So my saddle rails position was set up for knee over pedal in a shop. It all feels good when I'm properly back on the saddle, the width is good and pedalling feels smooth.

During the ride I keep finding myself slipping forward, which leads to the obvious resulting discomfort. I'm fine when I slide myself back onto the flats.

I think the saddle fore and aft is right, it's level and the height feels right.

My suspicion is that my stem is too long and that as I reach to get on the hoods, I wind up creeping forward on the saddle as I pedal.

Does this sound...sound?

Trying to sort out what might be causing me to slip forward on the saddle over time.

You can tell from the pic that the seat is a bit forward on the rails and I don't think due to pedal position I should move it any farther. If I measured the stem right, I measured center of the steerer to center of the bars at 100mm, I think I can drop to an 80 or so and that might "push" me back onto the saddle properly.

I have to say, this is the first bike I've ever owned where a bit too big was the issue.

One other bit, I'm in terrible shape...really really bad. Could it just be that my core fitness sucks and my hips are rotated poorly, causing the sliding forward?

Perhaps it's the pic but your saddle does not look level, which would cause your symptoms.
Can you check that by making sure tire pressure is the same F&R, rolling it onto a flat floor and placing a carpenter's level across the saddle?

It is normal to slide back & forth on the saddle: Back to push over hills, Up "on the rivet" when powering along TT'ish but you should be able to settle and not really notice the saddle at all.

-Bandera

Oh That bit? Definitely, miles & hours will give you the adaptation to physically support a proper fit.

Interesting machine, too sensible to be seen around here.

-Bandera

You may be right, I was looking at the pic, I think it's sloping down a touch, so I'll fix that. Tire pressures are even, but that sidewalk it was sitting on, sure isn't.

When I'm sliding forward on it, the nose is poking me in rather unpleasant spots :-) I'm basically forward enough that I'm not properly supported on the saddle.

The reach is about right if I ride on the corners of the flats, the top of the bar. If I slide up to the drops, that's where the creep happens and I'd prefer to be more centered for riding the drops.

Thanks, I really like the bike, it's a tank that I basically built so I could point it anywhere and not break it. I'm definitely not looking to make riding easier on me, it's all about fitness and enjoying the ride for me on this one. Eventually when it doesn't take me 90mins to stop sweating, I may use it on the commute too.

I'll tip that saddle back a bit and see if that helps out with the slipping, that would be a good start. The reach isn't bothering my back or neck, it's just my tail that's taking the beating.

Use a spirit level to get that correct, really hard to eyeball it.

It will take miles & hours for tail/saddle/harmony to occur anyway, just make sure you stand up enough to get pressure off & blood flow in.
Also, as you get stronger your legs will carry a great deal of the load so that the saddle becomes a fulcrum rather than a support.

-Bandera

Tilt saddle back (nose up) ever so slightly (2 degrees).

Tilt the saddle more rearward and if that hurts then look at a different saddle that you can tolerate nose up (ever so slight).

LC

I'm confused when you say 'slide up to the drops'... do you mean the hoods? I'd expect that if you were actually slipping forward, you'd feel like you were doing so regardless of hand position. Do you feel like you're bracing yourself to prevent that?


If so, then yeah, tip the saddle back a bit, but if no, address what you already indicated was a bike to big for you by replacing the stem with a shorter unit. It's easy and quite cheap to do this.

Yes sorry I meant the hoods.

I'll fiddle a bit tomorrow. my seat might be a cm or so high too.

I Note : saddle not level and so you dont feel like you are sliding forward ,

You appear to have set up the bars with the brake lever too low on the curve on the drops..

or just need to rotate the bars in the stem, upward.

upper-ramp portion almost level... aim the back of the drops towards the rear hub, not level..

The saddle was close to level so it wasn't as if I was falling to the bars. I would just gradually notice I was on the nose of the saddle...which digs right in to my perineum. I have to really sit on the nack of the saddle or it's very uncomfortable.

I was reading that people with bad lower back flexibility can have trouble with traditional saddles...maybe one of the noseless / drop nose types might be better.

I like the bike!

I have some ideas about slipping, tilt, and reach, so let me try to share them. I have fixed this issue on one of my bikes, and this is how I did it. I wish I still had it.

Slipping forward can be caused by saddle tilt, which your picture clearly shows, or a long reach. Some saddle setup approaches say to assess slipping in a seated upright position, pedaling on a trainer. If you aren't staying in place without your arms trying to reach the bars, the saddle is either not in place or it is tilted. First step is to pedal while sitting upright and see if you tend to slide forward. If you are exerting force to hold yourself on the sweet spot, level the saddle or gradually tilt up until the effort disappears. If it is tilted up too much you may find yourself tending to slide rearward.

Once this is resolved (sit bones naturally remain in the sweet spot), fold forward from the hips, not the lower back, and see if the reach to the bars feels natural or at least workable. It could still be that your bars are too far away, too low, too wide, et cetera.

As you pedal with your hands on the bars, you should find less hand pressure since you do not need to press yourself backwards to remain on the saddle. At this point it might be valuable to experiment with bar height, if you have a quill stem or it is similarly easy. I found that pressure on my hands (downward pressure) was relieved by dropping the bar (quill stem) by about 1 cm. It felt more natural for my hands to be in that position.

Although seat height, level and position on the rails can be set properly by an experienced fitter saddle selection is an individual's choice.
There are endless threads on choosing the "right" saddle but it's a road we each pedal alone. If you have a saddle that you were comfortable on from an old bike I'd move that to the new one and have your shop re-fit you.

If you don't have a favorite saddle the modern minimalist design I think can be seen in your pic may not work as well for you as a classic design w/ a long well padded nose & and bit of width such as a Sella San Marco Rolls. Not a recommendation, an example, ask your shop.

Remember it's miles & hours that build saddle/fundament cooperation as well as power & fitness.

-Bandera

Thanks all, good info.

Yeah I went with this saddle as years ago when I was last active, my favorite saddle was an unpadded rigid plastic type. So I do expect to grow into saddle time and comfort as a result, as far as sit bone pressure.

Will fiddle around and see what I work out.

The other option, of course, it to slide the saddle forward a bit to match where your body wants to rest on the bike. It may be that you just feel more comfy being more on top of the pedals, rather than more behind them.

Posting from phone post tweak ride.

Moved seat a degree or so back tilt. A tiny move but fixed my creep forward issue I think.

Moved seat forward as well. I would be dead center on a zero offset post. I may switch. This feels better. I also raised the seat a cm after, also feels right.

I also took a spacer out, dropped the bars, and rotated the bars back a bit. Now the hoods feel much better and I don't think the stem is as long a reach now.

I think dropping the bars actually helped with the seating position a bit too.

Funny how small things make all the diff.

Now to leave this alone for better evaluation.

Here's a pic at the MUP, not the most level surface to show but things are quite a bit better now with the sum of the tweaks. You can see the seat is nearly completely forward on the rails now, so I think a zero offset will be the ticket. The shop may even swap it out no charge when I take it back for the 100mi tuneup.

Still debating dropping 10mm off the stem length, but will see how this feels with some time.

I'm so out of shape that I have to weigh if it's my poor condition or a fit issue when doing all of this. The drop to the bars put more weight on my hands/arms today, but it was pretty minimal. I'm just so weak from being an office mushroom for so long that I need to give this time to adjust.

Seeing this pic is funny...I must be pretty big, LOL. The bike looks huge.

It's generally better to do one thing at a time so you can isolate the effects, but if it worked, that's unimportant. But yes, fit is a dynamic subject, and your setup will most likely change with fitness and strength levels.

I'm like you,I was out of the saddle way too long . Took a ton of tweaking before I was anywhere near comfortable . I hated to do it,but I had to give up on my old leather saddle. I am now about 45 pounds lighter and don't have much for cushioning my butt anymore. Feels good to be lighter but this old body feels fragile. I'm toughening up slowly though. Glad you are sorting this out.