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Old 07-01-2009, 03:31 AM   #1
Zombie_Stomp OP
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Rox anti-vibe bar risers: how are they constructed?

After finding that Rox antivibe risers (and even other neccesary maintenance parts, let alone "farkles") are now out of my price range, I've decided to make my own. "How is a guy that can't affford the mass-produced end product going to be able to afford a machinist's one-off of the same thing?" someone asked. Well, this and the other custom projects that are sure to follow will take a lot of time, but I have a way. But first to ask my question, "How are antivibe risers constructed?"


I see that there is a piece of aluminum that has been turned to go in place of the handlebars. This piece also has a block with a hole where the new clamps are bolted via rubber bushings, to dampen the vibrations.

Wait, if the rubber bushings are only clamped between the clamps and the blocks, top and bottom, isn't there a bolt running through the block, transmitting vibrations? That would not imrove one's vibration situation much.

So let's say the rubber bushing is actually continuous, througha big fat hole, and it is held in place by the compression from being bolted in and squished. Now the steering would be at the mercy of the rubber, so it can't be too soft now.

Let's back away for a minute now. The rubber bushings are kind of neat looking. They remind me of all those cool different rubber bushings you can buy for your skateboard trucks. Here are some favorites:


It would be nice to be able to change the buhings out for a different durometer of rubber to find the right level of dampening. The skateboard truck bushings are perfect for that need since they come in different durometers. This assumes that the bushings are not a one-piece that go all the way through the bolting block, though. So does the bolt in fact touch the inside of the block, possibly transmitting vibrations? We will need someone willing to disassemble one of their risers to find out.

The way I imagined building one of these was not much different from the way the Rox ones look. The bushings would definitely be skateboard bushing compatible. The bolt that connects the two pieces would have a length of vinyl tubing or the like whose inner diameter matched the outer diameter of the bolts being used somewhat closely, and then the holes in the two aluminum parts would be matched to the outer diameter of the hose somewhat closely. This would give the risers a somewhat preset level of dampening based on the types of tubing material with suitable wall thickness, o.d., and i.d. I could find. I'm sure there would then be a further dampening factor given by what durometer of bushings are used. If the design had the bolts free-floating, that is, if the holes through the blocks are much bigger than the bolts and do not touch, transferring no vibrations, are the bushings enough to keep handling of the steering within a reasonably tight range?

So the main question I need answered is, what do the insides of the rox risers look like?

Also, are you happy with the handling, or would you sacrifice some of the vibration dampening for tighter handling?

Looking forward to any input, including, but not limited to, "you are violating patent laws", "You are an idiot", "here are a free pair of risers for shutting up and keeping our trade secrets from enterprising hobby machinists", "you go boyy", etc...

There is a place called TechShop. I hear there are many opening up across the country. Anyway, volunteers get free shop time, which means acess to things like CNC mill and people who know how to use them. Possibly also people who know how to teach me CAD. That is how my broke ass plan to pull off making my own pair of highly specialized and adaptable handlebar risers.
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Zombie_Stomp screwed with this post 07-01-2009 at 03:37 AM
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Old 07-01-2009, 10:54 AM   #2
turbonotch
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you're right on...

the Rox risers just 'borrowed' an idea/design that's been on many bikes over the years:

bar risers attached by a shaft going through a bushing that expands as the nut is tightened down.

i believe the honda CRs used this design somewhat successfully on their upper triple clamp. there have been alot of street bikes with this safe fundamental design as well.

probably the CHEAPEST start without fabricating would be to find a bike that used that setup from the factory and steal parts off a junk bike.
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Old 07-01-2009, 11:14 AM   #3
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I have seen it on a bike close to mine but never sold in the u.s.: the XL600LM. Here's a photo for everyone of a similar design:

I'm not sure what bike I would find this on to remove it from that has my fork size, spacing, and a key ignition mount in the right place as well. I could be looking forever, I'd rather go machine something. Learn something about how to. Perhaps even make a bit of dough selling them.

If it is a rubber bushing that runs the full length of the main bolts and their holes, I may need to look beyond the skateboard bushings for my rubber. Some sort of industrial supplier may have a rubber or hopefully polyurethane tubing that is thick walled enough. Or perhaps there is suitable bushing stock available. Aww, but I'm sad I won't be able to have a pair of Doh-Dohs on there! '

I'ts not so bad. If I were to counter sink them in there far enough, it would have enough compression to have a similar effect as long as I use a bolt that fills the ID of the bushings, and the bolt hole in the aluminum block would be bigger so as to not touch the bolt, and avoid transmitting vibes.

Then again I can look on an industrial supplier site for polyurethane bushing stock. I don't want to make machining polyurethane a part of the process. Skateboard bushings would be fun but expensive by comparison, probably. That's extra costs to have them screenprint "bitch" or "doh-doh" on there. I could eventually find a way to machine something clever of my own onto the risers. I can't think of the name of the supplier I was looking for- they have every kind of material under the sun. Seems like it was two intials and a last name as the company and site address... anyone know the good materials suppliers?
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Zombie_Stomp screwed with this post 07-01-2009 at 11:28 AM
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Old 07-01-2009, 11:47 AM   #4
Chad M
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ZS, I recently went through the same issues you're facing when I designed and produced a small run of 640 engine/tank guards over the winter. My design uses a compressed grommet in the frame to secure the lower mount, much in the way a bark buster is secured. When I approached the rubber grommet manufactures, it was quite obvious this would be cost prohibitive for such small numbers. The breaks in cost weren't effective until you got into the hundreds sometimes thousands of units (grommets were around $7 to $8 a piece, for pieces no bigger that the skateboard parts). To complicate this, not knowing which durometer you will need means more cash outlay for R&D. If Rox was nice enough to share their propriatary information, you may be able to guess right the first go around. My advice is to concentrate on finding easily sourced off the shelf parts. Good luck, it sounds like a fun project!

Chad M screwed with this post 07-01-2009 at 12:31 PM
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Old 07-01-2009, 05:56 PM   #5
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You can look at my Rox and take measurements if that will help. Of course, that might mean I'd have to get off my ass and make it to Plan B some Thursday night......
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Old 07-01-2009, 06:18 PM   #6
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Here's how KTM does it. If it can absorb vibes from a 640, it can handle anything.



As you might guess, the KTM parts aren't terribly cheap.

The stack of # 40,41,44,41,42 are the vibration absorbtion. 6 runs through it all and holds it together.



An alternative might be to get a set of fatbar adapters for your bike and sleeve the bar clamps with rubber and use them with your regular bars.

Once you get some kind of isolation between the bars and the clamps, you can tune it with bar weights.
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Old 07-02-2009, 12:08 AM   #7
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As for sleeving the fatbar adapters with rubber and fitting standard bars, I would be hesitant to do that. In order to get a level of clamping force that will not leave the bars able to slip if jarred, I would probably need to get the rubber so tight, or rubber so hard that it woudn't dampen sufficiently. Or maybe my engineering spidey-senses are tingling erroneously.

I do want some rise out of the part I make...

I could get a section of steel pipe or the straight section cut off a pair of bent handlebars, fill it with lead shot (or solid lead bar stock if it is around), and cap the ends. There's my vibration dampener. Get 2 additional sets of bar clamps which have perfectly flat backs, or have 2 pairs machined to be flat on their backs. Sandwich those 2 pairs back to back to make the steel pipe clamp to my handlebars, and the third pair on top. Some long bolts through the clamp assembly, and I'm in business. I could also weld the 2 mated back to back clamps together for solidity. That's the cheapest and simplest way I just thought of. It is not the lightest, but I'm already ahead of the game by being on the lightest, most powerul dual sport besides a converted XR600.
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Old 07-02-2009, 12:20 AM   #8
turbonotch
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regarding the original ROX product... do they even work that well?

i've been considering buying the 'real deal' before my next trip. my KLX650C was putting my right hand to sleep on the last 1500mi trip...

is this product even effective? i'd like to know before spending $150!
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Old 07-02-2009, 12:41 AM   #9
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Quote:
Originally Posted by Zombie_Stomp
As for sleeving the fatbar adapters with rubber and fitting standard bars, I would be hesitant to do that. In order to get a level of clamping force that will not leave the bars able to slip if jarred, I would probably need to get the rubber so tight, or rubber so hard that it woudn't dampen sufficiently. Or maybe my engineering spidey-senses are tingling erroneously.

I do want some rise out of the part I make...

I could get a section of steel pipe or the straight section cut off a pair of bent handlebars, fill it with lead shot (or solid lead bar stock if it is around), and cap the ends. There's my vibration dampener. Get 2 additional sets of bar clamps which have perfectly flat backs, or have 2 pairs machined to be flat on their backs. Sandwich those 2 pairs back to back to make the steel pipe clamp to my handlebars, and the third pair on top. Some long bolts through the clamp assembly, and I'm in business. I could also weld the 2 mated back to back clamps together for solidity. That's the cheapest and simplest way I just thought of. It is not the lightest, but I'm already ahead of the game by being on the lightest, most powerul dual sport besides a converted XR600.

I'm sure the sleeve would work fine- until it gets wet. Some fancy bracket to hold the crossbar as well might do it, but that's just getting weird.

Consider that the triple clamps are going to move some distance due to the vibration no matter what you do. If you add enough weight to make the handlebars not move, then there will be flex in between the two parts. If it's rubber, great. If it's metal, you're setting yourself up for fatigue.
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Old 07-02-2009, 08:31 AM   #10
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Poly shock absorber and swaybar bushings are available at most autozones. Probably 10-15 bucks for as many as you need.

Dunno what they have patented, but do know that you will run into a lot of money on materials in small quantities if you are not careful.

Putting lead shot into the middle pipe is not going to do as much damping as you hope. It may actually make it WORSE at the grips (whole resonance thing).
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