A Better Nose Wheel Design

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Hale-Yes
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A Better Nose Wheel Design

Post by Hale-Yes »

I have an MT 7-235 and I often think of the inherent fragility of the nose wheel design, as compared to a conventional gear set up. Back in my misspent youth (or well spent, depending on ones point of view) , I did a lot of off road motorcycle riding. I had a friend who had a Sach 125cc motocrosser. It had a very unique front suspension design. It was tough as nails, relatively light, and more plush than anything else offered at the time. One really striking feature of this design was that due to the geometry, when the front brake was applied hard, the front end would raise instead of diving! It was an odd sensation at first, but it worked so well that you got accustom to it in just a short time. And because it would raise, all the suspension travel was still available under hard braking, so if you hit a rut, rock or stump, you were in much better shape than if you were on a conventional bike who's suspension had collapsed due to diving under hard braking ! Sound familiar ? The design faded away due to the fact that it was limited to 6 to 8 inches of vertical wheel travel, and the telescoping fork design surpassed it in wheel travel. Now most off road bikes sport nearly 12 inches if travel. But I think the Sach design was just put on the wrong vehicle, it belongs on the nose wheel on an air plane! Here is a picture. https://photos.google.com/u/1/photo/AF1 ... T5259Z3W4P

1:1 Scale
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Post by 1:1 Scale »

Image
It's funny- I had never seen this design until I watched 'On Any Sunday" a couple of nights ago. There were a couple of clips with work one of these in them, and I thought to myself "wtf is THAT?" Now I know!

Hale-Yes
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Post by Hale-Yes »

Yes Sir! That's it. BTY can you explain to me how you up load pictures like the one you just did ? That's so much better than posting a link. Regards, Ed Hale

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chazdevil
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Post by chazdevil »

These are leading link suspensions.
They do have some great qualities. Still the best front suspension set up for the unique needs of sidecar rigs. They remove the increase of steering angle as suspension compresses like typical telescopic fork legs. The rotational mass became off putting on motorcycles. Not an issue on sidehacks.
Nor aircraft.
Neat idea.
79 M5 235Turbo

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TomD
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Post by TomD »

Have a look at this thread on how to post pictures.

http://maulepilots.org/forums/viewtopic ... ight=imgur

CaseyM did a great job illustrating the procedure.

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crbnunit
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Post by crbnunit »

That's funny! I've ridden one of those! I've ridden Pentons and owned an Ossa 250 Pioneer and a Rocon RT-340. Flashbacks!
You have to make up your mind about growing up and becoming a pilot. You can't do both!

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Andy Young
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Post by Andy Young »

chazdevil wrote:The rotational mass became off putting on motorcycles. Not an issue on sidehacks.
Nor aircraft.
Neat idea.
Do you mean unsprung mass?

I'm not sure this design would be helpful on an airplane. It seems to me (and I might be wrong) that the weakness in the aircraft nose wheel setup isn't the strut itself, it's the levering motion it imparts to the attach points on the airframe if the wheel can't easily climb over surface irregularities. This wouldn't change that, as the trailing link arm still has to attach up high at a pivoting point. If it could go straight back and attach low, like the rear swingarm on a motorcycle, it'd help, but then it wouldn't be able to turn (unless we used center-hub steering, like a very, very few exotic motorcycles). I suppose the anti-dive properties would help a little bit...

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DeltaRomeo
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Post by DeltaRomeo »

It also occurs to me that the real advantage of this design is the unloading while braking. I don't think we want to put brakes on a nose wheel...
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Hale-Yes
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Post by Hale-Yes »

That Sir, is a good point, and a definite flaw in my theory. Ed Hale

Hale-Yes
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Post by Hale-Yes »

After thinking about that for a minute of two, Why not put a brake on the nose wheel, if using it, counteracted the diving force ? You should be able to stop faster. What am I missing ? Hum. It would clearly put more load on the relatively fragile front end and that's probably a good enough reason not to. Ed Hale

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Post by pilot »

I would think that since our hands and feet are pretty busy while landing, some of us would have to use our "third leg" to activate the nose wheel brake......
I can't remember if I fired six shots, or only five.....


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