Ah!
That bike is from the first pre-pro run of the Ridge 2.0 frames we made
right after Interbike 2004(I was working with Sinister then).
I spent a solid 4 days riding DH at Bootleg Canyon outside Las Vegas after the show. That bike had a 7" sherman singlecrown on it. It was really heavy but man- I rode
everything on it. I was actually nipping at Frank's heels most of the time and he was on his r9! I was XC fit then, as long as I was clipped it I could go fast, but my legs did turn to jello!
The final version of that frame did have a standard headtube- those would have shipped in May 2005. About 30 of the 2.0 frames were built. At 4 pounds they made an indestructible bike that was focused around trail riding instead of the weird hucking geometry that the original owners of Sinister wanted. The original ones were 6 pounds and essentially overbuilt Metalheads for low-speed woods riding. Those bikes sucked ass.
We really like those dropouts and still use them a good bit, even shaved down for road bikes!
A 5" fork would make that bike handle the best.
trust me- Get a 70mm stem with as much drop as you can, -15deg if you can find one and a wider(740ish) bar with the lowest rise you can get.
The bike will climb much better, descend much better and ride on flat ground much better.
Note- careful with the deraileur hanger- we're out of them right now and it might be quite a few months until we have time to machine more.
Hardcore Hardtails are awesome- the right way to do them is with 650b wheels- unfortunately even with the yoke there isn't enough room to fit one in the rear- I really wish there was enough room, because I have one of the proto frames stashed in the scrap bin(y'all would be jealous of our scrap bin!) that I want to build up with a 7" boxxer and fat tires and go huck shit!
Frank still has buckets full of parts for those frames. The last ridge-ish bike he built was a 29'r with a sweet tubular monostay to shave some weight-
p.s.-
Here's my r9!
Those bikes were SO FAST and they still are fast today.
By the end of Sinister the bike was getting a little too steep.
We built a shorter shockstay to get it lower and slacker- If the frame wasn't so heavy it'd be a fast bike even today. 10 really well controlled inches of travel makes it unstoppable in a straight line!