21" & 19" Rims

[smartfella]

Can anyone help.

I need  2 rim's.  21" 36 spokes & 19" 40 spokes for an old british restoration.
Any condition as I will be powder coating them.

If you know someone let me know, Thanks.

[murdo]

Are they anything special?
Most Japanese trail bikes have a 21" x 36 spoke front rim, cannot help with the 19" x 40.

[smartfella]

Thanks Murdo.

I will check that out.

[wink]

Itīs not that simple.  Wheel building is an art. In the 1980s I bought 60 used rims from a man who was  a wheelwright. Although they all started off as Dunlop rims from British bikes only 3 of them were the same. 1st you have the hub width, 2nd the offset, 3rd spoke length and angle.
Start with older Nortons and BSA, Separate brake drum and sprocket so the hub is say 4 inch diameter, long spokes but to keep the rim in the middle of the frame the brake drum side has less dish so the nipple holes in the rim are further across the dimple.  Full width hub, equal shorter spokes but a greater angle where they cross so the nipple holes are further round the dimples.
Triumph where the spokes are in the edge of the brake drum, 4 inch shorter spokes on the brake side but deeper dish and bigger angle as above so the rims only go on 1 way round.
very often on restored bikes you see the spokes bent as they leave the nipple because the hole in the rim is punched in the wrong place.
So if you find any usable rims file the holes oversize as you trial build it and put concave washers on the nipple when you do the final build. The oversize hole will allow for the powder coating. I presume you werenīt thinking of powder coating the wheel after it is assembled!
I hope this will start a discussion just in case Iīm wrong.

[john.k]

The Honda trail bikes of the early seventies have nice alloy rims in 36 spoke that fit  British 36 fronts,as they have half hubs and drum brakes.Some British bikes have six or eight different types of spokes in one wheel,inner and outer spokes will have different head bend angles.I made jigs up to dimple and drill rims,using old car flywheels for the division,and an adjustable bracket to hold the punch or drill.One for 40,say 120 tooth ringgear,one for 36,say 144,harder to find.Austin ,I think was one.A lot of "money charging"[dont call them professionals]wheelbuilders do it all freehand,and get an appallingly bad result.How" one size fits all" Indian rims that are sold on ebay go,well we ve all seen bowed spokes on restorations.Do you know which bike has 80 identical spokes?Two I can think of.Regards John.

[wink]

I knew thereīd be someone on here who actually knows how things should be done, if father hadnīt retired and gone to Spain I would have had a go at wheelbuilding.
80 equal spokes? possibly Vincent or brough with interchangeable wheels.
WD norton with sidecar wheel drive?

[cardan]

I love no aspect of the rebuild more than building the wheels. Very satisfying. Beware, though, because once you get good at it your friends start lining up. I have a Millenium truing jig that I've used for years, and recently obtained a Millenium jig for marking out spoke holes. It has a built in dividing head for 40, 36, 32 and 28 spoke holes, plus a means to tilt the rim for different left/right spoke spacing. I suspect the machine it dates from the veteran years (pre-WW1), and was originally designed to punch the holes in the rim, but in its present form I use it with a pointed tool that makes a perfect "centre pop". I have another device that I use with the drill press to get the hole angle correct.

Spokes in most "modern" (1920s on!) wheels use tangential spokes, so the three key hub dimensions are the diameters of the two flanges, and the spacing between them. The dimpling and drilling of the rim must be such that the spoke holes point towards the tangent of each flange (i.e. 3 or 9 o'clock).

Leon

[wink]

I just read in CAR magazine that Ariel patented the spoked wheel in 1870.
Presumably they mean with adjustable spoke length for tension?

[john.k]

 
James Starley,I think.He called the wheel the" Ariel" and fitted it to his "Ariel " bicycle.The  radial spokes were actually U shaped pieces of wire,thru the rim and then bent over to secure in the hub holes on either side.The wheel was tensioned by twisting the hub relative to the rim,done by a single tangential tie rod joining the rim and a rod sticking out of the hub.His partner was William Hillman,whose name would later be disgraced by being used on the worlds crappiest cars.Regards John.

[smartfella]

Got sorted with the wheels. Thanks with the help and info.
Now to find the rest....