Rotrax build

[Clydesdale Scot]

more googling provides this info
http://pardo.net/bike/pic/fail-024/000.html#harden

6.45mm flats. 5.6mm tall. 4.6mm diam. thread. 0.65mm pitch (approx). The original may have had a spacer between fitting hex and hub.

any help?

[RobertFrith]

more googling provides this info
any help?

Can't believe I didn't see that one before - I mean it's the second result
Anyway 4.6mm equates to 3/16th, right? And 3/16th I have and they don't fit. Just ran the caliper over them again and they're 4.8mm, so 0.2mm larger diameter than pardo.net's measure, that doesn't seem enough to prevent the thread even starting. Pardo's approximate thread pitch measure is very fine. The only thread it matches is ME which doesn't seem right. There are so few threads and they're so small that taking a measurement with any sort of accuracy would require special tools. Microscope comes to mind.

I emailed Peter Underwood. He suggested the threads may be the same as bottom bracket oilers. I've tried a BB oiler in the hub and it does thread in a few turns, anyone know what spec BB oilers are?

[WyvernRH]

[quote="RobertFrith"
I emailed Peter Underwood. He suggested the threads may be the same as bottom bracket oilers. I've tried a BB oiler in the hub and it does thread in a few turns, anyone know what spec BB oilers are?[/quote]
Without checking I can't give you the specs but Bottom bracket oilers came in at least three different sizes. If he meant the 'normal' flip top type then I can tell now they don't fit as I have tried this Most Tecalimit (sp?) types are also too big as well as they were normally meant for headsets.
However, in the end I did find a small Tecalimit nipple that fitted my rear Harden hub in my spares box (I think it came off an old wrecked hub of another make) but only one. The front hub has to make do with a blanking plug.
Have you tried pinching a grease nipple off an old Sturmey Hub?
Cheers
Richard

[RobertFrith]

Have you tried pinching a grease nipple off an old Sturmey Hub?

Thanks Richard, I hadn't but gave it a go just now. The SA nipple is too big.

[maryusdemetry]

have you seen this thread?

Quited helpful, thanks

[Clydesdale Scot]

have you seen this thread?

Quited helpful, thanks

one for the Foe list

[Clydesdale Scot]

at the risk of being

if you have a grease nipple which is very, very close, is it possible to retap the thread on the hub to suit?

[RobertFrith]

if you have a grease nipple which is very, very close, is it possible to retap the thread on the hub to suit?

I suppose you could. I have two in complete wheels with missing nipples though so that'd mean dismantling the wheels. Wouldn't it??

Following communication with someone selling some bacon slicers (sans nipples) on a popular auction site I bought some 2BA nipples. They look identical to the one existing one I have and they fit and screw in a couple of turns but not all the way. They didn't come with the tiny fat washers that my original has though. I suppose with those they'd be pretty good. Only thing I've found that fits at all.

Oh yeah, the bacon slicers were in Perth too, I could have picked them up if I remembered to bid! The pair went for $135 I think, which considering they were in good nick seemed reasonable. Oh well...

[RobertFrith]

I still have a few things to do on the Rotrax but I've been riding it a around a bit lately. I was up early this AM, conditions were cloudy (and thus perfick for photographing bikes), couldn't resist the opportunity. There's nothing very purist about this resto. It's a coastie for starters, the rims are modern H+Son TB14s with Conti 4000s. Reynolds domed topped seat posts are in short supply so there's a modern post hiding behind the Rapha toolbag. Seat post binder bolt is wrong I think. The head badge is taped on as per earlier suggestions. Have yet to put dummy rivet heads in place. Still it rides (and stops) quite beautifully, and nothing evil has been done to the frame. Big thanks to silverlight who sold me the frame in the first place and to all who've made helpful contributions. Seriously could not have done it without help!











flickr set here

[ghostpoet]

Brilliant stuff!! Fantastic build. Those bars look all the better for the cloth tape...any plans for similar pics of the 5 Star?

[RobertFrith]

Brilliant stuff!! Fantastic build. Those bars look all the better for the cloth tape...any plans for similar pics of the 5 Star?

Of course. I want to change the stem to a period one first. Then wrap the bars. Etc...

[Clydesdale Scot]

Robert,
I stumbled across the 1950 Harden Catalogue and thought I would post the link here in case anyone searching about Harden hubs stumbles onto this page.
many other period catalogues at that site

[RobertFrith]

This one had an outing on Cycle Exif recently. I can't imagine that anyone here isn't already a fan of Adam's work, but you never know check it out - best bike prawn site ever!