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(although the contact patch is behind).
And its this patch the forces are exerted on, translating into a right turning force. Maybe Ed or Tester can explain it better then I do
...but it's not there when a forked bike is travelling in a straight line, because the wheels are vertical.
True, although theoretically there is hardly a second where a bike actually IS going in a straight line, still theoretically true
That additional requirement for the precise matching of forces is a really inelegant.
I totally agree with that.
I guess the whole point of my project has had a different objective. (it may even be called recalcitrant)
From the traditional perspective: The introduction of the off-trail torque matching sure is inelegant. Id go as far as calling it plain ugly!
From a construction perspective: The traditional fork can bee seen as inelegant... (when you compare it to a straight tube)
I appreciate both perspectives
is that riders are very good at subconsciously correcting for spurious lateral forces
Ok, so that's a more substantial problem!
Then following your first argument that problem is solved. I will admit it is a side effect that still annoys me and I havnt found a way around it (there probably isnt anyway)
Bozo the Clown." - Carl Sagan
Exactly my point.. It was an (silly)attempt by me to move discussion beyond your Yes/No argument and appreciate different perspectives
have learned something new from this
Thats nice, whatever it is that youve learned.. learning new stuff is nice it is
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The kind that you've provided
But??
which are in front of the steerer-axis
Its actually hehind the steerer-axis...
inelegant design solution to introduce a lateral force
Is didnt need any introduction, it was already there. Your bike even haz it :), and you make use of it with every turn you take. It makes your bike take turns in a comfortable way.
More importantly I don't think you can prove that you have perfectly achieved it because riders are so good at subconsciously compensating for lateral forces.
I dont see what these two have to do with each other.. You saying Ive been kidding myself all this time?
As @mdcc_tester said, it's really a question of whether you can do it well enough for riders not to notice, not whether it will ever be perfect.
True!
Your comment suggests that setting up needs to be done fairly precisely with regard to canting vs. offset.
I guess Im just a perfectionist... you may hold that against me any time
If you change tyre size, the wheel radius will change, which will change the offset, so the canting will then presumably need to be changed if you want to precisely match the opposing forces.
But not that much of a perfectionist..
Camber force is also affected by loads of things including load and tyre pressure, so if these change the camber force will change. Will the counteracting force change in proportion for the handling to remain truly neutral, rather than just good enough?
This depends on how picky you actually are (I mean the rider.. not you personally) If you'd change the wheel diameter with lets say 5 or 10 mm, you'd need to adjust the lateral with... oh maybe as much as 0.01 mm... I need to think about that...
There is another effect much more obvious to the rider in the difference in taking left and right turns ... It responds in a different (noticeable) way
however, you are doing yourself no favours with this kind of phrasing...
More importantly I don't think you can prove
You sport the same kind of phrasing the Pope was using in reference to Galileo, I guess Im just not into your type of church but suit yourself..
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OK, maybe this is a better angle of explaining it.. (no pun intended)
Camber of wheel exerts a force on the wheel in the direction of the camber. Think of a circling coin. The camber force is directed to the center of the circle.
This camber force exerts on the trail. So if I have my wheel leaning to the left, the camberforce is directed to the left. But, the force is exterted on the trail! making the bike steer to the right. (this is counter intuitive) To counter that, a force steering the bike to the left has to be evoked. To accomplish that an offset of the trail is required to the left of the trail (here trail is the riding direction) The rolling resistance of the tire is exterted backwards on the trail (here trail is the tire patch trailing the axle of the headtube). So if I make the offset to the left (just a few mm), the rolling ristance pulls back on the trail, pushing the bike to the left. -
Well, its not so much the angle itself that needs accurate adjustment, its the cross-play between both angle and offset. Changing the angle slightly (lets say its down to 0,5 degree appr.) directly changes the offset by a much bigger margin. And the change in offset is counterproductive to the change in angle.
So, lets say if you make the camber smaller, it increases the offset, while you really want a smaller offset. The way I go about it now is setting the camber of the wheel first (so that it looks good ;)), then adjust the offset by sliding the axle in the stem a bit.
In general forces due to trail offset are larger then forces due to camber... on the other hand, the arm on the camber forces (which is the trail) is larger then the arm of the offset (which is just the offset itself) Having a bit of camber on a straight bike, both the camber forces and offset forces are directed in the same direction and add up much quicker to a noticeable effect. -
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@mdcc_tester, ow i though that was cleared somewhere back in the thread. Let me try to explain again...
The camber of the wheel exerts a lateral force to the trail in the direction of the camber. this lateral force generates a torque on the steering axle. To counter that the trail needs a little offset in the same direction. That way the rolling resistance of the tire patch exerts a contrary moment on the steering axle. With a moderate trail the offset needs about 4-5 mm -
So here's how this works.. The bush has a hole under 3 degrees, the axle as well. So with the axle in the bush.. both angles can be in the same direction, which makes the total angle 6 degrees. Or in opposite direction, which makes the angle zero degrees... Anything in between is possible by rotating the axle and the bush in contrary direction. That way the camber of the wheel can be adjusted quite accurately between 0 and 6 degrees.
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aha... wasnt aware of that,I thought all that was clear... :|
Headtube angle..Ive been using some rregular frames, peugeot Y10, Koga gents racer and a Romany custom build. headtube angles are slightly different but all are in the usual range. The make of the triple triangle frame i dont know. The headtube angle seems a bit slack.
Depending on the hight adjustment of the wheel-stem the headtube angle may vary a few degrees.
Rake... Ive used a couple of different stems but i tend to use a relatively short one, its about 40mm. If i sweep it forward its about 50mm. Another I use is 60mm, which makes steering a bit more responsive. Downside of the longer stem is that the trail offset needs to be considerably larger.
Rims.. Used various for those as well. Started with Kris Holm 40 mm wide in order to move tyre contact patch more to the middle, kind of wrap the wheel around the hub. Rigida was so kind to make me a couple of asymmetrical rims (i believe they are 25mm wide) to accomplish the same for more narrow tyres.
The Tires... it get dull, Ive used various as well. From Big apple 2.35, regular 40mm, now there is bontrager 25 mm on there, but my fav are the continental 30mm..
The thing is, the system is adoptable to a wide variety of choices.
The adjustable camber axle is the only real requirement which I had to make myself. I will try and make some pictures later on.. but its basically what Tester has pointed out already. Im curious if the stem he posted could be used for the same purpose. Then (?) anybody can put it together with off the shelf parts -
@ffm
I see what youre saying here and its been discussed over and over again. My daily bike has the same thing, the front wheel is canted due to a damaged fork... you can immediately feel the difference. That said, makes it completely obvious its easy to feel the difference between a bike that needs compensation and one that doesnt. The NoFork bike needs no compensation. If you reed back there have been a number of people riding the bike who have acknowledged that.
I can also see why it turns your otherwise comprehensible world upside down... what kind of "proof" are you looking for? -
motherfucker
trying to figure out how to post a gif here..
here's your laser
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havnt been here in years... and now this? :))