Pentagram/Star Wheels: My rebuild and How-To thread

[scott s]

While there are a few threads about these wheels floating around, the information is pretty scarce. Even more scarce is information about restoring them and actually fitting them on a bike.

This is a thread about how I did it for my bike. As you'll see as we go along, there were a few different options or ways of doing this.

A little history (and please correct me if I'm wrong. As I said, there's precious little information out there):
These wheels were a Yamaha dealer option "back in the day", probably mid-'70's. They were pricey then and few were sold. That makes them even more rare today.
The fronts seem to pop up more often than the rear. In fact, I've owned three fronts to just one rear, and I had to buy a set to get the rear.

That's probably due to the fact that the rear is a disc brake wheel. The XS500 and XS650 were drum brake models at the time, so maybe people just used the front and didn't bother fitting the rear? It's possible these could have been fitted to some RD models that had rear disc, but I've never seen that.

They were called "Star" wheels back then; most people refer to them as "Pentagram" wheels these days.

They seemed to have been made by Shelcore, or possibly Shelby Dowd. Both companies had ties to Carroll Shelby. The Shelby Dowd wheels are similar, but not the same, and were made for Honda's, as well as other models.
The wheels had a painted yellow center and no markings. One of my front wheels has "11074" stamped on it near the hub area. The other wheel, which appears to be NOS, has no markings in that area. The rear wheel might have a faint "75" in the hub area. Possibly build dates?



And these are mine. A Pile O' Pentagrams:

 

[scott s]

I'm not the best at knowing exactly where to measure a wheel to determine the exact width, but the front seems to be a ~2.15" wheel and the rear is a ~2.5" wheel.

The wheels I got were mounted on an XS500. I knocked out the bearings and saved all the spacers. The front wheel bearings and axle should be the same as the XS650.

For the rear, I sourced a set of bushings, spacers, etc., that went on an '80 XS650G disc brake rear wheel. No pics yet....they're en route.

The plan is to install new XS650 size AllBalls bearings and use whatever spacers are necessary to make them fit my '75 XS650B.

Rear wheel:

Front wheel:

 

[scott s]

Here are the wheels after knocking out the bearings and giving them a quick scrub.

The black on the rear wheel is paint overspray where someone painted the rear rotor center black.
I'm undecided right now as to how far I want to go on these things. The rims and highlighted areas could be polished to a mirror shine. There's a bit of oxidation on the front wheel and there's a little bit of cub rash on the rear. The spokes on both are slightly discolored from age and use, compared to the NOS front I have.

I'll probably end up polishing the hubs and spokes and painting the rest, probably some sort of grey.

 

[scott s]

Speaking of rotors, my wheels used a front rotor on the rear. I say MY wheels, because I believe that "back in the day" there was no complete "kit" to fit these. You were left to your own devices to figure out how to mount a caliper, master cylinder, etc.

I cleaned up and deglazed my rotors with some 80 grit and red SkotchBrite pads and some brake cleaner.

 

[scott s]

Here's a picture I nabbed from the InterWebs showing two different ways to mount a caliper. The front wheel is an RD wheel on a drum brake swing arm. That's the route I'll be going.

This picture shows yet another caliper mount:

 

[scott s]

I had purchased a disc brake swing arm, caliper, master cylinder, rotor, hose, bushings, etc. But after taking a closer look at the stuff that came with my wheels, it all clicked and I realized I could use that stuff and fit them on a drum brake arm.

Kinda funky, kinda weird, but vintage and period correct. So that's my plan for now.

Here's the bracket/caliper holder I have. Uses a Yamaha front caliper. This way, I'll have matching rotors and calipers, front and rear.

The lower hole uses the brake rod torque arm. The larger hole near the center goes on the axle. I might have to enlarge this hole slightly, as I think the XS500 uses a 17mm axle and the XS650 uses a 20mm axle. I'll address that later on.

 

[scott s]

Here's where things get really funky....

The XS500 used what I later found out to be a Hurst Airheart master cylinder. The bracket seems to be custom/homemade. It uses the passenger peg mount and, I think, a couple of holes drilled through the passenger peg loop and then is bolted on.

 

[scott s]

The master cylinder is 7/8" bore. Airheart is still around and I ordered a rebuild kit today. The M/C seems to be on the same plane as the caliper. If it's below the caliper at all, it's only by a couple of mm.

I mention that because Airheart sells an RPV, or Residual Power Valve. They advised me to just try it out and it the fluid leaks back to the M/C and makes the pedal spongy, then install the RPV.

This set up has a linkage arm and lets me keep the drum brake actuator lever. Had I gone to disc brake swing arm, that would have been changed and I would have had to weld on a couple of tabs to mount the Yamaha master cylinder.
This way, I can swap back to stock wheels, should I ever want to do that.

Gratuitous parts pics. Rebuild stuff is on the way.

 

[scott s]

That's about it for now. I'm waiting on parts and need to detail the wheels.
Once the wheels are detailed and "built", new bearings and spacers and such, I'll mount the tires and see exactly what it take to fit them to the bike.

The front should be a direct bolt on. The rear may or may not require me to get creative with some spacers.

I also have to eventually get a new rear hose made and I'm keeping my fingers crossed that the rear caliper is good.

 

[fredintoon]

Hi scott,
that's a great project so long as you ain't afeared of a pentagram's magic powers. While you are at it, drill those disks full of holes, eh?

 

[scott s]

I ain't skeert!

 

[fredintoon]

I ain't skeert!

Hi Scott,
I ain't afraid of no ghosts
My boys just about wore out my videotape copy of Ghostbusters when the show first came out.

 

[jamesgs4]

cool stuff man!

 

[deadchef]

good thread scott! i'm in the same boat and would like to get these mounted someday on my bike. do you plan on running tubes in these rims? i didn't notice any stamps on the these saying 'tubeless'.

 

[scott s]

I believe they are tubeless, but I'm not 100% sure. I wasn't planning on running tubes, but now you have me second guessing myself!

 

[turner]

Scott...you are correct on the lower bolts on the m/C mount, that's how it was mounted. Two holes drilled Also the tires did have tubes in them when I dismounted them.

 

[scott s]

What determines tubes/timeless? Is it the tires or the rims? I know some tires specify one way or the other, but is there anything about the way a rim is made that makes them require a tube (other than being a spoked wire wheel)?

 

[Jbinnington]

Hi Scott, it's the cross sectional profile of the rim that allows tubeless tyre figment. Tubeless bike tyres were a figment of imagination when these bikes were about, they'll be for tube tyres.
What do you guess the wheels are made of? Aluminium or magnesium/aluminium? I ask because I know that mag alloy doesn't age at all well and vintage mag alloy wheels are often know to fail in use. Aluminium alloy ages much better
Jonathan

 

[scott s]

Probably aluminum. Mag was expensive and these aren't nearly grey enough to be mag. I'm aware of the ups and downs of magnesium from back in my VW days. I know of a guy that was seriously injured when a BRM wheel exploded as he aired up the tire.

I use "mag wheels" like a lot of people use "Coke" for a soda or pop.

The wheels are fairly light. I'll weigh them soon.
I have some Lesters for Honda CB500/550 and they're pretty light. The Henry Abe wheels are heavy-ish, especially the rear wheel. (What can I say? I have a thing for vintage wheels)

 

[scott s]

I'll also get some snap shots of the wheel bead. I don't mind running tubes if I have to. Done that before on some vintage "mags".