Make each spoke from a riven (split, not sawn) billet of oak or hickory, shave it to a tapering rectangle about 4-5 cm by 2.5-3 cm at the middle, cut a rectangular tenon on the hub end and a round tenon on the felloe end, then drive it into its mortise with a heavy mallet. For a 120 cm wheel the finished spoke is about 52 cm long, and a loose spoke is a failed wheel.
Part of Wheelwright Craft
A wheel spoke is a seasoned, grain-straight wooden strut with a tenon at each end, which carries the load between the hub and the rim.
Splitting Follows The Grain That Carries The Load
A spoke is loaded along its length, and a spoke whose grain runs off at an angle to its axis breaks where the grain runs out. A billet split out of a log (riven) follows the grain wherever it goes, so the grain runs continuously through the finished spoke. A sawn spoke can cut across the fibres, leaving a weak plane. The parent article makes the same point.
What You Need
- Billets of seasoned oak or hickory, 1-2 years air-dried, split, plus a spare or two (Wood Seasoning)
- A froe or wedges to split, and a mallet
- Drawknife, spokeshave and a shaving horse for the shaping (Spoke Shaping)
- A trial mortise or the real hub, to test tenons (Hub Construction)
- A heavy mallet for driving
The Length Of A Spoke
The carrier specifies a spoke 4-5 cm by 2.5-3 cm at the middle, tapering slightly toward both ends, and the tenons: a rectangular hub tenon 3 × 5 cm and 5-6 cm long, and a round felloe tenon 2 cm across and 4 cm long. For a wheel 120 cm in diameter (an assumed example), with a felloe 5 cm deep and a hub radius of 12.5 cm at the mortises (both assumed):
- Radius of the wheel = 60 cm
- Free length between the hub surface and the underside of the felloe = 60 - 5 - 12.5 = 42.5 cm
- Total length = 42.5 + (5 to 6 cm hub tenon) + 4 cm felloe tenon = 51.5 to 52.5 cm
So about 52 cm, which is close to the 50 cm length assumed for the dish arithmetic in Engineering Principles. Make a test spoke first and fit it dry to the hub and a felloe, then copy its length.
Method: Billet To Fitted Spoke
Step 1: Split Split a log into quarters, then eighths, then individual blanks slightly larger than the finished spoke. Choose blanks whose grain runs the length of the piece, and reject any that run out at the edge.
Step 2: Shape Shave to the finished profile (Spoke Shaping).
Step 3: Cut the tenons Cut the hub tenon to match the mortise and the felloe tenon round, as above. Leave a shoulder at each tenon so the spoke seats against a flat face.
Step 4: Fit a trial Try each tenon dry in its mortise before driving. It should enter by hand to a depth and then need firm taps.
Step 5: Drive Drive the spokes into the hub in the order described in Driving & Fitting.
Common Mistakes
- Sawn billets with run-out — the spoke breaks at the exit of the grain.
- Green billets — the spoke shrinks after it is driven and the tenon goes loose.
- Loose tenons — shim with a hardwood veneer glued to the tenon before driving; the carrier is firm that a loose spoke is a failed wheel.
- No spares — a split spoke at the last step stalls the wheel; split two extra.
Safety
Splitting and shaving tools
A froe struck with a mallet and a drawknife pulled toward the body are the commonest injuries in green woodwork. Hold the froe by its handle with your free hand clear of the blade path, use a shaving horse to hold the work, and keep the drawknife’s edge pointing away from your legs when you rest it.
What’s Next
- Learn next: Spoke Shaping — the drawknife work in detail
- Combine with: Felloe Construction — the rim the spokes carry