Looking for advice on R80ST front triple inter-changeability

[bpeckm]

I am starting to do some "modrifications" on my ST, and have a "simple question" for which I have found no easy answer.... (We do miss Robert and his wisdom, don't we....) I had files with all kinds of information that I had cut-and-pasted into categories, but I lost my hard drive (and no, I didn't have a backup ) a couple of months ago, which was my reference library for the wisdom of this place.....

I am thinking of using the bottom of the standard triple, flipped over and machined to fit as a top, as is done occasionally on the Slash 5/6 series:



So it boils down to this: which other models use the same tube and offset as the R80ST and G/S... can I use a triple from an early-'80's monoshock? .... R65?

[Prutser]

The tubes of the mono are thicker than the ST/GS.

[bpeckm]

To be precise: what I need to know is what (or if?) other models have the exact same tube o.d. and spacing as the triple on the ST....I am hoping I can look for a used/wrecked triple that I can convert to a top "clamp-on" style. Or if I could find, somewhere, an un-loved ST or G/S that I could pickup.... The internals, how they work etc would not matter for what I want to do....



Here's another pic of a Slash 5 lower having been converted to an uber-upper... I want to the do the same thing, but obviously need a ST-compatible lower from something.

[Prmurat]

[Hugon fairing? Nice!!

[/QUOTE]

[Airhead Wrangler]

The other issue you'll have is that the steerer tube is too short for a "real" top triple. It's designed only to have a ~1/8" plate on it and doesn't have enough exposed length for a real aluminum triple to clamp onto. The threaded top with a cap nut is not exactly a conventional arrangement and you'll have trouble finding something off the shelf that'll play nicely with that. You might consider swapping the lower triple and steered tube for something else as well or maybe just make a longer steerer tube to press into the bottom triple that you have. I vote for a full front end swap though. The brakes suck and the forks suck even worse, so I'd get some later R100R or K bike forks. Oops. Scope creep.

[Chad M]

If I read right, you want to know which other lower triples will work on a G/S or ST? I replaced my lower triple this year on my G/S and found out that any of the same era lowers will work. I used one from a RT and for my purposes, just drilled and tapped the fender and instrument pod holes into the clamp and it works perfectly. I think even the part number is the same. The fact the other model lower clamps don't have holes in them makes them perfect for what you're proposing.

[bpeckm]

So you ^ are saying that the center-to-center from other triples would work? I don't give a freekindam about mounts for thisnthat, just that the tubes (outside diameter and distance from center to center) would work....

[Chad M]

I'm saying the lower triples from a 1979 R100RT fit my 1981 R80G/S perfectly. When I bought them I was told there was a large range of lowers that would work, with only a couple holes drilled being the difference.

http://www.advrider.com/forums/showp...&postcount=149

Here's where I got so smart!

[bpeckm]

Interesting... I happen to have one sitting in my parts bin, so I will be trying that, when I get into the project this wintah!

Thank you!