tie down and forks

[dravnx]

Does tightly strapping a bike on a trailer cause fork seals to blow out? I've always heard this but I don't understand why strapping a bike down would cause any more stress then actually riding it. I'm not talking strapping it down so the forks are fully depressed but enough to keep the bike from jumping around on the trailer.

 

[spdt509]

what you're referring to its the pic below(yes, its in a truck but the same applies). don't do it that way and you'll be fine...

 

[Busy Little Shop]

Chief causes for seals to leak are fork tube nicks or just being worn out not tie down compression...

 

[afm199]

Don't compress them fully and you will be fine.

 

[thedub]

Does tightly strapping a bike on a trailer cause fork seals to blow out? I've always heard this but I don't understand why strapping a bike down would cause any more stress then actually riding it

No, it doesn't. If you are at all familiar with the way oil seals are designed, it's obvious why not. Oil seals have a cavity on the oil side, so when the pressure builds up behind the seal it exerts more pressure on the sealing surface, which keeps the oil from being forced out. Your seals don't blow out when compressed, they just get better at sealing.
This video explains it better: https://youtu.be/Hy6cKKEdXB8?t=172

So why have you always heard that strapping your bike down will blow the seals? How did this often repeated and long standing rumor get started?

Strapping down a bike with good seals will not make them leak. But if the seal is already compromised, maybe there is a piece of grit in there, or maybe the lip is nicked or whatever, strapping it down with the forks compressed will force oil past the already bad seal.
If you arrive at your destination and there is a puddle of fork oil in the pickup bed, the incorrect conclusion you may draw is that tying the bike down is what caused the seals to leak, rather than revealing an already bad seal. Then you tell everyone on the internet and they tell everyone on the internet and here we are with a widely believed ongoing misconception.

 

[wheel_muse]

I don't think there's any damage done, if it's short-term. Of course, don't store the bike this way!

I had an unfortunate incident with an old Honda 350 XLR dual sport. It had a cool feature of coil spring forks with air adjustment; you could add air to increase the spring rate. :thumbup

I guess the air leaked down during transport. Straps got loose. Bike fell out of the hitch rack when I went over some railroad tracks. Luckily, not much damage.

Lessons: check bike on rack regularly, watch the rearview mirror, be especially vigilant with older bikes. :wow

 

[Maddevill]

You can put one of those plastic supports or even a piece of 2x4 between the front tire and bottom tree. Tighten it down to your heart's content.

Mad

 

[dravnx]

I've trailered bikes and never worried about the forks. The fork seal warning was brought up by another rider on another forum after someone posted a picture of a bike on a trailer. My posting is more about where the OWT came from and why.

 

[stangmx13]

I wonder if forcing the forks to hangout where there are probably some nicks accelerates the wear/damage.

The best solution to all moto transport issues is a Baxley chock and loose-ish straps or a strapless restraint system like the Pitbull TRS.

 

[anytwowilldo]

No, it doesn't. If you are at all familiar with the way oil seals are designed, it's obvious why not. Oil seals have a cavity on the oil side, so when the pressure builds up behind the seal it exerts more pressure on the sealing surface, which keeps the oil from being forced out. Your seals don't blow out when compressed, they just get better at sealing.
This video explains it better: https://youtu.be/Hy6cKKEdXB8?t=172

So why have you always heard that strapping your bike down will blow the seals? How did this often repeated and long standing rumor get started?

Strapping down a bike with good seals will not make them leak. But if the seal is already compromised, maybe there is a piece of grit in there, or maybe the lip is nicked or whatever, strapping it down with the forks compressed will force oil past the already bad seal.
If you arrive at your destination and there is a puddle of fork oil in the pickup bed, the incorrect conclusion you may draw is that tying the bike down is what caused the seals to leak, rather than revealing an already bad seal. Then you tell everyone on the internet and they tell everyone on the internet and here we are with a widely believed ongoing misconception.

+1

I created a fork seal leak on a dirt bike recently by allowing the clay on the fork tube to dry to concrete. It was behind the tube guard and I didn't see it. I then stuck it in a truck and cinched it down as usual, driving the baked clay up into the seal damaging it. I bought myself a couple hours work and a fork service.

 

[OaklandF4i]

How did this often repeated and long standing rumor get started?

The Russians are CLEARly behind. Therefore, I am going to blame Dmitriy.

Its as old as sin, been hearing about it since I was a kid. But agree, legend and not true.

 

[afm199]

I wonder if forcing the forks to hangout where there are probably some nicks accelerates the wear/damage.

The best solution to all moto transport issues is a Baxley chock and loose-ish straps or a strapless restraint system like the Pitbull TRS.

This.

 

[m0t0_ryder]

You can put one of those plastic supports or even a piece of 2x4 between the front tire and bottom tree. Tighten it down to your heart's content.

Mad

This is what I do.
Have a different 2x4 for each bike. Cut to a V shape on tire side.
A partial compress (w/o wooden/plastic blocks) can cause tie downs to slacken when you hit bumps. This can lead to the tie down coming unhooked at one end (or the other). It's happened to me... pre blocking the tires.

The best solution to all moto transport issues is a Baxley chock and loose-ish straps or a strapless restraint system like the Pitbull TRS.

Not possible on a hitch hauler.
And extra expense for moto trailers (i.e. Kendon) which already have wheel chocks.

I've also recently taken to placing a piece of wood over my rear tire when tying down as well when transporting. This after loosing a rear strap connection while travelling thru the horrible highways near Concord.

 

[OaklandF4i]

This after loosing a rear strap connection while travelling thru the horrible highways near Concord.

I'm a big fan of retaining clip systems on tie down straps. Won't use anything but a strap with one. It took losing a bike more than once for me to learn. :laughing

And for those who won't let go of the exploding fork seal legend, allows you tie down the bike a little looser. Even on a red flexy flyer harbor freight folding death machine. Win win.... :teeth

 

[kiwi_outdoors]

No

Does tightly strapping a bike on a trailer cause fork seals to blow out? I've always heard this but I don't understand why strapping a bike down would cause any more stress then actually riding it. I'm not talking strapping it down so the forks are fully depressed but enough to keep the bike from jumping around on the trailer.

No Nope Not Never on a trailer (assuming that you don not launch the trailer over a cliff)

Just buy a nice set of tie downs with capture clips on the hooks, and tie the forks down with a useful amount of compression, and trailer-on, dude!

 

[m0t0_ryder]

Although it could be minimal you will probably cause more degradation to the fork springs by holding them (near full) compressed for periods of time than to the fork seals for reasons mentioned above.

Springs, in general, are not meant to be compressed for extended periods of time.

HERE's some info.

snip...

Does Leaving a Spring Compressed Weaken It?
A spring under tension for an extended period of time can become weaker. Any object will either resist or deform when subjected to outside stress. Springs are specifically designed to deform in order to absorb energy from outside stress, then return to their natural state when they release that energy.

FATIGUE
Over a long enough period of time, fatigue can occur, which is a condition where enough stress has repeatedly acted on the object and some deformation becomes permanent. In this case, it is harder to regain its complete normal shape. This is essentially what happens when a spring wears out. If the spring is well-constructed, then under normal circumstances, you should go through many cycles of compression or release over many years before fatigue occurs.

CREEP
Creep is another phenomenon that may affect a spring under tension. Creep refers to when an object is exposed to a compressing structural load that creates a high level of stress that is less than the yield strength of the material. Creep is more often seen when the spring is subjected to high levels of heat for a long period of time, but it can happen anytime extended stress occurs.

As a result of creep, the spring deforms as normal but cannot regain its complete normal shape, essentially accelerating the effects of fatigue. If enough creep occurs, the spring may deform so much that it is unable to collect sufficient potential energy to do its job. As a result, the spring is weakened, sometimes even to the point where it does not function at all and must be replaced.

 

[Dmitriy]

The Russians are CLEARly behind. Therefore, I am going to blame Dmitriy.

Its as old as sin, been hearing about it since I was a kid. But agree, legend and not true.

don't worry they ride better without oil anyways in a Honda I hear....

 

[Eric B]

Let’s keep the myth going, ‘cause it can make for a good argument on the ‘net.

 

[ST Guy]

Although it could be minimal you will probably cause more degradation to the fork springs by holding them (near full) compressed for periods of time than to the fork seals for reasons mentioned above.

Springs, in general, are not meant to be compressed for extended periods of time.

HERE's some info.

snip...

Leaving a spring compressed does not weaken it. Unless you stack the coils in which case it will reduce the overall height of the spring just a little. Sometimes. And usually proper spring design accounts for this.

Facts is, a properly designed spring will not be weakened by holding it compressed. It's a fairy tale. And the same with cycling a spring. As long as you don't go to a fully stacked state all the time, the life of the spring is almost indefinite. Another fairy tale.

 

[Busy Little Shop]

You don't want to compress and hold any spring to the degree where the coils bottom...

Many Japanese fork and shock springs still employ piano wire or music wire which
is not fatigue resistant as Chrome silicon steel found in after market springs such as Ohlins...

Spring material is why some stock springs grow weak and sag over time whereas
quality after market springs don't...