Project Steel Belly

The "Pimp my Ride" section for Soviet bloc bikes. Everybody seems to have their own custom add-ons, modifications & accessories. Share your tips and post pictures of them here.
Forum rules
This is the place for topics concerining modifying and accessorizing your Ural or Denpr.
User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Project Steel Belly

Post by BinDerSmokDat » Wed May 01, 2019 9:22 am

Ask 10 people around here about skid plates and you will get 10 different answers.
A lot of those answers are based on feelings and not much real-world experience.
Fewer still are based on critical analysis of what a skid plate should do and how it should be designed.

I off-road a fair amount and have bent and broken sh!t on my bike that others haven't, so I'd say I'm hard on Urals.
I’ve broken a bike swingarm, a sidecar swingarm, hairline fractured my thumb, countless turn signals at all three corners, hammered the sidecar fender so many times it is permanently dimpled, bent two sets of handlebars, blown a final drive, dented the tub, tweaked front and rear fenders, broke the sidecar brake linkage bar, bent the stock left engine guard a dozen times, bent a raceway left side footbox and engine guard TWICE, etc. I've stopped counting how many times my bike has been on its side. With that off-road resume, my position on skid plates is this...
"99% of bikes don't need them despite what you might think. Most of those that get one, get one that at best is a useless farkle and at worse, is a false sense of security."
Now that everyone has their panties in a twist, hear me out on some things…
  • Most bikes just don't really ride off-road. Some do, but MOST don't. and even those that do go off-road, they aren’t ridden very hard or over terrain or obstacles where a skid plate would make a difference.
  • I'm going into my 9th year of off-roading with Urals. Never been on a ride where someone broke or has been hung-up by the oil pan or anything under the bike that a skid plate would have prevented.
  • You can jack up your bike by the stock oil pan and it won't hurt a thing.
  • I have dragged my oil pan over rocks, ruts and stumps, never came close to breaking it, put a few new shiny streaks on the fins, but that's it.
  • I have only heard of a couple of people breaking an oil pan. Literally a couple…2 people. And one was in Moab and from what I understand, it was a pretty advanced trail. A place that 99% of Ural riders wouldn’t go and of the few who ride in Moab, most of them wouldn’t go.
  • If you were really worried about being stranded with a broken oil pan, a spare oil pan and two quarts of oil fit in the trunk and are cheaper than a skid plate and you keep your ground clearance for the other 99.9% of the times you need it off-road. It just isn't an area of the bike that is a weak link. We don't have a "cracked oil pan" thread for a reason.
  • The majority of the bikes I’ve seen doing Moab do not have a skid plate. A lot do, but most don’t.
Let’s start with what a skid plate is.

The general idea is that you bolt a hunk of material to the underside of a vehicle to prevent damage to important parts and help the vehicle slide over obstacles. Faux skid plates AKA “Skid Fakes” are frequently bolted to vehicles for an off-road “look” but are not functional. We’ll discuss “Skid Fakes” in-depth later.

There are four factors to consider when determining the need for and design of a skid plate. (Technically it’s five factors, the fifth being “Tacticool” if you just want “the look.”)
  • The first factor is the Vital Area(s) to be protected. On our rigs that is pretty much the oil pan and exhausts. Those are the only things that hang down low enough to make a skid plate worth the while. You could argue that the brake pedal linkage is important, but it is tucked up underneath pretty well. The center stand hangs down, but a skid plate would have to come back pretty far and be engineered to cover the center stand without interfering with operation. Not sure that is possible, nor is a center stand critical. So basically for our purposes, the oil pan and exhaust, with exhaust being the less critical of the two.
  • The second factor is Clearance, both ground clearance and clearance between the skid plate and critical parts. You need to factor in whether the value of a skid plate is worth the decreased ground clearance. If the skid plate sustains a hard impact, what will happen to the components behind it? A skid plate that bends, deflects or is punctured will push against the components behind it.
  • The third factor is Material thickness and appropriateness. This area, more than any other, separates the real skid plates from the ones that are just there for looks. It is also one of the most controversial subject when skid plates are discussed. Too thin and soft, it just gouges or bends, rather than remaining rigid and allowing the plate to pass over the obstacle. It might even fail completely and transmit force to the components behind it or it may tear loose and cause the vehicle to get hung up.
    Skid plates on rock-crawlers and Baja vehicles use 3/16” steel or ¼” aluminum (usually 6061) to protect the parts they consider vital. You can argue that they are bigger and heavier vehicles thus need heavier materials. However a Ural has fewer points of ground contact and poor gearing so it generally needs to have more momentum in rocky terrain than Jeeps. I’d say those are appropriate metal gauges for a Ural with rider(s) flying over obstacles. And those thicknesses are for plates that are well fabricated, shaped and supported. The larger area you span the thicker or more support you will need. For a plate supported at the edges only, the strength is proportional to the thickness cubed. In other words, doubling the thickness will increase the load it can carry by a factor of eight.
    Steel versus Aluminum
    Given that some of the steel skid plates being sold are using 1/8” or thinner steel, which is inadequate to prevent bending, deflection and/or gouging, I am baffled by people who believe that they can use aluminum skid plates at similar thickness and they will be sufficient.
    Yes, aluminum is generally stronger per pound then steel. The key there is “stronger per pound.” You will generally need to go with a THICKER piece of aluminum than steel to get the same properties, which will usually still be lighter than the steel it replaces.
    For a main skid plate under the oil pan, I would say that 6061-T6 aluminum in ¼” thickness is the minimum to get a plate that will not deflect or severely gouge under a hard strike and allow the bike to slide over. In ¼’ thickness this material is stronger than most steel commercially produced Ural skid plates I’ve seen.
  • The fourth factor is design. If the skid plate takes some big hits, where will that force be transferred? Will the attachment method be strong enough to keep the plate attached? Will the force be transferred to a bike part that may break/bend? Do you want the attachment points to fail as a type of “fuse” to help dissipate impact energy? How far apart are the attachment points? Can the material span these distances AND take an impact without deforming and deflecting? Can you use thinner material but add some bends to improve it’s rigidity? Will you have angled sections fore and aft to help slide over obstacles? How wide past the mounting points will the plate be to protect exhaust, etc? Can the material take a hit in these cantilevered areas?
    A plate must handle forces in two major directions; upwards as the bike lands on an obstacle and rearwards as the leading edge of the skid plate encounters an obstacle. I’ve seen plates that use U-bolts on the frame uprights. Given the thinner material of these plates and the limits of clamping force, I have serious doubts about their ability to handle upward force and to a lesser degree, rearward force.
    Some plates use only two or three mounting points. This is usually some combination of engine mounting bolts and clamps.
    The strongest area of a bike is the rectangle formed by the frame, the engine mounts, the engine support rods, spacers and the engine itself. In that area the bike has to handle all of the weight the rest of the frame does, plus the engine forces, plus the weight of the rider standing on the pegs. It makes the most sense to tie into this area to mount the plate.
Those points aside, you need to decide if your terrain is worth the decreased ground clearance. Being in NJ we have sand and mud but not many rocks. Sand means vehicles make ruts so less options about which line to take and we often drag our underbellies over the high center. I think a skid plate is almost a handicap here. In PA and Moab where it is rocky, ruts are less common, so you can usually take a line that lets you put the bike crossing ledges perpendicular instead of straddling them. Not always, but usually. There are the occasional rocks in the middle of the best line and you do mumble a prayer as you pass over them, so I see why people want a skid plate if only for peace of mind. Ironically on rocky trails I find ground clearance to be less of a concern. Rocky trails just don’t have the deep ruts that soil/sand trails do. In 9 years of off-roading, solo to large groups, I have never had anyone hang up on a rock. They get stuck in ruts/mud.

Still want a skid plate? OK. If you think your oil pan is at risk, despite all the evidence to the contrary, why would you cover it with a thin piece of sheet metal that is practically body panel gauge? Do you want a disposable skid plate, replacing it like fuses every time you bash something? Your most likely scenario that could cause damage (yet still a very unlikely scenario statistically speaking) is your front wheel going over something big, be it a rock, ledge, railroad rail or concrete drain pipe and your bike comes down hard on the skid plate.

Picture an experiment that goes like this;
Sling the frame of your bike at the steering neck and attach a quick release mechanism, then attach that to a chain hoist above the bike.
Lift the front wheel off the ground a few inches. I’ll let you keep the rear and sidecar wheels on the ground for this experiment.
Place a nice jagged rock with a flat base that is 1” taller than your ground clearance under your oil pan.
Now pull the quick release.
If that made you cringe at the thought, you are starting to understand the forces involved. And that experiment is with no rider and no momentum. Imagine coming down on an obstacle with 3 or more wheels off the ground, with a rider and a little speed.
Or if you are too squeamish to do this, instead put your skid plate in a sturdy vice and wail on it with an engineer’s hammer. Still cringe at the thought? Then you don’t have a skid plate. You have a SKID FAKE.

SKID FAKE
These are thin, useless pieces of metal bolted onto bikes out of a combination of misguided beliefs and the “cool farkle factor.” At best they are used because people figure “something is better than nothing.” But for the price they pay, a quality bulletproof skid plate could be bought/made.

Skid Fakes persist because of the simple fact that MOST Urals don’t need a skid plate so these things never get banged up. As a result they aren’t ever shown to be the useless hunks of metal they are. (Don't EVEN get me started about sidecar skid plates.)
Many commercial skid plates use material that is on the thin side. Why do they do this? Cost. Thin material is cheaper and thin material is easier to fabricate, namely when it comes to bending. Read that last part again. Thin material bends easily. If we want a skid plate to protect vulnerable areas, the one thing we DON’T want a skid plate to do is bend.

If you are going to catch a rock in that area, you want to just slide off unscathed.
You don’t want to crush your $$$ farkle, you don’t want it to gouge, rip off or damage some other part of the bike.
To date I have only seen one skid plate worthy of the name.
I believe only a plate built to the design and specs of COB's plate is capable of that.
There might be some other homebuilt plates (can't think of what is on Van's Baja at the moment and can't find the pics of his bike) that are equal.

But I guarantee you, anything you bought other than a COB plate is not up to the task.
If you are planning on hitting places like Moab or other rock strew areas on a regular basis, skid plates offer more than just protection, they can offer the ability to slide over obstacle rather than being hung up on them. Keep in mind that the skid plate needs to be the lowest point on the bike for this to be an effective terrain negotiation strategy. If you are dragging stock pontoons through the rocks, the skid plate becomes moot. You need to look at the underside of the bike and determine what is at risk to get snagged, eliminating as much as possible. Look at COB’s Predator build and how he cleaned up the underside of the bike by relocating exhaust, removing the center stand, extending the skid plate back to cover the transmission, etc.

So why am I writing all of this? Well I decided I wanted a skid plate, so I built one.
A damn sturdy one, if I may say so myself. :pot:

User avatar
windmill
Order of Victory
Order of Victory
Posts: 7540
Joined: Tue Feb 12, 2008 1:17 am
Location: Kent, Wa

Re: Project Steel Belly

Post by windmill » Wed May 01, 2019 10:02 am

I bought a Mr Cob skid plate because I rode with Mr Cob off road. Our riding conditions here in the Cascade range is significantly different from the central Atlantic area or the pine barrens.

It's kinda like a helmet, one doesn't need it until they need it, and its best to have one up to the task.
Barry

"Take care, sir," cried Sancho. "Those over there are not giants but windmills".

2007 Patrol 100k km and counting,
2018 M70

User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Re: Project Steel Belly

Post by BinDerSmokDat » Wed May 01, 2019 10:24 am

windmill wrote:
Wed May 01, 2019 10:02 am
...Our riding conditions here in the Cascade range is significantly different from the central Atlantic area or the pine barrens.

It's kinda like a helmet, one doesn't need it until they need it, and its best to have one up to the task.
I recently had a chance to ride a little off-road in VA and WV.
The more I ride in new places, the more I find little pieces of "here" that are just like "there."
The "really deep sand' in Moab is just "sand" in NJ.
The "bad rocky stretch" in PA is just "the trail" in WV.
But I get what you mean.
Take all that, throw in ten thousand feet and a snowline...I imagine it starts to get really interesting.

And "helmets are like skid plates" is a very good analogy.
The difference being, if it gets whacked, you get a new helmet.
Does one want their skid plate to be a replacement item?

stagewex
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 6802
Joined: Sat Jul 14, 2012 10:45 pm
Location: New Rochelle, New York

Re: Project Steel Belly

Post by stagewex » Wed May 01, 2019 10:09 pm

Holy Crap, when did you start writing that thesis Richard?
My skid plate has welded itself to the bottom of the frame through the magic of rust, so is now a part of the natural evolution of the rig.
Stagewex

Current Herd all running amok:
2008 Vespa 150S (Elec & Kick Start)
2007 Ural Patrol (2WD, Elec & Kick Start)
2006 Honda "Big Ruckus" PS250
2006 Yamaha TW200 (Elec & Kick Start)
1995 BMW K75 (Elec Start)
1991 Honda XR250L (Kick Start Only)
1986 Yamaha BW200ES (Elec & Kick Start)

vitz
Comrade
Comrade
Posts: 90
Joined: Sat Jul 18, 2015 9:03 pm

Re: Project Steel Belly

Post by vitz » Thu May 02, 2019 1:14 am

I bought one of the Cobb skid plates and its saved my a$$ a couple of times already. I can asset for how well made it was made and designed. I do take our Ural off roading a bit and deal with good size rocks where I go ride. I've looked at other skid plates but all of them looked like thin sheets of paper compared to the Cobb plate.

Good point about the center stand. I never use it and its just eating up ground clearance. I did ditch the stock pontoons which helped out a lot too.

User avatar
Lokiboy
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 4029
Joined: Fri Apr 29, 2011 9:58 pm

Re: Project Steel Belly

Post by Lokiboy » Thu May 02, 2019 5:44 am

Nicely written and thought out.

I don’t think you gave the “cool” factor enough credit :lol: Just look at all the off road Jeep and pick up wannabes that will never see anything more than a gravel road. I fall into that category. Bought the Cob skid plate, which will long out last Erika, with big plans in mind, but will probably never do anything beyond the JDH (which was a blast BTW)
2011 Gear Up - "Erika"
Yorktown, VA

Mains: 127, Idle: 40, Needle: 1 shim
MKIII air filter
100,000 km and counting

User avatar
Tomcatfixer
Commissar
Commissar
Posts: 7175
Joined: Sat Oct 24, 2015 5:10 am
Location: Gordonsville, VA

Re: Project Steel Belly

Post by Tomcatfixer » Thu May 02, 2019 6:23 am

There might be some other homebuilt plates (can't think of what is on Van's Baja at the moment and can't find the pics of his bike) that are equal.
I believe Van used the transparent aluminum from Star Trek IV... :wink:
-
2019-05-02 06.19.21.jpg
2019-05-02 06.17.40.jpg
Project-Management-Skills-Are-Scotty-Approved.jpg
You do not have the required permissions to view the files attached to this post.
- Chad

Gordonsville, Virginia, USA

Current rides:
2015 Ural cT "Mobile Chernobyl", 2001 Ural Patrol "The Patrol", 1999 Ural Tourist "The RPOC", 1994 Honda VFR750F

Previous rides:
2007 Honda VTR1000 FireStorm (Super Hawk in U.S.)
2001 Buell Blast! - - - - - - - 2005 Yamaha FJR1300
1993 Honda CBR600F2 - -1984 Yamaha FJ1100
Two different 1986 Yamaha FZX700S Fazers

User avatar
S 854
Commissar
Commissar
Posts: 4909
Joined: Mon Dec 03, 2007 8:44 am
Location: Big Sky Country

Re: Project Steel Belly

Post by S 854 » Thu May 02, 2019 8:42 am

I’ve got enough scars on my skid plate to justify the time I spent building it... 8)
'07 Arctic: The Russian Raucous Ship

Things turn out best for the people who make the best of the way things turn out...

User avatar
cateyetech
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 1541
Joined: Sat Jan 05, 2013 8:23 am
Location: 72801 Russellville Arkansas
Contact:

Re: Project Steel Belly

Post by cateyetech » Thu May 02, 2019 10:46 pm

BinDerSmokDat wrote:
Wed May 01, 2019 9:22 am
Ask 10 people around here about skid plates and you will get 10 different answers.
A lot of those answers are based on feelings and not much real-world experience.
Fewer still are based on critical analysis of what a skid plate should do and how it should be designed.

I off-road a fair amount and have bent and broken sh!t on my bike that others haven't, so I'd say I'm hard on Urals.
I’ve broken a bike swingarm, a sidecar swingarm, hairline fractured my thumb, countless turn signals at all three corners, hammered the sidecar fender so many times it is permanently dimpled, bent two sets of handlebars, blown a final drive, dented the tub, tweaked front and rear fenders, broke the sidecar brake linkage bar, bent the stock left engine guard a dozen times, bent a raceway left side footbox and engine guard TWICE, etc. I've stopped counting how many times my bike has been on its side. With that off-road resume, my position on skid plates is this...
"99% of bikes don't need them despite what you might think. Most of those that get one, get one that at best is a useless farkle and at worse, is a false sense of security."
Now that everyone has their panties in a twist, hear me out on some things…
  • Most bikes just don't really ride off-road. Some do, but MOST don't. and even those that do go off-road, they aren’t ridden very hard or over terrain or obstacles where a skid plate would make a difference.
  • I'm going into my 9th year of off-roading with Urals. Never been on a ride where someone broke or has been hung-up by the oil pan or anything under the bike that a skid plate would have prevented.
  • You can jack up your bike by the stock oil pan and it won't hurt a thing.
  • I have dragged my oil pan over rocks, ruts and stumps, never came close to breaking it, put a few new shiny streaks on the fins, but that's it.
  • I have only heard of a couple of people breaking an oil pan. Literally a couple…2 people. And one was in Moab and from what I understand, it was a pretty advanced trail. A place that 99% of Ural riders wouldn’t go and of the few who ride in Moab, most of them wouldn’t go.
  • If you were really worried about being stranded with a broken oil pan, a spare oil pan and two quarts of oil fit in the trunk and are cheaper than a skid plate and you keep your ground clearance for the other 99.9% of the times you need it off-road. It just isn't an area of the bike that is a weak link. We don't have a "cracked oil pan" thread for a reason.
  • The majority of the bikes I’ve seen doing Moab do not have a skid plate. A lot do, but most don’t.
Let’s start with what a skid plate is.

The general idea is that you bolt a hunk of material to the underside of a vehicle to prevent damage to important parts and help the vehicle slide over obstacles. Faux skid plates AKA “Skid Fakes” are frequently bolted to vehicles for an off-road “look” but are not functional. We’ll discuss “Skid Fakes” in-depth later.

There are four factors to consider when determining the need for and design of a skid plate. (Technically it’s five factors, the fifth being “Tacticool” if you just want “the look.”)
  • The first factor is the Vital Area(s) to be protected. On our rigs that is pretty much the oil pan and exhausts. Those are the only things that hang down low enough to make a skid plate worth the while. You could argue that the brake pedal linkage is important, but it is tucked up underneath pretty well. The center stand hangs down, but a skid plate would have to come back pretty far and be engineered to cover the center stand without interfering with operation. Not sure that is possible, nor is a center stand critical. So basically for our purposes, the oil pan and exhaust, with exhaust being the less critical of the two.
  • The second factor is Clearance, both ground clearance and clearance between the skid plate and critical parts. You need to factor in whether the value of a skid plate is worth the decreased ground clearance. If the skid plate sustains a hard impact, what will happen to the components behind it? A skid plate that bends, deflects or is punctured will push against the components behind it.
  • The third factor is Material thickness and appropriateness. This area, more than any other, separates the real skid plates from the ones that are just there for looks. It is also one of the most controversial subject when skid plates are discussed. Too thin and soft, it just gouges or bends, rather than remaining rigid and allowing the plate to pass over the obstacle. It might even fail completely and transmit force to the components behind it or it may tear loose and cause the vehicle to get hung up.
    Skid plates on rock-crawlers and Baja vehicles use 3/16” steel or ¼” aluminum (usually 6061) to protect the parts they consider vital. You can argue that they are bigger and heavier vehicles thus need heavier materials. However a Ural has fewer points of ground contact and poor gearing so it generally needs to have more momentum in rocky terrain than Jeeps. I’d say those are appropriate metal gauges for a Ural with rider(s) flying over obstacles. And those thicknesses are for plates that are well fabricated, shaped and supported. The larger area you span the thicker or more support you will need. For a plate supported at the edges only, the strength is proportional to the thickness cubed. In other words, doubling the thickness will increase the load it can carry by a factor of eight.
    Steel versus Aluminum
    Given that some of the steel skid plates being sold are using 1/8” or thinner steel, which is inadequate to prevent bending, deflection and/or gouging, I am baffled by people who believe that they can use aluminum skid plates at similar thickness and they will be sufficient.
    Yes, aluminum is generally stronger per pound then steel. The key there is “stronger per pound.” You will generally need to go with a THICKER piece of aluminum than steel to get the same properties, which will usually still be lighter than the steel it replaces.
    For a main skid plate under the oil pan, I would say that 6061-T6 aluminum in ¼” thickness is the minimum to get a plate that will not deflect or severely gouge under a hard strike and allow the bike to slide over. In ¼’ thickness this material is stronger than most steel commercially produced Ural skid plates I’ve seen.
  • The fourth factor is design. If the skid plate takes some big hits, where will that force be transferred? Will the attachment method be strong enough to keep the plate attached? Will the force be transferred to a bike part that may break/bend? Do you want the attachment points to fail as a type of “fuse” to help dissipate impact energy? How far apart are the attachment points? Can the material span these distances AND take an impact without deforming and deflecting? Can you use thinner material but add some bends to improve it’s rigidity? Will you have angled sections fore and aft to help slide over obstacles? How wide past the mounting points will the plate be to protect exhaust, etc? Can the material take a hit in these cantilevered areas?
    A plate must handle forces in two major directions; upwards as the bike lands on an obstacle and rearwards as the leading edge of the skid plate encounters an obstacle. I’ve seen plates that use U-bolts on the frame uprights. Given the thinner material of these plates and the limits of clamping force, I have serious doubts about their ability to handle upward force and to a lesser degree, rearward force.
    Some plates use only two or three mounting points. This is usually some combination of engine mounting bolts and clamps.
    The strongest area of a bike is the rectangle formed by the frame, the engine mounts, the engine support rods, spacers and the engine itself. In that area the bike has to handle all of the weight the rest of the frame does, plus the engine forces, plus the weight of the rider standing on the pegs. It makes the most sense to tie into this area to mount the plate.
Those points aside, you need to decide if your terrain is worth the decreased ground clearance. Being in NJ we have sand and mud but not many rocks. Sand means vehicles make ruts so less options about which line to take and we often drag our underbellies over the high center. I think a skid plate is almost a handicap here. In PA and Moab where it is rocky, ruts are less common, so you can usually take a line that lets you put the bike crossing ledges perpendicular instead of straddling them. Not always, but usually. There are the occasional rocks in the middle of the best line and you do mumble a prayer as you pass over them, so I see why people want a skid plate if only for peace of mind. Ironically on rocky trails I find ground clearance to be less of a concern. Rocky trails just don’t have the deep ruts that soil/sand trails do. In 9 years of off-roading, solo to large groups, I have never had anyone hang up on a rock. They get stuck in ruts/mud.

Still want a skid plate? OK. If you think your oil pan is at risk, despite all the evidence to the contrary, why would you cover it with a thin piece of sheet metal that is practically body panel gauge? Do you want a disposable skid plate, replacing it like fuses every time you bash something? Your most likely scenario that could cause damage (yet still a very unlikely scenario statistically speaking) is your front wheel going over something big, be it a rock, ledge, railroad rail or concrete drain pipe and your bike comes down hard on the skid plate.

Picture an experiment that goes like this;
Sling the frame of your bike at the steering neck and attach a quick release mechanism, then attach that to a chain hoist above the bike.
Lift the front wheel off the ground a few inches. I’ll let you keep the rear and sidecar wheels on the ground for this experiment.
Place a nice jagged rock with a flat base that is 1” taller than your ground clearance under your oil pan.
Now pull the quick release.
If that made you cringe at the thought, you are starting to understand the forces involved. And that experiment is with no rider and no momentum. Imagine coming down on an obstacle with 3 or more wheels off the ground, with a rider and a little speed.
Or if you are too squeamish to do this, instead put your skid plate in a sturdy vice and wail on it with an engineer’s hammer. Still cringe at the thought? Then you don’t have a skid plate. You have a SKID FAKE.

SKID FAKE
These are thin, useless pieces of metal bolted onto bikes out of a combination of misguided beliefs and the “cool farkle factor.” At best they are used because people figure “something is better than nothing.” But for the price they pay, a quality bulletproof skid plate could be bought/made.

Skid Fakes persist because of the simple fact that MOST Urals don’t need a skid plate so these things never get banged up. As a result they aren’t ever shown to be the useless hunks of metal they are. (Don't EVEN get me started about sidecar skid plates.)
Many commercial skid plates use material that is on the thin side. Why do they do this? Cost. Thin material is cheaper and thin material is easier to fabricate, namely when it comes to bending. Read that last part again. Thin material bends easily. If we want a skid plate to protect vulnerable areas, the one thing we DON’T want a skid plate to do is bend.

If you are going to catch a rock in that area, you want to just slide off unscathed.
You don’t want to crush your $$$ farkle, you don’t want it to gouge, rip off or damage some other part of the bike.
To date I have only seen one skid plate worthy of the name.
I believe only a plate built to the design and specs of COB's plate is capable of that.
There might be some other homebuilt plates (can't think of what is on Van's Baja at the moment and can't find the pics of his bike) that are equal.

But I guarantee you, anything you bought other than a COB plate is not up to the task.
If you are planning on hitting places like Moab or other rock strew areas on a regular basis, skid plates offer more than just protection, they can offer the ability to slide over obstacle rather than being hung up on them. Keep in mind that the skid plate needs to be the lowest point on the bike for this to be an effective terrain negotiation strategy. If you are dragging stock pontoons through the rocks, the skid plate becomes moot. You need to look at the underside of the bike and determine what is at risk to get snagged, eliminating as much as possible. Look at COB’s Predator build and how he cleaned up the underside of the bike by relocating exhaust, removing the center stand, extending the skid plate back to cover the transmission, etc.

So why am I writing all of this? Well I decided I wanted a skid plate, so I built one.
A damn sturdy one, if I may say so myself. :pot:
Hey BDSD

1st WHAT A POST!

2nd There is another situation where the oil pan might be cracked/ damaged
by being hit from a rock that is thrown from the front tire :shock:
Jack up your rig and shoot the pan with a sling shot and several golf ball size rocks :lol:
We have had several rocks hit our skid pan and you know :lol:
the sound of ringing steel when hit with a large caliber bullet
that's the sound :evil:
Even a fake skid will protect from this, like many dual sport bikes come with
This is more frequent when we are adventure touring (25-40mph for miles & miles)
vs trail riding (riding in creek beds :twisted: )
And as a trail rider you stop more frequent and would probably see the oil leak
where as adventure touring I probably wouldn't know about the leak until the oil was gone
like my engine would be, because Ural doesn't have a oil warning lamp :(

3rd Photo's of your skid pan please :)
or it didn't happen you know :lol:

:foilhead:
Charlie ╭∩╮(-_-)╭∩╮
2003 Gear-Up Ромашка Мзй
765cc - Mikuni TM33 carburetors - Modified stock airbox with Uni foam filter
2-1 exhaust - Hand worked cylinder heads - Type V ignition system
A Warn XT17 witch that works from any angle - More handmade parts than I can list :foilhead:

The only Ural to post a second gear wheelie :evil:

2000 Patrol Teh Урал
Thanks DaveO, I'll try to ride it like you, I'll try :foilhead:

User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Re: Project Steel Belly

Post by BinDerSmokDat » Fri May 03, 2019 10:48 am

There has NEVER been an oil pan with so much as a cracked fin reported from a rock being thrown up by the tire.
The front tire isn't powered and would not be able to throw any rock up at a stock pan and so much as ding it.
In fact, in 9 years of Uraling I haven't seen a bike with a fin cracked off, outside of the two damaged pans I know of.
So if anyone is running a skid plate to protect your pan from "magic bullet" rocks, I call :bs:

Pics coming tonight...I started the post then realized I had cleared my phone camera out so all of the photos are on another computer... :oops:

User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Re: Project Steel Belly

Post by BinDerSmokDat » Fri May 03, 2019 11:04 am

Tomcatfixer wrote:
Thu May 02, 2019 6:23 am
There might be some other homebuilt plates (can't think of what is on Van's Baja at the moment and can't find the pics of his bike) that are equal.
I believe Van used the transparent aluminum from Star Trek IV... :wink:
-
2019-05-02 06.19.21.jpg
2019-05-02 06.17.40.jpg
Project-Management-Skills-Are-Scotty-Approved.jpg
I knew he talked about using a very shallow steel pan at one point but wasn't sure if he covered it with anything.

User avatar
windmill
Order of Victory
Order of Victory
Posts: 7540
Joined: Tue Feb 12, 2008 1:17 am
Location: Kent, Wa

Re: Project Steel Belly

Post by windmill » Fri May 03, 2019 1:37 pm

I agree rocks thrown up by the front wheel aren't a problem.
Most of my hard contacts have been from dislodging larger stones when the front wheel goes over them and they roll or tip in a manner where they stick up. The other common occurrence is when the front wheel drops off a high spot, the rig drops and high centers.

Typically the worst conditions are in avalanche feilds after the snow melts off leaving lots of freshly sheared rocks, stones, and bolders with tree remains mixed in.
Barry

"Take care, sir," cried Sancho. "Those over there are not giants but windmills".

2007 Patrol 100k km and counting,
2018 M70

User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Re: Project Steel Belly

Post by BinDerSmokDat » Fri May 03, 2019 2:09 pm

So I have always felt that I personally don't NEED a skid plate, for all of the reasons I mention above.
However, I HAVE always thought that a deep sump is a good idea.
We won't turn this into an oil thread or a deep sump debate, but I'm in the camp that a high volume pump and more oil is a good thing for these motors, especially when revs are high and there isn't much airflow over the jugs.
I had a deep sump laying around that came with a motor I bought. I never installed it because I felt that while a stock oil pan is pretty well tucked up in there, I HAVE gotten scratches on the fins from going over rocks. If I was scratching a stock pan a deep pan might get whacked.

One day I came out of the post office (after mailing some divorce documents) and leaning against a lampost with a bunch of trash was a 22" x 22" piece of steel. It is not every day that a man gets rid of a wife and gets free skid plate material.
I took this as a sign from the Ural gods; I knew what I must do.

I also knew if there was one skid plate I was going to copy it was going to be a COB-style plate. BTW I was not trying to cheap out and steal COB’s design for myself and by-pass the man who invented the thing. But I wasn’t sure if this was even going to work and I fiddled and thought and messed around for a few weeks before figuring out how it all might work. I couldn’t tell COB “make me a plate when you get a chance and BTW, not sure how long I need it or how wide or where it should angle up….etc.” So going custom was my only choice here.
(And before anyone asks, I won’t be making plates for anyone else. Beg COB to take time away from his fun and throw lots of money at him!)

The steel is quite appropriate for a skid plate. Here is the full sheet between two 6x6's, with and without me standing on it.
If it can clear span 18" with a 320lb load on it and deflect only an 1/8" it will be quite stout when supported by brackets about 10" apart.
Try this with your skid plate material. Double dare you.
20190311_183129.jpg
20190311_183314.jpg
20190311_183450.jpg

To Be Continued...
You do not have the required permissions to view the files attached to this post.

User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Re: Project Steel Belly

Post by BinDerSmokDat » Fri May 03, 2019 2:17 pm

Anyway the deep sump pan is a quite a bit taller than the stock pan.
Looking at them side by side, I could see that the deep sump was going to add over an inch in height and that any skid plate was going to add at least another 1/4" to 3/8" to that.

I tried fitting a piece of plywood and comparing measurements to ReCycled's bike which runs a COB plate.
I was going to lose about 1.5" at the lowest point when it was all said and done. Not acceptable.
I fiddled and played around a bit mocking up some stuff with plywood and wooden blocks to get max ground clearance.
I figured that covered by a skid plate the fins won’t be doing much anyway, so I cut them down.

When I test fit things, I still didn’t think it was enough ground clearance. So took the grinder to the fin stumps. The more I looked the more I realized the biggest killer of ground clearance at that point was the drain plug. You lose about ¼” or so to the boss it seats on and then another ¼” or so to the thickness of the hex head itself.
So I started to think. And when I start to think with a grinder in my hand, weird stuff happens.
I decided to just eliminate the drain plug. So how do you get the oil out of the pan? I got a quick drain valve and with my metric tap set, I drilled a hole in the rear of the pan and tapped it. The aluminum there is actually pretty thick, about 3/8” due to the compound curves left to right and front to back. I reinforced with an aluminum washer to create a level place for the valve to seat and some oil-resistant JB weld. But before I did that, I used some JB weld on a steel plug and inserted it form inside the pan, glopping more around the plug. Then I finally ground off the protruding plug flush with the pan.

That got me pretty close to ¾” less ground clearance than a stock COB plate at the front and about an inch less at the back. It’s a little more than an inch, as the rear of my plate extends further back before angling up to protect the quick drain valve.

In no particular order, here are the pics of that process...
20190303_111956.jpg
20190303_112020.jpg
20190302_143316.jpg
20190309_130009.jpg
20190311_173857.jpg
20190311_175036.jpg
20190311_181154.jpg
20190311_181925.jpg
To Be Continued...
You do not have the required permissions to view the files attached to this post.

User avatar
BinDerSmokDat
Hero of the Soviet Union - 2019
Hero of the Soviet Union - 2019
Posts: 3476
Joined: Thu May 06, 2010 2:35 pm
Location: South Jersey NJTP exit 6

Re: Project Steel Belly

Post by BinDerSmokDat » Fri May 03, 2019 2:20 pm

More pics...
20190311_183647.jpg
20190311_190625.jpg
20190314_182949.jpg
20190314_183253.jpg
20190314_184722.jpg
20190314_185728.jpg
20190314_192244.jpg
20190316_174928.jpg
20190316_175942.jpg
You do not have the required permissions to view the files attached to this post.

Post Reply