rear fender rubber buffer

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rear fender rubber buffer

Postby fiftysevenXL » Sun Apr 30, 2017 10:09 pm

Attached are some pictures (again, thanks to Stan) of a NOS 59798-52 rear fender buffer pad. One side has a smooth "skin", I'm assuming so the adhesive
won't soak into the foam when you glue it to the bracket. It appears to be the same material used in the solo seats, and suffers the same fate of turning to powder from age; even this NOS one is starting to disintegrate just from the few times I have handled it. I don't know when this changed to the more
common black foam, but this lighter foam is clearly visible in the '57 XL Museum bike. I have a used Parkerized bracket that also has remnants of this light
foam in place yet. I think when LorenC restored his '58 XLH he found a very close match at a local upholstery shop.
Can anybody tell me the difference between the 59795-52 bracket complete and the 59795-52A bracket complete that shows up in the '54 parts book?
Roger
Attachments
Buffer Pad 1.jpg
Buffer Pad 1.jpg (147.66 KiB) Viewed 16500 times
Buffer Pad 2.jpg
Buffer Pad 2.jpg (121.13 KiB) Viewed 16500 times
Buffer Pad 3.jpg
Buffer Pad 3.jpg (189.23 KiB) Viewed 16500 times
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Re: rear fender rubber buffer

Postby fiftysevenXL » Sun Apr 30, 2017 10:11 pm

One more picture of the package I found this in.
Attachments
Buffer Pad Package.jpg
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Re: rear fender rubber buffer

Postby EKHKHK56 » Sun Apr 30, 2017 11:32 pm

The Early one is smooth. The Later one has a hump in the middle of it for strength.
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Re: rear fender rubber buffer

Postby fiftysevenXL » Mon May 01, 2017 7:25 am

Thanks for the info; I don't think I have ever seen one of the smooth ones.
Roger
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Re: rear fender rubber buffer

Postby fiftysevenXL » Sat May 20, 2017 9:08 am

I forgot dimensions in my initial post on the NOS fender pad, so here is an update (thanks to Stan for creating this image). Still no idea from anybody as to when the black foam pad first appeared ?
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Buffer Pad Dimensions.jpg
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Re: rear fender rubber buffer

Postby wz507 » Sat May 20, 2017 10:58 am

Fiftyseven, thanks for that schematic, very useful since I need that exact info.

I’ve never had the benefit of handling the subject foam so am interested as to the relative density/firmness of the material. Without a means of measuring foam density my question becomes challenging to answer, but perhaps if we use a couple common foams for reference it might be easier to quantify. On the stiff end of the spectrum might be the ubiquitous thin blue polyethylene foam sleeping pad, used for camping, which can take fairly heavy load before bottoming out. On the soft end of the spectrum might be the very compliant foam used for packing delicate glassware, that takes only a small force to totally collapse it. That said I’ll pose the impossible question, “how stiff is the HD foam?”, as I just want to know if it’s firm, really soft, or somewhere in between.
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Re: rear fender rubber buffer

Postby strong56KH » Sat May 20, 2017 6:54 pm

I suspect after 50-60 years it will be hard to tell what the original consistency was. If it was the same stuff used in the seats I have, it crumbles now when you touch it. The parts book calls it a "rubber buffer" so I suspect it was probably some kind of foam rubber.
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Re: rear fender rubber buffer

Postby fiftysevenXL » Mon Jun 19, 2017 6:46 pm

As strong56KH mentioned, judging the density/firmness of the original buffer pad is just about impossible, and I still haven't found anything that would seem to be suitable for this application. I did find a July 1963 issue of Floyd Clymer's "Cycle" magazine with a road test of a new 1963 XLCH; it has a nice close-up of the left rear shock area that clearly shows the light-colored foam pad and (lightly) Parkerized bracket, so we should be good up to '63, at least.
There must be some original-paint mid-sixties Sportsters out there with at least remnants of the original pad so we can pin this down better.
Roger
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Re: rear fender rubber buffer

Postby hennesse » Sat Jun 30, 2018 12:15 am

I don't know if this is the "right stuff", but maybe it's a good direction for further investigation...

In another thread, I mentioned that my sheetmetal man told me the commonplace replacement buffer is an open-celled foam that absorbs water like a sponge, and that I should be using a closed-cell foam that doesn't. He gave me a small hunk of some black closed-cell.

Childrens' play areas in commercial buildings often have these interlocking jigsaw-puzzle pieces of dense foam on the floor. The hunk he gave me appears to be the same thing, but unfortunately, black.

I looked up suppliers of closed-cell foam, and The Foam Factory in Michigan sells closed-cell XLPE foam in yellow! It's bright Chicken Yellow - not some wimpy beige-ish. Note their description of low moisture permeability which is what we want.

Depending on how the consistency of this stuff compares to the original, we might have to adjust the thickness of the material. Chicken Yellow might not be 100% correct, but it might be closer than anything else we've found. Maybe another supplier offers it in another shade of yellow.

XLPE.jpg
XLPE in colors!
XLPE.jpg (31.55 KiB) Viewed 14184 times



BTW, my 65-year-old knees don't like kneeling on the concrete floor as much as they used to. Someone was tossing a bunch of the black jigsaw-puzzle pieces, so I scarfed them up. Much nicer to kneel on than concrete.
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Re: rear fender rubber buffer

Postby GaryM2 » Sun Jul 01, 2018 12:01 pm

I have access to these mats at my work. Notice the different colors available on the right side. It is 1" thick and would need to be sliced down to get the right thickness. See pic.

I can post pics of some of the other colors this week.
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mats.jpeg
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