I start with my PBH measurement, then multiply by 1.09. I set the saddle to this height measuring along the seat tube from the axis of the pedal to the top of the saddle with the lower crank arm in line with the seat tube. I do this with the saddle level and centered on the saddle clamp. Then I ride-test it.
Usually the bars are already in the correct position for me, which is about 2 cm below the saddle. If not, I change them. After this I have some rules for troubleshooting. I don't know if I should go into detail. The best shop fitting I had was when the coach used a goniometer to measure and set my knee angle at pedal bottom - between 25 and 30 degrees is the usual convention. This fitter used KOPS to set the saddle fore/aft position. The most critical thing is to get as much leg extension as you can without causing your hips to rock painfully. Will the simple knee extension rule do it for you? Only you can find out, but if another good rider says, "you look a little low," it's reasonable to see if going up, maybe 1/8 inch at a time, does you any good without adding negatives - there are a lot of ways to look at it these days. Sometimes it takes a few hours or days to tell if a change brings negative effects with it. Try to mark or record your old position to be able to go back to the old position if it doesn't work. There is such a thing as going too far too fast with a change, having some pain, and needing to go back to where you were. Sometimes you need to do this while out on a ride. Think of that classic professional rider (forgot who!!!!) who carried wrenches to set his saddle in the middle of TdF stages! On Mon, Sep 27, 2010 at 3:16 AM, travis.ha...@gmail.com < travis.ha...@gmail.com> wrote: > 2 centimeters, 4/5 of an inch? That's quite a bit. Did anyone ever > offer observation to you that your hips were rocking when you > pedaled? > > The other rule of foot-length is that heels just touching the pedals > when the leg is fully extended implies the "right" bend at the knee > when the distance from heel to place-of-foot over pedal is added. That > said, common advice is that for many riders, moving cleats a bit > behind the ball of the foot instead of under them is a better, if not > most powerful position. That would imply a lower saddle, but just > several mm. lower. > > On Sep 27, 10:28 am, Jeremy Till <jeremy.t...@gmail.com> wrote: > > If you want to double check, you could measure your pubic bone height > > (PBH) using the method on the rivendell site and then apply their > > formula for seat height, which is PBH minus 10-10.5cm. I did this > > recently and ended up lowering my saddles about 2 cm. So far, my > > hamstrings are thanking me. It also has the added advantage of > > raising my bars by 2cm relative to my seat, making everything just > > slightly more comfy cockpit-wise. > > > > On Sep 26, 6:29 pm, GeorgeS <chobur...@gmail.com> wrote: > > > > > > > > > I rode my club's century today and as I was toiling up a hill, a young > > > triathlete sort on a plastic thing (the tubes were not even round!) > > > came by me and he said "Sir, you might want to raise your seat a bit > > > so you'll get more leverage." Unsolicited advice is so cool. My > > > immediate thought was to tell him that I had been riding bikes since > > > before he was born, but I've been trying to keep my mouth out of gear > > > so I didn't say anything. But then I started thinking that back in > > > the day, the rule of thumb, at least as it was passed down to me, was > > > that when the pedal is in the 6 o'clock position, the knee should be > > > very slightly bent. I've been doing that with every bike I've set up > > > for lo these many years. Was that wrong? Has there been any progress > > > in thinking on this subject? > > > GeorgeS > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To post to this group, send email to rbw-owners-bu...@googlegroups.com. > To unsubscribe from this group, send email to > rbw-owners-bunch+unsubscr...@googlegroups.com<rbw-owners-bunch%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/rbw-owners-bunch?hl=en. > > -- Ken Freeman Ann Arbor, MI USA -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
