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Archive for September, 2013

with delta cruiser 700x35c tyres

with delta cruiser 700x35c tyres

I have been finding out first hand that wheel building is a time consuming activity, but not without its own satisfaction. Because I was building up completely different wheels from the originals I needed to measure the hubs and rims, and decide on the appropriate cross pattern in order to work out the new spoke lengths.

The online spoke calculator that I used has given me the wrong lengths, but I’m not sure why. I had also ordered those said wrong lengths which I only found out after completing a wheel.

I am going to have to find a reliable calculator, or at least one I can better understand.

Of course if you are rebuilding exactly the same wheel with new components then you only need to get the same length spokes again or re-use the old ones if they are in good condition … don’t forget to weigh up the cost of a similar pre-built new wheel, to see if it’s worth your time to do all this !

the front wheel radially spoked

the recycled front wheel, radially 36 spoked

The first wheel was the front one, and the ordered spokes were too long for 3-cross. I decided to use a full set of shorter spokes that I already had, which at 287mm were around the right length for radial spoking. Radially spoked wheels ( i.e. zero cross ) are pretty, but only suitable for front wheels because they lack torsional strength and are more stressful on the hub flanges. Hopefully this one can cope with rim braking but as the coaster rear will be the main brake I think they will be all right (touch wood) with some careful initial testing.

622x17 alesa alloy rim

recycled ETRTO 622×17 alesa alloy rim

Spoke crossing refers to the number of other spokes each spoke will cross between the hub and rim, with 3-cross wheels being the traditional norm. The last or outer cross is the opposite of the previous crosses e.g.. over-over-under or under-under-over for 3-cross. This is referred to as interlacing and helps give wheel strength.

The radial spokes turned out to be slightly long, so I had to file the ends down a couple of millimetres flush with the nipple ends so as not to puncture the rim tape and tube later on. The wheel was built with a little more tension than normal, as recommended by some sources for radial spoking, and I fitted eyelet washers under the nipple heads as an extra precaution against them pulling through the rim.

rear hub 4-cross

rear hub 4-cross

The rear wheel turned out to be loose, because the spokes were too long to fully tension for 3-cross. Frustrated, I re-tried for 4-cross and they worked a treat. 4-cross is supposedly the strongest pattern, though there is possibly no real advantage on this particular wheel over 3-cross, apart from using up the extra spoke length.

Also with 4-cross a spoke can interfere with the head of its adjacent partner unless the hub is small diameter, making them potentially harder to remove if broken.

I could have easily messed it up here, but if the lengths are only slightly wrong there is still a chance to line up a loose spoke against the built wheel and get a pretty good idea by eye whether the wheel will work with a different crossing.

I used the Lennard Zinn book – “Zinn and the Art of Road Bike Maintenance” – to learn the basics of lacing, it is a fairly repetitive process once you have worked out the position of the initial spoke in each set.

Therapeutic even, as long as you remain calm, focussed, and are not time constrained … otherwise put the wheel down and finish it at some other point !

park tool tm-1

pretty blue park tool tm-1

The tools I used were a Park Tool SW-7  spoke tool, a screwdriver for the nipple ends and a Park Tool TM1 Spoke Tension Meter. The latter is easy to use, comes with charts and instructions, and takes a lot of the guesswork out of tensioning, though they do suggest contacting the component manufacturers for their correct tension specs. Having a wheel fail while riding is not something to take lightly …

For reasonably accurate final truing I think that a wheel truing jig is almost essential.

park tool sw-7 spoke key

park tool sw-7 spoke key

According to Park Tool, the spoke tensions on each side of the wheel should be within plus or minus 20 percent of the average tension of all those spokes for the wheel to remain stable under normal use. This is not easy to guess by hands alone unless you already have a lot of experience, which of course I don’t.

Even if the spoke tensions are all exactly equal the wheel still might not be true, so fine tuning is generally always required.

Doing one adjustment affects everything else because the wheel components are all interconnected under tension – that’s why wheel building is considered another of the bicycle black arts, and why it pays to go step-by-step and slowly !

It would probably be easier to begin with new (hopefully straight) components for your first build, but with good used parts I suppose there is more freedom to experiment.   Do plenty of research on the subject beforehand, of course.

Happy Cycling !

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Over the past several years the fixed wheel has risen to some sort of cult status in urban cycling circles, but I would argue that it’s the freewheel that has the mystical mechanical properties. I mean, the fixed gear is easily understood from a mechanical viewpoint, having no moving parts – the appeal comes from the immediacy of transmission, its simplicity, and the anticipation needed to survive the many hazards of riding fixed in the ‘real world’ of obstacles, without coming a cropper !

NOS 1/8 inch ball bearings

NOS 1/8 inch ball bearings and the inside face of this freewheel

The freewheel was thus invented a long time ago to overcome the disadvantages of fixed and allowed the magic of “coasting” to enhance cycling’s appeal and safety. ( I defy any cyclist to convince me that coasting isn’t enjoyable and fun ).

Mechanically, the fixed wheel is a “sundial” to the freewheel’s “swiss watch” and, I confess, I had always been a little wary of those two small holes on the freewheel cover cone race. I was content to remove and swap freewheels complete from time to time but had no wish to delve any further within.

Now I have discovered that the most intimidating thing about them is the initial doubt about controlling the huge number of tiny ball bearings contained within and the ease with which said bearings fly in all directions when anything is loosened or reassembled … all the rest is straightforward.

the freewheel body

the freewheel body and pawls

My golden rule is :  ” Don’t touch anything unless there’s a container to catch all the bearings, and even then, make sure there is absolutely nowhere else they can roll away to and hide “.  This will probably still happen anyway !

the pawls removed with their fine spring retainer

the pawls removed with their fine spring retainer

Freewheels spin off anti-clockwise so that the motion of pedalling naturally tightens them, and it’s essential when refitting that the threads be well greased or anti-seize compound applied. They need a fair amount of force “down the track” to release this pedalling tightness. There are so many different removal tools for them that it’s not funny, so you may need the help of a friendly bike shop here. A vice is the next most helpful tool as you can then use the wheel’s inherent leverage to your advantage to spin them off on the vice-held tool.

To disassemble the freewheel itself there are generally two pin holes on the cover cone race that turn it clockwise to loosen, using a pin spanner or strong needle-nosed pliers to assist.

the cog and spacing leaf washers with the cover race left

the cog and spacing leaf washers with the cover race left

I think the rule is that the cone race will tighten in the direction of freewheeling though, as this one’s cover is on the hub side and it is right hand thread ( anti-clockwise to loosen ) – just to trick me again !

Freewheels can sometimes be flood cleaned in situ with light oil down the gap, spinning to make them work again, but often will make unpleasant gritty noises afterward as the dirt crunches through them, which is what happened with this 16T BMX single-speed.

you can see the one-way mechanism here

you can clearly see the one-way mechanism here

Amazing to think that all your pedal power goes through those two tiny pawls …

The screw on freewheel clusters of older ten-speeders are much the same internal arrangement … btw,  they probably should be oiled rather than greased, but I had to use some grease to make the balls stick in place for re-assembly. I will gladly take note of any sticky suggestions here !

you need plenty of balls to tackle this job (teehee)

i must have plenty of balls to tackle this job (teehee)

I’ll try to soften it with light oil, but the freewheel is at least engaging and running quietly so far ( see pic top ).

this is how i got it off - sans tool

and this is how i got it off the wheel – sans tool

The above view is from the “outside” though on most older derailleur bikes it is the pin holes for disassembly that are facing out with a left-hand thread.

Now I’m off around the lake, freewheeling with the wind…

see ya !

see ya !

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Anyone remember the Road Chief ten speed from several posts back ?

No ?

I’m not surprised !  Not a very desirable bike …

as found ...

as found …

But here is the surprise – the frame feels quite light compared with some of my other salvaged frames, and I think it would make a sound base for a semi-sporty single speed even though it isn’t made of anything exotic …

And for some time I’ve been wishing for a wheel truing jig so that I can swap and / or rebuild some hubs and rims for various projects.

I also want to reuse some of the many parts that are building up in the recyclist’s shed, meaning using as few new bits as possible and keeping the cost down..

One of my little jobs a while back was to repaint the frame in rattle can “Hunter Green”, while masking off the nicely cracked road chief decals to keep some history there.

a little better, yes ?

a little better, yes ?

The head tube decal was damaged, so I made a new metal one from some scrap copper, masking it off with clear coat and dipping in sodium polysulphide (sepia toner for photos) to blacken around the “R”, then I clear coated over it again and pop-riveted it to the frame. The back of the rivets needed filing down to clear the fork steerer. The bike is fitted with a new Dia-Compe headset as the old one was shot. Not sure about the gold now though !

all done with a few hand tools ...

all done with a few hand tools … i need to ‘antique’ the rivets yet

I was going to have a go at building a wheel jig, but never seemed to get around to it – ( as you don’t ! ). So I’ve taken the easy way out, being well over trying to true wheels in the frame…and bought this basic Ulix – it came with no instructions but the operation is straightforward and I have some repair books that include wheel building etc.

Upon having a quick play, it is obviously going to be much better than truing in a frame or fork…

IMG_2145

“Project Road Chief” will be a ‘poor person’s take’ on the Pashley Guv’nor – use the search term “path racer”  to get an idea, but don’t worry about the pedantic and opinionated forum arguments about the definition – I just loosely read it as ” all-rounder, single speed, moderately lightweight, cream ‘semi-balloon’ tyres, retro look, relaxed frame angles with inverted ‘tourist bars’ — hmmm.

Perhaps “cycle-path racer” or “cafe racer” would be better terms for such vintage style sports-roadsters …

I plan a caliper brake front and a coaster brake rear, 700c alloy wheels and cream 35c tyres, modern alloy chainset and a leather saddle. I’ve salvaged the alloy rims from my Apollo Nouveau Cross and removed the hubs as they run too roughly. This will be my first attempt to build up a new-recycled wheelset, and that brings me to the very basic but compact Falcon CF-E10 coaster hub, of which I have a couple of salvaged spares. I’m hoping that it is robust enough to perform well as it doesn’t look as finely made as the older coasters.

One of these is on a small wheeled Schwinn ( a salvaged kids bike ) with 28 spokes, unsuitable of course, as the intended rims are 36 hole. The other hub is a 36 hole 20″ wheel but the axle is too short for the spacers needed for 126mm dropouts ( coaster hubs are around 110mm wide ) … so what to do ?

the old innards - note the ususal rusty driver screw

the old innards – note the ususal rusty driver screw

Easy ! Swap the internals with the long axle to the 36 hole hub – well, it sounds easy … but we shall see. Extra spacers should cope with the dropout width as I am fitting small into larger. The issue here will be maintaining a straight chain line for efficiency, which will mean reducing the crank axle width and/or using an offset rear cog. Luckily this hub takes the 3-lug and spring clip Nexus/Alfine style cogs of which I have many examples to choose from ( thanks, Shimano ).

28 vs. 36 holes

28 vs. 36 holes

the overhauled coaster

the overhauled coaster

Another problem with updating the many old ten-speeders I am finding is that the front fork dropouts are designed for wheels having only 95mm locknut width and with skinny 5/16 inch axles. An easy way around the locknut width may be to fit thinner locknuts to a modern 100mm front track nutted wheel – not always possible. Filing the dropouts out for a larger axle could affect safety, so I can’t recommend it – or else one can fit a wider 100mm fork, but that’s  less appealing if it’s an ugly modern non-lugged unicrown type.

the recycled front hub ...

the recycled front hub …

In this case I am going to try fitting the 80s 700c Alesa brand 317 alloy  rim to an old but overhauled high flange steel hub. Many of the old chromed steel rims I find are too rusted to give pleasant rim braking and they are often dented as well, from having being ridden over bumps with low tyre pressure. For recyclists like myself, this often means having less good wheels than good frames on hand, which is another reason why I want to try some wheel rebuilding.

Speaking of wheels, here’s a trick for removing an old BMX 4-prong 40mm ‘Dicta’ brand freewheel without the proper tool – I used some old unidentified pawls from my scrap box and put them in a vice 40 mm apart as shown – put the freewheel on the “tool” – (with the wheel axle, bearings etc. removed first) – face down and turn the whole wheel anticlockwise – it beats a trip to the bike shop to be told “come back later we’re busy” – so there, LBS !

post-removal, showing "tool"

post-removal, showing “tool”

This freewheel is part of top secret “Project Haro” – but that’s another story !

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