|
|
Post by oldroadietehachapi on Oct 7, 2015 17:36:11 GMT
My Viscount project is taking a bit longer than I thought (procrastination can be a problem when semi-retired). The attached photo is during a test fit of components. As seen, the bike has a Tange CroMoly fork (27") which had the same dimensions as the death fork. I plan to fit the heavier death fork (with death fork stickers) for special occasions or when the mood strikes me. The rear derailleur is a long cage Shimano Crane. The shifters are the very pretty Shimano Golden Arrow (remembered by some of us). The brakes are Weinmann Carrera side pulls. The saddle, a Brooks B17 Imperial. The crankset is a combination of Viscount and Stronglight chain rings and TA Cyclotourist crank arms. The wheels are Titan Matrix 700C with Sansin hubs (instead of the original tubular setup). The front derailleur will be a Shimano 600 Deer Head triple which had the appropriate use of a lower cable housing.
A few problems remain unresolved: The triple crankset bolts and spacers do not fully tighten so I will have to fiddle with bolt or spacer sizes (I have a couple of sizes on hand). I have a pair of NOS Viscount center pull brakes which I prefer to use, but they lack center bolts. Weinmann, Dia Comp and Shimano center bolts do not seem to fit correctly; to use the Viscount brakes I may have to fabricate something. Perhaps one of you can suggest a correct set of center bolts?
Cheers Jim
|
|
bendo
Viscount
Posts: 538 
|
Post by bendo on Oct 8, 2015 7:07:16 GMT
Nice work Jim. I spied the Crane GS rear mech pretty quickly *drools*. And I love the Golden Arrow group. The paintwork looks great. I especially love the fork crown detail, just beautiful.
Sorry can't help you with the brake bolts. But a wise friend once said all bike problems can be solved with a sit down and cup of tea. (Might even have been someone here!)
b
|
|
|
|
Post by cusqueno on Oct 8, 2015 12:49:19 GMT
What is it about the alternative bolts you've tried that's wrong - the diameter the length or the head?
|
|
|
|
Post by oldroadietehachapi on Oct 8, 2015 21:08:22 GMT
A normal center bolt is M6 with a slightly enlarged area just below its' head. This allows the bolt to press fit into the caliper when the bolt is tightened. The hole for the center bolt in both of my NOS Viscount calipers is 6.43mm. larger than an M6 (I get 5.93mm diameter) or the enlarged area (I get 6.37mm diameter). This makes the center bolt in the brake caliper a sloppy fit; I don't like a sloppy fit, especially on brakes. Even if I try a quarter inch bolt, at 6.14mm it is still small and sloppy. Also, a Quarter inch bolt will not fit into the hole in the brake mount on the frame.
Furthermore, the head of Weinmann and Dia Comp center bolts are shaped as to hold tight in a slot on the brake caliper. The slot in the Viscount brake caliper is a little wider allowing the bolt to spin when tightened.
I can only make three conclusions: Viscount may have had their own special and different center bolt. This seems very likely. Viscount workmanship was very sloppy in. Which is less likely. The brake calipers, despite being unused and in original packaging were modified. After close examination, this seems to be very unlikely.
I can mount the caliper with M6 hex head bolts; which would be similar to Shimano. Still, it is a sloppy fit. I will try this with a little bit of aluminum tape wrapped around the bolt, just below its' head as a shim.
I have of course, added pictures for clarity and am open to suggestions.
Cheers Jim
  
|
|
|
|
Post by triitout on Oct 9, 2015 0:17:49 GMT
Hi Jim,
I would say your'e right on count 1...different size bolt head. I picked the same NOS Viscount brakes also without the mounting bolts from ebay a few years ago and have since mounted a pair with the smaller bolt head thats still available. Once I tightened everything up there has been no slippage or rotation so even though it's not ideal, I can report that it will work. Hope that helps.
Happy overhauling,
Michael
|
|
|
|
Post by oldroadietehachapi on Oct 9, 2015 3:36:04 GMT
That's encouraging!
Jim
|
|
|
|
Post by cusqueno on Oct 9, 2015 12:31:27 GMT
I'll try to dig out a Viscount brake and bolt from The Shed this weekend and make some measurements, take photos.
|
|
|
|
Post by 54roadie on Oct 10, 2015 5:20:33 GMT
The Viscount calipers I have on hand measure - centerbolt - 6.02mm straight, 5.89 threaded, the head is 15.06 across the flats and 16.80 at it's widest. The hole for the centerbolt is oversized - I get 6.43mm, likewise the notch for the head of the bolt is 16.26, quite a bit over. it makes for sloppy and at times difficult assembly and setup, but as triitout points out. it all tightens up and stays put. I'm wondering if there might be some thin wall copper or perhaps nylon tubing that might work.
For comparison, the centerbolt in a Weinmann 750 side pull I have on hand measures 6.05 and 5.9mm
FWIW, I don't recall the old Weinmann or Dia Compe CP calipers being very much tighter.
Coming along nicely, Jim
Frank
|
|
|
|
Post by oldroadietehachapi on Oct 10, 2015 14:18:04 GMT
Thanks Frank!
I think I will use M6 bolts with aluminum tape wrapped around the shank to tighten the fit. A bit of thin wall tubing is a great idea but I don't think it can be found in the right sizes. To make the tubing fit correctly, it would have to be fabricated on a lathe; if I were to do that, I think I would just make a better bolt.
Cheers
Jim
|
|
|
|
Post by oldroadietehachapi on Oct 13, 2015 18:46:52 GMT
My final solution is two M6 flange bolts (in 40mm and 50mm lengths) with a small strip of aluminum tape at the shank (to tighten the fit). This allows me to tighten and center the brake using one 8mm and one 10mm wrench. It also looks good and the fit is satisfactory.
All the Best Jim
|
|
Jem
Viscount
?
Posts: 3,389
|
Post by Jem on Oct 13, 2015 18:48:34 GMT
Very neat solution Jim.
|
|
|
|
Post by cusqueno on Oct 13, 2015 21:47:46 GMT
A couple of photos of a pair of Viscount brakes showing the pivot bolts. The second looks a bit odd because I've tied one calliper closed and balanced it on the other to give the best view of the head of the bolt. Attachments:
|
|
|
|
Post by oldroadietehachapi on Oct 14, 2015 4:33:26 GMT
Thanks for the pictures! The center bolts appear to have a very large head (as suspected).
Thanks Again
Jim
|
|
