Ok, so this morning I drove the bike course from Castaic Lake to Pyramid Lake. And this is the elevation profile:
Start Elevation: 1,214ft
Max Elevation: 2,953ft
Elevation gain: 2,451ft
Notes:
There was a gate 2.5 miles before the actual turn around point.The section from the 8th mile to the turn around point will be done twice. 
Me likeee! Bring on the hills!
soooo bring the roadie?
I say tri bike…it’s only 2500 ft of climbing over 56 miles. Most Ironman course are double that climbing if not more.
im looking at it though and it seems so up and down up and down
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Agreed, but it is hard to tell from those elevation profiles what the course is like. I did Silverman in Nov 08 and that course says 10,000 ft of climbing over 112 miles. I am glad I had my tri bike that day…but then again I dont think it would have made a difference what bike I had…a horrible day even if there was a tail wind the whole way. I have a friend that always does the Auburn 1/2 Ironman, which I believe he told me was almost 6,000 ft of climbing for 56 miles. He has told me every year he sees more and more tri bikes and everyone leaving their roadies at home. Either way you need to be comfortable with whatever bike you bring.
i live close enough to head up there and just ride the darn thing, thatd be my best bet to find out.
The thing is that it’s not spread over 56 miles. You go from 1200ft to 2900ft in 6.5 miles.
There aren’t flat sections on this course, you are either climbing or going down hill pretty fast.
I rode most of the course back in early February with the RD. I can’t find my Garmin file from the ride, but I think your estimates of total elevation gain are way off. I think you will find that total elevation gain will be much closer to 5,000 feet and most of that will be in the first 42 miles or so. So it will definitely be a very challenging ride under the best of conditions.
Again, I only drove from Castaic Lake to Pyramid Lake. And I did not do the 2 14-mile loops stated in the course description. The elevation gain is true only for the section I drove. Just by adding the missing 14-mile loop and the climb at the begining of the way back to Castaic and the slight climb to Magic Mountain the total gain for the whole course is way more. So, yes, the whole thing is more challenging than what appears on my graph.