I'm wondering what the advantages are to a sloping stem (versus one that is horizontal along its' top). My last bike ( an old racing bike) had a short stem, which was horizontal and was nice to lead along the pavement. My salsa casseroll gives a twist as I power off as the handle bars want to flop sideways.
https://salsacycles.com/bikes/casseroll_single/

I notice you can buy adjustable stems .
Looking at the Salsa set up my stem is much higher and my bars are quite high... I think so I can change it until I'm satisfied.

Update
I've lowered the stem and it has a completely different feel now. It still has a little lurch to the side when I power off but now I feel as though the bike is surrounding me.

Update 2
this topic here best describes my problem:
No hands balance: What makes a bike squirrelly?
https://www.cyclingforums.com/cycling...squirrely.html

Old style quill stems could be raised or lowered to get the handlebars to the desired height. Modern threadless stems can't, so you need to use stems of different angles to position the handlebars vertically. It's a huge downside to threadless stems. Really old stems had both vertical and horizontal adjustments.

You can get an adjustable stem for experimenting. A lot of people use them until they get the bars in a position they like, then they get a stem that matches that position and take off the adjustable.

So you agree a horizontal stem (if the right height) is better behaved?
Luckily my retailer left a lot of room for vertical adjustment if I move the rings around.

This is my setup so far.
Update: Later

I don't know the answer to that. Your problems may have more to do with the head tube angle and the design of the fork.

Every aspect of a bikes geometry is for a reason (we hope they know what they're doing).
I note that some manufacturers maintain a horizontal stem on all their road bikes.
https://www.avantibikes.com/race-endu...m.aspx?bid=210

Could the sloping stem be to unify the top tube (ie cosmetics)?

This was my last bike. it was way to big and I rode it with the seat down, but it sat on the road like an arrow in flight.

The choice of stem used for catalog photos might have a lot to do with aesthetics, but a good bike shop wouldn't hesitate to replace the stock stem with a different one to suit the needs of the buyer, including switching to one that were angled up or down vs. being horizontal.

The stem on my Specialized Allez came with a special shim that allowed you to use four different angles of rise depending on whether the stem was "flipped" or not and the position of the shim. So no, that bike at least wasn't designed to be used with a particular stem angle even though it has a sloping top tube. I don't know if any of the positions aesthetically complimented the top tube angle or not.

Can somebody explain how switching stems and spacers to change the stem angle (but not affecting the position of the handlebars) could possibly change the handling characteristics?

What about the arc of the handle bar as the bike leans and how this may affect stability on take off, leading (as along pavement) and no hands?

I flipped the over and adjusted the collars. It's still twitchier than I would prefer. Riding no hands is dicey.

Could the problem just be that the Casseroll is twitchier then your old bike, and just needs some getting used to? Is everything on the headset tight?

I have the same bike (different size), and I've found it to be a bit quicker, and more responsive then some other bikes I've ridden.

This article might help explain some of what's going on. I don't think the stem is playing a role but I'm not an expert.

Best stem ever.
https://www.velo-orange.com/vothstad.html
Height adjustable "quill" AND you can swap out threadless stems.
Makes tweaking fit super easy.

Why would you want a "lively" road bike? A unicycle is "lively" ...Your mainly going in a straight line??

I just read this review:
"The Salsa is a road bike at heart. We really like the fact that the fork complements the frame size, in that smaller frames get more fork rake. This compensates for slacker head angles - keeping handling light and lively. When loaded up at the back and using just a small bar bag, it takes a little more concentration to keep it steady at the end of a long day. It's a worthy trade-off though, especially if you prefer responsiveness over slower, touring-style handling. There's some toe overlap with mudguards, but none without. Losing the guards, we decided to try out a set of lightweight road wheels. As well as dropping the weight to just over 20lbs, this boosts acceleration and proves that the Casseroll can handle fast, unladen road rides just as well as a light tour."
https://www.bikeradar.com/gear/catego...eroll-07-19168

The stem has no effect whatsoever on handling. Two different stems of wildly different shapes will give the same exact handling provided they position the bar in the same position relative to the head tube.

Bicycle steering seems simple, but it's actually a complex interplay between lots of different forces that are not intuitive at first glance. The length of the stem can have an effect on the rider's perception of the handling of the bike (although not, in practice, on the actual handling). Raising and lowering the bars, by changing stems or by other means, can change the front/rear weight balance, which can affect that handling of the bike. However, two stems that put the bars in the same place will feel and handle the same, barring doing something really odd like hanging a weight from an arm attached to one side of one of the stems.

Here's a reasonably good article on bicycle steering dynamics, although it's not entirely complete - for instance, it completely neglects the effects of camber thrust steering, and in my quick read I didn't see any discussion of countersteering or the role of the height of the center of mass (or, for that matter, the mass distribution of the bicycle and rider about the center of mass - the radius of gyration about the axis of travel, if you will). He's captured the most important elements of bike stability, though, and what he's left out is of lesser importance unless you're working in a limiting case where the steering geometry does not provide adequate stability - for instance, the case with bikes built in the 30s through the 50s as mentioned in the Moulton article that tjspiel provided a link for. Still, he references Timoshenko, and it's hard to go wrong if you start there.

For better maneuvering in urban environments? Dodging wildlife on trails? Salsa markets the Casseroll as a sort of a "fun", "jack-of-all-trades" bike and I think the lively or twitchy handling (depending on your perspective) is part of that package. Salsa also sells some more traditional road and touring bikes for going in straight lines.

Keep riding it, you'll get used to handling.

"Salsa’s Casseroll Double is our relaxed road bike, perfect for everything from non-competitive road riding and commuting to credit card touring and charity rides.
An extremely versatile frameset is what makes the Casseroll Double so…well, versatile."
...
Mine is the single but the frame is exactly the same. I thought I was getting something between a touring bike and racing bike. My old racing bike let you take yours hands off the wheel -that's one of the main thrills of cycling, I think?
Buying a bicycle is difficult as you don't know what you've got until it's "used".

A "lively" bike will be responsive, handle beautifully and will have a certain ride quality that is palpable. If one is not accustomed to this, such a bicycle will feel "nervy", "twitchy", etc.

I would imagine the comparison is somewhat like getting into a ferrari after having driven a Lincoln Town Car. Unnerving at first, addictively exciting if you 'gel' with the feel of it.

Maybe it's got lively handling like a race bike but longer chainstays like a touring bike.

Are you sure that it's your right size, too? Your saddle's awfully low (unless you've got short legs, anyway).

It's just a way at arriving at the handlebar position.. up angled stem and shorter steerer tube , or ...
Taller steerer tube with more spacers under the stem, and a bit shorter extension level to the horizon
will put the handlebar out in the same height from the ground and distance from the seat post.

Funnily enough the guy who sold it to me thinks it's a 51, the frame, however says "Casse 49" He measured it as per the diagram on the website. I can't get 51 myself. From the center of the bottom bracket to mid point on the top tube suggests 49 (It seems to have a 765 stand over, suggesting it is a 49). If it is a 49 it has a 72 degree head tube and 74 seat tube. The wheel base seems to be about 1015. I'm 165 cm tall and my arms are fairly long in relation to my torso.
https://salsacycles.com/bikes/casseroll_single/
I suppose I'll get used to it but I keep thinking of those cyclists at the end of Tour de France cruising along at the end of the race
https://www.zimbio.com/pictures/uU7Ry...en/fVfjiFbFoKV

Forget the seat tube measurement. It goes out the window the instant you adjust the seat height.

The reason I'm asking is because that frame has a sloping top tube. Traditional frames with a horizontal top tube also had a rule of thumb that if you rode with a bit more than a fistful of seatpost showing, you were on the right size of bike. On your bike, however, with a seat tube that's comparatively shorter than that of a traditional frame, your seatpost can hardly go any lower than it is in that pic.

That means that you're either 1) built with a freakishly short inseam for your height (I know a couple people like that); 2) your seat isn't nearly high enough for proper pedaling; or 3) your seat is the right height for your body, but the whole bike is way too big.

Bike fit starts from the feet up. I'm going to keep ignoring the handlebars until we're positive that you have the right seat height. If you're 5'4", Salsa's own fit chart says you should be riding that 49... so I think your seat's way too low. It shouldn't even be lower than the bars on a bike like this.

I pointed out that it had 49 on the frame but the guy who sold it to me said "no that's wrong"....?
I think I could only get the seat up another inch.
'Cold outside but I'll head for the shed and try it.
============
My seat height seems o.k but I could lower the handle bars a lot. One retailer told me that seat height should be (about 2in ? ) above handlebar height.
At my height sizing is difficult due to the use of 700cm wheels

For some reason my seat slopes up and I can't see any way to adjust it.

Actually, the Casseroll frames are sized funny because of the sloping top tube. It used to say on the website (and I'm not sure why they took it down, or moved it?) but to add 2-3cm to the frame size to get the standard, or effective frame size. So the 49cm (Salsa) = 51cm anything else.

I'm 5'6, and ride the 49cm Casseroll.