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Discussion Starter #1 (Edited)
Searched the forum and did some googling but can't find and answer. I am looking at replacing the rear fenders of the U1200.

Called Polytech from PG and stopped by at CBS parts but it seems like the plastic fenders they sell are all 26" wide....

The originals are only 16" wide. Any idea's?
 

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I looked at some rear truck fenders for the dual wheels. I played with the idea of cutting it down the middle. The ones I saw were finished on both outer edges, the cut down the middle would be against the frame and therefore hidden. I also considered the grader or tractor ones from different manufacturers.
 

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Searched the forum and did some googling but can't find and answer. I am looking at replacing the rear fenders of the U1200.

Called Polytech from PG and stopped by at CBS parts but it seems like the plastic fenders they sell are all 26" wide....

The originals are only 16" wide. Any idea's?
Yeah, I used Polytech 26".
Cut them in the center, trimmed, I guess 8" inside and plastic welded back.
 

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Discussion Starter #11
Update; we found some time to finish our fender project. We bought 2 cheap poly standard semi fenders and cut them in half. Put them back together and created some brackets.

Very happy with the results! Thanks all for the great idea's and suggestions!
 

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Over the winter that isn't ending here in Nova Scotia (+2 C yesterday with the wind and enough rain this Spring to film the next 'Waterworld") I removed the water tank from my 1300L fire Mog and need to fit fenders to the rear. I don't have the spider frame or bed yet and don't expect those to be available for a few more months. So....I've been looking for rear fenders to affix to the frame so I can begin driving the beast after having spent many many hours tidying up small things that needed attention.

Following suggestions offered on this most helpful site, I was in contact with Poly Tech in Prince George and cannot say enough good stuff about their customer service. Their single wheel fender is not wide enough so Cal cut down the double wheel poly fender to provide me with a 16" width, and he plastic welded each so that I have an inner fender lip as well. Both were shipped clear across the country (3500 miles) for $146 Cdn. These things are stout. When I cut out the back I left about 7" of material to mimick an inner fender. If this proves to be a problem with rubbing or mud accumulation I'll cut them out.

I am appreciative of suggestions on how much space to leave between the bottom of the fender and the top of the tire. I have no weight on the rear right now so expect the springs to compress somewhat when a bed is added. A few photos are included that depict approximately 7 3/4 inches for the stock fronts, but that looks like too much for the rear, so I'm looking at 6". Most of the photos I'm looking at have less space in the back than the front. At 6" I have approx. 1 3/4 inches from the top of the fender to the top of the rear shock mount. Any suggestions?

I also have to fab the fender brackets from scratch. I'm not finding many examples of the configuration of fender brackets mounted directly to the frame and see that a few of you have fabbed these up. If anybody want to shamelessly self promote your creative skills, or post somebody else's, these will be helpful as I decide how to bridge that gap between the frame and the fender mount.....C channel, square tubing, round tubing... I have a mig but no metal bending equipment.

Cheers!
 

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I am appreciative of suggestions on how much space to leave between the bottom of the fender and the top of the tire. I have no weight on the rear right now so expect the springs to compress somewhat when a bed is added. A few photos are included that depict approximately 7 3/4 inches for the stock fronts, but that looks like too much for the rear, so I'm looking at 6". Most of the photos I'm looking at have less space in the back than the front. At 6" I have approx. 1 3/4 inches from the top of the fender to the top of the rear shock mount. Any suggestions?

I also have to fab the fender brackets from scratch. I'm not finding many examples of the configuration of fender brackets mounted directly to the frame and see that a few of you have fabbed these up.
Cheers!
Never one to tell someone what to do, but usually willing to throw out some observations, so here goes. I think the dearth of frame-attached rear fenders is likely due to the huge suspension travel of the Mog, and the fact that any bed/ body has travel of its own, i.e. the potential is for the total travel above/ below the fender to be very large.

By way of starting point, I did some measures on my RW1, 7450 kg GVW. Sitting static in the shop, with partial tanks in a gutted/ rebuilt "camping" firebody (itself a Wackenhut original), I'd guesstimate the weight at 13,500-14,000 lbs, with a fair amount over the rear wheels. Tires are Conti 365/ R80 MPT's, with little wear. Firebody floor is 1/8" +/- (transmogrified when transshipped from a metric universe) aluminum.

Top of shock tower to bottom of floor plate 1 1/4"
Top of tire to bottom of floor plate 8 1/2"
Top of frame rail (at rear, level section) to bottom of floor plate 9 1/4"

Track width approx 90"
Width of rebound bump stop limit bumpers 34"
Static clearance/ travel room below rebound limiters 3 3/4"

The width ratio between limiters and track suggests a multiplier of about 2.6, which suggests that there resultant travel at the outer edge of the tire could be almost 10 inches. That would undoubtedly announce itself quite vociferously, so I am inclined to think there is a modifier at work, namely that the axle as a whole will move away from the body, as regulated by the pivot points of the Panhard rod, so as to achieve a balance of total upward force from the TWO springs as measured against the axle loaded weight. Long way of saying, the 8 1/2" clearly (so to speak) works, but good reason not to reduce that.

On to the frame flex/ body torsion side of the equation. The twist deflection limiter studs on the rear subframe crossmember are 16" outboard of the center of the truck frame, which is coincident with the pivot point of the subframe (what a surprise-super symmetry). One half of the track is 45", so there is a travel distance multiplier of 2.8. Measuring 1 7/8" of clearance at the frame bump stops/ studs suggest a theoretical possible downward travel of the firebody at the outer edge of the wheel of 5 1/4".

Lacking the ambition to pull out of the shop and find a large rock to surmount (the truck, not me), I have to mentally model the combination of spring compression and torsional twist in the firebody. I confess, the only thing I can definitively state is that I have wound the truck up a reasonable amount (but not to an extreme) and haven't scraped or bound up anything. What I am fairly confident of is that the suspension travel allowances on my truck are not to be reduced, and any fender on a similar Mog probably needs to respect those kind of clearances. It may be that , at least in some circumstances, the body will twist upward as the corresponding wheel rebounds upward; diverging rather than converging.

Another method of analysis is to look at the Atlas catalog, specifically their subframe and the fender liners they fabricate for use with. I have the Atlas subframe as a kit, but not yet assembled (time and money, natch). Michael Dennig told me the top of their subframe would be 75 mm lower than "standard", which is the amount they need the wheel well to intrude upward above the top of the subframe, to allow for wheel/ suspension travel. Their fender liners use all of that upside clearance, and are a subframe mount, NOT a frame mount.

A suggestion: do a real simple frame-fixed crossbar(s) mount for the new poly fenders, that will allow you to drive around now, and then do a snazzy subframe/ bed/ body mount when that becomes a reality.
 

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Photobldr; many thanks for the thoughtful analysis and the measures. I will go with your suggestion ": do a real simple frame-fixed crossbar(s) mount for the new poly fenders, that will allow you to drive around now, and then do a snazzy subframe/ bed/ body mount when that becomes a reality". Making changes can tax the grey matter when fabrication experience is slim to NIL, particularly when there's no tangible example or drawings to copy. Trying to avoid outsourcing at shop rates where possible. Cheers.
 

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Update - rear fenders on temporary mounts

A quick update on the Polytech rear fenders; temporary frame affixed mounts are welded up and installed. Now I can drive the truck (mud flaps will go on asap). The little things that needed attention (ones I could find or found me) have been remedied and the old girl has been running along well. Spider frame is next. Cheers!
 

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That is looking good.

A little late to the party, but here is one shot of something that Mercedes uses to put fenders on trucks, UNIMOGs or otherwise, that need to be driven for delivery, etc., but do not have rear beds or bodies installed.

The fenders have a series of pockets moulded into the fender, which stair-step up the outside of the fender. By grabbing lengths of wood (about 2" X 3" ) and picking the appropriate pockets, they can quickly hang legal fenders on a variety of trucks. The examples I saw at Wörth used plastic strapping to secure the wood to the frame rails, and torx drive wood screws to anchor the fenders to the lumber.

I know I have more photos of these things, but I can't find them at the moment.
 

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Smart if not a little hokey but not in a bad way. Wonder if those fenders are in the film, should be easy enough to get metric metal to match.

Nominal Actual Actual - Metric
1" x 2" 3/4" x 1-1/2" 19 x 38 mm
1" x 3" 3/4" x 2-1/2" 19 x 64 mm
1" x 4" 3/4" x 3-1/2" 19 x 89 mm
1" x 5" 3/4" x 4-1/2" 19 x 114 mm
1" x 6" 3/4" x 5-1/2" 19 x 140 mm
1" x 7" 3/4" x 6-1/4" 19 x 159 mm
1" x 8" 3/4" x 7-1/4" 19 x 184 mm
1" x 10" 3/4" x 9-1/4" 19 x 235 mm
1" x 12" 3/4" x 11-1/4" 19 x 286 mm
1-1/4" x 4" 1" x 3-1/2" 25 x 89 mm
1-1/4" x 6" 1" x 5-1/2" 25 x 140 mm
1-1/4" x 8" 1" x 7-1/4" 25 x 184 mm
1-1/4" x 10" 1" x 9-1/4" 25 x 235 mm
1-1/4" x 12" 1" x 11-1/4" 25 x 286 mm
1-1/2" x 4" 1-1/4" x 3-1/2" 32 x 89 mm
1-1/2" x 6" 1-1/4" x 5-1/2" 32 x 140 mm
1-1/2" x 8" 1-1/4" x 7-1/4" 32 x 184 mm
1-1/2" x 10" 1-1/4" x 9-1/4" 32 x 235 mm
1-1/2" x 12" 1-1/4" x 11-1/4"32 x 286 mm
2" x 2" 1-1/2" x 1-1/2" 38 x 38 mm
2" x 4" 1-1/2" x 3-1/2" 38 x 89 mm
2" x 6" 1-1/2" x 5-1/2" 38 x 140 mm
2" x 8" 1-1/2" x 7-1/4" 38 x 184 mm
2" x 10" 1-1/2" x 9-1/4" 38 x 235 mm
2" x 12" 1-1/2" x 11-1/4"38 x 286 mm
3" x 6" 2-1/2" x 5-1/2" 64 x 140 mm
4" x 4" 3-1/2" x 3-1/2" 89 x 89 mm
4" x 6" 3-1/2" x 5-1/2" 89 x 140 mm
 

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Being in possession of various forms of cellulose re-sizing technology, I just stock Universal Wood Product, and cut to fit any particular application. Inventory consolidation, streamlined logistics.
 
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