It is a long cold winter...sorry for the novel.
A little about me. I’m a 5’11” 38 year old – 280# down to 230# clyde who hopes to be un-clyde sometime this summer. I rode like crazy as a kid and then didn’t ride for 20 years. My buddy got me back into cycling. He just moved up to CAT 1 from comp in XC mountain biking and has been a CAT 1 roadie for a while. I’ve had a number of injuries throughout my life and also have a thyroid problem. The guy who fit me on my road bike commented about how I’m a bit of a mutant based on my body measurements. Last summer I rode 1500 miles or so.
So I've been riding my 29er a lot more lately as a commuter rig when it is not sub zero outside. It works OK, but I've never been completely happy with the way it handles. Just cruising down the road or on a gravel trail it is fine. It works OK for open areas and faster flowy sections when I'm getting after it and racing. It is not very good in tighter technical sections with quick switchbacks or close quarters where you gotta lean quickly to avoid trees. I've caught the bars a few times, but most often I hit trees with my shoulders. I've given the bike 2 seasons to impress me and it hasn't. Truthfully, I never feel confident or trust the bike will do what I want it to. I do not crash too often, most of my mishaps involve hitting trees or going over berms and into the pickers when the bike won't lay down like I want it to.
I want to do more local XC races next summer. I've finished dead last in every event I've entered. I get passed by all of the girls and all of the 50+ guys. I catch and pass them where the trail is open or there are moderate climbs. Then everyone re-passes when the trail gets tight or the climbs are very steep. This bike doesn't climb all that well; even locked out the front end gets light if I have to roll back to keep traction in the rear. The bike is heavy, well the rider is too.
So here is what I ride. It is a medium/18” 2011 GT Karakoram.
I've only upgraded the stem and bars to Bonty XXX and the grips to ODI clamp on. I run a set of monster Conti Trail King 2.4 on P35 hoops for winter and spring, but race on the Alex/Kenda SB8 tubeless setup.
I don't have new bike money, but want to have more fun riding and be a bit more competitive in the races I enter(at least beat some of the 60 year old guys...lol). I had been looking at maybe shaving some weight by changing some components, but that will not fix the geometry. So I was reading reviews about new generation 29ers and how they are making them with shorter chainstays and better geometry.
I test rode a Stache in size large recently and felt even more uneasy than I do on the GT. This got me thinking I may be on the wrong frame size as well as having the wrong geometry. During the summer I rode a buddy's old school, steel, single speed, rigid 26er for a while on a tight course, what a fun little bike. My legs were burning and my lungs wanted to jump out of my chest, but the bike did everything my GT couldn't, at least on the tight singletrack we were riding that day.
I've been doing a little more research about fit for mountain bikes. I get re-fitted for my road bikes (2011 Specialized Roubaix 56cm and Soma Double Cross 56cm) early every season because I get more flexible and stronger so the seat has been moving up and the handle bars down over time. I've never really paid attention to the fit on my mountain bike. I am a bit of an oddity in my proportions. I have fairly short legs for my height. One leg is considerably shorter than the other and I had an ulnar impaction which required cutting 3/8" out of my arm bone, so one arm is shorter too. I’ve had a knee surgery, shoulder surgery, hamstring surgery and broke my back too.
I went on the Competitive Cyclist website and filled in the measurements for mountain bike fit.
Here are my dimensions as entered into the calculator
Lower Leg 22.5"
Sternal Notch 57.0"
Total Height 71.0"
These are the dimensions given by the calculator
Standover Height 28.6 to 29.2" (726 to 742 mm)
Virtual TT Length 23.4 to 23.8" (594 to 604 mm)
Stem Length 960 to 1120 mm
BB-Saddle Position 657 to 672 mm
Saddle-Handlebar 531 to 547 mm
So in essence I'm small in the legs and at the top of medium in my torso and arms. My current bike is a medium. Its TT length is 603mm. Its stated standover is 772mm(I bang my nuts a lot). I have a 110mm stem on it. I’ve tried to match my road bike fit as close as I can but I am back a bit and can’t get the bars down any more.
I've been looking at other bike geometries that people seem to like. Canfield, Scott, Santa Cruz, Orbea, Specialized, Trek. It looks like, in most cases, I should be on a small with a longer stem. Is this a contributing factor to why I feel perched on my bike instead of "in" it?
I'm hoping I can swap everything over; so a non-tapered headset would be preferred from a budget standpoint. Also, I will be servicing the RockShox Recon Silver TK fork in the spring, so I could bump the travel up to 120mm if the frameset dictated more travel.
So here is the million dollar question? Can I truly just transfer the fit from a road bike to a mountain bike? Should I get the reach and stack off the Roubaix and start to look for a mountain bike with the same numbers? How will that play into the handling portion of the geometry?