The mad antics of the Knights of Mayhem inspired me to do some research into pre-1600 lance construction. I doubted that they used 1 5/8" hemlock dowels, and my suspicions were justified. What they did use was complicated.
Ash, Beech and Pine are all mentioned as lance materials in pre-1600 sources. Chretien de Troyes, writing in the 12th century, often described ash lances. Luis Zapata, a 16th c. Spaniard, recommended pine lances as superior for jousting to beech or ash, "because using lances of ash or beech for jousting (which when all is said and done is a game) among friends would be a cruel game indeed; and lances made of those woods are for enemies." Fir was also used. Compared to ash, pine and fir were lighter and allowed a thicker lance for the same weight, improving stiffness. Lances for Rennen could be 7 centimeters thick and those for the Gestech could be 9 centimeters thick at their greatest diameter.
By the end of the 15th c. hollow lances were in use in Italy. For the same weight a hollow lance could be thicker than a solid one, improving stiffness, or a lance of the same diameter could be lighter, or some combination of the two. Philippe de Commines described the Italians at the battle of Fornovo using hollow bourdonnasses that were "no heavier than a javelin, but well painted". As that example shows, they were used on the battlefield as well as within the lists.
Chastelain's Chronique de Jacques de Lalain describes Lalaing jousting with bourdons that were "marvelously long and thick." Their construction is not specified but it seems very plausible that they were hollow.
The hollow lances like VII.550 now in the Royal Armouries, seem to have been built up from staves like a barrel and then turned. The Brandon lance was made up of four pieces. At 20 pounds, it is heavier than many solid lances. The hollow lances at the Tower ranged from 1.4-.8 pounds a foot of length, compared to .5-.4 pounds a foot for the surviving solid lances. Here is another photo of a VII.550.
Here is a photo of, from left to right, VII.634, VII.551 and VII.550.
Here is another photo of VII.551, now in Leeds.
Here is more on the lances from the Tower:
Viscount Dillon's Nos. 1&2 are VII.550, 3&4 seem to be VII.551, and 9&10 appear to be VII.634.
Commines reported an exceptional number of bourdonasses collected after Fornovo, discarded by the Venetian man-at-arms in their retreat. At the same time, he treats their construction and lightness as remarkable.
Polish and Hungarian hussars also used hollow lances on the battlefield: the hollow construction allowed their lances to be unusually long, at the cost of reduced durability.
This site has more on the Hungarian and Polish hollow lances, including the detail that the lances were hollow only from forward of the grip to the tip, which would move the balance point closer to the grip. A wooden ball forward of the grip resembles the knobs on pilgrim's staffs or bourdons, and may explain why hollow lances were called bourdonnasses.
The Polish lances were made from fir or aspen shafts that were split, hollowed, and glued back together, and reinforced with cord or twine wrapping.
Cesar d'Evoli, writing in 1583, described and disparaged the Hungarian hollow lances for their fragility, although he admitted their greater reach was an advantage. In contrast, he praised Italian solid lances as less likely to shatter.
The Arabic writer Al-Jāḥiẓ, writing in the 9th century, wrote that the Turks at that time favored short hollow lances "and short hollow lances have greater penetrating power and are lighter to carry."
Here is Galileo on hollow lances:
For any given weight, length and wood, hollow lances were stronger. They were also required more labor to construct, so that virtue came at a price. Viscount Dillon's article noted above indicates both that hollow lances were used in Tudor England and that solid lances were used as well, and were at least as common in the weapons that survive.
I conclude that hollow lances in the 16th century were common among two groups:
1: Lancers, typically the hussars of Poland and Hungary, who were expected to use a lance that was unusually light for its length to gain a reach advantage over opponents.
2: The wealthiest men-at-arms, willing to pay a premium for a lance that they might use in the lists or on the battlefield that was either stronger or lighter than the simpler solid lance used by their peers.
Giovanni dall'Agochie, writing in 1572, recommended a lance in two pieces for practice. The lower part was some four feet in length, the end of which was fitted halfway into a soldered metal tube nine inches in length. The other piece forming the sharp end of the lance was six feet long and fitted into the other half of the metal tube, which was painted to match the rest of the shaft. Presumably, most often the fore piece would break, so the two piece lance would avoid replacing the entire lance for each break.