What is the travel on that fork? I dont see how it could possibly be one to one unless it has very short travel. I have a friend with a K1300S, I need to look at his a little closer, but even if I rode it, I dont have a useful baseline as I have so little moto experience.The BMW Telelever is a linkage design with a 1:1 damper. As mentioned above it is used on the best-selling adventure moto on the planet.
(I won't argue it is the BEST adventure moto, just the best selling. Thanks, Ewan)
They try to hit a certain price point. The smaller bikes are cheaper and use forks not produced by BMW to get there.
Sorry, I should have clarified. They don't run it as a 1:1, but because it uses telescoping legs, you could easily run traditional fork springs and dampers if you wanted instead of an external shock.
So what you're saying is that that $60,000 manitou dorado should have been a linkage fork.
I reckon there is some potential in something like this design, as far as it being a trailing-link kind of setup rather than leading link like almost everything else, which I just couldn't see working well as far as axle path and anti-dive go. This is the only bicycle fork I've seen that would appear to have an intelligently placed IC as far as both anti-dive and axle path characteristics go. It looks like it would be a struggle to get more than 3-4" of travel out of it though.
Ideal traits IMO:
). This characteristic is absolutely achievable with a "floating brake" for a tele fork though, which IMO would combine the benefits of a telescopic fork (existing advanced structure, well-established spring and damping rates, familiar handling geometry and dynamics) with the main dynamic benefit of a linkage fork (anti-dive characteristics)
I'm up for a Monkey Fork!
I've tried Scott's bike a couple of years ago with that fork on- Very disconcerting with 100% (I think) anti-dive. Just unfamiliarety of the feeling.
The problem with leading-link setups is that to get the same axle path as a tele fork, you are more or less required to have a pro-dive configuration based on the position of the instant centre. It needs to be behind and below the axle, yet above ground level, in order to achieve both comparable axle path and anti-dive effects. Draw a 100% anti-dive line from the contact patch up through the centre of mass; this is the line on which the IC must lie to get 100% anti-dive.
No, I think it should start at or just below 100%, maybe remain at that level for the first 20-25% of the travel (until the sag point), then drop off afterwards. The reason for this is bump absorption - as the spring and damping forces pick up when the fork compresses, the anti-dive force decreases to reduce the overall force being transmitted to the rider. This should result in a fork that sits up in its travel pretty well but doesn't suffer from excessive harshness. No credit for this idea though, it's pretty much exactly what DW-link does with anti-squat.
I see exactly what your saying- i am currently designing a gearbox bike to have exactly this trait in the rear.(I have a g-boxx sitting waiting in the workshop)
Yeah I agree with the familiarity/learning thing, and without a rear end with >100% anti-rise, you'll end up increasing the height of the centre of mass if you actually have 100% anti-dive throughout the whole travel. I reckon around 80% (near the sag point) should give you some amount of squish to give some feedback, but still reduce brake dive quite significantly.
What you have to also remember though is that even 0% anti-dive in the front is preferable to a telescopic fork with it's PRO-dive attributes.
Sorry, i think you mean "Draw a 100% anti-dive line from the contact patch up through the intersection of COM height ABOVE the REAR tyre contact point."
Not according to Tony Foale - http://www.tonyfoale.com/Articles/Dive/DIVE.htm
Can't see s**t captain! Got a more detailed shot?
What about something like this on an DH bike?
That's one possibility but I think then you'd have quite a lot to worry about, possibly even moreso than with a floating steering axis. Not out of the question though.yup, I think your right, the Hossack system shows good potential.
To get around the spherical bearings you could have a suspended headtube like the MX bike of Hoyt McKagen;
So, would a Monkey Fork need a special Monkey frame?
Is constant trail desirable? As far as I can tell you want a larger trail value for straight line/ higher speed stability then have your trail reduced to something more manageable for corner entry. It seems like a constant value would be a compromise in one area. I don't see why that couldn't be designed into a linkage fork though. You'd lose some of your anti dive in the process but at least you could tune your dynamic geometry with something other than spring rate and damping.
Well I've got bugger all money to contribute to such a project, but definitely keen to help with the design if you're interested in doing it.Looky what I've found
A weird italian MTB linkage fork!
Pretty hefty links. Maybe the other side makes it clearer:
Looks like it starts travel in PRO-dive
I must admit i'm getting a bit obsessional abot all these linkage forks. I'm seriously thinking about integrated one into my frame designs. On paper it looks a good deal if done right;
Less/No dive
Suspension more active under braking
Constant trail
If I were serious about building one who would be in too? Any CNC engineers/millionaire philanthropists interested!?
Good answer, thank you.
I don't think brake dive was the main reason for the linkage fork, these bikes were built around the time the RockShox Judy DH was awesome.
