Handlebar Risers

[IanB]

I'm in the process of installing higher handlebars on my '99 VTR. Thanks to endless help from board members here and general internet scouring, I think I'm getting close to a solution.

My aim was (is) to be able to use standard Renthal-type bars, and arrange it so that the bars don't foul the tank or make cutting the fairing necessary. I haven't installed the bits yet, but mockups looked promising. Here's how it started:

note - first attempt at posting a pic - let's see if it worked

[IanB]

Good, that worked, thanks Chris!

I had some nice azobe left over from a patio job, I made these, stuck them to the top yoke with double sided sticky tape. It was fine for mockup purposes (although I probably wouldn't take it on the road with bars held in place with the tape!)

Then made some nice handlebars up. Slight delay here, while I had to explain to the wife why her sweeping brush now had a somewhat shorter handle. I'm going for the "fat" bars, with a 28.6mm diameter centre section.

Here are the bars on right lock:

[IanB]

Close, but with some tweaking, should work - yes, I still need room for twist grips etc.

I wanted to be able to return the bike to original condition, so I ordered a used top yoke from some breakers in Belgium. A bit grubby, but fine.

As others noted, the top yoke metal isn't that thick - I measured 4.7mm, so it needed stiffening. I had a lump - er, billet of aircrat grade aluminium in the scrap bin, 12mm thick. I cut a cardboard template, traced it onto the alloy and milled them to shape. Then spent ages sanding them to get the radiused edges. Had to mill a pocket to accommodate that little Honda badge. Finally managed it. Here they are before being epoxied in:

[IanB]

The top face of the top yoke was sort of flat, but a cleanup with the mill made things nicer. I epoxied a bit of alloy into the hole where the badge was, as it would get half covered. The badge was held with double sided foam tape, it levered out nicely:

[IanB]

Then came the risers. They started out as a bar of alloy 50mm wide bandsawed from a sheet of 25mm thick plate. I sliced bits off the ends, these became the top caps. Drilled, tapped & counterbored them, stuck the left & right risers together with double sided tape, then bored a 28.6mm hole.

When I bolted the caps on, I shimmed the faces with bits cut from a beer can; readers of Zen and the art of motorcycke maintenance should recognise this. Beer can shim is 0.13mm thick fo reference, I used 2 layers.

[IanB]

Next was to cut the odd angle on the bottom ends. After much hacking of bits of wood, the angle of the cut came out to 60 degrees. I used my shaper as I could get a nice large radius in the corner. I made a short video, but it's way too big to post. Never mind.

After cutting teh angled end faces, i drilled & fixed the risers on, 4x M10 cap screws and epoxy for good measure. Here's how it came out:

[IanB]

I fillered the corners to make it look nice, sprayed it silver and gave it a couple of coats of transparent lacquer. I'd also epoxied stainless washers on where the fork pinch bolts go. I'm replacing the bolts with M8 studs so that when I tighten it all up, it's steel on steel rather than steel on alloy, which I'm never too keen on.

So this is as far as I've gone so far. Next step is to swap the yokes, so I'm looking at making a bike stand.

[IanB]

Those pockets were milled out on my IanC milling machine - no CNC, just me twiddling the handles. Good enough for what was needed. More for appearance than actual weight saving. The whole design principle was "anything I make / add on will be at least as strong as what it's fixed to". Having the bars come off in your hands at speed would ruin the day.

Doing some other workshop stuff at the moment, and trying to figure out how to make something like that 1Jac lifting thing. All straightforward, except attaching it to the bike. They sell adapter kits, which permanently fix hollow receivers to the bike. I can't see how they won't stick out and get in the way. I already made pins that fit to both ends of the swingarm pivot. I think a modified version of those will do it.

[IanB]

Here are the swingarm lifting pins. There's a 42mm diameter hole in the frame where the pivot bolt is - this is what the black overs snap into. I made the pins with a 42mm diameter spigot, 18mm long. Bored out to 35mm inside, to clear the pivot head / nut. The 2 pins are held in with a length of M8 threaded rod, all the way through:

[fabiostar]

that was a great read nice machining skills sir

i have serious mill envy here

[sirch345]

Ian, well done in working out how to post-up your photo's

As Rob (fabiostar) said "a great read", you have a wicked sense of humour so you will fit in well here. The bar risers look like they have aways been there, and the swinging arm pins look great

I made support plates to fit under the top yoke like you have done when I did the Renthal handlebar conversion to my Firestorm. I didn't epoxy them in place, this is something new to me. Is epoxy resin really strong then
The only epoxy resin I have ever used is Araldite,

Chris.

[IanB]

Thanks guys!

Chris, yes, epoxy - done properly - is very strong; most aircraft are assembled with something similar, it's stronger than riveting. The epoxying I did wasn't done for strength, but simply to hold parts in place for the enxt step of machining. I epoxied the risers to the yoke, then set the whole lot up in the mill to bore & tap the bolt holes. I used epoxy on the bolts. (Virtually) all of the strength comes from the 4 M10 bolts. The epoxy now simply prevents water ingress.

When picking an epoxy, go for the ones that don't set in 15 minutes. They're generally not as strong. For larger quantities, West Systems make very good stuff. Unless you add a filler, epoxy will flow like water, and drip out anywhere it can.

The milling machine is an old Beaver VBRP. There's a bit of slop in the table slides, but it does what I need. I posted the video of the shaper in use: This is probably my favourite machine in the workshop - I paid 140 euros for it. 2Hp. 18" stroke, about 60 years old, almost never used. If I hadn't have bought it, it was heading for the scrapheap the next day.

Let's see if my (first ever) uploaded Youtube video works!

[IanB]

Just on epoxying; the main thing to worry about is cleanliness, the joint doesn't tolerate any oil / grease at all. Epoxy also won't work on most plastics. Rubber can be stuck, see below. Some people go to silly lengths on the mixing - yes, mix it well, try to get to the stuff in the corners of your mixing container. But I've never had a joint fail due to poor mixing. When setting, heat is your friend - 100 deg C is good, the epoxy will set a lot quicker, and bond strength will be quite a bit higher. But viscosity will decrease, so it has even more chance of dribbling out. Masking tape dams will keep it in place if needed.

Beware of mixing up large volumes; the reaction when it cures is exothermic. I once had a bucketful of mixed epoxy start bubbling and giving out evil fumes.

Painting over epoxy is easy, just scuff it with sandpaper once set.

Rubber. In a previous life, I worked on fatigue testing Buccaneers & Phantom F4's. We had to epoxy 10" diameter rubber discs to the wings & fuselage, to which hydraulic rams were attached. These then bent the airframe thousands of times, caused fatigue cracks. So epoxying rubber to aluminium: We soaked the rubber in sulphuric acid for an hour or so. This hardened the surface. We then beat the living hell out of the discs with a hammer to put tiny cracks in the hardened surface. This gave the epoxy loads of tiny crevices to penetrate, and a joint (cured with heat lamps) rarely failed.

These guys make excellent epoxy: https://www.westsystem.com/ They have a how-to guide, very much worth a read: https://www.westsystem.com/wp-content/u ... ritish.pdf

[IanB]

I made a tongue in cheek reference to "billet" aluminium. Just a word or two on that.

The word "billet" only exists in the world of car & bike enthusiasts. It has no significance, it's a term that came from the advertising departments, not the engineering ones. Not sure when the phrase was first used, maybe 1990's? What I mean is, a billet of aluminium has exactly the same mechanical properties as a piece sawn off the end of a bar of the same material (which is how most metal arrives). Check any book of mechanical properties of materials - there isn't a separate table for "billet metal".

Very, very occasionally, a component will be forged. This is a completely different process and can give benefits, usually to do with the grain structure of the metal. "Billets" are normally produced with a bandsaw, not a forging press.

"Aircraft aluminium", "military grade" and "surgical stainless steel" fall in the same category. Go to a metal supplier, ask for any of these and they won't have a clue what you're talking about. Aircraft use all sorts of aluminium grades, including the cheapest. The only thing "military grade" about metal is the inspection process that it goes through, and the resulting audit trail. Surgical stainless steel can be anything, from common 304 / 316 (which can't be hardened, not enough carbon) to 420 / 440 grades which can be hardened. Unless a component needs to be hard, it'll be a 3 series.

Another one that occasionally pops up is "cryo treated". There are some very specific areas where it works (some hardenable steels can undergo an austenite - martensite conversion) but the effect is minimal - you'd need lab tests to tell the difference. Certainly, dunking bits of aluminium in liquid nitogen does nothing of any practical use. Cryo is a holy word in the hifi world - they even "cryo treat" copper cables, and then claim they can hear the difference

Many products are "CNC machined" these days, simply because it's the cheapest way to mass produce items. As long as the resulting part has the required dimensions and properties, it doesn't matter how it was arrived at - CNC, manual or chewed from billet by well trained mice.

[gilson]

Brilliant. Between yourself and Bazzer I'm learning. Thank you for posting.