Grannygear and I had the opportunity to ride the new Jamis “sixfiftyB2”, a full suspension bike based upon the 2009 Jamis XCT 3 model with optimization for the 27.5 inch wheel. The bike has a claimed 5 inch travel and is set up with a White Brothers fork built specifically for 650B wheels. Here is a detailed ride report from Grannygear on this 2010 model:
Jamis Dakar Sixfifty B2: So what is 650B good for? Is it the tweeners dream, blending the best of both wheel sizes without the drawbacks of either? Is it the answer to keeping that moto feeling and yet have the extra rolling bennies of a larger hoop? Or is it the next fad to fizzle, an experiment in making something that too few people asked for? I had never ridden a 650B bike so I went in search of answers to those thoughts in the hills of Bootleg Canyon aboard the Jamis Dakar Sixfifty B2, a 5” travel trailbike aimed at the growing 650B market. Looking at the bike it is not that obvious that there is anything but 26” wheels on it. There is not the dramatic difference that a 29er puts forth just sitting there. Talking with Craig Hoyt, MTB Product Manager for Jamis bikes, he spoke about how the bike was meant to be an all around trail bike, not really a race bike or shuttle bike, etc, but something with broad appeal and versatility. Call it your basic everyman’s weekend bike.
I had just recently ridden a 26” bike, something I rarely do anymore, and I was wondering if I could tell the difference? Short answer? Not really. Was the 27.5” wheel working for me to the positive? Probably, but it was just pretty subtle about it. Compared to the average 29er, it was quite a bit more moto as far as wheelies and tossing it around, no doubt. It was very flick-able. But the sand and rocks still grabbed at the wheels and slowed them down more then I expected. If this is a good example of the middie-sized wheel and how it performs, it sure does not have the ability of a 29er wheel for rolling over the terrain.
As far as the Jamis itself, it was a fun bike. I felt that it pedaled well and handled the twisties of the Bootleg XC courses with no drama. I think the shock or linkage may need some thought as it seemed to get a certain ways into the travel and then it would blow through the rest too quickly, hesitating to get back to neutral. The White Bros Fluid 650B-130 fork needed to break in before it was as supple as the rear end on smaller bumps, but it moved smoothly and felt rock solid in the bigger drops. I lament the dearth of water bottle braze-ons due to the suspension design placing the shock right in the way and you will have to decide how you like the looks of the reinforcing strut that spans between the seat tube and the downtube underneath the shock.
The Jamis is well worth looking at if FS and 650B are on your list. It was a fun bike and with some refining, and that may happen yet before full production, it is a viable option in the emerging world of the middle sized wheel choice.