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Spec II classic mounting on v.s. rearsets

Started by Greaser Greg, March 28, 2021, 09:37:02 PM

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Greaser Greg

The plastic spacers where the bolt goes through the mounting bracket on the rearset are cracked and one nearly disintegrated when I tried to prep it for repair.  Do the mounting points have to float a little or can I just use washers that fill the gaps and mount that side's pipe rigidly?
  I imagine there will be a lot of vibration in the footpeg, but will it be enough to crack stuff?  I'm pretty good with a razor and plastic, but I already ground some flat edges on a couple washers and am just wondering what the worst case scenario might be if I go with those.  Anybody done this?
Every day above ground is a good one.
'71 R5B "Rusty"  '71 R5B "Decaf"   '99 KZ 250
'97 XL1200S "The Vibrator"   '08 XL1200N  "Greenie" (totalled)
'78 CB750F "The Skunk"   '74 CB550 "Blackie"    '78 Honda Hobbit

DesmoDrew

    They need to have some 'float'.  I use fender washers, 1/8" thick rubber washers (two on each side of the chamber mounting tab, a 10mm bolt and a nylock nut.  Tightened to where everything is snug enough to not flop around, but still allows the exhaust to move.  I like the thick part of the chamber to have about 1/4"-3/8" side play.  Which is only about 1/32" movement at the mounting point.

Greaser Greg

Every day above ground is a good one.
'71 R5B "Rusty"  '71 R5B "Decaf"   '99 KZ 250
'97 XL1200S "The Vibrator"   '08 XL1200N  "Greenie" (totalled)
'78 CB750F "The Skunk"   '74 CB550 "Blackie"    '78 Honda Hobbit

Hawaii-Mike

I second what Desmo Drew said.  That's how you can keep chambers from cracking and breaking.

m in sc

yup. i used nylocks on the bolts not tightened all the way , i have specIIs and VS rearsets on the lightweight.

Striker1423

I'll remember that when I remount my pipes. They are just really close to the rear bracket hard to slip a rubber washer between them.

Dvsrd

#6
What about a "re-engineering" of the pipe bracket?
A proper rubber grommet, and a metal sleeve that the bolt passes through. Then the bolt can be proper tight without crushing the rubber.
I was thinking of something like on these Fukui pipes, there is a decent detail picture of the mounts:
https://www.samurider.com/?p=25110

Jspooner

Quote from: Dvsrd on March 29, 2021, 08:11:57 AM
What about a "re-engineering" of the pipe bracket?
A proper rubber grommet, and a metal sleeve that the bolt passes through. Then the bolt can be proper tight without crushing the rubber.
I was thinking of something like on these Fukui pipes, there is a decent detail picture of the mounts:
https://www.samurider.com/?p=25110

That would be an awesome way to do it but not everyone has the means to do stuff like that. Fender washers are cheap and easy and available at most any hardware store.
"Just quit brain fucking it and get it done"

Dvsrd

Quote from: Jspooner link=topic=3081.msg26927#msg26927
That would be an awesome way to do it but not everyone has the means to do stuff like that. Fender washers are cheap and easy and available at most any hardware store.

Or one could modify the hanger plate instead, if there is enough material. That may be easier, at least not involve any welding.

m in sc

ive had mine on for many years no issues. use  a nylock.

those are harley isolators, if they can take -that- kind of vibration, they are just fine for an rd.


DesmoDrew

#10
These are the bolts I use.

https://www.ebay.com/itm/Yamaha-YZF-R6S-2009-Front-Brake-Caliper-Bolts-R6/124522394192?fits=Make%3AYamaha&hash=item1cfe1cf250:g:FrcAAOSwS3Ff-6rW

I like them for a couple reasons. Number one, they are a factory Yamaha part. Number two they are hollow and have a big-ish 'washer' made into the head already.  And while I have never had a nylock come loose, I like running a piece of safety wire through the middle of the bolt and around the whole assembly.  It's something I have to do on the race bike anyway, since all exhaust hangers have to be safety wired. I also use them to hold on my brake caliper (Grimeca, not stock RD). I drill the flats for safety wire. They're trick because they are pretty light without spending the money for titanium. But I'm pretty sure they are 10 mm fine thread, so that is something to remember if you use them.

Dvsrd

I just had a quick look at the Vintage Smoke rearsets. The hanger plate seems to be quite thick, 10 or 12 mm. And the oval hole is quite big too. So shaping some sheet rubber to make a new rubber mount (grommet) should be fairly easy. 2 thin pieces, and a thicker in the middle. Then a top hat spacer, maybe 10 mm OD and 6,5 mm bore, that goes through everything, plus an M6 bolt, fender washer and nut. This is how the mufflers on 90s Ducati SS and Monster models are fitted. Lightweight, slick and easy to remove. The bolt just holds everything together, the weight of the exhaust is supported by the top hat bushing. Almost aircraft style engineering :)

m in sc

all of that is completely over kill and not nec. at best a shouldered bolt and a nylock thru the bushing. .

you standing on your pipes? 

Dvsrd

#13
Quote from: m in sc on March 29, 2021, 02:47:07 PM
all of that is completely over kill and not nec. at best a shouldered bolt and a nylock thru the bushing. .

you standing on your pipes?
Nah, just like neat details. At least whenever I can be bothered to work on them. My old Allspeed pipes have just been bolted with a single M6, directly to some home made alloy hangers, without falling off.
But if I will use these pipes in the future, I'll try to replicate that Fukui style mount with some alloy top hat bushings and M6. Just because.
On my stock 350 exhausts, I made alloy replica "nuts" (those that go inside the rubbers), and used some  TI M10 bolts. Just because the stock setup was sort of heavy. No real sense in that, but felt satisfying to do anyway.

Btw, do you say that those grommets/spacers that come with the VS rearsets are HD parts? Then the solution is simple for the OP.   :)

m in sc

they are.

I used TI bolts on mine as well, but didnt get that fussy w the spacers and stuff.