Hi All!
Ah! Contrast, sweet contrast!
I've been riding the Nomad almost exclusively since it arrived, but today decided to try a relatively short-distance back-to-back comparison between the Nomad and my most-favored Other ride, my beloved derailleur-geared blue 1983/84 Centurion ProTour 15 rando/touring bike with nearly 32,000 miles of use. In feel, geometry, and materials (Tange Champion No. 2 .9/.6/.9 in standard road-bike diameters), it would be roughly akin to a Thorn Club Tour with light wheels/tires and includes the usual assortment of dyno lights, mudguards, bottles/cages, and F/R alu pannier racks. Its wheels use Phil Wood freewheel hubs, 1.8mm spokes, narrow Mavic MA-2 box-section rims, and 700x32C Bontrager SelectK road slicks aired up to 85psi/~5.9bar. Weight is 32lb/14.5kg.
Although it was an apples-to-oranges comparison, I gained some interesting insights from riding each unladen, moving back and forth between them.
The Nomad was first out of the gate, with its Rigida Andra-shod 26x2.0 Duremes set F/R to 29/32psi or 2/2.2bar. Unladen dry weight is 45lb/20kg.
Riding along on the Nomad using these tires at these pressures, it is a revelation how well they damp low-amplitude high-frequency vibrations. I can spread my fingers like bird feathers while riding the brake hoods, and they are steady as can be. Concrete expansion joints, rough chip-sealed road surfaces, minor frost heaves and tree roots just disappear below these tires at low pressures despite the Nomad's very stiff frame.
In contrast, the rando bike
accelerates much faster. For one thing, it weighs a lot less; 12lb/~5.5kg is some difference, and the rims/tubes/tires are lighter even though larger in diameter. There is a greater
sensation of speed, though the bike computer showed
actual speed was comparable in steady-state riding. Much of this impression of speed is due to the rando bike's greater ambient level of vibration, which is just constant. Spreading my fingers apart while riding atop the brake hoods, my fingers vibrate till they are a blur at the ends. Those same concrete expansion joints I breezed through on the Nomad hammered directly up the seatpost and into
me, feeling like short sharp impacts from a shot-filled hammer. I ran over an ant and will feel it for a week.
All this from my previously most-comfortable bike!
The rando bike is a friction-shifted half-step "15-speed" (24/45/50T chainset, 14/17/21/26/34T freewheel) yielding 13 chainline-usable combinations, though I rarely if ever use the two highest gears (96in, 87in), so call it 11 available gears. In comparison, the Nomad's 36x17T Rohloff has 14 available combinations with no chainline issues so all combos are usable. The Rohloff's 80in high gear is about equal to the highest (79in) I ever truly use on the blue bike. All the intermediate gears are the same within a gear-inch or so, and the Rohloff adds two additional low gears (15in, 17in) below the blue bike's 19in low and includes a 20in as well. In practice, I find the shifting comparable with the Nomad getting the edge for having just one shifter (no double-shifts), for being truly in gear as soon as I hear the click, and for being able to change gears while stopped. I pause while shifting with both bikes and rarely shift under load (old friction-shifting derailleur habits die hard). The T-bar mounted Rohloff shifter is a little more convenient (closer) than my high-mounted downtube derailleur shifters.
The real difference I noticed between the two bikes relates to how they handle the big bumps...and how *I* handle them as a result. Now that I've been running the Nomad's tires at appropriately low pressures, the ride is largely comfortable but really firms up when I hit larger bumps and sometimes has the effect of snapping my neck a bit. I have been trying to figure out why, and got my answer today: The blue bike vibrates all the time, and so I know enough to "post" (stand up on the pedals when something Bigger comes along). Because the wider, higher-profile, low-pressure tires on the Nomad handle the little bumps so well, I get lulled into complacency and forget to post when a big bump -- something larger than a soft tire can absorb -- comes along. For comparison, I found an abrupt up-down-up crossing ramp on a multi-use path and repeatedly tried it with both bikes at the same speed. It snapped my neck a bit when riding the Nomad...and nearly took out my teeth on the stem of the blue bike while seated. Taking the same abrupt up-down-up ramps while standing on each bike was no problem.
Thanks to today's back-to-back comparison, I can better judge what constitutes a "seated bump" versus a "standing bump" on the Nomad; I hadn't realized I was posting so frequently on the blue rando bike. The Nomad's wide, low-pressure tires do such a great job with the smaller bumps, I forget that once they compress on hitting big bumps, the effective spring rate rises to where one *can* abruptly feel them. Understandable 'cos they
are big bumps and would be on
any bike! And, too, appropriately low tire pressures are more important with the unladen Nomad. It has a heavy, stiff frame appropriate to its role as a loaded expeditionary tourer. When riding unladen, the tires provide a suspension element critical to comfort, as intended. It really works out very nicely. I can feel the Sherpa Mk2's DNA in the Nomad Mk2, but just as the Sherpa was a heavier-duty touring bike than my blue rando/touring bike, so is the Nomad "more" bike than the Sherpa, biasing it more firmly toward the heavy-touring end of things and further from the role of general all-'rounder. For a visual comparison of ride/cargo characteristics, see the little chart I posted here:
http://thorncyclesforum.co.uk/index.php?topic=4713.msg23329#msg23329I feel really fortunate to have both ends of the touring spectrum covered so nicely in just two bikes (though I have others, I ride these most). I hope today's comparison will be helpful to those riders considering a move from conventional 700C tourer to fat-tired 26"-wheeled Nomad Mk2.
Best,
Dan.
