5 myths discussed

[woodsguy]

FIVE DIRT BIKE BELIEFS: FACT OR FICTION?

Even though our sport isn’t that “old” compared to some others, it has its own share of beliefs, some rooted in truth and some not so much. In this feature we’ll be looking at different things riders and racers say about off-road motorcycling and try to determine whether they are true or false…or...

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[_RG_]

Great article. Thanks Rob.
I've used a board between the front tire and fender for years when hauling. Fork seals have lasted remarkably well. The 1190 with stock fender doesn't really lend itself to doing that. It's been hauled by just cranking down on the strap till it seems stable. I'm currently replacing the 1190 fork seals. Way too early for this compared to the other bikes. I'm a believer.

I've heard reputable folks say that running low octane fuel is actually a better choice at higher elevation. It'd be great to have a proper explanation for how this could be. Seems pretty counter intuitive. For what it's worth...two buds put high octane fuel in their tanks at a station in Colorado last summer. Both motorcycles fuel pumps failed within ten miles of each other that day. We've batted this around the campfire and could only theorize that the high octane gas pump gets used a fraction of the amount of the regular fuel. Gas is older... pump and hose develops more crud...who knows?

That's doggone interesting about the difference in break-in between two and four stroke engines.

 

[Johnf3]

Great article. Thanks Rob.
I've used a board between the front tire and fender for years when hauling. Fork seals have lasted remarkably well. The 1190 with stock fender doesn't really lend itself to doing that. It's been hauled by just cranking down on the strap till it seems stable. I'm currently replacing the 1190 fork seals. Way too early for this compared to the other bikes. I'm a believer.

I've heard reputable folks say that running low octane fuel is actually a better choice at higher elevation. It'd be great to have a proper explanation for how this could be. Seems pretty counter intuitive. For what it's worth...two buds put high octane fuel in their tanks at a station in Colorado last summer. Both motorcycles fuel pumps failed within ten miles of each other that day. We've batted this around the campfire and could only theorize that the high octane gas pump gets used a fraction of the amount of the regular fuel. Gas is older... pump and hose develops more crud...who knows?

That's doggone interesting about the difference in break-in between two and four stroke engines.

The thin air at high elevations effectively lowers the compression ratio of an internal combustion engine. Less pressure at top dead center on the compression stroke means an engine is also less prone to pre-detonation, which is a main reason you would want to run higher octane fuel in the first place. As much time as you have spent in Colorado, I am sure you have noticed the fuel at the pumps is all lower octane than what we get even here in Texas. I don't think the lower octane fuel is "better" at high elevation. It is simply all that is required.

 

[_RG_]

That makes sense. The thin air surely takes it's toll on hp... specially north of 11K. Thanks John.

 

[Johnf3]

That makes sense. The thin air surely takes it's toll on hp... specially north of 11K. Thanks John.

Here is an example that happened on a ride me and you were both on. Remember when the guy's lower leg shattered in Oklahoma? If you remember that same day, my old Husaberg was not starting good when it got warm and that bike had no kick start back up at all. When I got back to Lubbock, it started perfectly like it always did. What happened was the increased compression at near sea level (which resulted in a harder to crank engine due to compression) in Oklahoma vs. 3200 ft here caused the starter torque limiter to slip enough that the starter would not turn the engine over. It only happened that one day, and it would work when the engine was cool (engine compression down just enough to get the torque limiter to grab).

The torque limiter was a known issue on those year bikes, and I took it apart and tightened it up so it would grab all the time, but just the difference in effective compression was enough to give me issues that day in Oklahoma.

 

[Irishcoffee]

Way back in the 70s I got to know a guy named Slavens and he did some work on my Maico. He told me to just use regular in my/our bikes in Co. After work on several bikes with him in the ensuing years I have learned to trust him.

 

[Tourmeister]

I've hauled a lot of bikes over the years and never used a block on the front forks, just straps. I've never had a problem with fork seals because of it. That said, I don't crank the ever living snot out of the straps either. I DO use bungees to secure the hooks at each end to each other to keep the hooks from coming loose if we hit a big bump and the strap loses tension. It is interesting that they did not mention strapping a bike down and leaving the kick stand down. I always put mine up. I don't want the weight of the bike bouncing off it if we hit a big bump and potentially damaging it. I see cruiser folks hauling their bikes on the side stand all the time, occasionally with just straps on the kickstand side of the bike

 

[woodsguy]

I've never left side stand down either, not sure why the cruiser guys do but seems most leave it down.

 

[SL350]

I didn't read the article because of ad blocker but...

IIRC, when we went to Denver every year in the 60s, most gas stations only sold regular.

 

[SilverBullet]

I didn't read the article because of ad blocker but...

IIRC, when we went to Denver every year in the 60s, most gas stations only sold regular.

..and had gas pumps that couldn't be set higher than 99 cents a gallon. Remember having to double the pump amount for a couple years in the 70's?

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[_RG_]

Here is an example that happened on a ride me and you were both on. Remember when the guy's lower leg shattered in Oklahoma?

I remember that day way too well. Mostly just the parts of puzzling how the heck we could get him down off that trail. Thank goodness for GPS (and Tylenol 3). We need to go back up there this spring and pick up where we left off.

We see farmers leaving equipment suspended on hydraulic cylinders and folks hauling motorcycles with the forks strapped down all the way. It's awful hard to feel good about either one. A seal left under pressure long enough has got to get a bad attitude eventually. If I was hauling a little ways, eh... wouldn't be too concerned. Hauling for a couple (or more) days - well, with my luck there'd be a puddle of oil under both forks when I got there. *Confession of sins* I had the 1190 almost bottomed out with straps. It's too dang heavy to have bouncing and banging around in the RV... and it got hauled a long ways. It'll have some kind of spacer before the next trip. Yeah, seals are gonna go sooner or later but later seems really good.