I made my newish Trek Fuel EX-9 into a Trek Fuel EX-69 with some "spare" parts I had laying around.
What is a 69er??? Well it's a sort of a Frankenstein bike that pieces together a 29er fork and front wheel (29" wheel) to a 26" wheeled frame and rear-end...69er! Trek has been developing just such a bike and I am anticipating that I could like it...so I made my own just to quell my own curiosity. My 69er version is missing a few of the Trek refinements such as a rear rocker arm that is tuned for a 69er, a lower front end (they used an integrated headset and a prototype Fox 29er fork with a different offset...blah, blah, blah), but I think I got some feel for the 69er idea with my setup.
There are many naysayers out there on the idea of a 69er (just like there was with the origin of 29ers)...I personally think these individuals are a bit narrow in the head.
The setup I did put the front of the bike equivalent to running the height adjustable 26" Fox fork (original equipment) at 130mm (it's tallest, longest travel setting). I have found that the 130mm setting is essentially only good for rapidly decending down bumpy hills...it is not very good for climbing or technical stuff on the flat or going up. The best all-around setting is at 110mm. That said, I was already anticipating that the 69er setup would not be my favorite since the front-end would be sketchy over technical stuff. I took it out for a test ride and put a couple of miles (...uhhmm 97-miles to be exact) on this setup before I put my original 26" Fox fork back on.
What I found was that this thing was an incredibly fast and stable downhill thrill ride. On the flats and non-technical climbs it was good too, but as I thought it really sucked on the technical, rock-infested, tight turns going up-hill...one of my more favorite "local" single track climbs (Foredyce Trail) proved to be way more difficult than usual...I struggled through sections of the trail that are typically fun.
Assuming that Trek brings the front-end into "compliance" on it's new 69er, this bike could be a seriously fun, fast enduro-machine...hmmm