Oak Guides for Sled?

[Warren Lake]

going way back, 1/2 baltic birch sled base with Hard maple runners. Hard maple front and rear on the top of the sled. Left the baltic full width so the sleigh would cross cut 4 x 8 's if your runners shrink at some point you keep the sleigh to one side and it still cuts square.

[Jon Grider]

My sled has plain sawn red oak runners. Never had a problem with seasonal movement making them too tight or loose.

[Tom M King]

Another vote for Corian. I still have some special purpose sleds that were made in the '80s that still work fine. They don't get used often, but they still slide nicely.