Monday, August 17, 2009
I now feel qualified to write a little about the Jones.
What & why: Jones frame, ti compact, diamond frame with fat truss fork.
The Jones geometry is something i have been moving towards for some years. When i discovered 29" wheels, with the kelly roshambo, i was a little upset in some ways. I used to have a beautiful Seven verve singlespeed which - at the time - i thought could not be improved upon for the riding i do. It was made after having a couple of Curtlo frames that were adapted from wtb phoenix geometry. Unbelievably, it was more reasonable financially to get a custom brazed frame from doug, than to buy a second hand phoenix. I have always liked compact frames. It allows a lot of leeway when riding technical stuff - try stepping off when the trail side is a foot lower than the trail and you discover that level top tubes dont cut it. I also like the way a long seat post can flex and take a lot of sting out of the ride. So the Curtlo's taught me that i liked a slacker seat angle, and a relatively short stretch to the bars given my height. I like a stiff rear triangle for power transfer with a lot of flex from a quality seatpost. The Curtlo's had 12" bb heights, which lowered with the Seven, to 11.7" but the bar height remained similar, a more 'in' the bike design.
Then came the roshambo - a size small frame - so i could keep similar stretch but compare the wheels. It turned my riding around. Sitting so deep inside the frame, with a bb drop of 70mm rather than 25mm at most on a 26" wheel bike led to incredible security in balls-out technical riding. It also allowed me to rail corners like never before, along with the extended tyre contact patch a 29" wheel provides. Despite fairly knob-light tyres, i could pin it with no worries in the twisty, rooty, rocky trails i prefer. Damn. The Seven sat around while i rode the roshambo.
Unfortunately, the roshambo had a steeper head angle to pull the trail back as it kept the same offset as popular forks at the time. This has all changed with the advent of 29"ers, jeff jones, and gary fishers conversations with jeff at the singlespeed worlds and hence G2 geometry. Perhaps the burgeoning 'all mountain' market with slacker angles helped as well. A bad trait of the rohambos ride was the front wheel tucking under in fast steep corners. So when a new home was found for the Seven, i had an IF made with slacker angles front and rear, and used a longer offset fork to bring the trail back. Damn near perfect.
By then, i had ridden jeff's personal 29"er with super low spaceframe design, and a 26" wheel model as well, and was impressed by the overall geometry but wasn't convinced of the short front centre. When i had a frame made by IF to use racks for some bike packing, i did however relax the geometry of the new IF more, actually to the same angles as jeff uses, but with 5mm less fork offset, and longer chainstays. The idea was that once loaded it would remain stable but lively enough to ride fun trails. It worked. I needed to use a longer head tube as i 'rotated' around the bb, but the weight distribution took some shock off the arms and made for very comfortable long days in the saddle. Hmmmm!
At this point i wanted to have a bike that was basically a cross frame with my IF/relaxed geometry so that i was biomechanically in the same position as the others, but i could ride from home to trails with less skwootching around on low pressure fat tyres. Thus was born the Iron Maiden.
This bike is pretty curious in some ways. Short cross specific fork, Road transmission clearance at the bb but 135mm spaced at the rear with 425mm stays. 71/72 angles and a 50mm offset fork. If you look at this closely, the trail, low bb, front centre and wheel base end up *very* close to Jones geometry. I *really* enjoy riding this bike. Short, quick, but it can be carved into corners and flicked around tight stuff until the tyres explode.
It was then i realised that slowly and surely i was moving towards getting a Jones frame. Particularly as i had been using a fat fork and front wheel on the roshambo for awhile. I really think the 135mm front end needs to replace a 100mm front wheel for general use.
So, a long chat by email and phone and my frame arrived. Standard Jones geometry but with an uber compact frame.
Initial rides: Disclaimer - I dont make snap decisions on bikes, and i dont gush unless i like something after using it in many situations and for enough time to come to a conclusion born of experience.
My first rides were great. The Jones is so quick in technical trail it almost second guesses your moves. I got myself in trouble by hitting stuff too fast and over-steering and tying myself in knots. Then as i became more used to the ride, i sat back, put the weight over the rear wheel and used the hips and arms more. You can lean steer the bike, but it doesn't *need* to be leaned like my IF 29"ers. It also responds much faster to steering input - i think due to the truss forks incredible front/rear stiffness and precision. As you weave between the trees, the more you ask or need of the bike, the more it delivers. There is always a little more on tap, i have so far never got to the stage that i have hit a tree or rock due to not being able to pull the bike out of a corner. The more rearward weight distribution and higher front end takes shock off your arms, and the flattened stays and long seat post mean sitting shock transmission is very low. On my usual trails, i am riding faster. Simple as that.
I have also re-discovered drops, jumps and generally being in the air. I'd forgotten how much a short back end helps the bike land from unexpected drops. In addition, the short rear end and wheelbase in general get up and over steps in the trail really quickly. Before you know it, that rise or fallen tree is behind you. All you have to do is unweight the bike, ease yourself and glide. Arms loose, you can take on prety much anything unexpected with no need to pucker and hope.
With slack angles, a 55mm offset fork and a high front end, you would be forgiven for thinking that the front end would lift on steep climbs. Nope. The relatively short front centre and the design of h bars mean you can easily keep weight over the front. Never any issues.
So what is not to like about the ride? errr....yes. Um. Well, nothing really. Is that just new bike-love speaking? No. I'm pretty objective and i have ridden a lot of nice bikes. No gushing, it is by far the best riding mtb i have ever swung a leg over. Incredibly engaging but forgiving.
Speccing a Jones is one of those 'do it justice' situations. Everything is the way it is for a reason, from the brass front nipples to the grip length.
The frame and fork you know. Jones loop bar, ESI chunky grips 6" in length and Paul components love levers, 2.5 fingers, to gore ride on cables and steel conduit where possible. Avid bb7's with shimano rt SM76 front rotor in 180mm and 160 slx rear rotor. Better braking than stock: better modulation and power. Smooth.
Stem was initially a 10 degree thomson in 110 length, to rotate me further back round the bb due to the slacker geometry. The 10 degree was too high, so i swapped out to a 0 degree. Perfect.
Seat post is a lay back thomson. Strong and long. Good adjustment. Selle san marco zoncolan. Personal choice for long term comfort. Jeff mod'ed sm 960 cranks, 175mm length, xtr pedals, king bb.
The wheels for this build were based on my experiences with the endomorph on an uma 50mm rim with the Jeff/Paul 135 mm front hub. Strong and massively shock absorbing with amazing traction through the rocks. As an experiment i had built a 29 uma 50mm rim onto a dt 240 hub, with comp spokes and alloy nipples. It worked, was stiff and seemed to take a beating. But for how long? I think if you are using a front single wall/wide rim, low tyre pressure and are hitting things, a wide front hub is a must.
In order to give me plenty of leeway i used the un-drilled rim and brass nips with comps for the front. The rear wheel is a dt singlespeed with the new 36 tooth star ratchets, a king 20 tooth steel sprocket and comps/alloy nips to a Bonty duster rim. Tubes are wtb, tyres maxxis ardent front/crossmark rear. Chain is a dura ace with sram link plate. Front cog is an old Boone ti with 34 teeth.
Anything i'm going to change? Yep. The front wheel can take more than the rear. But it is heavy - 800g rim, brass nips and i think i may have to use a downhill tube to eke out the full benefit of low pressure (i'm pinching the sides of tubes in rocks) So, for racing im going to be using an Edge composites AM rim to dt singlespeed rear/paul Whub front, with dt comps. I will then build a rear fat wheel with an Uma rim, or perhaps a kris holm 47mm rim. One for chunky conditions, one for speed.
I am also getting some carousel design bags for the truss fork, as it is a great bike packing bike - so stable loaded.
More in time :-)~