The loose dirt on top of the sand just slips under the tire as you climb, similar to climbing in mud or snow. So to go up a hill, lets say you need to put down 40lbs of force to push you up hill, BUT the dirt only needs 35lbs of force to move sideways. Well, you’re going to spin your rear wheel . This happened to me often.
If you have FRESH Terra Speeds and you’re not trying to win’ I’d bring them. If you’re not trying to run 28-30c tires, just go straight to 38c+. I wouldn’t mess with something with a smooth center, you need center knobs; I wouldn’t mess with a textured tire (G-One Allaround; GK SK) as it won’t be able to bite through the dust. . Terra Speeds or Challenge Gateway would good choice for the mixed race. If You need to check the gravel sectors for climbing and braking inclines when considering your choice.
If you’re were going for a fun ride on vacation, without much road, you’d be better served by something light, fat, and knobby like a G-One Bite or Rene Herse juniper ridge (size for the lower pressures/more rubber on the ground and the trails are built on dry creek beds). Braking is also a concern as they decents are -18%. It really is XC MTB territory. Maybe bring an extra knobby tire set in the box with you and return them if you don’t use them.
Also note the BWR trails are ‘hand selected’ with 30c tires in mind, but running 30c tires is for the 150lb dude putting out 350w hitting the climb with some momentum.
Other thoughts: if anyone’s out there on vacay-
- there’s ZERO water out there and the SD weather forecast lies to you (it’ll say 70, but it’s 90 after the first set of hills).
- Sand - bring some lube or something to clean the chain mid ride. Not wax based (prewax = yes)
- There are PLENTY of excellent bike shops down there in Carlsbad/Encinitas/Solana/DelMar/etc, but they may not have your tire of choice.