with more than the usual amount of setback adjustment, what's the point of the original question? Anyway, various seatpost models have varying amounts of setback. I would suggest talking to a knowledgable salesperson at a good bike shop or online store like Excelsports, who could recommend models with more setback. I'm not sure it would be any less expensive than a saddle though. If you're in the market for a saddle, check out www.koobi.com, which has reasonable prices and a 30-day return policy of the saddle doesn't fit. Koobis allow more setback than any other saddle I have tried, and I've tried a lot of them.
How much adjustment do you need?Kerry
Jan 13, 2003 5:03 PM
A typical saddle allows 3-4 cm of fore-aft adjustment, the equivalent of 3-4 degrees of seat tube angle. That's a lot. Rather than a superleveraged post, maybe you need two posts for different duty (one for road riding, one for TTs?).
Re: How much adjustment do you need?kilimanjaro
Jan 14, 2003 10:07 AM
Maybe a few centimeter more? Currently when I am on the drops I wan to push my butt off the back of the saddle. I thought a new post would be cheaper than an new saddle.

Thanks for the input
Wait a minute!Kerry
Jan 14, 2003 4:37 PM
Now we have new data. You don't move the saddle to change the reach to your handlebars. You move the saddle to change your position relative to the BB. A plumb line dropped from the bony protuberance just below the knee cap should fall somewhere between 1 cm in front of the pedal axle to 2 cm behind. It's a matter of personal preference and physiology where you end up - forward for spinning and/or "short" femur, backward for pushing and/or "long" femur. Once you get your position correct relative to the BB, then you change your stem length to get the bars in the right position. If you can't get your bars right with a reasonable stem length, then your frame is too large or too small.
just curious ...tarwheel
Jan 15, 2003 5:02 AM
How do you determine if your femurs are long or a short (or normal) length? I tend to ride with my knees a little in front of the BB, and I'm also a spinner. But I have no way of knowing whether my femurs are short or not.
Theory and practiceKerry
Jan 16, 2003 5:05 PM
You can go to physiological tables to get the average dimensions of males and females, and then measure yourself to see where you fall, but in practice there are other things that come into play, such as flexibility. The average thigh/lower leg ratio is 1.11 in men and 1.14 in women. Thigh length is taken from the front of the knee to the wall when you are sitting with your thigh horizontal and your butt pressed against the wall. Lower leg is the top of the leg to the floor on the axis of the tibia while sitting in the same position. You really need to experiment to find what position is proper for you. E.g. even if you have "long" femurs, if you are a spinner you'll want to move forward.