I'll add that trail, the contributing dimension, can allow induced flop from surfaces you ride on.
When there is a greater distance between the tire contact patch and the projected pivot point of the steerer tube a greater lever arm is provided to the input of the riding surface. On flat smooth surfaces going in a straight line that difference stabilizes the front wheel. When a lateral force, the weight of a front bag or other input occurs, the trail dimension defines the length of the lever arm provided to that input that can produce flop. Riding very slowly can cause this, as Jim B. described. Steve P. has described riding his Rambouillet on a slow uphill climb that produced flop-induced steering that had him zig-zagging enough to stop and dismount. I had a bump from a dismounted cyclist that induced a sharp front wheel pivot on my Rambouillet. When designing a custom frame and fork I considered my interest in riding multiple surfaces and multi day trips I wanted to increase my tire volume for comfort and control, reduce my front/rear wheel load difference and maintain the capacity of my Rambouillet and the Carradice Nelson Longflap saddle bag. I went to 650B to reduce toe overlap of my under square (ST>TT) geometry with larger volume tires. I went to lower trail to accommodate front loading to better balance the load of the wheels (no more higher PSI in the rear wheel). The unexpected handling outcome I ended up experiencing was a reduction of road or trail surface influence of the direction of the front wheel. No more jerks or yanks of the bars in my hands. As many have said of lower trail geometry, I don't have the ease of riding without hands that the higher trail of my Ram or Disc Trucker commuter allow. Even with that said, I found myself less worn out after long rides with a front load on low trail than I did on high trail with a rear load. This comparison includes differing wheel sizes and tire widths that may have a large effect too. I go back and forth between these bikes without any issues. Andy Cheatham Pittsburgh On Wednesday, January 3, 2024 at 5:23:36 PM UTC-5 Patrick Moore wrote: > This, plus the RH page, explains flop well. One way I notice it is, how > inclined is the front wheel on a bike to turn to one side or the other when > you are standing next to it and holding it up by the saddle? Jim G's trail > calculator page includes a calculation for flop: > http://yojimg.net/bike/web_tools/trailcalc.php > > I agree that you can't decide whether a bike is "good" or "bad" based on > trail figures and flop numbers alone, and I agree too that one can get used > to a certain amount of variation here as with so many other variables, but > different preferences do fit different trail and flop numbers. I tend to > like medium flop; low trail bikes feel vague to me, one big reason I sold > the Herse, but I find the tendency of the front wheel with too high a trail > to wander when climbing slowly with a lot of weight on the back of the bike > annoying and even a bit frightening. One reason I sold my first generation > Sam Hill was that it did this; OTOH, none of my customs or the Ram felt > like this, or felt like this to the point where it was annoying. > > On Tue, Jan 2, 2024 at 2:45 PM Mackenzy Albright <mackenzy...@gmail.com> > wrote: > >> ... This has all lead me to think to focus on trail and flop is a bit >> overblown within reason. We all have personal preferences but it feels like >> a marketing ploy these days. Trail and flop is really specific and niche >> aspect of the bike that really should be determined by a good builder or >> designer (Riv etc) based on wheelsize, tire size, ride quality, utility, >> and preference. Obviously Rivendell does this with their bikes - i've seen >> attempts to "low trail" a hunq or atlantis - but the reality is these bikes >> are really well designed and functional as is. With my current custom being >> built by a montreal builder - I was very insistent on low trail like my >> Romanceur. However after several consultations he suggested going slightly >> more mid trail as it would fit the build and purpose of the bike better. I >> trust the builder to understand the geometry. >> > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/06890b95-25b7-4cbd-9b3b-a14f39a2ef83n%40googlegroups.com.
