dit

I have been riding my road bike off and on for 30 years and I have always had a tendancy to slide forward on the seat which reduces my hiney comfort. Does it make sense that the reach may be too long and that by shortening the stem this tendancy could go away? thanks for your thoughts.

kpug505

Before replacing parts I'd tilt the saddle nose up a degree or 2 and maybe raise the bars to within an inch of drop from the saddle. You may need to slide the saddle forward a mm or too also. Do small adjustments 1 at a time and put some miles on in between adjustments til you get it dialed in....
What saddle are you using? Got a good side view pic of your bike?

SweetLou

It could be the reach or it can also be the angle of the saddle.

dit

I will try to attach a pic. The pic shows the saddle tilted up at the nose but it was not comfortabe at that angle. It is an old old Brooks saddle bought at a Schwinn dealer about 1970. It has been on 3 bikes through the years.

purevl

My experience with B17s is that if the drop is too great I will slide forward on even a dead-level saddle. It also causes my hip to pop in and out viciously (other things do this too, not necessarily a cycling thing) and is just generally uncomfortable. I've heard it said many times that you shouldn't use a B17 on a bike with much drop and I find this to be true in my case. I believe both the sliding and the general discomfort is because of its width, in an upright position it's fine. I haven't had the necessary funds to try a narrower model.

CACycling

I'm not surprised it was uncomfortable at that angle. I usually have my saddles slightly nose down. From the picture, it doesn't look like you have much drop but the top tube length looks quite long compared to the seat tube length. You can try a shorter stem but it may be this frame is just too long for you even if the seat tube length is correct.

Amani576

I have this problem with my Raleigh Grand Prix. I can't even ride it because I'm too stretched out to be comfortable. My DX-6000 on the other hand has a top-tube about an inch shorter and is SO MUCH more comfortable. They're the same "size" bikes though. This is a very likely suggestion, IMO.
-Gene-

Mike Mills

Here's a thought - he has poor posture. Stretch before riding. Do the pelvic tilt to change the angle at which your buttocks and pelvis engage the seat.

I'm saying this because that is aa RADICAL seat tilt. You are trying to use the seat tilt to make up for some other ergonomic deficiency. It would be better if we could see a profile view of you seated on the bike, rather than just the bike.

dit

I have recently measured the tt and it is about 4 to 5 cm longer than the seat tube. The stem is about 80mm by my measurement. I will say that I was surprised by the longer length of the tt. I have been thinking about getting a taller stem to get the bar height a little higher so I could also get it a little shorter reach. I do have the seat adjusted toward the front. The old girl rides good and quite responsive for a sport tourer. There is more weight on my arms and hands than I currently prefer. 30 years ago the weight on my arms was not a problem but I was several pounds lighter in them there days.

jgedwa

Might be the wrong size bike.

But here are some things to try (mostly already stated above)

Free:
-Give the saddle a slight tip up. Less than the pic, but more than you had before?
-move the saddle back a bit on its rails.
-raise the stem. Raise it a lot if you need it. No cool points are lost for this. Except in Brooklynn.
-change your riding posture? try other hand positions and see if you can find a comprimise

Not-free:
-shorter stem
-seatpost with a set-back

That is pretty much all you can do to deal with it. If those don't work, or if those mess up the rest of your riding position, then you have the wrong size bike.

dit

It appears that I need to add that the wild angle of the seat in the pic is not how it has been ridden. I did try it to see if it helped. It did keep me back on the seat but the boys did some complaining. It is currently back in a more level attitude. The seat is quite comffy when I stay pushed back but I just keep migrating forward.

Mike Mills

This is why I think it might be a posture-related problem and not a "fit" problem. Do that pelvic tilt. Strengthen your stomach muscles and your gluteus maximus. This will flatten your lower back and make you "longer" rather than humped forward on the bike.

I could be entirely wrong.

JunkYardBike

Might also try dropping your saddle height a bit. It's worked for me in the past when I've found myself slipping down the nose of my saddle.

luker

This is a 52, right? It's not jibing with the rest of the story, but it looks like that frame is too small, the way you have it set up in the picture. How tall are you, in inches?

dit

I am 5'9" with average body ratios. The bike does not seem to be too small but I do think that a 54 cm would be a better fit. I would think that if it is too small I would not be tending to slide forward but maybe I am wrong.

It was suggested that I may have poor posture since I some lower back problem but not major so that will probably not improve. My back problems are not new. I have delt with them since a teenager. I am an old fart now.

I want to thank all for thier thoughts.

Grand Bois

The frame is much too small for you.

WNG

Besides being a tad too small for your 5'9", just by looking at the seat's height, makes me suspect you're riding with the seat too low. The frame looks like a 52cm, possibly.
Are you straddling the saddle when you place you feet on the ground? If so, that means your riding position is wrong. You are roughly the same height as me. And I see the use of the extended stem to compensate for the frame. The seat post should be higher if I were to be fitted on that frame. 4-5cm longer top tube means it should be roomy enough to be ridden. Rule of thumb, adjust the seat height until you are flat footed and leg straight. Set the seat's fore/aft position by having your knee vertically above your pedal when the right crank is at the 3 o'clock position.
Not sure of a Brooks, but the saddle should be horizontal to 1 degree down from horizontal.

dit

I can not touch the ground even with my toes when on the seat. My knees are approx. straight above the pedal axel when the pedal is in the 3 o'clock position. My seat is horizontal and not as shown in the picture. When sitting on the saddle and my heels on the pedals and the pedals in the 6 o'clock there is a very slight bend in my knee. I might be able to raise the seat some. I have intentionally fudged a slight amount on the seat height to keep the handlebar/seat height relationship about level. The stem is set at the max. height.

WNG

Well it sounds like you're set up properly. It may be that your back problem is causing you to inadvertently slide forward to relieve some strain somewhere.

The bike sounds like it's not too cramped to ride. (btw, it's a nice bike)
It has a long enough top tube.
The longer stem may be the fix.

oldbobcat

I'm with Mike 100 percent on that. Working on core strength, posture, and flexibility will help many other aspects of your life besides riding a bike--digestion, circulation, sex life, and how good you look in a suit . I also recommend working with a chiropractor if you can afford it.

And return that saddle tilt to something more closely resembling horizontal--you might be unconsciously pulling yourself up on the nose to ameliorate the sensation of sliding off the back.

dit

By longer stem are you refering to taller or longer reach? I have been considering a taller stem and maybe a shorter reach of about 60mm.

In my late 30's I was riding about 150 miles a week. (excluding the crappy Indiana winters) I am anticipating 100 mile weeks this year so I am not doing day long rides and probably won't. There are not many 60+year old crazies in my area. Solo day long rides can get lonely.

SlowRoller

Another thought is to try and raise the saddle a bit, and then move it back (aft) a bit. The more upright you are, the more forward your pelvis position. If you raise the saddle, you'll have a little more bent over position. This will cause your balance point to move backwards, and your butt will follow. So, if you have some wiggle room, as you say, then try maxing it out.

WNG

I meant a higher stem like those Nitto Technomics.
It's commendable that you still ride, and put in the miles! So, do what's necessary to ride comfortably and safely. No one says you must run drop bars on your bike. Do whatever is required to keep things fun.

dit

I would to thank you all for your thoughts. I will try raising the seat and possibly moving it back first. The current setup seems to put a little too much weight on my arms. If this doesn't work I will get one of those Technomic stems from VO. It will be well worth the change out effort if it gets me the position needed to fix my antique comfort requirement.

treebound 

I'm not going to tell you to move things up or down or forward or rearward, I will simply say to go back to the basics and begin your bike setup from scratch.

Start with the saddle tilt, level or slightly nose-up.
Next set the saddle height relative to the pedals.
Next set the fore/aft position of the saddle based on the relative position of your knees over the forward pedal when the pedals are at 3 & 9 o'clock.
Next set the stem height so that you initially have roughly a 90deg bend (varies depending upon who you talk to) in your hips and a comfortable weight on your arms (close to neutral).
Finally adjust the stem length, many ways to measure this but I like the handlebars to block the front axle from my view when I'm in riding position.

https://www.coloradocyclist.com/bikefit

https://www.peterwhitecycles.com/fitting.htm

https://www2.bsn.de/cycling/ergobike.html