Continuing from my previous post, my spokes finally arrived and I was able to start to lace up my drum brake wheelset for my Raleigh Superbe. I decided I had had enough of rod brakes which just seemed outright dangerous in the wet, they have a tendency to not work at all in the wet and when they do work their modulation is atrocious if your rim is out of round radially - they tend to pulsate as imperfections in your rims cause the brakes to grip harder. Also I wanted low/no-maintenance as well as a modern 3.0w dynamo; the Sturmey Archer AG currently on it only supplies around 2.0w or thereabouts. This is the fourth or fifth wheelset I have built now, so I think I'm slowly getting better at figuring out spoke length because this time it was bang on correct front and back, in the past I have got them a little too long and have needed to grind the extra spoke from the backside of the nipple otherwise they would puncture the inside face of the tube when inflated.
The picture above shows 6 spokes laced up to give test the spoke length, which I learnt from this book, it allows you to put a little bit of tension on the wheel. I've found it's pretty accurate however you just have to keep in mind that once you have all the spokes on you will get more tension and thus slightly longer spokes.
When I got the X-RD3 in the mail I also ordered a Mk III indicator rod to go with it, for some reason I couldn't thread it into the axle key, I spent like about an hour or so trying desperately even resorting to spraying some WD-40 up there to clear gunk with no result. To this end I figured I'd have to pop open the hub and have a look, I thought maybe there was a broken or stripped thread or who knows what. Anyway it all looked fine and I was able to thread it in fine once I took it apart. I now know that the axle key must have moved out of place because I loosened the bearing cones too much and it must've shifted out of place.
I'll have to tear it down later to clean it out and refresh the grease once I get the proper Sturmey Archer grease, the factory uses a very thin grease (rated at NLGI #00 for those who know what that means) which stops the pawls from sticking in cold weather and is thin enough to lubricate all the internals by capillary action. The newer style hubs are different because they don't use thin oil like the older units; from what I gather the grease means you don't have to add oil every month or so but will need to be replaced ever few years according to this article. Because I sprayed a bit of WD-40 up there which mixed with the grease I'll need to do it anyway, but I'll have to order the special grease first.
|the indicator rod fits fine!|
It was interesting to pop open one of the later hubs to see the difference as I'm only really experienced with the older hubs, and then only 70's era AW hubs. The Sturmey Archer storey is really interesting, their origins, rise, decline and then resurrection by Sunrace is written about here, it's really quite tragic as they started out very innovative but were so starved by their company parent Raleigh of funds which forced them to design products which were good for their bottom line but not for improving their hubs.
Sturmey Archer's most ubiquitous and famous hub is the AW model which is solid and reliable but not without it's fatal flaw, between normal and high gear there is a neutral, most users will know of this when the hub is a little bit out of adjustment the pedals will just spin when pushed on with no connection to the drivetrain. This wasn't always the case with their hubs however, originally their early 3 speed hubs defaulted to the low gear when there was no pull on the indicator rod, and there was no neutral position, the AW introduced this "feature" as a cost cutting measure as well as defaulting to high gear.
Going forward in time, since the sale of Sturmey Archer to the Taiwanese company Sunrace in the early 2000's they have been making somewhat of a comeback. The current crop of hubs feature a new clutch design which was derived from an older Sturmey Archer design from the 80's that never saw the light of day, schematic drawings here. You can clearly see the different design of the clutch which has ramps to prevent disengagement in high gear as well as eliminating the neutral position. The X-RD3 I have features this type of clutch which you can see pictured above, I'm quite impressed by the insides. Compared to the AW's I've opened up the machining on these modern hubs is a lot more precise, the pinions and all the internal parts are a lot beefier generally.
|The driver now has it's own pawls which you can just make|
out under the grease
Back to the build now, I managed to realign the axle key and found the indicator rod threaded in perfectly, so I slipped the unit back into the shell and put it all back together, more or less ready to go now. Now to start on the front wheel, the XL-FDD is a big boy, the flanges are about 110mm in diameter and it weighs 1350g by itself. The spoke holes are made for 13g and 14g spokes, I found them a little big but they fit the spokes I had fine without the need for brass washers. I used DT Swiss Competition double butted spokes, I would have preferred to use straight gauge because they are cheaper but they didn't have one length in size and it was only £10 more so I just went for it. I would ideally liked to have used the DT Swiss Alpine III triple butted spokes but they didn't have them in the lengths I needed.
All the lacing is now done and they just need to be tensioned and trued. I'll probably do this in a few days when I can do it on the Raleigh itself, I'll need to spread the forks and file out the dropouts to get the front to fit. I'll probably do this on boxing day when there's nothing else to do, stay tuned for more updates...
Part 2 continues here...