To me the key difference with low trail is that it is less reactive to weight shifts. Low trail has less flop factor (i.e. less drop in the front end as the wheel is turned to the side) and that’s what reduces its reactivity to body-weight shifts.
This reduced reactivity to weight shifts explains all the things people report they like about low trail: 1) less reactive to front loads, 2) less tendency to wander due to stray body-weight shifts at very low speeds, 3) less arm effort or bar-width needed / desired for steering (because your arms aren’t overcoming as much flop/front end drop), 4) ability to change line mid-curve (because you can steer more with arms where a body-weight shift mid-sweeper is not as easy).
This reduced reactivity to weight shifts may also explain the things people report they dislike about low trail: people who are used to accurately and telepathically steering by subtle body weight shifts like you do with classic mid-trail (~56mm) bikes will likely miss this effective way of steering on a low trial bike as they will find themselves steering more by arm movement to which they are not habituated. They may be likely to oversteer and then overcorrect as the bike doesn’t steer in the “natural” way they’re used to. This could explain why experienced expert riders might feel low trail bikes veer around more, while others say they veer around less. That doesn’t mean those riders wouldn’t eventually get used to and possibly like low trail, but why should they. If they have an effective and happy steering feel that works well on other bikes it’s reasonable to stick with that.
Habituation to one steering feel or another is easily under-emphasized in these low trail pro-con discussions. Some people habituated to higher flop mid-trail and/or high-trail bikes really like the lighter feel of low trial steering, and others may miss the accurate effective subtle weight-shift steering they’re habituated to. Habituation varies a lot from person to person. Not only what have you been riding for years and habituated to, and not only which do you prefer, but also how much do you prefer it, and how much you want to change your style of steering vs how much do you want to keep using steering habits that have been effective for you.
My own habituation experience is that I got my first low trail bike as a teenager in the mid-70s. I had no idea it was low trail, or what trail was. All I knew is that it steered way different from the sport bikes (mid-and high trail) I’d been riding. Steering felt twitchy or too light and reactive too me, and I couldn’t ride it no-hands at first. (No-handed riding being a body-weight shift thing.) I didn’t like it at first, but it was a ~high-end 531DB race bike and I was a kid and my goal was to learn to like it. I did learn to like it a lot and I still have it and ride it today. I also continued to like mid-trail steering a lot, and when I would go back and forth between my low trail race bike and mid-trail race bike I had to adjust to the different feel–usually only for out-of-saddle riding, and only the first 2 or 3 standing pedal revs is all it takes.
To add another trail characteristic–high trail bikes (~62mm and up) tend to develop more and more self-steering stability at speed. That can feel reassuringly stable on a rough loose descent or it can feel like the bike’s on rails and won’t initiate a turn when descending pavement at speed (higher speed is where high trail has most stability and tarmac adds resistance to turning). The key to initiating turns on pavement on high trail bikes is counter steering, and all motorcyclists know this, or learn fast, because all/most motorcycles are built with high trail (by our standards) even bullet bikes. At one time I didn’t like riding high trail bikes on pavement because of this. Even though I knew about counter steering I seldom used it (it’s seldom useful on low and mid- trail bikes) and would forget to do it on a high trail paved descent and the bike’s on-rails feeling would annoy me. After I’d started riding motorcycles a lot of miles, and had made counter-steering an intuitive automatic part of every motorcycling turn, I happened to be on a high trail bicycle and noticed how easy it was to turn. I’d habituated myself to high-trail by means of habituating myself to subtle counter-steering.
These two features of bicycle trail explain for me all of the commonly discussed traits of bike trail. 1) low trail bikes have less reactivity to weight shifts, and 2) high trail bikes develop more and more steering stability at speed (mainly on pavement because loose surfaces mitigate high-trail stability, and may be a reason adventure bikes are built with lots of trail).
This is also why mid-trail really needs to be it’s own category. I realize having just a low-high binary would have a simplicity advantage, and I realize there are various degrees of each within the three categories. But mid-trail is different because it has lots of reactivity to weight shifts (plenty of flop) but it does not have the steering stability that high trail bikes have. This is the reason many here dislike mid-trail bikes–they flop with a big front load, they wander at low speed if you don’t constantly watch it, and even at high speed they can turn on a dime so you can’t zone out and cruise like you can on a stable high trail bike (in the 80s they made triathlon bikes with high trail for this reason). But it’s also the reason mid-trail has been the main/most common race and sport bike geometry for 40+ years. In my own habituated experience, mid-trail is great because it is responsive and always ready to turn, even at high speeds, where it still has enough stability to cruise. That said, I can say the same thing (habituated) about my low trail bikes, which are mostly what I ride now (30mm and 38mm) because I can’t find anything they don’t do well. For me.
–Mitch
no mut silti