Rotrax build

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hiflange
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Re: Rotrax build

Postby hiflange » Mon Jun 18, 2012 11:33 pm

No bids yet, they may be cheap enough to have a punt on I suppose. While they may be in keeping with the period they seem a less attractive solution than the coaster brake hub. Thanks for the tip though :)

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hiflange
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Re: Rotrax build

Postby hiflange » Tue Jul 24, 2012 6:24 pm

Making (slow) progress. I'm going to build three wheels, one with a modern coaster brake hub and a pair with Harden bacon slicer hubs. I picked up the bacon slicers in separate auctions and it wasn't until last night, whilst measuring up for spokes, that I discovered that the flanges are different sizes. The diameter of the front one is 15mm bigger than the rear.

Only one of the Hardens has a grease nipple so I need to get another. Anyone have a clue what size thread they are?

Oh, and I went with TB14 rims;
Image

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hiflange
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Re: Rotrax build - wheel build speed bump

Postby hiflange » Thu Aug 02, 2012 7:44 pm

This is my rear Harden hub. Bought it off fleabay and it came with a sprocket.

Image

Said sprocket obstructs access for spoke threading. I don't have a lockring tool so I took it to an LBS at lunchtime. The mechanic had a crack at it but without the purchase afforded by spokes and rim he couldn't budge it. I gotta build a wheel to get the sprocket off, gotta get the sprocket off to build a wheel :( Helpful suggestions welcome

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Re: Rotrax build

Postby Johnj » Thu Aug 02, 2012 7:54 pm

Chainwhip on the cog?

I hope you and the mechanic remembered that the lockring is left-hand threaded....

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Clydesdale Scot
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Re: Rotrax build

Postby Clydesdale Scot » Thu Aug 02, 2012 8:09 pm


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hiflange
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Re: Rotrax build

Postby hiflange » Thu Aug 02, 2012 8:42 pm

Clydesdale Scot wrote:have you seen this thread?
That thread is quite helpful. I think I'll go the vise route.
According to the LBS mechanic using a chain whip will preclude the use of the lockring tool. Mind you he said this whilst holding my vintage hub in a pair of vise grip pliers padded with a scrap of rag.
Johnj wrote:Chainwhip on the cog?
I hope you and the mechanic remembered that the lockring is left-hand threaded....
thanks for the reminder :)

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Re: Rotrax build

Postby HappyHumber » Thu Aug 02, 2012 9:02 pm

If you've got some spare spokes that are faintly/remotely/ballpark the correct length (but better longer than shorter!) just lace up an on old duff rim at consistent spaced interface on the NDS so you can thread them. I did it once with a freewheel on a spokeless hub with only four spokes at loosely 12, 3, 6 & 9 o'clock. Not knowing the history of this yourself though you may want to use 8 or 12 spokes still evenly spaced

Put the lock ring in a vice, work out the way it should turn to relase and exercise some controled brute force with the rim as your extra "steering wheel" type leverage.

For the cog.. try the same with the chainwhip, or I have seen similar solutions with the hub cog down on a piece of wood with nails evenly banged in between cog teeth. Put that piece of wood in the vice. Try to turn the opposite direction you got the lock ring off with :D


Hard to tell from the pic - but is it a proper lock ring or a merely a "suicide" extra nut using the same right hand thread?
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Re: Rotrax build

Postby hiflange » Thu Aug 02, 2012 9:49 pm

haven't got any old spokes or rims. Clydesdale Scots "this thread" recommends against this method on the basis that applying torque to the non drive side could result in twisting the hub body. Just not going to go there with a vintage high flange hub :?

This is my only exposure to fixed wheel lock rings, can someone explain the diff between proper lock ring and suicide extra nut? The lockring I'm looking at shares the same thread as the sprocket as far as I can make out.

Couple more pics;

Image

Image

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Re: Rotrax build

Postby HappyHumber » Thu Aug 02, 2012 10:03 pm

sorry.. itchy reply fingers.
constant source of keyboard in mouth syndrome for me.

I did go an read the thread *after* and did see the weakness or undue stress angle. Banish me to Facebook for such a lack of attention ;)

You can actually fudge a fixie on an old freewheel hub. the Sprockets use the same threading as a freewheel, just they're narrower in width. Addtionally, you will find that the lock nuts on old adjustable cup brackets are also the same thread. You can therefore just put one of these BB lockring nuts on after a fixed sprocket on any old freewheel hub. The kicker is, it risks undoing also because it loosens in the same direction you're likely to resisting or modulating your speed through your legs. This in net parlance is a "Sucide Hub" Apparently quite a number of people who ride fixed this way have done so quite safely no incident, but I would wager they're running higher gears and do not fit into the "wikkid skiddaz" brigade.

A true, dedicated track hub has the outer portion of the thread noticably smaller in diamater - and reverse or left handed threaded. The idea being should the sprocket ever want to undo itself for whatever reason, it can then only really force the outer ring to tighten.

Quotes from Saint Sheldon here on the topic, using different hub types for conversions. here
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Re: Rotrax build

Postby hiflange » Thu Aug 02, 2012 10:15 pm

thanx HH. I checked out Sheldon in the meantime and, looking at his specs for lock rings, I reckon I'm dealing with a real lock ring not a suicidal imposter. His little chart shows English/ISO as 1.29" thread. The measurable inner end of the lock ring on my hub is 1.23";
Image

sigh... I don't have a vice or a lockring spanner so I guess it'll be another week or so before I make further progress

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Re: Rotrax build

Postby HappyHumber » Thu Aug 02, 2012 10:26 pm

Either way, I'd say this one is a bit beyond the capability of your typical modern bike shop. Might luck out if you have a good, older experienced mechanic though.

I was going to suggest some DIY lock ring pliers. But then I notice your odd little puppy only has one notch!

Image

But, FWIW take 1 pair of cheapie multi or vise grips and get them accquainted orally with a grinder wheel
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Re: Rotrax build

Postby silverlight » Thu Aug 02, 2012 10:37 pm

hi,
What i have done in the past is get a rim thats not needed and build it up with 8 spokes on either side of the hub and then that should be enough to remove the lockring and get a good grip on the cog,
Its worked for me in the past on numerous times,
The vice method for me hasn't worked too well in the past.

cheers
SL

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Clydesdale Scot
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Re: Rotrax build

Postby Clydesdale Scot » Thu Aug 02, 2012 10:47 pm

Mario, any experience with the bacon slicers?
The Classic Lightweights site has
In 1945 Harden obtain a patent for the Haupage alloy hub design with cartridge bearings. Manufacture began at the end of that year. Initially all hubs were large flange and undrilled, a style that became known in Britain as ‘bacon slicers’ These were offered in versions typical for the time e.g. double or single fixed, gear /fixed and gear only. One problem with these hubs is that the spoke holes are drilled very close to the edge of the flange. This can result in the flanges cracking. This can be caused by a number of factors including spokes over tightened, a chain coming off the rear usually fixed sprocket or now simply the age of the metal (around 60 years old).[my emphasis]

I'd be nervous.

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Re: Rotrax build

Postby LG » Fri Aug 03, 2012 7:44 am

I'd be nervous too no matter what method you choose! Can I suggest you try using timber blocks in a good solid vice to clamp onto the sprocket, which should dig into the wood, and will probably also clamp onto the flanges. If you can't arrange it so a lockring tool can be used with this, give the notch in the ring a tap with a punch to loosen it first up.

One advantage you have compared to the thread linked by Clydesdayle Scot is that most of them are dealing with a freewheel, yours is fixed and should provice good leaverage.
LG = Low Gear

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Re: Rotrax build

Postby WyvernRH » Fri Aug 03, 2012 8:49 am

RobertFrith wrote: Image
Me, I'd be using a HSS drill to put a hole in the body of the lockring abd the sprocket then using a Dremel fitted with a cutting disc to cut a slot thru the holes thus splitting the lockring and the sprocket. This will enable you to tap a screwdriver into the slot which will 'pop' the threads and they will easily unwind. You destroy the sprocket and teh lockring but save the hub.
Cheers
Richard

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hiflange
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Re: Rotrax build

Postby hiflange » Fri Aug 10, 2012 1:00 am

I reckon I'll be able to take her for a spin on the weekend. I haven't made any progress on the Harden rear hub which is a little disappointing. I'd always intended to build two back wheels though, one with the Harden fixed gear and another with a coaster brake hub. The rest of my spokes arrived and I spent the past couple of evenings building the other wheels.

All I have left to do is apply a chain and point the seat in the right direction. Things that can wait include bar tape, why one of my Lyotard pedals won't fit the left crank while a Sheffield one will and a seatpost more in keeping with the vintage of the machine
Image

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Re: Rotrax build

Postby hiflange » Sat Aug 11, 2012 10:07 pm

Bar tape on.

Image

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Re: Rotrax build

Postby rkelsen » Fri Aug 17, 2012 11:50 pm

Wow. That came up nicely. What kind of bars are those?

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Re: Rotrax build

Postby WyvernRH » Sat Aug 18, 2012 6:40 am

rkelsen wrote:Wow. That came up nicely. What kind of bars are those?
They look like a set of Marsh bars? If so Robert is either lucky or rich :)
Nice fancy work with the bar tape!
Cheers
Richard

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hiflange
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Re: Rotrax build

Postby hiflange » Sat Aug 18, 2012 9:43 am

WyvernRH wrote:They look like a set of Marsh bars? If so Robert is either lucky or rich :)
Yep, they're Marsh bars. They weren't a bargain of course but still good value - just look at 'em :!: .
First time I've had a crack at a harlequin tape pattern. It tested my patience severely. Two colour would be easier to apply in that you can more readily distinguish tape heading in one direction from the other. Bit showy for my taste though :wink:
The bars are skinny (22mm) and disturbingly flexible riding with your hands at the back of those very long drops, methinks I'll confine myself to the tops and deep in the drops.
I have shellac on order for the tape and I still have to sort out the head badge which is held on with blutack at present. Once those tasks are done I'll post a proper set of pics

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hiflange
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Re: Rotrax build

Postby hiflange » Mon Sep 10, 2012 11:32 pm

Shellacking complete (no more pics till I sort out bar plugs!).
New head badge and fork transfers arrived today
Image
Could still do with some advice on the spec for Harden grease nipples (have one missing on this bike and 2 on another)

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Re: Rotrax build

Postby Clydesdale Scot » Tue Sep 11, 2012 7:24 am

RobertFrith wrote:...
Could still do with some advice on the spec for Harden grease nipples (have one missing on this bike and 2 on another)
there is this reference about the Harden Hubs on Classic Lightweights
..its elegant curve from flange to hub barrel and Tecalemit grease nipple they are certainly some of the most attractive hubs ever produced.
The 1952 Brown Bros catalogue is a bit too small here go to thumbnails page 36 and then it is on page 168, bottom left
so from my electronic copy of the catalogue
Image
now just hope someone who knows something about these will provide some useful advice.

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hiflange
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Re: Rotrax build

Postby hiflange » Tue Sep 11, 2012 9:21 am

Thanks CS,
sadly classic lightweights doesn't mention size anywhere. I was in O'Connor a few weeks back and went round the obvious places, hub in hand, but no-one had anything smaller than 1/4. I took a fairly inexpensive punt and ordered some 3/16th grease nipples online but they're too big. I guess I'll have another punt and order some 1/8th.

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Re: Rotrax build

Postby Clydesdale Scot » Tue Sep 11, 2012 9:39 am

There is a link on the Classic Lightweights page to a guide on servicing the hubs. it is written by the website administrator. An email to Peter may give you the details and a possible supplier.

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hiflange
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Re: Rotrax build

Postby hiflange » Tue Sep 11, 2012 7:18 pm

Clydesdale Scot wrote:There is a link on the Classic Lightweights page to a guide on servicing the hubs. it is written by the website administrator. An email to Peter may give you the details and a possible supplier.
Yeah, I'd thought of that but the terse note on the home page kinda put me off ... "Please note that the webmaster is not able to give advice on restoring bikes, provide any form of valuation, or to identity 'finds'. If you are unable to find the information you need on this site please try some of the other sites listed under Links"
I'll drop him a line anyway, what's the worst that can happen?

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