Wednesday, August 8, 2012

Interlude… Whoosh! Wheels (a product review)

I have been in search of the best option for  wheels on my A.I.R. Carbon base-tube. Wheels are insurance for those days when things don’t go according to plan.. all alone on an XC flight, thermal at the wrong time and suddenly you find yourself paying for some expensive carbon parts (or worse). With that said, I still don’t fly with wheels. I have yet to find anything that looks right on the sculptured A.I.R. base-tube. Sure you can get wheels… that look like they belong on a Farm tractor! Big rubber tires that may be great for landing but not so great in the drag department.

Below is a set of wheel we got (Via, A.I.R.) for Mia’s VS:

wheel01

Not a bad shape, aerodynamically clean. Very stable on the CB (stays put), can be completely removed to allow the CB to be stored in the D-Cell. Down side?… heavy and sadly jam up, stop turning with any sign of dust (the fine dust of the Columbia basin stops them dead).  Better then nothing but….

Next set we had a look at where the “Radsystem” for the ATOS (Radsystem Link)

 

raederaerodynamischbasis_480

Nice and light, very clean profile, acceptable size. Unfortunately, same old problems with dust (even worse) plus I don’t believe they are good for the base-tube. They need to be mounted inboard of the carbon stock skid points and it leaves a pretty long lever that is likely to damage the base-tube on a hard landing  (that and the fact the contact width of the hub is very narrow, not much area to distribute the load). Oh, and one other nagging issue. The hubs should be left on (because the little tiny screws that hold them in place are most likely to strip or lost. With the hubs left in place you can’t stow your base tube in the D-Cell….. translate : your going to end up with your glider at the flying site and your base tube someplace else? (or at least I would Winking smile )

So, our most recent look at wheels.. the Whoosh! Wheels by Raven Sports 

Below is a photo of the Whoosh! wheels mounted next to a set of Radsystem wheels:

P1000541

The Whoosh Wheels are heavier then the Radsytem but they are stronger and more durable. They also have the ability to easily remove the hub (which btw, is much wider then the Radsystem hub and requires no tools). So far, they appear to have enough clearance to deal with dust but we have yet to establish if we can expect them to survive. The hubs have both a weak and strong points. They are wide and mount outside the stock skid points, leaving only a short lever and IMO better support for the base-tube. The weakness is they do not securely fasten to the base-tube. To keep them in place you are supplied some bicycle “inner tube” …. not a solid solution. Using some heavy duty shrink wrap over top of some 205 leach line (and some industrial double back tape under both the shrink wrap and leach line) I was able to make something a little cleaner (and so far, more secure):

P1000546

Still, I find the hub to be the weak link on the Whoosh! Wheels (ATOS version). The special angle machined into each hub makes it necessary keep them where they belong, and they do have a pretty loose fit to the base-tube profile so that looks to be a difficult task. I think, in the end they need some sort of clamp or hardware to gip the hub to the base-tube in a more positive way (might make this one of my winter projects). For now, Whoosh! Wheels appear to be an ok option even with the issues that I have noted (Mia says she is going to continue to fly with them on her VQ)

BTW, I did leave out one of the other options. “Skids”. These are beautiful works of carbon “art” but for mishaps on rough real world conditions I’m doubtful. They come in two versions, with and without rollers (kind of caterpillar track, that I’m sure would die a rapid death in our desert dust) . (you can find the roller style skids listed at the bottom of the A.I.R. parts page)

(Update 13/08/2012). Thought I would add a few more comments about the Whoosh! Wheels. 

After a few days of our Mansfield dirt, they simply stopped turning (to be honest, this is probably the harshest environment I could ask any product to perform). I’m a little disappointed as they did look as if they had enough clearance to maintain some moment but the “hinged hub” seems to bind or open with the friction of the dust.  I think another issue is the hub can not maintain a good alignment (toe in or out), the twisting of the alignment causes the inner hub to open, acting as a brake. 

One other observation, the version of wheels we are testing have the holes in them (to reduce weight).  Rolling through our mood dust the holes pick up the dirt and sand and dump it onto the edges of the hub, effectively loading the bearing with dirt. If your going to try these wheels in a sandy or dusty environment, order the “solid” wheels (and yes they will weigh more). Last, the pin/dowels used to assemble the wheel half’s are pretty close tolerances making the process of pulling them apart a little challenging.. .I assume they will loosen up with use.

So for now, I do not recommend the Whoosh! Wheels  if your going to be operating in harsh dirt/dusty conditions. Looks like skids will be the better choice…. or the farm tractor tires Winking smile

Have I given up on the Whoosh! Wheels? Nope…. later this fall I might experiment with some form of hub latch to prevent spreading of the inner hub and maintain alignment. If I can’t get satisfactory roll I will continue my quest for a “better wheel”.

4 comments:

  1. Hello Martin,
    Thanks for your thorough updated review of the whoosh wheels!! I did understand from it that in a non dusty environment with a different hub (willswing litestream basetube) , and with minimum adaptation on the tube, it should be fine... I ordered a pair and will see soon.
    Fly high, land safe!
    Ralph.

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  2. Felix spends countless hours designing and wind tunnel testing the most aerodynamic control frame imaginable and pilots are adding wheels, reducing the glide by a half-point. I had a carbon fiber basetube break BECAUSE of the intense point-loading of wheels.

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  3. Wheels are not reducing the glide by a half-Point ! And even if,the security of wheels will give you a relaxed flight which will help you to fly "better". If you land so hard,that the basetube breaks,what would have happened without the wheels ?
    The wheels and the skids by AIR work well.

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    1. Well normally I would not publish and anonymous comment but... what the heck....

      Perhaps you feel you can defy the laws of physics? The big wheels do cost you performance, especially when you consider the speeds that our rigid wings fly at. Skids will have the least effect, the AIR farm tractor tires the most.... 1/2 a point... sure why not... its frontal drag, plain and simple. Is it worth the performance cost, that's up to the pilot to decide.

      Now, as to if they work or not, I'm suggesting pilots should not rely on them. I see a trend to serious complacency when wheels are used. Pilots with bad landing skills, fall back on wheels for safety when in fact they should be dealing with their landing problems. At no point am I saying do not use any of these devices, I'm saying don't count on them to save your life..... Nosing a rigid wing over while fully prone trying to "roll on" is a deadly combination.

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