Weird vintage tech thread.
Likes For tricky:
#102
Strong Walker
In the defense of whoever designed this, pendulums were/are not all that rare as a means of measuring slope. I used to deal with inclination sensors in my job, and was familiar with the current technology. In fact, I found an inclination sensor on the road while riding once! It must have fallen off a Klaus combine (a piece of farm equipment), and it used a pendulum in an oil bath. The oil just slowed the pendulum and made it less sensitive to mild vibration, bumps, etc. The pendulum was connected to a potentiometer, which provided a voltage that changed with the slope angle. Nothing fancy or expensive, but it did the job, more or less.
These have largely been replaced by solid state accelerometers that are fairly small and cheap. Surprisingly, GPS receivers seem to be cheap enough and accurate enough that most modern devices just keep track of their X, Y, and Z position, and can track the elevation gain by simple addition and subtraction.
Steve in Peoria
These have largely been replaced by solid state accelerometers that are fairly small and cheap. Surprisingly, GPS receivers seem to be cheap enough and accurate enough that most modern devices just keep track of their X, Y, and Z position, and can track the elevation gain by simple addition and subtraction.
Steve in Peoria
#103
Senior Member
Join Date: Nov 2004
Posts: 23,223
Mentioned: 654 Post(s)
Tagged: 1 Thread(s)
Quoted: 4722 Post(s)
Likes: 0
Liked 3,036 Times
in
1,874 Posts
Cool, thanks! I saw this years ago at a swap meet and thought it was pretty interesting. Any ideas as to the function of the two small fixtures midway along the curve of the forks?
Wish I had a close-up of some of the details; for example, I can't quite make out exactly what the linkage in front of the head tube goes and if it's gear or brake related.
Shoulda given it a test ride
DD
Wish I had a close-up of some of the details; for example, I can't quite make out exactly what the linkage in front of the head tube goes and if it's gear or brake related.
Shoulda given it a test ride
DD
Thats actually a rear brake linkage. The rod extends from the brake lever to a bell crank at the base of the head tube. Another rod extends from the bell crank to the spoon brake behind the bottom bracket.
Likes For T-Mar:
#104
Banned.
Join Date: Jul 2009
Location: PAZ
Posts: 12,294
Mentioned: 255 Post(s)
Tagged: 0 Thread(s)
Quoted: 2588 Post(s)
Liked 4,824 Times
in
1,709 Posts
The fixtures 1/2 way up the fork legs are foot pegs. You'd place your feet on them when going down steeer hills, when the crank rpm exceeded you maximum leg cadence. Remember, these were fixed gears, so there was no coasting downhill, unless you put your feet on the pegs.
Thats actually a rear brake linkage. The rod extends from the brake lever to a bell crank at the base of the head tube. Another rod extends from the bell crank to the spoon brake behind the bottom bracket.
Thats actually a rear brake linkage. The rod extends from the brake lever to a bell crank at the base of the head tube. Another rod extends from the bell crank to the spoon brake behind the bottom bracket.
DD
#105
Senior Member
Join Date: Feb 2008
Location: Peoria, IL
Posts: 4,476
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 1829 Post(s)
Liked 3,376 Times
in
1,580 Posts
The Slingshot used a sprung cable instead of a down tube, and had some sort of fiberglass hinge at the rear of the top tube. It seems like it should have been far too flexible to be useful, but I've heard of some folks who really liked it.
I'm not sure how there is enough torsional stiffness in that frame to work, and the marketplace seems to have decided that it wasn't a good idea, but some folks liked it. I'd love to hear from any BF folks who have experience with it.
... of course, I have a friend who loves his Schwinn Varsity too, so I guess you can never tell what someone might like.
Steve in Peoria
I'm not sure how there is enough torsional stiffness in that frame to work, and the marketplace seems to have decided that it wasn't a good idea, but some folks liked it. I'd love to hear from any BF folks who have experience with it.
... of course, I have a friend who loves his Schwinn Varsity too, so I guess you can never tell what someone might like.
Steve in Peoria
Likes For steelbikeguy:
#106
Senior Member
Join Date: Feb 2008
Location: Peoria, IL
Posts: 4,476
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 1829 Post(s)
Liked 3,376 Times
in
1,580 Posts
For measuring the steepness of a road, I've used the Sky Mounti inclinometer. It's just a bubble level, with all of the sensitivities of such a gravity based sensor. It is definitely sensitive to fore & aft acceleration, so you do need to keep a steady pedaling rate. This isn't always easy to do when grunting up a steep hill, but I thought it worked well enough.
The marketing material:
and a photo while stopped on Bouquet road, southwest of St. Louis, which indicates a 19% grade. Normally you'd just glance at it while riding, but I was trying to record key features of the ride route. I think I slipped and almost fell over when I tried to get started after taking the photo.
I think I've got a spare Sky Mounti, if anyone is interested.
Steve in Peoria
Likes For steelbikeguy:
Likes For old's'cool:
#109
Strong Walker
I suspect that it was intended to compete with the Avocet 50, which had a barometric altimeter and could calculate total feet of climbing (with a reasonable degree of accuracy, I guess).
For measuring the steepness of a road, I've used the Sky Mounti inclinometer. It's just a bubble level, with all of the sensitivities of such a gravity based sensor. It is definitely sensitive to fore & aft acceleration, so you do need to keep a steady pedaling rate. This isn't always easy to do when grunting up a steep hill, but I thought it worked well enough.
For measuring the steepness of a road, I've used the Sky Mounti inclinometer. It's just a bubble level, with all of the sensitivities of such a gravity based sensor. It is definitely sensitive to fore & aft acceleration, so you do need to keep a steady pedaling rate. This isn't always easy to do when grunting up a steep hill, but I thought it worked well enough.
#110
Senior Member
Join Date: Nov 2004
Posts: 23,223
Mentioned: 654 Post(s)
Tagged: 1 Thread(s)
Quoted: 4722 Post(s)
Likes: 0
Liked 3,036 Times
in
1,874 Posts
Thanks again! Didn't know that was a fixed setup, so the pegs make sense. And yeah, I thought it was likely that was a brake linkage but my photo didn't seem to show enough detail about the wheel end of the braking system for me to make a definitive determination.
DD
DD
Perhaps the attached photos will help will your understanding of the braking system.
Likes For T-Mar:
#111
Senior Member
Join Date: Feb 2008
Location: Peoria, IL
Posts: 4,476
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 1829 Post(s)
Liked 3,376 Times
in
1,580 Posts
yep that tiny level gauge or what you want to call it was around, I remember I had an avocet wrist watch altimeter, in fact several of them, and loved them. Very intuitive menu design, unlike my Suunto or *shudder* any polar, for that matter. The Avocets were very precise. I remember having read somewhere that the Jobst Brandt was involved in the design, but I don't know if that's true.
Some time ago, I was in contact with a fellow at Specialized who was working on their bike computers. I must have met him on the Bikecurrent list or the iBob list?? He did end up sending me a computer to play with and evaluate, which was interesting. I think it died an early death, which isn't a surprise for a product in development. I think it must have been typical of a lot of consumer electronics, where some company wants some particular device designed, but the company doesn't know how to design the item. The company puts together a specification of what the device should be and should do, and then manages the development process with the electronics design company. I've done similar things with electronics for earthmoving equipment.
Steve in Peoria
#112
Senior Member
Join Date: Oct 2005
Location: Upper Left, USA
Posts: 1,915
Mentioned: 50 Post(s)
Tagged: 0 Thread(s)
Quoted: 634 Post(s)
Liked 444 Times
in
298 Posts
Yikes! That's pretty bad. Thanks for the explanation. I only knew the story about how suspension forks won Roubaix for 2 or 3 years in a row.
#113
Senior Member
Join Date: Dec 2006
Location: Houston, TX
Posts: 895
Bikes: 2017 Co-op ADV 1.1; ~1991 Novara Arriba; 1990 Fuji Palisade; mid-90's Moots Tandem; 1985 Performance Superbe
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 390 Post(s)
Liked 572 Times
in
332 Posts
Litigation Limiters
My daughter's 1987 Schwinn Sierra has clips in place of lawyer lips:
Clip.
Clip snaps over an eyelet on the fork.
I always forget this bike is different and end up unscrewing more than I need to.
Clip.
Clip snaps over an eyelet on the fork.
I always forget this bike is different and end up unscrewing more than I need to.
#114
Senior Member
Join Date: Dec 2005
Location: Ashland, VA
Posts: 4,420
Bikes: The keepers: 1958 Raleigh Lenton Grand Prix, 1968 Ranger, 1969 Magneet Sprint, 1971 Gitane Tour de France, 1973 Raleigh Tourist, 3 - 1986 Rossins, and a '77 PX-10 frame in process.
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 221 Post(s)
Liked 237 Times
in
129 Posts
In 1954 BSA produced a modified version of their amazingly venerable 'X' three-speed hub that allowed the wheel and hub mechanism to be removed from the cog. Very handy on bikes with full chain cases! This design was not done in by technical flaw or lack of consumer acceptance, but, alas, by corporate merger.
Diagram from Hub of the Universe by Tony Hadland.
__________________
Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)
Syke
“No one in this world, so far as I know — and I have searched the records for years, and employed agents to help me — has ever lost money by underestimating the intelligence of the great masses of the plain people. Nor has anyone ever lost public office thereby.”
H.L. Mencken, (1926)
#115
Full Member
#116
Senior Member
Join Date: Feb 2020
Posts: 2,820
Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1106 Post(s)
Likes: 0
Liked 1,328 Times
in
784 Posts
For those interested in this sort of thing I recommend Sharp's book; one of his own contributions in this vein was a hub with helical grooves, as many as and each the width of the spokes; said spokes being a single wire for a pair, the middle of the wire being wrapped partially around the hub in its own groove.
https://archive.org/details/bicycles...ge/n8/mode/2up
Published in 1896, 550-ish pages of text and diagrams/drawings, and I bet Jobst would have agreed with every word.
https://archive.org/details/bicycles...ge/n8/mode/2up
Published in 1896, 550-ish pages of text and diagrams/drawings, and I bet Jobst would have agreed with every word.
#117
Senior Member
Join Date: Feb 2020
Posts: 2,820
Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1106 Post(s)
Likes: 0
Liked 1,328 Times
in
784 Posts
a: the friction between the (unkeyed) axle axle nuts and the frame; and
b: a small machine screw bolted through a hole connecting the two parts that should NOT rotate relative to each other (the brake mounting arm and the frame), said hole about an inch or so from the axle.
Of course the torque was enough to break the bolt, it was only about 4mm dia, and when that happens the arm rotates forward; the rider is then pulled forward out of the seat; if lucky their nether regions missing the chainring as they are launched out of the trike and into the path of whatever they were trying to avoid.
After this happened I contacted the inventor/seller, got a reply saying essentially nothing other than he wasn't in business anymore. I see a relative is making a similar trike, with the same torque-arm system - the screw looks a bigger diameter but if that's all there is I wouldn't trust it.
I did tell the inventor how I modified the trike I had so it was safe; a strip of aluminium triangulating the end of the brake mounting arm, a hole in each end, two matching holes on the trike, two screws and it looks the same as the rest of the machine. He didn't seem interested, probably thought he was litigation-proof.
Likes For grant40:
#119
Newbie
I don’t have 10 posts yet so imagine the slingshot pics from a few posts earlier.
Back in about 1984 I had a 20” slingshot BMX bike. Dual tension cable “down tube”. It was a pretty cool bike. I still remember the serial # after all these years. It was A0022 so I assume it was a very early frame. Wish I had it now.
Back in about 1984 I had a 20” slingshot BMX bike. Dual tension cable “down tube”. It was a pretty cool bike. I still remember the serial # after all these years. It was A0022 so I assume it was a very early frame. Wish I had it now.
Likes For mattswabb:
#120
Senior Member
Join Date: Mar 2014
Location: City of Angels
Posts: 4,870
Bikes: A few too many
Mentioned: 42 Post(s)
Tagged: 1 Thread(s)
Quoted: 1364 Post(s)
Liked 2,181 Times
in
1,183 Posts
Maybe not CV, but weird.....META-VERSE?
__________________
"EVERY PERSON IS GUILTY OF ALL THE GOOD THEY DID NOT DO"
Voltaire
Voice recognition may sometimes create odd spelling and grammatical errors
"EVERY PERSON IS GUILTY OF ALL THE GOOD THEY DID NOT DO"
Voltaire
Voice recognition may sometimes create odd spelling and grammatical errors
#121
Full Member
Curious ... what's the Q-factor on those things? Looks suitable for a pregnant hippopotamus...
Also, the two middle chainrings on the Quad (is that a 1/2 step + uncle + granny?) -- are the missing/worn-down teeth in line with the crankarm really intentional?\
Also, the two middle chainrings on the Quad (is that a 1/2 step + uncle + granny?) -- are the missing/worn-down teeth in line with the crankarm really intentional?\
#122
Palmer
Join Date: Mar 2007
Location: Parts Unknown
Posts: 8,625
Bikes: Mike Melton custom, Alex Moulton AM, Dahon Curl
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 1668 Post(s)
Liked 1,821 Times
in
1,059 Posts
Folding bicycle shipping crate:
Likes For tcs:
#123
Palmer
Join Date: Mar 2007
Location: Parts Unknown
Posts: 8,625
Bikes: Mike Melton custom, Alex Moulton AM, Dahon Curl
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 1668 Post(s)
Liked 1,821 Times
in
1,059 Posts
Kellog three-stage pump:
Likes For tcs:
#124
Palmer
Join Date: Mar 2007
Location: Parts Unknown
Posts: 8,625
Bikes: Mike Melton custom, Alex Moulton AM, Dahon Curl
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 1668 Post(s)
Liked 1,821 Times
in
1,059 Posts
The first commercially successful folding bike, the 'Captain Gerard':
Peugeot began production of these in the late 1890s. The French military adopted these and commercial fabrication was killed off by ~1920 with the glut of war surplus machines on the market. Prevent theft; carry it into your flat or workplace:
Accept a lift in Le Auto:
Peugeot began production of these in the late 1890s. The French military adopted these and commercial fabrication was killed off by ~1920 with the glut of war surplus machines on the market. Prevent theft; carry it into your flat or workplace:
Accept a lift in Le Auto:
Likes For tcs:
#125
Palmer
Join Date: Mar 2007
Location: Parts Unknown
Posts: 8,625
Bikes: Mike Melton custom, Alex Moulton AM, Dahon Curl
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 1668 Post(s)
Liked 1,821 Times
in
1,059 Posts
Before .gpx files we had 'Dan Henrys':
Likes For tcs: