Wheel Building: the Musical, Part II

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As I have written before, wheel building is now considered an optional skill for most cyclists.  However, if you ride a vintage or custom bike, or enjoy doing your own wrenching, acquiring the knowledge to build your own wheels can prove invaluable.

Vintage bicycles often need a replacement wheelset of the same era, which requires sourcing period hubs and rims.  Or, the original wheelset may need an overhaul, with new spokes.  Because older bicycles have narrower rear drop outs compared to modern bicycles, learning to build wheels can help you complete a restoration project that would otherwise be impossible, as new rear hubs generally cannot be used for older machines.

Serving as the inspiration for this post, the rear hub on my winter bike needed to be replaced – a Quando/Quanta hub whose cartridge bearings had failed.  The wheelset is one that I previously built and served as the platform for “Part I”.  To replace my failed hub, I ordered a new Velo Orange Grand Cru 126mm hub with freewheel threads and 36 holes – exactly what I needed to complete my task.

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Materials and tools needed.

First of all, let me say that there are excellent resources on the web and in print for anyone who wants to learn how to build bicycle wheels.  Many years ago, I built several wheels on my own, with no classes or any training, by following Sheldon Brown’s wheel building guide and using Jobst Brandt’s book, The Bicycle Wheel, as a technical resource.  Those wheels are still perfectly true and in service.  So, if you are methodical, patient, and not drinking or smoking anything while building the wheel, you may be able to be a completely self taught wheel builder.  However, I also later took several wheel building classes which helped with those little tricks and tips that only an experienced builder can show you.

I can’t say enough about Sheldon Brown’s online wheel building guide.  In it, you will find an overview of the process, a list of all the tools and materials you will need, and an easy and non-geeky step by step process which can instruct novices and experienced wheel builders alike. And, it is a free resource.  I printed out my copy years ago, but checking the link recently I see that it has been updated with new information.

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Spocal spreadsheet for VO Grand Cru hub and SunRims CR 18 rims.

Before starting you need to determine what length spokes will work for the hub and rim that you have selected.  You will need to take some key measurements off the hub, unless you are able to locate your hub in one of the on line spoke length calculators available.  If you are using a vintage hub, Sheldon Brown, again, has a helpful resource which shows you how to measure the key elements of your hub.  The VO hubs that I am using for this example, though modern, were not included in the Spocalc spreadsheet data base – which is a great tool developed by Damon Rinard.  Fortunately, VO’s website gave me all the measurements needed, so I plugged those numbers into the spreadsheet, as shown above, and that yielded spoke lengths of 260mm for the non drive side and 258mm for the drive side (for a dished rear wheel, the non drive side spokes will always be about 2 mm longer that the drive side spokes, due to the greater distance they must travel).  You will also need to take measurements from the rim you will be using.  If it is a vintage rim, it will not appear in data base of the spoke calculator you decide to use, so you’ll need to measure the effective rim diameter.

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Spoke Prep Instructions – not to be ignored!

I always use 14 gauge spokes (butted or straight depending on the application) and 2mm brass nipples.  Generally, I use DT spokes and nipples, which have a good reputation for reliability and strength.  The spokes, which are always under tension, need to have their threads treated with something that will act as a lubricant, and ultimately as a thread locker.  I use Wheelsmith’s Spoke Prep.

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You must follow the Spoke Prep instructions and dip your drive side and non drive side spokes into the solution, and then let it dry completely.  Since I was working outside to build this wheel, I put each set of spokes on a separate chair.  Drive side and non drive side spokes must not be allowed to mingle!  And it’s best to separate each spoke after dipping it into the Spoke Prep solution, so that when it dries you won’t have to separate it from the other spokes.  The above photos show the spokes before I have separated each one to dry.

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I haven’t invested in any high end spoke nipple drivers or spoke wrenches.  I use Park spoke wrenches, plus a square wooden handled screwdriver with a straight blade that I have filed slightly to a point, so that it will contact the spoke nipples with more gusto.  And, the square handle of the screwdriver makes for easy manipulation of the spoke nipple.

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The Key Spoke

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Setting up the Key Spoke for my hub and rim.

The night before, I got out the hub and rim to select the location of the Key Spoke.  By setting up the Key Spoke correctly, the hub’s logo will be visible by peering through the valve hole, and there will be no crossing spokes above the valve.  Setting up the Key Spoke correctly is the mark of a mindful wheel builder.

I used a water soluble marker to indicate which hub hole and rim hole were to be use for the Key Spoke (which I will later clean off). In my case, the SunRims CR18 rims were set up so that the Key Spoke hole was 2 holes to the right of the valve hole when looking at the rim from the right hand side.  The Key Spoke is a trailing spoke, meaning that it angles backwards from the hub when you look at it straight on.

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I lubricate the spoke nipples with a drizzle of automotive oil.  This helps the spoke nipples seat against the rim eyelets and move around as needed while you are bringing up the tension on the wheel.

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My VO hub looks very nice – it came packaged in this elegant black draw string bag.  A touch of marketing finesse. The hub is cold forged and then CNC machined.  Hopefully, the cartridge bearings were installed correctly and will last for many thousands of miles.  I wear protective gloves for the initial spoke installation.  Spoke Prep and automotive oil are bad things to have going into your skin.  Later, I’ll take my gloves off for the truing and tensioning process.  The night before wheel building, I re-read Sheldon and Jobst’ guides.  Since I don’t build wheels every day, it is important to refresh my brain with an overview of the process and of the physics and engineering concepts involved.

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The photo above shows the trailing spokes, which are inserted from the outside of the hub shell.  You start with the drive side spokes first (after inserting the Key Spoke), then move on to the non drive side.  Then you twist the hub clockwise as far as it can go.  The above photo shows my wheel after inserting the trailing spokes and twisting the hub clockwise.

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Now it is time to install the leading spokes.  These spokes are inserted from the inside of the hub and angle toward the front of the bike.  In a 36 hole 3 cross pattern, the leading spokes cross over two trailing spokes, and then are laced inside the 3rd spoke before securing them to the rim

Once that is done you have laced your wheel.   That is actually the hardest part of this process.  Now it is time to begin bringing up the tension on the wheel so that it can be trued and dished.

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A source of comfort is seeing that you have installed the Key Spoke correctly and can not only see the hub logo through the valve hole, but you can also see that the valve hole has no crossing spokes above it.

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Park Tension Meter

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Optional equipment

You should now gradually tighten all the spokes so that their overall tension is equal.  I follow the musical note method, by plucking the spokes, and bringing them all up to the same level.  Then it is time to true the wheel, then check for radial (up down truing), and check for proper dishing.  For this particular wheel, the wheel tension came up much quicker than expected, so I ended up backing down the spoke tension after checking the maximum tension for this rim. I use the “musical note method” to check spoke tension, but I also reference my spoke tension back to the rim OEM manufacturers specs, if those can be found.  If not, take your tension meter and check other wheels on hand (being mindful that rear wheels and front wheels may have different spoke tension, and that smaller diameter wheels will have higher tension).  If you have handled a lot of wheels, you’ll have a feel for proper spoke tension that will be confirmed by using a Tension Meter or a musical note.  If not, don’t panic. Rims can tolerate a lot of variance in spoke tension.  Mainly, you want to true the wheel, laterally and radially, and bring it into dish.  And, it is critical that you relieve spoke stress by mashing the heads of the spokes against the hubs and by pulling pairs of parallel spokes against each other.  Also, when you tighten spokes you need to be mindful of spoke wind-up – which happens when the spoke twists instead of the nipple threading into the spoke threads.  You can do so by holding a finger over the spoke while tightening to feel for this, and then backing off your effort slightly to unwind the spoke.

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Velo Orange 126 mm hub on SunRim CR 18 rims, 36 holes.

Now my wheel is built and its time to install the rim protector.  I always use Velox rim protectors for rims with double walls.  Be careful not to use too wide a size, as that will prevent the tire from seating correctly. Now, I look forward to installing the wheel and getting back out on the road.

Quando/Quanta Hubs Long Term Update

Quando/Quanta hubs

Last week, while getting ready to climb a steep section of my route home, I vigorously shifted into my lowest gear while riding my 1987 Panasonic MC 7500 winter bike.  That resulted in my chain over-shifting and falling into the spokes.  Uh oh!  It took about 15 minutes for me to dislodge the chain and ride home, after turning the bike upside down for diagnosis and repair.  I had to remove my Paul’s chain keeper in order move the chain, as it had gotten wedged between the chain keeper and chain ring.  Still, I wasn’t worried because I stopped the bike the minute this occurred, and didn’t expect that I had done much damage.

I had built this wheelset about a year and a half ago using Quando cartridge bearing hubs, laced to SunRims CR18 rims. For the few weeks preceding this mishap, I had been hearing a clunking noise in the rear of the bike, occurring while pedaling and coasting, but louder when riding at speed.  It took a while for me to clue in to what the noise might mean.  At first, I thought it was the saddle rails or seat post, because I only heard it when working hard at accelerating. But then I began hearing it while coasting.  Then I thought it was the replacement freewheel I was using – perhaps the freewheel cover plate was coming loose and the body was clunking around.  Bicycle noises can be maddening to diagnose!

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Spoke damage.

When I finally had time to get the bike into the shop stand, I was saddened to see that the chain had damaged all the drive side spokes in my little mishap.  Doh!  Good thing I checked.  So, I proceeded to disassemble the wheel, all the while wondering whether I had the right length replacement spokes (that’s why you always buy extras…), and questioning whether I was up to a wheel building experience on this nice sunny afternoon.

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Once I had the spokes out, which I removed very slowly and methodically (spokes under tension are dangerous projectiles), I examined the hub body.  It looked pretty good.  Okay, let’s build the wheel again with some new spokes.  Fortunately, I had 9 spokes on hand of the exact length needed.  In a sort of thoughtless way I began turning the hub axle, perhaps in an attempt to delay the inevitable.  That’s when I heard a strange grinding/clicking sound.  I held the hub close to my ears to listen further.  Finally, the sound stopped, but was replaced by a very tight spot when turning the axle of the hub.  Very tight.  Not normal!  The source of the clunking was now illuminated.  But, what to do?

I could attempt to diagnose the cartridge bearings, or I could try to find the right rear hub with 126mm rear spacing (mission impossible?).  The latter turned out to be the best course of action.  Velo Orange sells a 126mm rear hub with freewheel threads and 36 holes – just what I needed.  Mission accomplished.

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Meanwhile, I removed the dust covers on the Quando hubs.  Perhaps with this winter’s especially rainy and muddy rides, bad stuff had made its way into the cartridge bearings and could be simply cleaned out.

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No such luck.  The bearing grease (which has been removed in the above photos), was pristine.  Undaunted, I decided to clean the bearings and re-grease them, to see if by some chance that would change the hub’s tight spot (which was illogical of course).

The bearings on these Quando hubs are either bad, or not properly adjusted, or the races and cups in the hubs are damaged.  Cartridge bearings do not work in the same way as cup and cone style bearings.  The latter’s adjustment is achieved by the correct position of the cone against the cup, something most experienced mechanics can do easily.

Cartridge bearings are engineered differently.  The preload adjustment is done by the factory when the bearings are pressed into the hub.  If it is wrong, correcting it can be a problem.  A cartridge bearing hub’s races can also be damaged by improper installation (or removal).

While it may be possible to have these hubs diagnosed and repaired by a mechanic with the right equipment, the cost to do so is not justified here (throwaway technology strikes again).  Now, I will try to look forward to rebuilding the rear wheel with my new VO hub, when it arrives.  The front hub spins just fine and has no issues, for now.  But, given this experience, I will plan to monitor it in the future.

It’s Not Me, It’s the Bike

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These are the words I say to myself when I am riding especially fast.  Or especially slowly, as of late.

This winter I have been using my Panasonic MC 7500 winter bike as my primary commuter, which is a change from past winters, partly driven by this winter’s wet and colder conditions which heralded the onset of a typically Portland rainy season last November.  Very recent winters have been gloriously warm and dry, so my choice of commuting vehicles was vastly expanded and even included scooter rides in the dead of December.  But, not this winter.  Portland is back to typical seasonal weather which can include anything from 35 degrees and raining hard, to light sprinkles in the lower 50’s (like today), and the occasional freezing rain and snow.  The short days also come with twilight seeming to descend in apocalyptic fashion in the middle of the afternoon.

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This bike was actually quite the machine in its day – the top of the line Mountain Bike in Panasonic’s line up in 1987.  It is built with Tange Prestige Cro-Mo double butted tubes, with forged drop outs and chromed chain stays.  The geometry on the smaller frame that I am riding features a slack 70 degree head tube combined with minimal fork rake, which would normally make it less than ideal for commuting, but its long wheelbase (107 cm) makes up for the higher than ideal wheel flop.  Consequently, I can usually avoid putting my foot down as I approach red lights and four way stops.

I bought this Panasonic as a frame and fork, then built it into a city commuter.  It went through various iterations, and now is set up for maximum comfort and utility.

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I was using a Shimano grip shifter and a 6 speed cassette, but after a black ice crash in 2012, the shifter broke apart (because it is made of plastic), so I splurged on a $7 no name friction shifter, made of good old steel.  That meant that I could install a 7 speed freewheel, and increase the bike’s gear range a bit.

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I had been using these UNO city bars, pictured above, but the shape and width did not agree with my anatomy, so I swapped them out for a vintage steel Northroad bar.  This bar is a great improvement in comfort, being narrower and putting my hands and shoulders in a much more neutral position, and increases the bike’s un-coolness factor by a few thousand degrees.

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Steel Northroad bars

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Further agitating bike snobs in Pdx, the Panasonic is sporting a duct tape rear fender repair job, and a ghastly kickstand.

The kickstand is a convenient accessory, and this design is useful for any bike where mounting in back of the bottom bracket is not an option (in this case due to the U-brakes residing there).  The stand is adjustable to any wheel size, and keeps the bike secure, even when I have my bags loaded up with groceries.

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I like using these Jandd Hurricane bags, which are aptly named and can handle just about any kind of weather.  Their vibrant colors augment my winter bike’s 1980’s color scheme, and add a lot to its visibility.  If you haven’t used Jandd bags, you are missing out on the ultimate in practicality and quality.  I have a set of Jandd panniers that are 30 years old, and still look new.

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The Panasonic MC 7500 is a bike that enthusiasts have embraced, but the frame does have its downsides – one of them being that on some builds, holes drilled in the seat stays (necessary to allow heat to escape while brazing), were actually drilled very close to the seat stay attachment.  Fortunately, on my frame, the holes have been drilled near the dropouts.  Unfortunately, the seat stay holes have caused a stress riser to appear on this cyclist’s bike.

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Paul’s chain keeper for my 1×7 drive train, with vintage Peugeot branded crankset.

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Specialized Nimbus Tires. Never a flat in six years, and the exact opposite of supple side walls.

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Possible stress crack

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After sanding to remove the paint, no stress crack visible.

On my own frame, I had concerns about the paint cracks which had developed near to the U-Brake braze-ons on the chain stays.  Whenever you heat the tubes to braze, there is a danger of overheating and weakening them. Since the frame was already cosmetically challenged, I had no qualms about taking my emery cloth and sandpaper to this area to see what lay beneath the cracked paint.  Fortunately, nothing at all.  But now I can monitor this area.  I will paint it with Testor’s clear paint so that I can watch for any future changes.

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SunRims on the wheelset I built for this bike – holding up okay but the sidewalls have been scored by my too hard brake pads.

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Offending hard pad on the U Brake – showing no wear which is a bad sign. Meaning that my rims have suffered instead.

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Repair job on the broken fender attachment.

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Repaired fender bracket.

While I had the bike in the shop stand, I decided to do a full tune-up.  I washed the wheels (a new wheelset which I built last year, and which are working well), picked rim material out of the brake pads, sanded the rear ones, replaced the too hard original Tektro pads which had messed up my new rims, and cleaned and lubricated the SunTour freewheel (more on that, below).  I repaired the broken fender attachment by rummaging through the parts bin to find a reasonable facsimile with which to repair the broken bracket.  I drilled a new hole through the center of the fender, and installed the new bracket.  Hopefully, it will survive and thrive.

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New front Kool Stop pads – replacing the original Tektros which badly scored my new rims.

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But now, to my chagrin, my newly cleaned and lubricated 7 speed Suntour freewheel is making very odd grinding and clunking sounds.  I have always loved Suntour freewheels, and have never had one fail on me.  After doing some research, Sheldon Brown (RIP) came to the rescue.  He described a situation similar to mine, where my newly lubricated freewheel began sounding clunky under load, and noisy while freewheeling.  I believe the problem may be a loose cover plate.  Meanwhile, I have a fun old Atom 5 speed freewheel from the 1970’s with English threads which I am going to install while I troubleshoot the beloved Suntour. The higher geared old Atom freewheel should make me ride even more slowly.  But, as I said before, it’s not me, it’s the bike.

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28 lb machine ready to hit the road.