No-Fork project, bicycle geometry hacked

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.

@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

Not that visible but you can see the axle and the bush in the steering part of the stem here

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ow i though that was cleared somewhere back in the thread

I think everybody who understands single track vehicles gets that you can offset the camber steer with a bit of off-track trail, it's just that those of us who haven't done the experiments which you have are not sure how precisely you need to tweak the geometry to fool people into thinking it doesn't ride like a crab. Is ±2° good enough, or do you really need to dial it in to ±0°15' to stop it feeling like there's something not quite right?

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.

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.

Maybe Ive just had a beer too much, I ll read it again tmorrow and edit

Have you considered a no fork with two fork legs and a wheel with the camber set at roughly 0?

I have, The girls just like the big single brainy one better

re the trail thing;

I wasn't taking the time to understand the issue, but now on my third visit to the thread i've accidentally stumbled across it. Correct me if i'm wrong. You've effectively got two trails now. One in line with the track and one exactly 90 degrees from it from it.

that truly sucks. although i applaud the mad effort, the second trail introduced a level of complexity far beyond that of a typical fork.

The symmetry i can get over. This, i'm not so sure.

https://45.media.tumblr.com/a65d48e78729916c9b76f76d6765cfe0/tumblr_nyg46jD67b1qjdb42o1_400.gif

How about a fork with one leg and two steerers :-)

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You might want to add a bushing to angle your axle a bit.

You might want to add a bushing to angle your axle a bit.

It's not immediately obvious, but the axle is fixed at 3 degrees. Yes, I'm that much of a tart that I actually bothered to camber it even on a gag pic :-)

But how many stems will you use?

how many stems will you use?

Only two

Everyone reading this thread thinks the people who are being rude are... well.... rude.

Frankly you can just stick with that.
Find a way to incorporate coaster hubs then it'll be legal in Denmark.

What?

When in... Denmark?

Actually front brakes now a legal requirement, which mean he's fucked unless he finally developed an actual working brakes.

Which beg the question of why fucking around with stems instead of making a brake work on those fork?

Well, I like the fact he's playing with the idea and producing working prototypes and he's obviously enjoying it so I think that's enough of a modus operandi there.

Braking on a canted wheel-shirly the calliper just has to be mounted at the same angle as the fork. Possibly on another stem, possibly several. I just don't know.

what kind of "proof" are you looking for?

The kind that you've provided over your last few replies, thank you; however, you are doing yourself no favours with this kind of phrasing...

I can also see why it turns your otherwise comprehensible world upside down...

...because that is the language of snake-oil and perpetual-motion-machine salesmen the world over. From the bulk of the thread, it's really not been clear what you've been claiming. At some points it seemed like you were saying that you'd worked out how to run a canted wheel such that it produced no camber thrust, which is obviously not true. What is clear from your more recent posts is that what you've done is some calculations as to how to counteract it with a contrary steering force. On that topic, this is not clear to me:

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)

The wheel is canted to the (rider's) left, this exerts a force to the left on the fork-ends, which are in front of the steerer-axis, so how does that produce a turning force to the right? The answer to this isn't really relevant to the explanation, since I (think I) understand that what you're doing is moving the contact patch out of the plane of the frame (in whichever direction is necessary) to counteract the camber force. This was not at all clear, since I thought you were working within the constraint that the contact patch had to stay in the plane of the frame.

In general it seems to be a really inelegant design solution to introduce a lateral force (camber force from the wheel canting) that you then have to counteract, when the lateral force could simply be omitted in the first place (by having the wheel in the plane of the frame). Having to balance the two opposing forces perfectly in order to produce a truly neutral bike just seems like a lash-up. 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. We do it all the time with less-than-perfectly true or badly seated wheels, asymmetric loads, road camber etc. I did it for 3 years without it feeling strange enough for me to do anything about, even though I could see that my front wheel was out of whack. 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. On a normal (forked) bike any lateral force is wrong; on a no-fork bike it could just be due to poor resolution of two intentionally generated forces.

The requirement for precisely matching the opposing forces also raises further questions:

Your comment suggests that setting up needs to be done fairly precisely with regard to canting vs. offset. 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.

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?

I actually bothered to camber it even on a gag pic :-)

This
is
amazing

Jaw dropped : ))

Only thing missing now is lateral adjustment, or are you planning to do it with the spokes?

or are you planning to do it with the spokes?

Yes, it's easy enough to dial in the offset by adjusting the dish on the wheel build.

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..