1x10 is my fav. That is how I ride my 29ers. I am pretty sure the Jekyll rear swing will not fit a 27.5. It is an older low pivot frame. I feel best to keep these original (26x26), for the few that are out there. A lot of these have died and given their life to a uber V build. For your fork, just remember the rake. These are rear travel 135/140mm. They came with 80mm-100mm forks.
I decided to go 1x10 after spending a few weeks tracking what gears I actually used on my 3x7 on my M700 I use the most when riding. Turns out I spend about 80-90% of the time on the middle chain ring. That alone convinced me to switch to a 1x setup for this bike. Then it was spending some time researching what is currently on the market and the prices are pretty good on 10 speed cassettes ATM so I can save huge $$$ by avoiding a 1x12 setup. I can't wait to ride this one when it's done...
I did think about putting a 27.5 fork on it, but ultimately decided that is just didn't make sense. Doing that would mean I'd have to carry 2 spare tires/tubes on any non local ride among a few other concerns that keeping it 26" all the way around solves. The only challenge is finding a decent 26" wheelset that is in stock, or optionally building them myself.
I chose to use the Manitou over the RockShox because of a few reasons since feature/price wise they are pretty close. First being that I liked the overall build quality I saw in the 27.5 Manitou model I looked at the LBS when compared to the RockShox. Second reason was pretty much vanity's sake, the rear shock is a Manitou shock. Silly reason to choose a shock, but hey it's my bike! I'm sure I'll be happy with it, since I don't expect this to be the the best bike ever. It is 16 years old after all. I am building it to be fun to ride, be reliable and to look nice too.
Speaking of looking nice, got any ideas of where to find a Cannondale branded chainstay protector for a '04 Jekyll 1000??? I am pretty certain I will need one too keep the replacement decals on the swing arm looking nice after I give it a good polish with some Mother's. The frame decals are nearly perfect so I'm leaving them alone. I'm thinking of using a little of the ceramic coating on the bike to keep it shiny longer. I've been amazed at how well it helps repel water/mud and dirt on the paint on my brothers Jeep.
I forgot to add, I'll be uploading a few pictures tomorrow of the XT crankset I installed today. I forgot to take them while doing it. Plus I will snap a few of the minor rub points on the frame that give the bike character.
