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View Full Version : Mia Culpa - Trail Damage Review BOWAGW


ttubb
06-12-2009, 06:05 PM
For those that were on the BOWAGW Wednesday, I would ask for a bit of a critique on the trail damage I experienced. See:
http://www.risingsun4x4club.org/forum2/showthread.php?t=10136

As a life-long pilot, it has alwas been very important to take good care of the equipment. I think I failed on Wednesday. In spite of the minor nature of the damage to the fender, it really bugs me to "bend the tin" on these rigs.

I was hoping perhaps Chris Davis (who was ahead of me) , Ricardo Maestas, Jeff Zepp, Dan Kucera (40 drivers) and Kipper (who was behind me and saw the event) could give me some insight on what I did to cause the incident. Since I was not able to be at the pizza dinner, I was not able to get your comments first hand. Anyone else with suggestion please chime in.

Background - I tried to follow Chris' line into the pit, but I think I may have used too much throttle coming out of the hole. How did the other 40 drivers negotiate this area? Kipper, did you see anything you could share?

Pride be damned, I just want to get better at this. Thanks, Terry

theboomboom
06-12-2009, 06:25 PM
We took the bypass terry :p:. Don't beat yourself up over this, things like this just happen. Your rig was plenty capable of making it through the obstacle, as was the driver. It wouldn't have taken much, and things could have been a whole lot worse. Live and learn, the guys in this club are excellent coaches and should have some additional comments to help ya. :risingsun

Air Randy
06-12-2009, 06:26 PM
Clearly, it was pilot error.............

Sorry, I wasn't even there, I just wanted to be the first one to say that :hill:

Tch2fly
06-12-2009, 06:55 PM
Ahhh yes, introspection is the mark of a great pilot :thumb: a good post flight always improves the next mission.

I was behind Kipper and also saw it happen. It was a combination of things like the line you took and amount of throttle. I really think tire pressure/width may have been a large factor. Look at how far the sidewall is deflected here ...
13206
It is hard to descrbe but it really looked like the truck did a little extra "shimmy" or "dip" to the right just before you went over. I think the tire buckled/folded and that may have been enough weight shift to cause the flop. Notice the ridge... you would have been right along the edge of that dip and you slipped down pulling the tire over. As we were pushing you over I really thought the tire was off the bead.:eek:

Regarding the line, it looked OK but IMO you could have been a bit more to the left or taken a slightly different angle as you came from the right. Obviously the wheelbase is a big factor but I came through without any of the big air the other wagons got because of the angle I took.

Beater
06-12-2009, 07:04 PM
I think it was the lack of rust on an umpteen year old 40 that did you in...

MountainGoat
06-12-2009, 07:04 PM
I took the bypass as well. I was ahead of you and didn't even know anything happened until we all stopped at the end of the loop. I would have considered trying the obstacle in my open diffed saggy springed 40 on 235s had someone been spotting. I have been through it in my 85 Longbed Hilux (open diffs & 31s) and my 95 FZJ80 (locked with 33s) numerous times, but those long wheelbases make it hella easier.

I saw Zepp drive right through it in my rearview, but I obviously couldn't really discern what line he took. In my longer wheelbase rigs I enter it tight on the right and then cross to the left as I come through it. That way both my rear wheels aren't trying to climb that wall at the same time. Haven't tried it in my 40 yet, so I don't know if that would work or not.

I would be totally willing to take my 40 up there with you (and anyone else who might want to play) and spend some time on it to get it figured out. Only trouble is that the trail is a madhouse on the weekends with atvs and dirt bikes and such. A weekday would be much better.

ttubb
06-12-2009, 07:07 PM
Ahhh yes, introspection is the mark of a great pilot :thumb: a good post flight always improves the next mission.

I was behind Kipper and also saw it happen. It was a combination of things like the line you took and amount of throttle. I really think tire pressure/width may have been a large factor. Look at how far the sidewall is deflected here ...
13206
It is hard to descrbe but it really looked like the truck did a little extra "shimmy" or "dip" to the right just before you went over. I think the tire buckled/folded and that may have been enough weight shift to cause the flop. Notice the ridge... you would have been right along the edge of that dip and you slipped down pulling the tire over. As we were pushing you over I really thought the tire was off the bead.:eek:

Regarding the line, it looked OK but IMO you could have been a bit more to the left or taken a slightly different angle as you came from the right. Obviously the wheelbase is a big factor but I came through without any of the big air the other wagons got because of the angle I took.

Thanks, Mike. Cheeseman mentioned he thought for those tires I had aired down too much (I used 18psi which is what I have been using on the 80). He suggested a higher pressure due to the large sidewall area. Thanks for the comments and pictures. Terry

ttubb
06-12-2009, 07:09 PM
I would be totally willing to take my 40 up there with you (and anyone else who might want to play) and spend some time on it to get it figured out. Only trouble is that the trail is a madhouse on the weekends with atvs and dirt bikes and such. A weekday would be much better.

Thanks very much, Dan. TT

ttubb
06-12-2009, 07:11 PM
We took the bypass terry :p:. Don't beat yourself up over this, things like this just happen. Your rig was plenty capable of making it through the obstacle, as was the driver. It wouldn't have taken much, and things could have been a whole lot worse. Live and learn, the guys in this club are excellent coaches and should have some additional comments to help ya. :risingsun

Thanks, Rick. It was nice meeting you and your dad. TT

RicardoJM
06-12-2009, 08:31 PM
As Rick indicated, we took the bypass. We were right behind Jeff Zepp who went through. I don't recall the line he took, but I do vividly recall his front tires were up in the air 2-4 feet. I was at the dinner and do not recall any discussion of the incident that had the "Monday morning quarterback" tone. The discussion was much more along the lines of how unfortunate it was for such a nice truck and how fortunate it was that no one was hurt.

corsair23
06-12-2009, 11:35 PM
Terry,

Probably the only way for you to truly learn how to get through the obstacle will be to run it again with a fellow 40 owner who can point out the proper line and why, drive his/her rig through the obstacle while you watch, and then is comfortable with spotting you through it, knowing full well that the next time you do the obstacle it could be different.

I've done it twice now...Once in the 40 last year and then this year in the LX. Both times it was a :eek: moment for me. Much more so in the 40 though as I stalled right in the pit, with the DS front tire in the air. This year in the LX I about took out the poor guy trying to snap pictures :doh:...Not sure what line I took or what went wrong but the front came up and then pretty violently swung hard to the PS (starboard for you boaters) before coming back down. Both myself and the guy taking pics had the :eek: look on our faces. Having done the obstacle last year, and watching several folks go through it this year, I felt confident the obstacle would be uneventful for me...I was wrong. For as much grief as I gave Mike W. for getting no air, I'll be the first to admit I liked whatever he took much better :D

This was me last year (fwiw I'm on 33x12.5" tires and they were at street pressure of 30psi or so because I arrived late and didn't bother to air down). You can tell from the direction of my front tires I wanted nothing more at that moment that to turn and get out of the obstacle...Not the right decision in hindsight:

.

Kipper
06-15-2009, 08:57 AM
2 things I think I can share. the first is something this is common with every flop I've see like this, wheelspin causes you to slip off of your intentional line, and the loaded, downhill tire slips into a hole that you where originally avoiding and over you go. there is something to said for "staying in it" with steady throttle to give your front end a chance to hook-up, but there is also something to be said for knowing when to ease up. your truck bounced once before the flop, bouncing is 100% sure sign IMHO that you need to ease up and get the truck stable quick. i think the biggest thing you'll learn from this is to think past the line and start thinking "if I take that line and start slipping, where are by rear tires going to end up"

the other is what everyone else has already said, 33x9.5 bfg at's look totally sweet, but after seeing this, I don't think I'd take them offroad and if I did I wouldn't air them down much. your rear pass tire buckled when you went over. the rest of the trail I was really watching them and they were really bouncy at 18psi. next time try 22

Hulk
06-15-2009, 10:16 AM
There is definitely an art to maintaining the right amount of throttle. You don't want to punch it, but you need to have enough momentum to roll through the obstacle without stopping and without bouncing. Once you start bouncing, your vehicle repositions itself, and the results are never better than your original line. Gravity is not your friend.

One lesson I've learned over the years is to not panic and hit the brake at the scary moment when your tire is in the air. If you stop, this often will create a dangerous, tippy situation. Assuming that you have chosen your line and you have a good spotter, you need to keep rolling and let your tire sit back down. "Drive through the obstacle." I distinctly remember getting schooled on this courtesy of Cheeseman back in 2001 on the Golden Spike. In other words, don't stop at the most dangerous part of the obstacle -- drive on through and stop where your vehicle is safely level and back on all four tires. This assumes that you have the appropriate amount of momentum to drive through the obstacle on your original line, without bouncing.

I run 33 x 12.50 tires on my FJ40, and I routinely air down to 14 psi. I'm surprised that 33 x 9.50 tires don't work well at 18 psi. That's not something I would have known.

In terms of lessons learned, here are a few for future BOWAGW runs:


All short wheel base vehicles should be spotted through that obstacle.
We should put the 40s together for this obstacle with an experienced driver at the front, so that other 40 drivers can observe his/her line.

ttubb
06-15-2009, 08:26 PM
Kipper, Jeff, Matt and all, thanks very much for taking time to share your thoughts. This has been very educational.

I still have the stock tires and other wheels. I may put them back on for wheeling or just use the 40 for trails and hunting/fishing. Terry

AxleIke
06-15-2009, 09:33 PM
Obviously I wasn't there so I can't comment on the roll.

However, 33x9.50 BFG AT tires do great at 17-18. 15 is better in terms of traction, but you can blow beads much more easily. Too low for these tires is 10-12, as they won't stay on the rims, and you lose too much ground clearance.

I run these tires and haven't ever found them to be the cause of instability.

That obstacle feels nice and sketchy at 103". I can't imagine it in a 40. I'm impressed more don't roll there. I don't think the tires had much to do with it. It may have been the straw that broke the camel's back, or the 40's fender, as the case may be, but the rig had a lot more going against it than the tire pressure.

If it were me, I wouldn't hesitate to air down that low again. Above 20, these tires won't hook up on the rocks nearly as well.

ttubb
06-16-2009, 06:06 AM
Obviously I wasn't there so I can't comment on the roll.

However, 33x9.50 BFG AT tires do great at 17-18. 15 is better in terms of traction, but you can blow beads much more easily. Too low for these tires is 10-12, as they won't stay on the rims, and you lose too much ground clearance.

I run these tires and haven't ever found them to be the cause of instability.

That obstacle feels nice and sketchy at 103". I can't imagine it in a 40. I'm impressed more don't roll there. I don't think the tires had much to do with it. It may have been the straw that broke the camel's back, or the 40's fender, as the case may be, but the rig had a lot more going against it than the tire pressure.

If it were me, I wouldn't hesitate to air down that low again. Above 20, these tires won't hook up on the rocks nearly as well.

One of the issues I have is that I have a 4 inch lift and longer shackles, which puts the body higher. It is more "tippy" than stock. Even my wife commented on it while driving it.
I think I will have to modify it a bit or just stick to trails that do not have serious off-camber sections. Thanks for the comments. T :thumb:

wesintl
06-16-2009, 10:12 AM
I wasn't there either but i'll comment anyway :D

I ran bfg 33x9.5's and they suck. That's why i'm hesitant to run the 33x10.5 or 255-85. they have a toilet paper sidewall. They are a flimsy tire on a heavy truck like a 40 with 4" lift. You would be better off with 10.5's but on a 4" lift 40 with extended shackles I would run 35 x12.5. You will have much better stability and traction. For some reason I thought you had OME lift. 18psi isn't too low for the tires but you need learn to take the bypasses on things like this depending on your set up. I'm sure it's a combination of things as well, not just the tires.

AxleIke
06-16-2009, 10:40 AM
I wasn't there either but i'll comment anyway :D

I ran bfg 33x9.5's and they suck. That's why i'm hesitant to run the 33x10.5 or 255-85. they have a toilet paper sidewall. They are a flimsy tire on a heavy truck like a 40 with 4" lift. You would be better off with 10.5's but on a 4" lift 40 with extended shackles I would run 35 x12.5. You will have much better stability and traction. For some reason I thought you had OME lift. 18psi isn't too low for the tires but you need learn to take the bypasses on things like this depending on your set up. I'm sure it's a combination of things as well, not just the tires.

I've had good experiences with the tire. They aren't up to the traction needs of a full time offroad truck to be sure, but for trucks that see mostly highway, with some dirt and rocks thrown in on the weekends, they are a great tire.

They do suck in the mud. Big time. Everything else though, they do pretty well.

I also disagree with Wes' sidewall assessment. They are quite good for an AT tire. I've had 2 flats with mine, and they've been due to very sharp objects hitting the side. MTR's have gotten ripped out in the same locations. The rest of the time, they have been great.

Obviously, if you can run the 12.5's, there is very little reason not to. I've found they hydroplane a lot more than the 9.5's, but they are decent.

I run the 9.5's so I can abuse my stuff with less breakage. The resistance to turning is much greater on the 12.5's. I've run the 12.5's and wasn't a huge fan.

wesintl
06-16-2009, 11:12 AM
I actually had the mt way back when and performed pretty decent in the mud. I guess that's mute now though :P