Why would someone put PVC spacer in my fork tube?

[FLrider]

I took the fork nuts off to install a parabellum windshield. When I removed the nut, between the the nut and the fork spring, was a 3/4 " pvc that the previous owner had used as a spacer.

 

Why ? What's going on there? Springs bad? Ride too soft? Before I put it all back, I'm wondering if I should leave the spacers out or put them back in.

 

What do you guys think?

 

 

[dirtrider]

Evening FLrider

 

I really don't know what you have there but keep in mind a lot of aftermarket spring kits use spacers just like you are talking about.

 

Without knowing what springs you have in that bike you might be best off just to leave the spacers in there as long as you don't notice ride issues.

 

[Paul Mihalka]

Those spacers are used to adjust preload on the springs of the forks.

[SageRider]

Assuming you are talking about the F800GS, there have been complaints that the stock spacers are not quite long enough, thereby allowing the stock spacers to move up and down in the fork tubes and making a banging noise.

There are also fork modifications readily available (although I'm blanking on the name of the products) which require a change in the spacer length.

[Firefight911]

It's all about setting preload. Completely normal and very common! My Super Tenere has them in currently and everyone of my road race bikes had them.

 

Look up suspension tuning here and on the internet and you'll see what is going on.

 

Not going to get in to it too deep but preload is something entirely different than spring rate. You must get the right rate first and then set the preload accordingly. I state this as it is tough to answer the question of what to do without knowing what springs are in there, how you ride, what you are after, and all your rider data to determine the right rate.

[FLrider]

OK. I posted in the non R/K Airhead thread but I should have been clearer. These pvc spacers (looks like he cut them from some sprinkler pipe) were in the R90.

 

Your answers however are probably the same whether it's my f800 or the R90.

 

I've never hear of such a thing.

 

I'm inclined to leave them out and see if I can tell any difference in the ride. I'm curious.

 

I don't run this bike hard. It's my around town and occasional highway cruiser.

 

Thanks for the input guys. I thought something was broken down there and he had mickey moused a solution.....

[Bill_Walker]

Don't leave them out! Odds are they're just longer (more likely) or shorter replacements for the stock spacers (I'm assuming here that Airheads use spacers. I think most bikes do). Without them, you'll likely have excessive fork sag and your forks will bottom out over bumps.

[FLrider]

Too late. Already reassembled. Now I just want to see / feel the difference. Going to go looking for a bumpy road

 

Actually, I was going to put them back in but had a helluva time compressing the spring with the spacers and getting the nut back on.....couldn't do it. Thing is, it's a one person job and I haven't figured out the trick to releasing the spring pressure yet. Putting the bike on the center stand helps but still a bear.

 

 

[dirtrider]

Evening FLrider

 

I have a metal bar made up for installing stiff fork springs or long spring spacers. The bar is about 3' long with a hole drilled in the center.

 

The hole is JUST large enough to pass the square end of a 1/2 drive extension through but small enough to keep the large end of another extension from passing through.

 

I put the socket for the upper fork tube nut on a 4" 1/2 drive extension, then put a 10" extension on top of that 4" with that metal bar in between the extensions. Then with a helper (sometimes my wife if I'm feeling brave) we both push that bar down which pushes the lower extension, socket & fork nut down in place. Then using my free hand I turn a ratchet on top of the upper extension & start the nut.

 

That method works pretty good & I have used it many times as I have a few bikes with soft progressive springs that use very long spacers above the springs.

 

[FLrider]

Evening FLrider

 

I have a metal bar made up for installing stiff fork springs or long spring spacers. The bar is about 3' long with a hole drilled in the center.

 

The hole is JUST large enough to pass the square end of a 1/2 drive extension through but small enough to keep the large end of another extension from passing through.

 

I put the socket for the upper fork tube nut on a 4" 1/2 drive extension, then put a 10" extension on top of that 4" with that metal bar in between the extensions. Then with a helper (sometimes my wife if I'm feeling brave) we both push that bar down which pushes the lower extension, socket & fork nut down in place. Then using my free hand I turn a ratchet on top of the upper extension & start the nut.

 

That method works pretty good & I have used it many times as I have a few bikes with soft progressive springs that use very long spacers above the springs.

 

I tried real hard to envision that but my brain just couldn't picture it. Next time you are into your springs, snap a picture of what it looks like.. Thanks for the idea though.

[FLrider]

Without them, you'll likely have excessive fork sag and your forks will bottom out over bumps.

 

Went down along a nice old brick road this morning.

 

I I I I d d d didn't no no no notice a a a any dif dif f f f difference.

[dirtrider]

Afternoon FLrider

 

see if this helps?

 

 

[FLrider]

OK. Now we know what you do for a living....

 

Excellent ! Better than a picture... I got it, THANKS !

[lkchris]

I've never hear of such a thing.

 

Never watch NASCAR?

 

They're forever puttin' in or takin' out spring rubbers.

[outpost22]

Spacers are the easy way to adjust fork preload. They can be too long like anything else and limit travel, or even cause spring binding.

Spacers work wonders on my F650 that comes stock set up for 120 lb rider. With my 190lbs +, over 1/2 of the available suspension travel was taken up by initial sag. Working with preload spacers and fork oil weight, it really dialed the forks in for a great ride at a cost of under $20.00.

 

You should check your laden vs. unladen "sag" of your forks before you simply remove your preload spacers.

[scottnew]

At work and don't have time to read all the reply's so it may have already been brought up.. People in the sport bike and dirt bike world tend to buy 3/4" pvc at their local hardware store to put into forks to stiffen them up.. I read about this years ago and thought it sounded like a really cheap fix.. I wouldn't try it but I have read about dirt bikers that swear by it.. Totally understand why it would make it really hard to compress back in while at the same time trying to thread the caps back in place..

[SteveHebert]

If the springs in there are progressive, the kit comes with PVC spacers. They are a vital part for the preload as previously stated. I would put them back in. My R75/6 rides as smooth as my 1150RT with the progressive springs.

[PAS]

The spacers add preload and are used to adjust the sag height. I have them in my 81 R100RT and they also came with a set of Works performance springs since their springs are shorter then the stock springs. Did you have the front wheel off of the ground when you tried to re-install them?

 

Look up the specs on your stock spring free length and compare that to whats in the bike now.

 

[kmac]

Here is a link to a Harley kit. You use the PVC to set the ride height with their new spring pack.

 

It is EXTREMELY common to use PVC sprinkler pipe as a spacer.

 

http://www.progressivesuspension.com/pdfs/updates/3055-110HarleyForkLowerKit.pdf