M
Mark Stonich
Guest
http://bikesmithdesign.com/Paul/PaulAndBike.jpg
The goal was a bike with the seat and BB heights of a Giro,
but lighter and without pedal steer or heel strike. And with
optimized steering ergonomics and without chain idlers. The
rearward CoG eliminates the typical SWB quick response on
the roll axis, often called twitchyness. Less weight on the
smaller of the tires should yield lower total rolling
resistance than an SWB.
WB = 55" Head angle 65 deg, Trail 0.5", Tiller 7", Weight
distribution 1/3F - 2/3R BB ht. 25.5" Seat Ht. 22.5" (to
compressed foam) 155mm Cranks. 559 x 42 rear, 406 x 37 front
Unlike an SWB, the rider's heels overlap the front wheel so
close to the steering axis that heel/fender interference
isn't an issue.
After a test ride the new owner is one very happy fella.
He took off down my street and turned around to come back
when all of a sudden he started grinning like a fool. He'd
suddenly realized that after 50 yards on a new bike, he'd
felt confident enough to make a U turn on a narrow, dirty
street, without unclipping his SPDs. "I wouldn't have done
that on my own bike." After a bit more riding, including
getting it up to speed and diving into some turns, he said
"I never realized any bike could feel so confidence
inspiring."
AFAIK It's the first 'bent that's been designed *completely*
according to http://bikesmithdesign.com/Design/12Steps.html
What makes this bike handle even better than those I've
built for myself is that while my last two have the steering
ergonomics dialed in, I couldn't optimize weight
distribution with the low BB without making them longer. But
one was a light monotube, so more WB would have been too
flexy, and the other has to fit in a confined parking space.
Of course I'm biased, but I think it's the best handling
bike I've ever been on. Rock solid from sub-walking speeds
to bombing down the steepest hill in S. Mpls. More Pix
http://bikesmithdesign.com/Paul/Right.jpg
http://bikesmithdesign.com/Paul/RightRear.jpg
http://bikesmithdesign.com/Paul/Bars.jpg
http://bikesmithdesign.com/Paul/SeatMount.jpg
http://bikesmithdesign.com/Paul/Left.jpg
The frame was designed by me and built by Terry Osell and
me, for a guy we ride with. The rear frame configuration is
dictated by the need for a seat height that works for a 5'
7" rider, but wanting as high a BB as we could get without
the chain hitting the seat or needing power robbing chain
idlers. The new rear configuration gives a ride that is
nicely compliant in the vertical plane, but without chain
tension induced pogoing.
Even with fenders, the heavy Rans seat, and Terry's
humongous fillets, it weighs 28 lbs. The final handlebar
riser will be less adjustable, but save about a half pound.
Mark Stonich; BikeSmith Design & Fabrication LLC
http://bikesmithdesign.com
The goal was a bike with the seat and BB heights of a Giro,
but lighter and without pedal steer or heel strike. And with
optimized steering ergonomics and without chain idlers. The
rearward CoG eliminates the typical SWB quick response on
the roll axis, often called twitchyness. Less weight on the
smaller of the tires should yield lower total rolling
resistance than an SWB.
WB = 55" Head angle 65 deg, Trail 0.5", Tiller 7", Weight
distribution 1/3F - 2/3R BB ht. 25.5" Seat Ht. 22.5" (to
compressed foam) 155mm Cranks. 559 x 42 rear, 406 x 37 front
Unlike an SWB, the rider's heels overlap the front wheel so
close to the steering axis that heel/fender interference
isn't an issue.
After a test ride the new owner is one very happy fella.
He took off down my street and turned around to come back
when all of a sudden he started grinning like a fool. He'd
suddenly realized that after 50 yards on a new bike, he'd
felt confident enough to make a U turn on a narrow, dirty
street, without unclipping his SPDs. "I wouldn't have done
that on my own bike." After a bit more riding, including
getting it up to speed and diving into some turns, he said
"I never realized any bike could feel so confidence
inspiring."
AFAIK It's the first 'bent that's been designed *completely*
according to http://bikesmithdesign.com/Design/12Steps.html
What makes this bike handle even better than those I've
built for myself is that while my last two have the steering
ergonomics dialed in, I couldn't optimize weight
distribution with the low BB without making them longer. But
one was a light monotube, so more WB would have been too
flexy, and the other has to fit in a confined parking space.
Of course I'm biased, but I think it's the best handling
bike I've ever been on. Rock solid from sub-walking speeds
to bombing down the steepest hill in S. Mpls. More Pix
http://bikesmithdesign.com/Paul/Right.jpg
http://bikesmithdesign.com/Paul/RightRear.jpg
http://bikesmithdesign.com/Paul/Bars.jpg
http://bikesmithdesign.com/Paul/SeatMount.jpg
http://bikesmithdesign.com/Paul/Left.jpg
The frame was designed by me and built by Terry Osell and
me, for a guy we ride with. The rear frame configuration is
dictated by the need for a seat height that works for a 5'
7" rider, but wanting as high a BB as we could get without
the chain hitting the seat or needing power robbing chain
idlers. The new rear configuration gives a ride that is
nicely compliant in the vertical plane, but without chain
tension induced pogoing.
Even with fenders, the heavy Rans seat, and Terry's
humongous fillets, it weighs 28 lbs. The final handlebar
riser will be less adjustable, but save about a half pound.
Mark Stonich; BikeSmith Design & Fabrication LLC
http://bikesmithdesign.com
