Constructing bicycle wheels

Applies to all wheels from single sprocket BMX internal gear hubs, child's wheels to external multiple external gear road racing to mountain  bike wheels.

While it's true spare wheels supply a useful amount of donor parts like nuts, axles, spokes making up a wheel from two different wheels hubs and rims has it's fair share of issues.

The main issue with multiple external gearing wheels ( road, commuter, mountain bikes ect ) what is expressed as dished and symmetrical wheels. If you look head on the rear wheels of these bikes ( or any bike wheel ) you'll be able to detect the spokes give the gear cluster sides a noticeable dish appearance while the opposite side spokes are not seen head on making that side look flat inwards. If you look to the rim you notice it looks off set towards the gear cluster side while it's perfectly aligned central between brakes in the drop out stays.

You will also come across gear cluster where the spokes are not clearly obvious looking flat inwards while the opposite side spokes are seen making that side look dished. You will notice even when the rim seems off set away from the gear cluster side towards the opposite side it is still perfectly centred between the rear wheel drop out stays or front forks.

Then there are bikes with both sides looking dished while the rim is still perfectly centred between the drop out stays or front forks. The combinations of the dish like appearances is expressed as dished wheels.

The point is dished one side wheels are off set left or right while the rim is perfectly positioned centrally between the rear dropout stays and front forks.  However you will come across wheels both sides looking flat like while the rim looking perfectly centred in the drop out expressed as symmetrical wheels.

 If we do the math's on this we can count up to six possible combinations of four gear cluster/opposite side combinations, one side dished one side symmetrical both sides dished or both sides symmetrical. All six combinations are designed to accommodate a specific number of rear wheel and front chain wheels ( the peddle crank ) sprockets at the same time maintaining the rim central between the drop out stays.

If a wheel is dished on the gear cluster side the hub flange where the spokes support is angled inward slightly to create the dish effect on that side and straight the opposite side to create the symmetrical side. The opposite is true. If the opposite side of the flange is angled inward slightly the gear cluster side is straight. Where both sides look a bit angled inward is a both sides dished wheel. If both the flanges look straight is a symmetrical wheel hub.

Correspondingly the rims designs and rear wheel drop out designs for each type of hub. If I may use a extreme case if a hub deigned for a dished gear cluster and symmetrical  opposite side re-spoke onto a hub designed for a dished opposite side and symmetrical gear cluster side will create problems the rim will not centralize properly. If there is a wrong angle in a hub flange forces the rim to be off-centered between the rear wheel drop out stays and front forks to much the towards the opposite side. You have a misalignment between the two wheels resulting in slight crabbing of the bike during riding.

The result will be a strain on spokes. Off set to to much the gear cluster side will be consistent with constantly braking spokes on that side. If consistently braking spokes on the opposite side is consistent to off set to much on that side. Careful inspection of the angle of disassembled spare hubs helps identify the type of wheel is often a prudent when intending to build a wheel on them.

Tape measures is a helpfully in determining a dished or symmetrical wheel arrangement. The measure a slight difference of a centimeter or so across both front forks and rear wheel drop outs. The rear drop out widths accommodate room for a variety of rear wheel sprockets and front chain wheel sprocket symmetrical or dish wheels centralizing the rim between the rear wheel drop out and front forks. It also effects the angle of the drop out stays as well. The narrowest rear wheel drop out is a five rear wheel sprocket allowing for either symmetrical of dished wheel allowing room for a double front chain wheel arrangement of typical ten speed arrangement. If there is a triple chain wheel set, room is needed for the third sprocket and symmetrical or dished wheels accommodating for them aligning centrally in the rear wheel drop out stays or front forks of a typical  fifteen speed bike.

More room is needed to accommodate six rear wheel sprockets and either only allowing for a double front chain wheel arrangement ( twelve speed )  or if a triple front chain wheel which symmetrical or dished wheel arrangement accommodates for the three sprockets of eighteen speeds. Lots of room is required to accommodate seven sprockets allowing room only for a double front chain wheel arrangement ( fourteen speed ) or if a triple chain wheel arrangement extra width room is required for the three sprockets (A twenty one speed ) and to accommodate for a symmetrical or dished wheel arrangement.

Tap measures are an ideal tools assessing profile information of any bike frame dimensions specially if there is any wheel rebuilding intentions choosing the right wheel parts suitable. An example the measure the shortest  length of hubs ten speeds and the longest twenty one speed hubs respectively. The length of each hub determines and the symmetry of the wheel determines the the width of both rear wheel drop out and front forks   

They are ideal in assessing the length of spokes required. Knowing the rear wheel drop out width's can help in choosing the right speed, dish or symmetric wheel arrangement suitable fitting the drop out properly of the intended frame.

I I may use another extreme example intensions of converting a ten speed into a twenty one rebuilding the original  ten speed rim onto a twenty one speed hub meant for a dished drop out the twenty one speed hub designed for a symmetrical wheel will off-set forcing the ten speed drop out stays apart to fit mere millimeters from the rear wheel drop out stay possibly even rubbing the wall of the tire not to mention on the rim  brake arms and brake rubbers and will not not fit properly. If you  have a disc brake bike the disc won't fit between  the gap of the brake pad caliper. The opposite effect has the same problem only the ten speed hub forces the twenty one speed stays inward. The bike will only grab as you ride.

You will have problems trying to get the wheel cantered. The effect the rear wheel won't be following aligned with the front wheel the why they should. You'll be riding a crabbing frame wearing out tires unevenly.

There are different number of spokes between wheel issues too. If you count the spokes of wheels that look identical  you'll find one wheel will have thirty two and another up thirty six.

Thirty two, and (but more common), thirty six are common and rare forty spoke wheels will be encountered. Sometimes you'll came across less than thirty specialist high performance weight reduction large diameter skinny racing wheels aimed at sports athletes and forty for back packer tourist bikes in both skinny road and mountain bike wheels. Never neglect to check the same spoke number match in the donor rim and hub when collecting the parts together. Fortunately custom swapping an external donor hub for a internal that will have different diameter flange and the diameter of the donor rim is not critical.

If you don't check the donor hub and rim spokes the same number of spokes holes it will only revel the mistake when you had gone to all the trouble half way though assembling the spokes. That and as bikes come in various speeds influences the final out come of the wheel.

Ten speeds are two front churning chain wheel sprockets and five external rear wheel sprockets  If there is six rear wheel sprockets is a twelve speed. Mountain bikes with only two front churning chain wheels, can have up to seven rear wheel sprockets making them fourteen speed, and if eight rear sprockets sixteen and so on. However mountain bikes commonly have a triple (three) front chain wheel arrangements.

Triple front chain wheels with five rear sprockets is a fifteen speed. Six an eighteen, seven a twenty one, and if eight a twenty four speed. In other words overall, two to the five, two to the six, two the seven, two to the eight, three to the five ,three to the six, three to the seven or three to the eight ratios. In other words two fives, two sixes, two sevens, two eights, and three fives, three sixes, three sevens, and three eights respectively The significance determines the customization of changing rear wheel hub arrangements. The more the rear wheel sprockets the longer the hub fit between the rear wheel drop out stays.

The shortest is a five sprocket hub and the longest is eight. What ever the length hub chosen determines the fit to size between the rear wheel drop out stays. You may find it a helpful  to check the donor hub between the drop out stays before you start striping down the only wheel you have. There is a certain amount of tolerance, but you will be stretching things with an eight sprocket hub between the drop out stays of a five sprocket drop out stay frame. What looks like the same diameter donor rim often turns out to be a different size.

Rim diameter given in imperial inches, range from six, (half foot)  twelve,( a foot)  eighteen (one and a half feet) twenty, twenty four, (two feet), twenty six, twenty seven and twenty eight inch skinny road bike wheels. It is not unknown for one or two rare mountain bike models to be as large as twenty nine. The metric equivalent of the imperial twenty seven and twenty eights is rounded off to seven hundred millimeter (just under three quarter meter) making them look the same diameter at a glance but are a little larger than a twenty six and a little smaller than a twenty seven and twenty eight called seven hundred C. Make sure the donor tire is the same as the rim. A 700C tire is too big for a twenty six and two small  for a twenty seven specially if a twenty eight.

You should be aware twenty seven and specially twenty eight road wheels are no longer produced in favor of a standard seven hundred C which makes the twenty seven and twenty six inch wheels pretty well rare now. If the donor rim is a 700C and the donor tire a twenty six or twenty seven is all your have looking for a replacement either way most new bike show room shop sales personal won't be interested in any technical details other than the wheel size of the different models on the show room floor.

Only a shop with a workshop like environment the second you walk into the door will have experienced mechanic staff serving you that makes all the difference when looking for straight answers. Comparing two tires and rims that look the same size will determine if a seven hundred C or a twenty six or twenty seven inch wheel. After a while you should begin recognize a seven hundred C a twenty six or twenty seven inch wheel when you see one with out comparison. Make sure all your donor spokes are the same length. Fortunately swapping for a different hub you can use the other wheel on your bike  as paten to copy showing you spoke cross paten you follow.

Observing the other wheel you  will observe a spoke crossing the head of the spoke on in the hub flange, crossing another spoke and another and so on. You will come across a variation of crosses. At your local library there are plenty of bicycle repair book with plenty of illustrations illustrating the cross arrangement.

Besides the other wheel of your bike or if you have a spare wheel or two or when ever you get the chance you can observe spoke cross arrangements at bike shops. Which your curiosity doesn't arouses  a shop sales personal to cause any suspicious of what you are up to. You'll find a variety of spoke crossings some only once or twice and others as much as four times. Four crosses are relatively rare for common commuter bikes. Once or twice are professional athlete wheels and crossing four times added strength mountain and back packer bike road wheels. Four cross is the strongest for those who carry a lot of personal gear using their  bikes like donkeys.

The most common is three cross wheel from mountain to common commuter bikes. Fortunately though the rim and hub diameters are not critical. The only result would be a different cross than the original wheels. A  twenty six inch donor rim can be re-spoked with all the spokes the same lengths on any diameter hub. The longer the spokes the more cross for each diameter of rim and vice versa the short the less. For example spokes salvaged from twenty eight inch wheel used as donor spokes will likly turn out to be four cross or  more on a twenty six inch donor rim or salvaged from a twenty six inch rim  will be two cross or less respectively.

It is a mistake to do a work round arranging spokes different lengths because the end result all on one side will give you a different cross one side then the other. This is why to insure that does not happen insure there no odd length spokes what ever lengths of the donor spokes. Investigating the spokes you need for your donor rim at bike shops sales personal in new bike show rooms is not the best pace to ask those type of questions. The sales personal are only interested in the current new bike sales not technical stuff.

They are not a proper workshop personal so either not interested or not experienced mechanics. Only workshop like environment and mechanic personal environment working on all sorts of bikes all day long can answer those questions. A better place are a lawn mower and cycle repair workshop like atmosphere  rather than just observing  a shop with a row of brand new bikes to visit when you see one. Avoid them like the plague. Theses shops won't even have the interest to help you select the right tire let a lone advising you on the right parts for rebuilding your wheel. You see rims come in a variety of widths less than an inch (a couple of centimeters ) for skinny road bikes to as much as a in and a quarter, for mountain bikes. The width of the rim is crucial for the ire.

For example if a mountain bike tire is given as twenty six by two point five means the diameter across the tire is twenty six inches to fit a two and a half inch wide rim. A twenty seven by one and a quarter inches respectively. Failure to observe a width match of a donor tire and rim can lead to constant flat problems. A quarter inch to wide or to narrower has stress consequences on the tire dedicated mechanics will tell you new bike shop personal not interested in that kind of detail hearing your story rebuilding your wheel from dissembled parts of other bikes. The rim width also has consequences between the front forks and rear wheel drop stays.

Don't approach new bike shop personal with a technical issue like that because they are not interested. For mountain bikes they come one and three quarters inches, two inches, two and a quarter,  even two and a half  inches and so on. If you ever do visit a new bike shop just use you discretion observing the width of the wheels on display.

It is important to recognize the technical issue of width of both the rim and tire otherwise you'll have damaging the tire result staying inflated problems. Reading the tire size printed on the tire wall of a potential donor tire for your bike is an indication if the rim width and diameter is going to be a compatible fit. The best bet is to use your spare wheels as a model observing the tire wall specification then with a tape measure, measuring the rim check on both the width and diameter.

The new wheel can cause several new issues that will need to be addressed. If the rim is wider than the original will drag on the rim. If narrower to far away making your brakes feel slack. There is a work round that can be applied in this area when you come to mount the wheel. Simply by re-adjusting the brake from the cable lock nuts on the brake spreading them apart or closer to accommodate a wider or narrower rim often helps solve that sort that sort of problem. Also if this issue isn't addressed will cause truing the rim issues when adjusting the tension of the spokes. If the axle has been dissembled  it is next. There are a few mistakes issues that need to be addressed when refitting.

If you haven't already notice examining the rear wheel axles there is a unthreaded part in the centers. This is an indication of the difference of the different speeds. Take a short unthreaded center. The resulting long threads each end accommodate a, six, seven or eight sprocket hub. ( fourteen to Twenty four speed bikes ). Longer unthreaded centers resulting in short threads each end can only accommodate for up to a maximum of five sprockets.

The distance of the rear wheel drop out is determined by the speed of the bike. Common school rulers will measure  a variation of a few centimeters difference across the drop outs. A 12 speed mountain bike  drop out width will read significantly narrower than a eighteen, twenty one and twenty seven.

For example modifying a twenty seven inch road commuter bike speed into a twenty four speed you will need to re-build a twenty four speed mountain bike hub to the original twenty seven inch rim. Another way to do this is to build an internal gearing hub for the purpose of utilizing the full range of the front chain wheel while keeping the chain at a minimal angle.

The rear wheel stays should be spread naturally as they want or you'll find a very uncertain road handling. 10 speeds in 21 speed frames need spacers to take up the space. If a 21 speed mounted in a 10 speed frame frame replace with narrower lock nuts. If you've disturbed the axle there is a few things you should know. Rebuilding using donor parts from your spare parts bin salvaged from various bikes can degrade your bike handling. Using your other wheel  you can use it as a model to spoke the donor wheel parts.

Observe closely on the hub flange of the other wheel the heads alternate "In out, in out" respectively. Copy the other wheel as a guide when stringing spokes to the donor hub flange. A mistake is to cross a spoke over the head of first cross. The stress often breaks the heads off from the constant torque  pull you apply to the to chain transferred to the hub. Follow the other wheel example by arranging the spoke to cross under the first spoke spoke cross without touching the spoke it's crossing.

On the donor hub flange note each spoke hole has a "V" shape recess in them. It is important to make sure the spoke heads nest in each "V" recess properly or you'll end up continually breaking the heads of spokes. Replacing them you'll only keep snapping the heads again.

Thread the first spoke though a hub hole the spoke head "in" or out" (it doesn't matter which to start) neatly nesting in the "V" of the flange spoke hole. You can tell when the spoke head is flush with the hub flange. Using the rim valve hole as a reference point counting "that" spoke count 5 rim spoke holes along threading another spoke.

Don't maximum tighten the nipple just finger lose. Check the spoke nipples are properly nested flush in the rim by continually holding the hub twisted nesting them in every rim spoke hole. Watch what you are doing  using the other wheel as a guide miss a hole in the hub flange threading the spoke head in the same position the same as the first. Counting the spoke just fitted count five spoke holes in the rim along.

Keep the nipples neatly nested flush in the rim so the second spoke tip flush with it thread a nipple. According to what you observe of the other other wheel hub flange miss a flange hole threading the head the same paten as the other two spoke  head counting the last spoke fitted five spoke holes along threading the nipple. Again when the reach of the third spoke is flush with the rim you have the right angle. Correspondingly miss another flange fitting the head the same the paten as the other spoke counting that last spoke counting 5 spokes holes in the rim along threading the spoke threading the nipple.

Miss another hub spoke flange hole threading the head the same spoke head paten as the other two spokes counting the last spoke fitted counting five along fitting the spoke in the spoke hole threading the nipple. By this stage you should make sure the nipples aren't caching the rim keeping the spokes keeping the hub twisted so all the nipples are always properly nested in each rim hole.

Miss another hub spoke flange hole threading the head the same the paten as the other spoke heads counting the lat spoke fitted counting five spoke holes along. The tip of the spoke should just be flush with the spoke hole threading a nipple. Miss another hub spoke flange hole threading the head the same head paten as the other spokes counting the last spoke fitted counting five along the tip of the spoke just flush with the spoke hole threading a nipple.

Keep making sure the the other spokes are nesting the spokes in each spoke hole properly by keeping the hub twisted. Miss another hub spoke flange hole threading the head the same the paten as the other spoke heads counting the last spoke fitted counting five along the tip of the spoke just flush with the spoke hole the the spoke threading the nipple. Repeat with the next spoke and so on till you have come full circle round the rim. In the hub flange you should have a spoke hole between every spoke head. Now you will be filling in the spoke holes between each head in the hub flange according to the other wheel.

This is where the spoke cross comes into the picture. Using the other wheel as a model to work with using the valve hole as a reference point thread a spoke head  opposite the spoke heads of the spoke already fitted. Counting that spoke count 5 spoke holes in the along.

Keep the nipples neatly nested flush in the rim the tip of the spoke just flush with the rim spoke hole threading a nipple. Don't think maximum tightness. Just finger loose only To gain experience keep an eye on the other wheel as a guide insetting another spoke in the hub flange opposite head paten as the other spoke heads exactly like that wheel. As you fit the spoke  Counting that spoke counting fiver spoke holes along it will cross the head of the first fitted, angled crossing another and a third one the tip of the spoke just flush with the spoke hole threading a nipple making sure the spokes neatly nested crossing the other spokes. By this time you should have a uniform number of crossings.

Correspondingly fit another spoke counting. that spoke counting five along lining up the spoke flush with the spoke hole, angled crossing the other another spokes, the tip of the spoke just flush with the spoke hole threading the nipple and checking the spokes are neatly crossing. Correspondingly fit another spoke making sure it is inserted head opposite the first spokes you fitted counting that spoke counting 5 spokes holes in the rim along it will cross the head of the third you fitted, angled crossing another and a third one, the tip of the spoke just flush with the spoke hole threading the nipple keeping the spokes neatly crossed.

Make sure the nipples aren't caching the rim keeping the spokes properly nested in each spoke hole keeping the hub twisted so all the nipples are always properly nested. Again repeating the procedure fit another spoke making sure it is inserted head opposite the first spokes you fitted counting that spoke counting 5 spokes holes in the rim along that this spoke will cross the head of the fourth fitted, angled crossing another and a third one, the tip of the spoke just flush with the spoke hole threading the nipple the spokes are neatly crossing they should.

Repeat with the next spoke and so on till you have come full circle round the rim. There one side is finished. Comparing the hub of the other wheel is double checking your work making sure every head in the flange ends up exactly like it. Every spoke head should be opposite way to each other just like the other wheel. By the time assembled you'll have a head "in" the next one "out", the next "in" the next "out" the next "in" the next........  round the flange respectively. When you have completed that side you can start on the other side. Use the valve hole as a reference point repeating the same procedure using the other wheel helping you double check you work.

Once you've finished the whole wheel do not tighten any spokes at this point. Make sure the rim is wobble loose on the spokes. Now we are ready to true tightening the spokes using the brake rubbers as a guide.

Using the brake rubbers as a guide is very tricky. They need spread apart evenly not uneven because uneven brake rubber be off center causing rim truing problems. You need to be aware of the brake rubber spread. Depending on whether you are left or right handed you'll find the best viewing angle to observe both sides of the rim moving round with a even gap between each side of the rim.

Turning your attention back to a couple of spokes away from the spoke between the brake rubbers fine tune only turning no more than a half turn observing the rim between the brake rubbers. From the bike upside down point of view do the same with the spoke on the opposite corner (top of the wheel) spoke only a half turn observing the rim between the brake rubbers. Do this as you move the rim round observing the rim move between the rubbers. At this stage you should be fine tuning. If you haven't created a dip in the various parts of the rim you should never need maximum tightness to adjust the rim movement. Only firm tighten will be more than enough.