Tail dolley wheels?

Is it ok to use a solid rubber tyre for my tail dolly wheel, or do I risk
damaging the glider?

On Sun, 29 Sep 2019 13:11:43 +0000, John McLaughlin wrote:

Is it ok to use a solid rubber tyre for my tail dolly wheel, or do I
risk damaging the glider?

You don't say what the glider is or how your tail dolly works, which
would be useful information.

That said, I think a solid rubber tyre is fine *provided that* the dolly
is off the ground when the glider is being towed by a vehicle, i.e. the
weight of the dolly and rear end of the glider is carried by the tow
ball. The dollies for both gliders I've owned have been lifted off the
ground when the tow bar is attached to a vehicle. With this arrangement
the only time you'll move the glider on the dolly when is when the towbar
is detached and you're moving the glider slowly by hand, so having a
solid tyre is no problem.

The type of dolly that rolls along the ground when being towed by a
vehicle may benefit from having a larger wheel with a pneumatic type
fitted, but I have no experience of using this type.


--
Martin | martin at
Gregorie | gregorie dot org

On Sunday, September 29, 2019 at 6:15:04 AM UTC-7, John McLaughlin wrote:
Is it ok to use a solid rubber tyre for my tail dolly wheel, or do I risk
damaging the glider?

Ease of replacement depends on the caster used.
If you're in USA, I suggest a "flat proof" wheel from Tractor supply. Easiest to see what will work if you take your tail dolly into the store.
TSC carry a few. The tire of the one I used JUST fits inside the yoke but may not fit every caster. In my case the axle diameter of the caster was smaller than the wheel required, so I added brass bushings from True Value Hardware to enlarge the axle plus another bushing to give the correct offest.
TSC Part number 3553230
Lasted 3+ years so far. Has a little shock absorption, not as much as a pneumatic but way more than a solid caster wheel.
Jim

https://www.tractorsupply.com/tsc/pr...nd-truck-wheel

is what I replaced mine with after the previous (same one) being shredded to pieces after landing with it on. There's a lesson there about hurried take-offs...

On Sunday, September 29, 2019 at 6:15:04 AM UTC-7, John McLaughlin wrote:
Is it ok to use a solid rubber tyre for my tail dolly wheel, or do I risk
damaging the glider?

Schleicher supplied me with a solid tire dolly for my 31Mi, so it must be okay.

Tom

The Grob 103 in our club has a solid tail wheel dolly. Pretty heavy airplane so it shouldn’t be a problem.
I don’t get the comments about towing behind a car. My ASW-19 & 20 both lift the tail dolly wheel off the ground when I tow them.

It's the kind of dolly where the car doesn't take the weight - it's all on
the
dolly wheel.
A hard wheel seems a bit brutal, but since the dolly will spread the load
over a decent area and I'm looking at 5mph, compared to the 50mph
impacts at the tailwheel during landing, I guess it should be ok.
If there was a case of a glider being damaged in this way, I think someone

should have heard about it?
I tried a foam filled wheel, but it suddenly developed a huge flat spot and

pneumatic tyres haven't worked for me at all.

Schleicher supplied me with a solid tire dolly for my 31Mi, so it must be
okay.

Tom


Was it hard rubber, or foam filled?

I don’t get the comments about towing behind a car. My ASW-19 & 20 both lift the tail dolly wheel off the ground when I tow them.

There is a fairly common tow bar system (Initially offered by DG, I believe) which uses a long square tube with a round tube at the glider end welded at 90 degrees. This tube slips into a round tube receptacle mounted at the tail dolly caster. The opposite end of the long tube has a tow ball hitch. With this system, the glider is towed with the tail dolly wheel on the ground. A pneumatic tire can wear out or go flat if you have to tow long distances or over rough terrain. A solid tire is a better choice, provided it isn't TOO hard. You should try to find a solid tire that is similar in "softness" to a pneumatic tire to avoid vibration and shock.

On Monday, September 30, 2019 at 3:15:05 PM UTC+1, John McLaughlin wrote:
Schleicher supplied me with a solid tire dolly for my 31Mi, so it must be
okay.

Tom


Was it hard rubber, or foam filled?

My recently delivered IMI tail dolly has the optional larger than usual foam filled tyre and also suspension to reduce the bouncing around of the glider on tow out. Its not on the website yet for some reason.