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James Wheel Pants on a RV-4

RV-4

Well Known Member
Hi everyone

I've got the old style wheel pants on my RV-4 and I've been thinking about replacing them with the Sam James wheel pants.

My question is for those of us here who have installed them on how hard are they to install and is it worth the 25-30 hrs of work just to get 3-4 knots...

If anyone has pictures of their install it will be nice to have a look at them.

I've looked at the pressure recovery wheels pants from Vans but find them too bulky on a short gear -4.

Thank you for your imputs.

Bruno
[email protected]
 
Fairly sure the speed with James or Vans PR pants will be pretty close to identical. Both should give you 3-4 Ktas. I did Vans pants so I could do 380 tires. Short geared -4, no regrets. :D
 
I’ll also be upgrading to Vans’ pants and 380 tires on my short gear -4.
I have a 72 in CS prop...
 
Hi Gents

Thank you for the reply.

The speed increase is what I was expecting.

Anyone of you have pictures you could post or send me so that I can have an idea how they look installed and how low to the ground you cut them??

Thanks

Bruno
[email protected]
 
over size tires and wheel pants

I have the 380's on my RV4 now and I'm 1/2 way through the process of installing Vans PR wheel pants.

I initially installed as per the instructions for 1" above the tire but found out it that I was cutting away too much wheel pant to get 1/2"+ clearance on the sides. It was suggested here on the forum to go with 1/2" clearance with the over sized tires on the Top, and that seems to be working well with getting proper clearance on the sides.

For the holes on the U-808 bracket I was able to make my marks for the holes with dabs of paint on a Q tip with the fuzzy cut off. Worked well.

The other holes were marked with using a láser lever with + marking the spot.

What I did find out in using new hydraulic jacks that there is a small amount of bleed down in the time I would line up the láser with the bracket to the time that i had the wheel pant mounted and ready to drill the hole that I would be out 1/2 hole. I would suggest with hydraulic jacks to have a clamp on the ram to prevent this from happening. I worked through it but it was a pain and if I was to due it in the future that is what I would do.

20 or 30 hours? Not in my case but that is me. I'm all ready double that and still need to finish them.

Tim
 
If anyone has pictures of their install it will be nice to have a look at them.

[email protected]

Click on the links in my signature below. One takes you to my build log on VAF and the other to the rest of my pics in Google. There is a section for wheel pants under "landing Gear".
 
Hey Axel,

Your "Landing Gear" link takes me to your Interior pictures. Might be a bad hyperlink. I was hoping to spy on some wheel pant speed secrets :)
 
James Wheel Pants

Thanks a lot for the pictures Axel, greatly appreciated.

It give me a good idea of the work involve.

Cheers

Bruno
 
Shimmy with the pressure recovery WP

The speed increase was worth but, now with these wheel pants and the 380 tires I have a shimmy when landing that is impossible to live with.

I've tried air pressure from 20 psi to 50 psi. Its better lower but not great. I will probably go back to trying the 500*5 tires. Mine are the Vans wheel pants and are slightly larger so that is probably a contributing factor and the gear is the short gear on my 4.

Note, on the original tire size and pants there was no shimmy. When I went with the larger tires and of course no pants as the original pants didn't fit the 380 tires I did pick up an occasional shimmy that hardly ever happened as long as my tire pressure was under 28 psi. But with the new PR wheel pants its un livable.
 
Balancer

Yup, bought a balancer off amazon and then rebuilt the balancer so it doubled my investment but at least now it can actually balance properly.

I have the wood stiffeners in place and wrapped in fiberglass. Once it warms up I'll pull the gear leg faring off to ensure nothing has changed there.

Tires are fairly new, no signs of obvious wear and not flat spots.

Gear is tight in the mount.

Wheel bearings are snug but not to tight. Even bought some shims to get the bearings preload just right.

Hardware on the axles are new and tight.
 
gear shake

I had a severe gear shake on my Wittman Tailwind at around 25 statute on the gps on rollout. After trying everything possible I clamped an aluminum rectangular bar to the trailing edge of the gear with adel clamps. There is still a little shake but huge improvement. I think the bar is 1/4" x 1 1/2", with seven clamps. The bar suggestion came from VAF.
 
I've been down that road

I have a short leg RV-4 with oak gear leg stiffeners, double wrapped with glass/resin and PR wheel pants and have no shimmy issues
...until I added the 380-150 tires. I balanced them, tried a wide range of tire pressures from 22 psi to 50 psi and could not eliminate the shimmy.
It was occasionally acceptable at the lower end of the pressure range, but then I got several pinch flats. I ended up going back to the 500-5's running 45 psi and all is good, except for the excessive gap around the wheel pants.
Maybe I'll add a gap seal?.
 
Hydraulics are for lifting, not holding

I have the 380's on my RV4 now and I'm 1/2 way through the process of installing Vans PR wheel pants.

I initially installed as per the instructions for 1" above the tire but found out it that I was cutting away too much wheel pant to get 1/2"+ clearance on the sides. It was suggested here on the forum to go with 1/2" clearance with the over sized tires on the Top, and that seems to be working well with getting proper clearance on the sides.

For the holes on the U-808 bracket I was able to make my marks for the holes with dabs of paint on a Q tip with the fuzzy cut off. Worked well.

The other holes were marked with using a láser lever with + marking the spot.

What I did find out in using new hydraulic jacks that there is a small amount of bleed down in the time I would line up the láser with the bracket to the time that i had the wheel pant mounted and ready to drill the hole that I would be out 1/2 hole. I would suggest with hydraulic jacks to have a clamp on the ram to prevent this from happening. I worked through it but it was a pain and if I was to due it in the future that is what I would do.

20 or 30 hours? Not in my case but that is me. I'm all ready double that and still need to finish them.

Tim

I know a guy trying to do a gear inspection on a Cessna 310 learn that issue the hard way
 
Lots of better hydraulic jacks, winches etc don't leak down.

Not sure what happened with your friend and the 310.

Lots of better hydraulic jacks, winches etc don't leak down.

Mine were from P. Auto and I got what I paid for. From the start I knew that there was a possibility that a slight leak down could happen. For 99%of the work I do its not a big deal. But for pant alignment it was a minor inconvenience. When I was done for the day, I'd block the gear and relieve the pressure and re-level the next day

Next time I will buy a clamp to put on the ram. The jacks work too good for what they are to try and reinvent the wheel.


TK
 
I have a short leg RV-4 with oak gear leg stiffeners, double wrapped with glass/resin and PR wheel pants and have no shimmy issues
...until I added the 380-150 tires. I balanced them, tried a wide range of tire pressures from 22 psi to 50 psi and could not eliminate the shimmy.
It was occasionally acceptable at the lower end of the pressure range, but then I got several pinch flats. I ended up going back to the 500-5's running 45 psi and all is good, except for the excessive gap around the wheel pants.
Maybe I'll add a gap seal?.

I'm thinking that's probably going to happen with me and going back to the 500-5s. Any loss of speed with the big gap?

I've read there has been some success with attaching a bar or aluminum strip but I'm not so sure how much of a difference there is between that and the oak.

TK
 
Gear and wheel pants

The aluminum bar is a lot easier than the composite wrap. The late Bob Axom(sp) discussed wheel pant gap seals years ago.
 
The aluminum bar is a lot easier than the composite wrap. The late Bob Axom(sp) discussed wheel pant gap seals years ago.

Is there any value or benefit in removing the composite wrap and replacing it with the metal bar?

I'm thinking our gaps are larger than what Bob had referred to in his testing?

TK
 
Gear

I had a hardwood stiffner wrapped with filament tape which some RV people have had success with. That didn't help in my case. The odd thing is that only the left side shakes.
 
I have a short leg RV-4 with oak gear leg stiffeners, double wrapped with glass/resin and PR wheel pants and have no shimmy issues
...until I added the 380-150 tires. I balanced them, tried a wide range of tire pressures from 22 psi to 50 psi and could not eliminate the shimmy.
It was occasionally acceptable at the lower end of the pressure range, but then I got several pinch flats. I ended up going back to the 500-5's running 45 psi and all is good, except for the excessive gap around the wheel pants.
Maybe I'll add a gap seal?.


This was exactly my experience with the 380 tires to a t. Spent close to grand fooling with these. Shut down a local runway at night for a few hours and busted up an almost new wheel pant dealing with a pinched tube. A friend who dealt with the same issue on his -4 warned me, but I didn’t listen, thought I was smarter than him. Nary a hint of shimmy since replacing the 380’s with the 500x5’s. I think my airplane actually picked up a knot or so with the smaller tires in the same wheel pants and a slightly lager gap.
 
Wood or aluminum bar for shimmey

Ok, that sounds like it is an option then. Mine is worse on the right side then on the left side.

Might be worth trying before I throw the towel in and go back to the smaller tires.
 
dropping the wood and going with the metal

This was exactly my experience with the 380 tires to a t. Spent close to grand fooling with these. Shut down a local runway at night for a few hours and busted up an almost new wheel pant dealing with a pinched tube. A friend who dealt with the same issue on his -4 warned me, but I didn’t listen, thought I was smarter than him. Nary a hint of shimmy since replacing the 380’s with the 500x5’s. I think my airplane actually picked up a knot or so with the smaller tires in the same wheel pants and a slightly lager gap.

Yes, its time consuming and expensive. It will be interesting to hear if anyone else has had more luck with dropping the wood and going with the metal.
 
Pants

They look much less like an Easter Egg than Vans .
Time consuming…yes . But you can still fly while you’re working on them .
 

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