FD Swap Bushing

[Clyde K.]

Gents, I an doing the 750 FD swap and have gotten to the point of making the spacer. My query is would 1/16in wall aluminum work as well as copper since it isn't really load bearing? Or, am I AFU?

TIA, Clyde

[mxmikie]

it will work fine i made mine out of urethane

[Clyde K.]

Yikes! That is plastic kind of stuff isn't it? How long has yours been in service?

[b.walker5]

It's only a spacer, Urethane or Aluminium will work fine. Theres no load and nothing wearing against it so, theres nothing to wear out.

[cywelchjr]

My only concern would be to make sure it would hold up to the grease and oil it will be exposed to in that area. Other than that, it is true that it's under no stress, and is under no load and so doesn't need to have any real strength. Think about it, the tech tip recommends that you use copper pipe, and that doesn't have a lot of strength, so I don't think that would be an issue, I would be concerned with the PVC holding up to the grease that the driveshaft can tend to end up coated with, at least mine has quite a bit of the stuff in the shaft housing.

[Clyde K.]

That is in line with my rationale. I figure to use the aluminum and check things out again after a couple hundred miles. Thanks for the reply. Clyde

[James England]

I think there is a small load from the drive shaft spring at the FD end, isn't there? But, it can't be much and it's not as if the pipe bit is rotating against anything. It seems to me it's just a spacer which is held firmly in place by the FD spring, rather than a load-bearing surface subject to friction and therefore wear.

I did think about a thick urethane collar myself! I just happened to find the right size steel pipe first, hence using it. I suppose certain types of plastic degrade over time and heat does strange things to it like making it brittle. Does the drive shaft get hot through conduction of engine heat, do you know?

[DGXSER]

The only additional force I could see being applied to the spacer is when the swing arm rotates it would apply a small amount ot the spacer as it pivots the u-joint. But still, nothing appreciable.

Reality is I bet that aluminum spacer you have has more strength than the copper fitting that I have used for it before. As to the urethane, I would not expect alot of heat to transfer into the U-joint and clear back to that spacer. The rubber boot protects it from UV exposure. So, I do not see any real hazard to it. If it is fully intact after a good hard pothole jumping the suspension around, then it should last the life of the bike.

[cywelchjr]

The only additional force I could see being applied to the spacer is when the swing arm rotates it would apply a small amount ot the spacer as it pivots the u-joint. But still, nothing appreciable.

Reality is I bet that aluminum spacer you have has more strength than the copper fitting that I have used for it before. As to the urethane, I would not expect alot of heat to transfer into the U-joint and clear back to that spacer. The rubber boot protects it from UV exposure. So, I do not see any real hazard to it. If it is fully intact after a good hard pothole jumping the suspension around, then it should last the life of the bike.

The only issue I could see/worry about would be the affect of grease on the PVC. Many plastics don't react well to long term exposure to petroleum products, and being on that shaft in that tube is probably what I'd call long term exposure, at least on my bike, which has been having grease pumped into that grease fitting right on schedule for almost 200,000 miles now. And since almost none of it got into the coupling between the FD and the driveshaft, guess where it is? And no, I wasn't going to dig it out, I don't figure having some grease wandering around and migrating onto those moving interconnections making sure that at least a little lube is getting there is doing any harm. There is NO way that I got that into the yoke without getting grease into the splines in the process.

[b.walker5]

Think Latteral

Who has Progressive springs in their Special. I do, and in the fitting instructions there is details on the PVC spacer required to take up the space left by the shorter springs. These are bathed in oil all the time and under a helluva lot more stress than any spacer in the driveshaft is ever going to be. Good enough for me.

[James England]

Who has Progressive springs in their Special. I do, and in the fitting instructions there is details on the PVC spacer required to take up the space left by the shorter springs. These are bathed in oil all the time and under a helluva lot more stress than any spacer in the driveshaft is ever going to be. Good enough for me.

There are many different types of PVC though. Often, it's not even PVC, which people use as a generic term for plastics of many different types.

[b.walker5]

Correct James. Mine are uPVC, unplasticized polyvinyl chloride, which is a high density, rigid plastic widely used in the plumbing industry.

[James England]

Sounds like the right stuff then! Many automotive bushes are synthetic material which is similar/the same and are subject to oil leaks, grease thrown at them etc. They don't degrade. I did think of using a PVC bobbin like you get on car bushes... nice and thick and supportive.

[greengoon3]

fd bushing source

In regards to the bushing. I bought 2 from McMaster Carr. Bronze I believe perfect fit.
~$8.00 a piece.
Hoping to start on mine very soon. I have aquired and extra u joint boot, drive shaft, and 2 final drives to mock up what I need.
Actually planning on having a complete swingarm unit that I can swap out easily if needed or desired.

[greatnw]

greengoon, what did you actually order? I was looking at their website and it looks like you custom order? I just started prepping my 750 drive.