Old 09-23-18, 06:39 PM
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cudak888 
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I wrote a big reply 5 minutes ago and the browser just ate it. Can't get more "classic and vintage" than that.

Anyway, I'll keep this short:

Tore the back end of the Twenty apart today. Kickstand is in a really sorry state of operation and is the one thing I haven't taken off just yet. Since I want a dual stand to keep it upright when parked, I'm going to cut it off and dress the BB smooth when I get the chance.

Excuse the disaster zone, but I bought some toolboxes recently and am in the middle of reorganizing the entire workshop. Hence, mess.




Soon to be eBay bait (most of it, anyway):



I decided to verify the operation of the modern Sturmey AW, as I'd never ridden it before. I used the Pastor Bob Stump Dump™ '80 Raleigh Sports (Stumpy?) for testing. This bike has been sitting completely unused in the shed for years, thanks to my grand scheme of putting an FW in the original AW hub shell. I effed up something in the reassembly and never got the clutch to engage.

The new wheel - even as a test - gave Stumpy life that it hasn't had in years. It also gave me an interesting test ride, as you might notice the Weinmann sidepulls were removed long ago for dual pivots that never materialized...



What a modern AW looks like. It must have the spiral-type clutch that Sturmey developed in the 1980's to eliminate sudden disengagement between gears, because the shifting is much more immediate when the shift actually happens. No longer do you lose 10 degrees of rotation at the crank when the shift happens. Not sure if I like it or not from a C&V perspective, but it should cut down vibrations at the camera.




Originally Posted by RobbieTunes View Post
+1 on the double-barrel brakes.

While I've always liked the GoPro, I've never liked the mounts. Have you thought about wider bars and hanging a GoPro under it? The "hanging" mounts seem to work better in some applications, though I suppose in theory the vibration issues would be the same. They have mini-steadycam setups now, I think, and the software is pretty good.

The last time I helped anyone with bike-mounted video, we put rubber 0-rings between the frame and all the rack mounts, and put a Sony digital video camera (studio style) right on the rear rack, on a rubber mat, with a 650b rear tire, then he did a lot of editing.
Mounting anything on the bars means a wandering crappy shot. Vibration issues have been OK, if not great, on the existing Twenty; the GoPro image stabilization helps a bit. Gimbal should take care of that.

This is the setup that I'll be using with the new bike:




Originally Posted by gugie View Post
I think I have those tires, just walked out to the Atelier, which is a mess right now. I'll check again later.
Someone just offered me a pair of built wheels for the project with tires, so this part of the plan may have changed. Thanks though.

Originally Posted by Tamiya View Post
Interesting project! More so as I've been bitten by the Twenty retromodding bug plus have been thinking how to mount GoPros for Ride2School day come summertime (downunder!).

You haven't mentioned circumsizing the headtube to upgrade the headset to top bearing. Right now I kinda prefer the damped feel of original bushing & have kept it on my fleet so far, even making new bushings for the wornout ones.

Don't see any need to upgrade BB, old tech work fine & the cotters don't bother me.

Modern dual calipers work fine on my steel 451s.

Does new AWs fit into dropout without opening them up? So far I've been resurrecting original AWs, every one has come back alive so haven't need to modernise... however I tried using new-style Sturmey hardware & the key washers won't go into Twenty's dropout slot. Even bought a twist shifter yet to install.

For stop-start ease i've geared down with larger sturmey sprockets.
I've thought about the headtube. I figure I can keep most of the original setup (which I like) by putting a standard Raleigh upper headset on it and using a shaft collar clamp to keep it from loosening up. Honestly, I'd rather sleeve and extend the steerer than shorten the headtube; after all, the Twenty is short enough as it is in this area. Lots of effort for little result though; probably easier to chop a bit out of the headtube when the time comes.

The cranks and brakes are two of the things I'm immovable upon, the cranks for the following reasons:
  1. The cotters always catch my pantlegs at the worst possible moments (e.g., cranking hard)
  2. I tend to bend the squared-off Raleigh crankarms that you find on Sports, so the ovalized Twenty arms can't be any better (pretty sure one of the arms on the brown '70 is slightly tweaked, come to think of it.
  3. I have access to a framebuilder who can fill the BB with brass so we can tap it out with 24tpi threads
  4. I've yet to see someone put a Hollowtech-style 73mm BB and crankset on a Twenty and I just want to be a silly braggart about it (if the opportunity arises to install such components).
The new AW I have (which is probably already 10 years old) is identical to the old externally, except for an aluminum shell. Uses the same exact shaft paired with the thicker centering washers that came out around '77-78 or so when Raleigh finally increased their dropout slot size to match the rest of the world. All I have to do is swap in the older, narrower washers.

If you need another twist shifter, let me know. The modern hub had one tied to it, and I have no use for it.

Originally Posted by Drillium Dude View Post
I just came here to say "Hi, Kurt!"



Glad to see you're mind is still wandering...

DD
Hey DD! What have you been up to? Have you resisted the urge to drill every piece of aluminum at the house?

Originally Posted by delicious View Post
Good to see you posting again, Kurt. This is going to be a fun build to watch!
Should be equally fun to build! Looking forward to it - it blends two passions of mine. Hopefully it goes well.

-Kurt
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