there's a lot of info there. While the science might not support it , the smaller tires just "feel " to me more responsive to steering input. And by that I am speaking of the drop -in moment of a corner - or chicane ect or a swerve around object in road. More my head upper body steering inputs than my hands .
Interesting on the stem . Im running 90mm if we are measuring to bar center to stem bolt center.
Any shorter I will hit my knees on the bars when out of saddle standing over front of bike .
The bikes very stable just one hand on the drop bar, in this case I think the stability is in the geometry of the bike. Im curious the geometry of the bike you shortened the stem on.
The "science" of turn in that includes leaning into a turn or swerve is a rather controversial and even complicated topic in cycling.
I didn't believe it at first but the bike "counter-steers" right before we lean into the turn.
It must be from the gyroscopic forces that makes the front wheel counter-steer and wheel weight and tire width would be a factor. But from personal experience, I couldn't tell the difference in turn in between 28 mm and 35 mm tires on the same wheelset.
I know exactly what you say when you lean into a turn to get around an obstacle, a pothole, a distracted pedestrian or filtering between traffic at 20 mph. I ride quite aggressively in traffic and I do a lot of evasive maneuvering on rides if you can imagine the brutal road conditions we have and I really don't find it any fun and rather found it very stressful! Bike becomes harder to turn in at high speed as you can feel the bike is resisting efforts to turn. Yet, having a short stem made it easier. In fact my bike now feels easier to turn than a friends race bike that is only half the weight of my bike!
My theory is that longer stem better resist forces that turn the front wheel. Most riders prefer this behavior as it feels more stable. Short stem does the opposite and will affect turn in. GCN confirms this but came up short by not giving themselves a chance to get used to a short stem and referred to it as "too twitchy". It takes a month to get used to the handling of a short stem, not one day!
Ofc some would be more sensitive to small changes. It's just these things never crossed my mind. When my bike didn't turn in as well as now, I rode less aggressively and more slowly around traffic. I didn't see the the need to improve the situation, thus, why I probably didn't noticed it but I notice it now when I changed stem.
The real reason I went for a short stem is because I positioned my saddle all the way to the back and it made me feel like I'm over-reaching with the 80 mm stem and so I replaced it with 32 mm stem. I like my saddle all the way back to avoid over-engagement of quads when cruising on the flats and also to unload the arms. It's a strategy to be able to complete a 70 mile ride without stopping by maximizing comfort and reducing overall muscular fatigue. The short stem improving turn in at all speed speed is a huge bonus for me.
Interesting on the stem . Im running 90mm if we are measuring to bar center to stem bolt center.
Any shorter I will hit my knees on the bars when out of saddle standing over front of bike .
My knees still have good clearance on the drop bar when I pedal out of the saddle with 32 mm stem. I'm even using two sizes smaller frame size!
I think we simply have different out of the saddle position. I prefer an out of the saddle position that is further backward to avoid over-engagement of the quads in order to save the quads to avoid bonking a long ride or a long climb. The same reason I set my saddle all the way back.
The bikes very stable just one hand on the drop bar, in this case I think the stability is in the geometry of the bike. Im curious the geometry of the bike you shortened the stem on.
Geometry is typical of modern road bikes. It's only unstable when when hitting bumps while riding one hand. Remember our poor road conditions that is quite bumpy and uneven. Absolutely stable riding one hand on smooth road sections.
The shock of the bumps will get to your hands. When riding one hand, the forces from the bumps would only only act one side of the handlebar and cause unwanted steering inputs. This sometimes caused steering wobble. With the short stem, the wobbling goes out much quicker or doesn't wobble at all.
I don't know exactly why having a shorter stem is able to dampen or completely eliminate steering wobble after unwanted steering inputs.
