OverviewThe Ellsworth Isis is a single pivot machine with a monocoque structure. The top tube and down tube eminate from the monocoque and have almost a semicircular profile. The design is beefy and the frame very stiff with plenty of standover height. The pivot is just above the chain line which means that there is virtually no bob in the granny ring when climbing. 4" of plush travel is now handled by a Fox RP23 shox. The SL version is shot peened and anodised for a durable finish. I paid £1000 for this frame in 2001. The longish top tube (23.2") make it very predictable and the high bottom bracket (12.9") means it will go over some big stuff without grounding.
Bullet proof design. Simplicity of design means pretty well zero maintainance unlike other full suspension bike designs e.g. only renewed pivot bearings after 5 years! Shock is out of the firing line of mud. Shot peened looks good even after 8 years of abuse! Lifetime warranty. Beautiful CNC work on the pivot and drop outs. Climbs like a mountain goat.
WeaknessesSlight loss in rear suspension on rear braking which all single pivots are prone to. Cable routing is not for hydraulics. Quite hard to physically replace the bearings without bearing drifts etc.
Bottom LineThis bike is awesome. After riding loads of others I come back to my Isis and think this is the best bike around. It has had a right hammering off the worst that the UK can throw at it. All mountain, no problem it takes it, coping with insane downhills off Helvellyn etc. XC, it rails corners and berms on man made trails.
The Isis will get up anything that you have the legs for. There's stuff I've climbed and thought how did I get up that? The ride is stable and predictable. I honestly don't know how I could descend faster on any other bike. When I changed to discs I bought a 135mm rotor for the back. This was a big mistake as it was not powerful enough to stop me and kept overheating. I changed it for 165mm which did the trick. I have a lock out on the rear shox and never use it, don't need to!
This bike is an all round great bike, which will do everything you want it to do. Fast dowhill, XC, slow rolling over steep rocks. It's bullet proof design is made to last and 8 years on it is as good, if not better, than the competition.
So why Ellsworth stopped making this bike I'll never know! I just know I'm glad I bought one!!