Getting the right cockpit position. Sliding forward. What should I adjust to keep my sit bones on the seat?

Question

I am experienced rider and I'm looking for some advice on how to adjust my cockpit position. I am a daily commuter, and do regular 40-50k rides on the weekends, and with the warmer weather will work on some 100-200km rides.

On my current bike, I continue to have a problem sliding forward in my seating position. I have short arms and legs compared to my body length (32 inch / 81cm inseam at 6'1"/185 cm tall) and my bike is fairly comfortable if not one size too small. The bars are currently about 2"/5cm below the hieght of the seat. I find that I am consistently sliding forward my seat and pushing back with my arms to stay in a decent position. My saddle is currently pushed as far forward as the current post will allow, and the stem that came with the bike is quite long. The seat post off-set is not large at about 1". The Brook saddle (B17 Special) is dead level as measured at the rails. I have no knee or back pain.

What should I adjust to keep my sit bones on the seat?

I think my options are:

• Shorten the threadless stem to xx cm or so from the current 120ish?
• Buy a new seat post that will allow the saddle to come forward more?
• Buy a new bike that fits better (Probably not going to happen this year)?
• Other? Seat height? Seat angle?
• Stretch more? and get a flatter back, better hip position?

Answer 1

Try changing the seat angle. I'm tall as you, and had the same problem. I changed to a bigger frame, but the real solution was to set my seat a bit off the horizontal (back is lower than front). Seat and handlebar are at same height. No more sliding.

Answer 2

I know I'm late on this thread but try sliding your saddle backwards and not forwards. Likely too far forwards over your bottom bracket and is causing your pelvis to pull forwards. If you have your pelvis further back the pressure from just your pedaling alone will help to keep you seated further back on the saddle.

Answer 3

As suggested in other answers your saddle angle may be key. I don't know what your experience with Brooks saddles has been, but the set up tends to differ a little from more modern saddles, especially if you wear modern cycling clothing.

Brook saddles tend to work like a sling and depending on how well you have broken your saddle in and the tension you have on your saddle you may find yourself sliding forward even when the saddle is perfectly level. If you haven't nailed your setup synthetic clothing may highlight this fact making it easier for you to slide forward. By comparison modern saddles often have textures that grip synthetics which may help offset any inaccuracies in setup.

This problem is relatively easy to solve. On many models of Brooks I found that you generally need to keep the nose up ever so slightly higher than the back to keep your position. Because the saddles act like a sling you can can have the nose higher than more modern saddles without sacrificing comfort. Once I have the put the Brooks slightly nose up I found I remained firmly in place.

If you do try this, make sure to take your time with small incremental adjustments. Setting the nose too high will eventually cause discomfort. Depending on how extreme you this may only show up on longer rides. So start for with a small change ride it for a while to see if it works for you, then adjust as apporpriate.

I also found that as the saddle warms up I sink into the saddle a bit and find that it acts like a shelf for my sit bones, keeping me in place. I currently have my Brooks (Professional) set up such that I just creep forward at the start of the ride (when the leather is cold), but after a few minutes the leather warms up, becomes more compliant and I settle into position. After that point I don't slide forward for the remainder of the ride.

Don't give up on your Brooks yet! I have never found a modern saddle that equals a Brooks in comfort on all day rides.

Answer 4

I would try some different shaped saddles. Possible your Brooks is too wide which would encourage you to slide forward. Your KOPS (knee over pedal spindle) may be too far forward as well which won't help your situation. You might try pushing the seat back on the rails a couple of cm and shortening your stem to 100mm. Try different saddles first.