Leading Link Designs - Post Pics

[dmobrien2001]

[claude]

Possible a thread on center hub steering is in order?

[Bad Cat Racing]

[img]

[Ural Australia]

Originally Posted by Pezz_gs

G'day Ural Australia

Can you post some pics of what you have seen and ridden please

Unfortunately a vengeful-ex put paid to that. She thought photos made great fire starters.

[Ural Australia]

Originally Posted by vortexau

I encountered the same sort of misunderstanding during correspondence with Craig Vetter! Initially he considered Hossacks to be Girders!

The Britten is often described as having a girder front-end even though it's clearly a Hossack/Fior design.

Originally Posted by vortexau

Norman had difficulty getting any motorcycle builders to try his system, and only BMW seemed to appreciate its advantages. Then, BMW's main version was only half-Hossack until the K1200S with its (full Hossack) Duolever front end.

The BMW Telelever is a Saxon-Motodd copy and operates quite differently from the Hossack. In the Saxon-Motodd design, suspension is still a function of the uprights (telescopic forks) but suspension loads are input into the chassis from both the A-arm and steering head. In the Hossack design the upright is merely a steered component and all suspension loads are carried by the two A-arms.

The Hossack system should be ideal for sidecar useage and if combined with a steerable sidecar wheel (about 50% of the front wheel input) and a torsion bar interconnect to the rear wheel (a concept well-proven by MZ-Stoye with the Superelastik) would create a delightful outfit.

Unfortunately the Australian ADR width limits tend to make a steerable sidecar wheel VERY difficult.

[Pezz_gs]

Well,

This thread went quiet as a few months back I had a friend with a set of 'Unit' leading links at the right price. I called him the other day and said give me your bank account details. he said what for, I said to pay for the Units.

He said Oh %@#&, I sold them last week. I thought he was having a stir, but no, he forgot he said they were mine. No hard feelings really. He is a good mate albeit a little bit forgetful.

So now I am back in the designing stakes. so keep posting pics and ideas.

Centre hub has its merits but for off-road work would the unsprung mass be a little higher?

[larryboy]

Originally Posted by Pezz_gs

Centre hub has its merits but for off-road work would the unsprung mass be a little higher?

I'm very interested in hub center, but worry about wheel travel mostly. Strength seems to be there..LL is easier to build.

Maybe we do need a hub center thread?

[Bad Cat Racing]

Originally Posted by larryboy

I'm very interested in hub center, but worry about wheel travel mostly. Strength seems to be there..LL is easier to build.

Maybe we do need a hub center thread?

When it comes to sidecars, Hub Center Steering is the bomb.

Steering effort is featherweight since you're not fighting the tire, it tracks -so much better- and the tire does not go up on edge when you turn it. Your contact patch remains flat during the entire turn of the bars, lock to lock.

Not only that, But since a hub center bike moves it's axle straight up and down as opposed to in an arc, your numbers are constant throughout suspension travel, you can get your chassis -perfect- with Hub Center Steering.

Oh, and let's not forget ease of service. Knock off one nut, or four lugs and your wheel is dropped off the carrier. Access to your brakes, spindle, bearings, everything... in about five minutes. As opposed to leading link which is a PITA to simply remove the wheel to get access to anything if you're running a meaty front rim like I am.

All high performance sport touring or serious performance sidecars with wide front rims should be running hub center steering front ends, it's the only way to fly.

I'll be thrilled when we switch over to an LCR chassis next year and I have the luxury of knocking off one nut and pulling a wheel right off our double wishbone front end.

[Pezz_gs]

Sounds like the go.

So where does one find info on setup ect?
[img]bimota_tesi2d.jpg[/img]
I have seen talk of using a car front wheel drive (Civic) hub.

home.planet.nl/ ~dreuning/mygts2.html

[img]http://home.planet.nl/~dreuning/mygts/frontwheel3.jpg[/img]

[img]http://home.planet.nl/~dreuning/mygts/frontwheel14.jpg[/img]

[img]http://www.partsmag.com/0503/V-Twin-Expo-0503/Center-hub-Custom-p72.jpg[/img]

[Bad Cat Racing]

Originally Posted by Pezz_gs

Sounds like the go.

So where does one find info on setup ect?

Personally... you'll want to start by talking to the guys at the HP Sidecars Forum.

http://hpsidecars.com/forum/

Look at the front end on this week's feature rig... sexy. I even see a concentric bottom adjuster for changing the caster.



There are several threads right now just on hub center design specifics and theory. Here's a new one for example...

http://hpsidecars.com/forum/viewtopic.php?t=538

And here's a cantilever A-arm setup on a Hayabusa HPS

and i very empressed of this system. This is the best i could find on the market. Also the break is out of the wheel and can better cooling by air while running. So also the break power is fantastic and cannot compare with other existing systems.

They are 2 breaks on the wheel. One (blue) is for the foot break and the second (black one) is for hand break.
So in case you can push both. Amazing

These parts look heavy, but you can't think in 'motorcycle' terms any longer, you have to think in 'race car' terms now, since once you slap three big wheels on a motorcycle you've essentally turned it into a very light and fast car. And if you do that... these components are pretty light weight for what they do.

Aside from that. Look at the photos on LCR's website and other professional Formula 1 sidecar builder websites.

I'm in the process right now of desiging my own F1 sidecar chassis in SolidWorks driven by the inspiration from dpcars.net. I'm going to use all the drivetrain (minus engine) wheels, and suspension components on my monocoque chassis design sourced from the Radical SR4 and SR3 mass production club sports race cars.

Why redesign the wheel when you can order exactly the components you need right off the shelf from someone else ready to go and fit them to a chassis of your own design? Everything is there in the 'Suspension System' catalog to build a 100% complete turnkey Hub Center Steering front suspension down to the bushings for the A-Arms.

That'l give you somewhere to start.

-Mike-

[Pezz_gs]

Thanks Mike.

That gives me a LOT to work through

I have joined the HP sidecars site and will start reading

[HogWild]

Originally Posted by larryboy

I'm very interested in hub center, but worry about wheel travel mostly.

Looking at the two rigs above, it looks like they both have quite limited suspension travel. That's probably fine for a street rig, but for dual sport or off-road, you would definitely want a system that gives more travel than those. The other negatives are the un-sprung and overall weight. A leading link setup looks much better in those respects. Again, for anything going where there are bumps, weight is definitely bad. The one thing that I like about the center hub system is that the tire stays level while turning. That's definitely nice if you have a wide and flat profile tire up front.

[Pezz_gs]

Originally Posted by HogWild

Looking at the two rigs above, it looks like they both have quite limited suspension travel. That's probably fine for a street rig, but for dual sport or off-road, you would definitely want a system that gives more travel than those. The other negatives are the un-sprung and overall weight. A leading link setup looks much better in those respects. Again, for anything going where there are bumps, weight is definitely bad. The one thing that I like about the center hub system is that the tire stays level while turning. That's definitely nice if you have a wide and flat profile tire up front.

As I am looking more towards the all road front end, the simpler LL's is the lightest way to go when considering travel.

Enjoying the thought process of Centre Hub steering too, and it would look a bit out of place on an old Airhead

[larryboy]

Originally Posted by HogWild

Looking at the two rigs above, it looks like they both have quite limited suspension travel. That's probably fine for a street rig, but for dual sport or off-road, you would definitely want a system that gives more travel than those. The other negatives are the un-sprung and overall weight. A leading link setup looks much better in those respects. Again, for anything going where there are bumps, weight is definitely bad. The one thing that I like about the center hub system is that the tire stays level while turning. That's definitely nice if you have a wide and flat profile tire up front.

It's a trade off type of thing it seems. I could go with a hub center front, shock with 4 inches of travel or so and a big bouncy tire I can air down. Or LL with 8 inches of travel and a lower profile tire for better street manners. I'll probably go with a LL for a little better dirt performance on this project.

Thanks to you and Bad Cat for the info, very helpful.

[kliff]

Originally Posted by Ural Australia

Unfortunately a vengeful-ex put paid to that. She thought photos made great fire starters.

I know that feeling.....SUX, too!