VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #1  
Old 01-10-2008, 07:42 PM
chuckh1197 chuckh1197 is offline
 
Join Date: Jan 2006
Posts: 43
Default RV-7A front tire problem

I am having a problem with the front tire on my RV7A. I have had 3 tire failures in the past 3weeks. 1st was in Reno . I repaired tube which had a large break on side of tube. Had similar failure in same place as repair. Then had failure today in Dominican Republic on landing. I am very conscious of no nose wheel contack and all failures have been on roll out.

Tire pressure is 30psi.

Tire rotates by hand pressure but does not rotate freely when spun. Any ideas.

Cant keep changing tires!
Reply With Quote
  #2  
Old 01-10-2008, 08:09 PM
AlexPeterson's Avatar
AlexPeterson AlexPeterson is offline
 
Join Date: Sep 2005
Location: Maple Grove, MN
Posts: 2,333
Default

I have two recommendations, and I am assuming that the leaks are on the sidewall, the widest portion of the tube. They seem to come from a spallation of the inner tube as it moves around against the tire.

First, use LOTS of baby powder. I mean, perhaps a tablespoon. Make sure the entire surface of the inner tube is white. Second, keep the air pressure towards the high end (which it appears you are). I can never remember exactly what I use (it is written on the wheel), but I think it is 35. This is minimize flexing of the sidewall, and it has the added advantage of lowering risk of flipping. When initially inflating to seat the beads, be sure to completely deflate again, so that the inner tube can relax where it stretched across the moving beads.

I had about three flats in the first 250 hours, and none since doing these two things. I think the baby powder will fix your problem.

See another thread that I started about one method for installing the tire without risk of mashing the innertube. On that picture, you will see how much baby powder is being used.
__________________
Alex Peterson
RV6A N66AP 1700+ hours
KADC, Wadena, MN
Reply With Quote
  #3  
Old 01-10-2008, 08:12 PM
gasman gasman is offline
 
Join Date: Mar 2007
Location: Sonoma County
Posts: 3,821
Default

Are they tube or tire failures? If it is a tube fail, it is not good to repair and is best to have an extra tube with you. They are hard to find. But most airports have 5X5 tubes for the mains.
If it is the tire that is failing, then check the clearance on the wheel pant. A finger down the side and 1 1/2 fingers at each end. Check the inside of the tire with a rag, wipe around in there to see if there is anything that can cut the tube. GOOD LUCK
Reply With Quote
  #4  
Old 01-10-2008, 08:52 PM
bryanflood's Avatar
bryanflood bryanflood is offline
 
Join Date: Aug 2006
Posts: 114
Default Nose flats

I can't reinforce what Alex P says enough. I had the exact same problem you are having. Lots of nose flats early on, if fact 3 in the first 130 hours. The solution seems to be using so much baby powder it's almost scary and increasing the tire pressure. The problem is that too much tire pressure can lead to nose wheel shimy.


A buddy of mine has a vari-eze and the mains are the same size as our nose wheel. I talked to him last year about the exact same problem, cuts on the side of the tube. He said that early on all of those vari-platic guys were having the same problem. Now I guess they all run like 40 or 45 psi, but I think this is just too high for the RV nose wheel. It's way over Van's specs, but I suspect Van is trying to run pressures too low to try to prevent nosewheel shimy. So personally I run 35psi and have not had a problem since (but I do have an extra tube in the back).
Reply With Quote
  #5  
Old 01-10-2008, 10:37 PM
Norman CYYJ Norman CYYJ is offline
 
Join Date: Feb 2005
Location: Victoria B.C.
Posts: 1,266
Default

That many failures in such a short time. I wonder if some how when you are installing the tube that it might be getting pinched during assembly. It doesn't take much to pinch it and cause a weak spot or a tear.
Reply With Quote
  #6  
Old 01-11-2008, 04:30 AM
n468ac's Avatar
n468ac n468ac is offline
 
Join Date: Jun 2005
Location: C09 - Morris
Posts: 579
Default

like everyone ...
1. LOTS of baby powder
2. Up the air pressure to 40psi
3. check the inside of the tire for a rough spot that can stick the tube
__________________
(This post by: Christopher Checca EAA Lifetime Member #799388)

Allen Checca (father)
Christopher Checca (son)

RV-6A - N468AC
ENGINE: Lycoming 180 HP O-360-A1A
PROPELLER: Senisentch 72FM859-1-85
WEIGHT: Empty Aircraft 1152 lbs
BASED: KC09 - Morris, IL.
Flying since June 6, 2005
N468AC Web Site
Reply With Quote
  #7  
Old 01-11-2008, 05:54 AM
chuckh1197 chuckh1197 is offline
 
Join Date: Jan 2006
Posts: 43
Default Thanks

I will try the baby powder and a little higher inflation. The cut is on the side wall of the tube about the same spot in the tube from the valve stem. I just put on a new tube and tire which we brought with us just in case. I would suggest if you are going anywhere outside US to take a tube and maybe a tire with you. No chance of getting one of these anywhere. Just before I left Reno I spent several hours and contacted every tire repair, tire shop , RV, ATV store and no one has this size tube.
Reply With Quote
  #8  
Old 01-11-2008, 10:42 AM
JAT JAT is offline
 
Join Date: Feb 2007
Location: Durango, CO
Posts: 126
Default

Chuck,

When you put the new tube on take the valve stem out, but don't inflate the tube at all. Leave it flat. Coat it with powder, slide it into the tire and then put the valve through the rubber grommet on the wheel. Lay the wheel half flat on the table and make sure the tube is seated over the wheel and clear of the aluminum mating surface. Have your traveling partner carefully place the second half of the wheel on until you hear the mating surface come together (metal on metal). While holding the halves together put the bolts in and tighten them, so the halves are held together. My tube had gotten pinched between the halves and I suspect that may have happened to yours. I have flown two more years on that new tube and haven't had any problem since. I do carry a new tube with me just in case, though. Good luck and call me (970-259-5988) if you need any of this clarified.

Jim
Reply With Quote
  #9  
Old 01-11-2008, 02:45 PM
casper casper is offline
 
Join Date: Jan 2005
Location: Derby Kansas
Posts: 146
Default

Quote:
Originally Posted by chuckh1197 View Post
I will try the baby powder and a little higher inflation. The cut is on the side wall of the tube about the same spot in the tube from the valve stem. I just put on a new tube and tire which we brought with us just in case. I would suggest if you are going anywhere outside US to take a tube and maybe a tire with you. No chance of getting one of these anywhere. Just before I left Reno I spent several hours and contacted every tire repair, tire shop , RV, ATV store and no one has this size tube.
I had the same problem. The area you indicate is the same as mine. Some of these shin fin tubes have a built in defect. That is what i found. I posted about this sometime back.
__________________
Doyle Reed, Casper 2
Reply With Quote
  #10  
Old 01-11-2008, 05:43 PM
Walt's Avatar
Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,686
Default

I have been running for 3 years, 700+ hours and never had a problem. I also replace the tire/tube every year whether it needs it or not (cost is about $50). Lots of talc, careful assembly and 40-45 psi religiously.
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 04:25 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.