Dunstall twin disc spoke details

madass140 · Sep 28, 2020

just a long shot, looking for spoke details for Dunstall,s twin disc hub

chaztuna · Sep 28, 2020

madass140 said:
just a long shot, looking for spoke details for Dunstall,s twin disc hub

Don,
I have one of those wheels sitting about 20 feet from me right now. What do you want to know? Would photos help? FYI, the SmugMug web link did not work for me.

Charlie K

madass140 · Sep 29, 2020

close up photos of course will help . can you take a measurement from the rim to the spoke hole in the hub?
thanks, Don madass140@gmail.com

chaztuna · Sep 29, 2020

Emailing photos now. Sorry for the delay. For some reason, the computer in my shop just did not want to transfer the photos from my phone. Using a different computer, with same cable, works great. Ahhhh...... The joys of Windows 10. NOT!

dynodave · Sep 29, 2020

Plus Borrani rim 1x1 pattern.
The earlier Dunstall (actually Rickman) single disc was outrageous to lace. They actually made 2 different drilling spacings.
The Dunstall dual disc is quite easy to lace up. I even had to make 2 new rotors. Blanchard ground then nickle plated.
Yes WIN 10 sux. My computer crashes ocasionally and only when on this site/forum??? Have to re boot from scratch.
XP never did that.

chaztuna · Sep 29, 2020

dynodave said:
Plus Borrani rim 1x1 pattern.
The earlier Dunstall (actually Rickman) single disc was outrageous to lace. They actually made 2 different drilling spacings.
The Dunstall dual disc is quite easy to lace up. I even had to make 2 new rotors. Blanchard ground then nickle plated.
Yes WIN 10 sux. My computer crashes occasionally and only when on this site/forum??? Have to re boot from scratch.
XP never did that.

Dave,
The 1X1 statement, does that reference the early single rotor wheels? I ask, because my dual disc has the Borrani rim, but is a "cross 2" spoke pattern. XP was good, Windows 7 was great! I'm still running 7 on one machine. Contrary to Microsoft's claims it has not halted and caught fire yet!

This wheel assembly has sat for decades. Any suggestions for getting the axle out? It rotates in the rusty bearings, but will not slide. I've tried mild heat [MAP gas torch] PB Blaster, Allen socket and hand impact to get the flush screws out, which retain the rotors. No joy. I'm half tempted to drill the heads off the rotor screws. That way, at least my drill will be in the center of the screws. I could then drill out the screws and install HeliCoils to repair.
What is inside the hub, between the wheel bearings? Just a spacer tube, like a stock wheel?

Charlie K

madass140 · Sep 29, 2020

chaztuna said:
Emailing photos now. Sorry for the delay. For some reason, the computer in my shop just did not want to transfer the photos from my phone. Using a different computer, with same cable, works great. Ahhhh...... The joys of Windows 10. NOT!

thanks for that, much appreciated.

dynodave · Sep 29, 2020

Not refering to spoke crossing pattern.
I'm refering to the RIM dimple pattern on my Dunstall dual disc front end. OEM Borrani rim. Rim dimpling can be 1x1 or 2x2 or like on commando MKIII 1x3 which seems to be rare.

Not even sure Akront was around back then? Dunlop alloys were probably gone by then?
I have Dunlop alloy for my BSA A-10 RGS. The Dunlop are by far the lightest of the 3 brands that I have weighed followed by borrani then akront being the heaviest.

The counter sunk disc screws are BSF. Had to order from england.
FWIW these rotor retaining screws were probably hand drill as there was NOT a symetrical bolt pattern. They were dimple marked for orientation on the disc and hub. They go on only one way and only on the correct side.

Stuck axle ? The bearing spacer IIRC (from what I can see) is a continuous solid one piece of steel which also act as a bearing ID reducer to fit the axle.
The additional external collar on each end is outboard of the bearing.

chaztuna · Sep 29, 2020

dynodave said:
Not referring to spoke crossing pattern. I'm referring to the RIM dimple pattern on my Dunstall dual disc front end. OEM Borrani rim. Rim dimpling can be 1x1 or 2x2 or like on commando MKIII 1x3 which seems to be rare.

Thank you for educating me on that.

dynodave said:
The counter sunk disc screws are BSF. Had to order from England.
FWIW these rotor retaining screws were probably hand drill as there was NOT a symmetrical bolt pattern. They were dimple marked for orientation on the disc and hub. They go on only one way and only on the correct side.

Great to know. I wouldn't have immediately thought of that. I will be sure to be cognisent of the orientation when I finally get them free. If I'm forced to drill out the original rotor mounting bolts, replacement hardware won't be an issue. I'll simply install USC [aka NC] HeliCoils & use US hardware.

dynodave said:
Stuck axle ? The bearing spacer IIRC (from what I can see) is a continuous solid one piece of steel which also act as a bearing ID reducer to fit the axle. The additional external collar on each end is outboard of the bearing.

Are those external collars locked onto the axle in some manner? I don't see any snap rings holding the bearings into the wheel hub? If the collars aren't locked, what keeps the bearings from moving outboard? Are the collars threaded onto the axle?

Charlie K

dynodave · Sep 30, 2020

chaztuna said:
Are those external collars locked onto the axle in some manner? I don't see any snap rings holding the bearings into the wheel hub? If the collars aren't locked, what keeps the bearings from moving outboard? Are the collars threaded onto the axle?

extra support/thrust collars are just spacers pressed on to the steel tube to space the fork leg bottoms.
IIRC the steel cross tube is a bearing bore reducer as well as the spacer between the bearings. The length must be well calculated? since the fork legs arel nipped up on both ends by the axle. I did the rebuild almost 15 years ago.
I had this full 71 dunstall kit all assembled on my combat for a year or two but pulled it back off and reverted my combat to almost stock.

chaztuna · Sep 30, 2020

dynodave said:
extra support/thrust collars are just spacers pressed on to the steel tube to space the fork leg bottoms.
IIRC the steel cross tube is a bearing bore reducer as well as the spacer between the bearings. The length must be well calculated? since the fork legs arel nipped up on both ends by the axle. I did the rebuild almost 15 years ago.

I was referring to the external collars [aka spacers] on the axle. They are outboard of the wheel bearings. This wheel has sat for decades, unused. The axle won't come out. I'm trying to determine why. I don't see any snap rings holding the wheel bearings in. I'm beginning to think that the axle has rusted itself to the internal spacer tube. Would a photo of the dual disc wheel/axle help jog your memory?

dynodave said:
I had this full 71 dunstall kit all assembled on my combat for a year or two but pulled it back off and reverted my combat to almost stock.

What came in the "full Dunstall kit"? I ask, because this 71 Roadster basket case came with the dual disc front end, Borrani rims front and rear, Fiberglass front fender and the 810 big bore kit. Did you remove the dual disc set up due to no real gain in braking? Or simply to get the bike back to stock?

Charlie K
PS Thanks for taking the time to answer my questions.

dynodave · Sep 30, 2020

Th axle is in front of me on the desk, the hub/rim/wheel is on the floor behind me. Looking down the bore, I see nothing that looks like a parting line that makes me think it is anything other than a stepped spacer with pressed on collar on each end.

My kit: dual front end/ Borrani F&R , glass fender, aluminum top triple tree, clipons, mild cam, skimmed barrels, 810 kit may have bee removed? big valve rotated intake, ported early 6 fin manifolds, 2-1-2 side winder exhaust hung on long aluminum plate hangers, rear sets, chopped rear fender under dual seat

I removed the whole kit. Didn't really want another cafe' bike for riding. I had parked my stock MKIII. I like the stock combat roadster for around town.