BSO: Which way does the fork go?
11-08-17, 10:38 PM
#51
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from the images provided, there is no need to worry about the offset of the forks on those 20" Huffys... and that offset will increase as the bike gets ridden.... :-o
sorry 'bout derailing your thread, RubeRad... but even the experts need review from time to time... and sometimes the only way to achieve that is to get them to think they're teaching someone else at times... let's hope some knowledge was gained on this subject.
sorry 'bout derailing your thread, RubeRad... but even the experts need review from time to time... and sometimes the only way to achieve that is to get them to think they're teaching someone else at times... let's hope some knowledge was gained on this subject.
Last edited by maddog34; 11-08-17 at 10:44 PM.
11-08-17, 10:58 PM
#52
https://en.wikipedia.org/wiki/Bicycl...cycle_geometry
BTW, I'm actually with you on this. The term "rake" has definitive "angular" roots. It should be used for angles. And it is used much more properly in motorcycle terminology. Using the term "rake" to refer to offset is preposterous. However, that's just the way it is. This term, as many other terms before and after it, fell victim to the typical American lack of basic technical literacy. Various bicycle-riding Billy-Rays-from-Milwaukee-Wyoming used it that way, others learned from them and eventually cemented this ridiculously improper usage. Now we have to live with it.
BTW, I'm actually with you on this. The term "rake" has definitive "angular" roots. It should be used for angles. And it is used much more properly in motorcycle terminology. Using the term "rake" to refer to offset is preposterous. However, that's just the way it is. This term, as many other terms before and after it, fell victim to the typical American lack of basic technical literacy. Various bicycle-riding Billy-Rays-from-Milwaukee-Wyoming used it that way, others learned from them and eventually cemented this ridiculously improper usage. Now we have to live with it.
Last edited by AndreyT; 11-08-17 at 11:08 PM.
11-08-17, 11:03 PM
#53
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11-08-17, 11:27 PM
#54
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https://en.wikipedia.org/wiki/Bicycl...cycle_geometry
BTW, I'm actually with you on this. The term "rake" has definitive "angular" roots. It should be used for angles. And it is used much more properly in motorcycle terminology. Using the term "rake" to refer to offset is preposterous. However, that's just the way it is. This term, as many other terms before and after it, fell victim to the typical American lack of basic technical literacy. Various bicycle-riding Billy-Rays-from-Milwaukee-Wyoming used it that way, others learned from them and eventually cemented this ridiculously improper usage. Now we have to live with it.
BTW, I'm actually with you on this. The term "rake" has definitive "angular" roots. It should be used for angles. And it is used much more properly in motorcycle terminology. Using the term "rake" to refer to offset is preposterous. However, that's just the way it is. This term, as many other terms before and after it, fell victim to the typical American lack of basic technical literacy. Various bicycle-riding Billy-Rays-from-Milwaukee-Wyoming used it that way, others learned from them and eventually cemented this ridiculously improper usage. Now we have to live with it.
and i refuse to buy boxes of overpriced dirt with a touch of perfume in it, then teach my cat to crap in it. I teach them to crap outside.
what the crowd does has never impressed me one bit. Mosh pits are fun to watch from above, though!
an old, rather sneaky, professor taught me a few things about TEACHING... one of which you all just witnessed. ;-)
to those that didn't catch on, i say ZOOM.... they focused on, and defended, an improperly used term... the real lesson eludes them to this point, sadly...
Last edited by maddog34; 11-08-17 at 11:33 PM.
11-09-17, 12:40 AM
#55
Calamari Marionette Ph.D
dig it.
and i refuse to buy boxes of overpriced dirt with a touch of perfume in it, then teach my cat to crap in it. I teach them to crap outside.
what the crowd does has never impressed me one bit. Mosh pits are fun to watch from above, though!
an old, rather sneaky, professor taught me a few things about TEACHING... one of which you all just witnessed. ;-)
to those that didn't catch on, i say ZOOM.... they focused on, and defended, an improperly used term... the real lesson eludes them to this point, sadly...
and i refuse to buy boxes of overpriced dirt with a touch of perfume in it, then teach my cat to crap in it. I teach them to crap outside.
what the crowd does has never impressed me one bit. Mosh pits are fun to watch from above, though!
an old, rather sneaky, professor taught me a few things about TEACHING... one of which you all just witnessed. ;-)
to those that didn't catch on, i say ZOOM.... they focused on, and defended, an improperly used term... the real lesson eludes them to this point, sadly...
Do you believe your own crap? That's pretty sad. We caught on when you demonstrated how little you comprehend about basic bicycle geometry. Terms aside.
11-09-17, 08:26 AM
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Making up and using new terminology that nobody else in the industry uses, in place of terminology long agreed upon and currently understood by all (except for you), will AVOID confusion?
And seeing how offset is a measure of distance, not angle, your terminology does not even make sense. All it will do is make people confuse offset/rake with head angle (just like you have done).
And "more" is not in any way ambiguous. Everybody who actually understands what rake or offset is will know exactly what that means.
The only confusion here is being generated by you.
11-09-17, 08:36 AM
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an old, rather sneaky, professor taught me a few things about TEACHING... one of which you all just witnessed. ;-)
to those that didn't catch on, i say ZOOM.... they focused on, and defended, an improperly used term... the real lesson eludes them to this point, sadly...
to those that didn't catch on, i say ZOOM.... they focused on, and defended, an improperly used term... the real lesson eludes them to this point, sadly...
Last edited by Kapusta; 11-09-17 at 09:34 AM.
11-09-17, 10:26 AM
#58
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Just to stir the pot, here are the top 5 results from searching for "bicycle geometry chart" at images.google.com
11-09-17, 10:29 AM
#59
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#2 just calls it "I", but the value of 39 is a linear, not angular measure. #4 is poorly labeled, with the label "Rake" simply pointing at the line which is the steering axis., I'm guessing that arrow should have pointed at the line on that diagram that all the other diagrams calle Rake.
Google confirms that (not surprisingly) Dave Moulton is right.
"when referring to bicycles, rake and offset are different terms for the same thing. Both are the term for the distance the wheel center is set from the steering axis, regardless of the head angle."
Sometimes you gotta just let language be what it is, instead of trying to force it to keep being what it was.
Google confirms that (not surprisingly) Dave Moulton is right.
"when referring to bicycles, rake and offset are different terms for the same thing. Both are the term for the distance the wheel center is set from the steering axis, regardless of the head angle."
Sometimes you gotta just let language be what it is, instead of trying to force it to keep being what it was.
11-10-17, 09:41 AM
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#2 just calls it "I", but the value of 39 is a linear, not angular measure. #4 is poorly labeled, with the label "Rake" simply pointing at the line which is the steering axis., I'm guessing that arrow should have pointed at the line on that diagram that all the other diagrams calle Rake.
Google confirms that (not surprisingly) Dave Moulton is right.
"when referring to bicycles, rake and offset are different terms for the same thing. Both are the term for the distance the wheel center is set from the steering axis, regardless of the head angle."
Sometimes you gotta just let language be what it is, instead of trying to force it to keep being what it was.
Google confirms that (not surprisingly) Dave Moulton is right.
"when referring to bicycles, rake and offset are different terms for the same thing. Both are the term for the distance the wheel center is set from the steering axis, regardless of the head angle."
Sometimes you gotta just let language be what it is, instead of trying to force it to keep being what it was.
Also, I would not assume (as one or two others in this thread have) that this terminology was ever any different for bicycles. Nor do I understand why it is assumed that the terminology for motorcycles is any more legit or unchanging than for bikes. They have both been around for a very long time.
11-10-17, 10:25 AM
#61
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Entering the danger zone... This bloke also gets it wrong on TED.
https://bicycle.tudelft.nl/schwab/Pub...b2013rider.pdf
Of course I would not wish to argue the point that he has missed because everyone misses it and accepted knowledge is irrefutable. After all everything has already been done and there is nothing that can be contributed to the sum of knowledge by questioning its original basis...
https://bicycle.tudelft.nl/schwab/Pub...b2013rider.pdf
Of course I would not wish to argue the point that he has missed because everyone misses it and accepted knowledge is irrefutable. After all everything has already been done and there is nothing that can be contributed to the sum of knowledge by questioning its original basis...
11-10-17, 11:14 AM
#62
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Bottom line: caster comes from the combined effect of head tube angle and rake (whether rake is defined as linear or angular deviation from head tube angle/steering axis). So 0 rake is possible; head tube angle alone provides caster/trail/stability, and kids are not gonna die from a straight fork, or from a fork so near straight that it might get installed backwards causing negligibly negative rake instead of negligibly positive rake.
11-10-17, 12:03 PM
#63
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Really?
Making up and using new terminology that nobody else in the industry uses, in place of terminology long agreed upon and currently understood by all (except for you), will AVOID confusion?
And seeing how offset is a measure of distance, not angle, your terminology does not even make sense. All it will do is make people confuse offset/rake with head angle (just like you have done).
And "more" is not in any way ambiguous. Everybody who actually understands what rake or offset is will know exactly what that means.
The only confusion here is being generated by you.
Making up and using new terminology that nobody else in the industry uses, in place of terminology long agreed upon and currently understood by all (except for you), will AVOID confusion?
And seeing how offset is a measure of distance, not angle, your terminology does not even make sense. All it will do is make people confuse offset/rake with head angle (just like you have done).
And "more" is not in any way ambiguous. Everybody who actually understands what rake or offset is will know exactly what that means.
The only confusion here is being generated by you.
11-10-17, 12:10 PM
#64
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Of course I would not wish to argue the point that he has missed because everyone misses it and accepted knowledge is irrefutable. After all everything has already been done and there is nothing that can be contributed to the sum of knowledge by questioning its original basis...
11-10-17, 01:24 PM
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11-11-17, 08:38 PM
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That's it, I'm going to go offset some leaves in the yard.
11-12-17, 04:50 PM
#68
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One measurement is worth a thousand assumptions (or in this case two measurements)
With front wheel secured in fork and pointing straight ahead... measure from the BB to the front axle. Swing the front wheel and fork 180* and re measure. Are these dimensions the same? If not there is a rake, even if not obvious. Andy.
With front wheel secured in fork and pointing straight ahead... measure from the BB to the front axle. Swing the front wheel and fork 180* and re measure. Are these dimensions the same? If not there is a rake, even if not obvious. Andy.
11-12-17, 09:42 PM
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No, but close to the rake (as defined as a dimension from the steering axis to the axle and 90* to the steering axis). What my suggestion will allow to be measured (and then split in half) is along a horizontal to the ground, not perpendicular to the steering axis. The 20* (plus/minus) of difference between these two lines of dimension will produce a different number. If one knew the steering angle and BB drop the real rake is mere trig math away.
Since the OP's question was rake or no rake I offered a quick method of finding that out. Andy
11-12-17, 10:50 PM
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Wow, my computer's freeze up really effected my posting here. So here's the post that was lost-
Some bike builder/designers call castor the angle between the horizontal and a line connecting the point on the ground that the steering axis intersects and the front axle. Attached is a freehand drawing from nearly 45 years ago showing this, in the red. It was Bill Boston who brought this dimension to my attention. He kept this angle to around 81* for his handling goals (and not discounting other frame dimensions and their effect on handling).
Steering geometry and handling is far more complex yet trial and error simple then most are willing to take on competently. Andy
Some bike builder/designers call castor the angle between the horizontal and a line connecting the point on the ground that the steering axis intersects and the front axle. Attached is a freehand drawing from nearly 45 years ago showing this, in the red. It was Bill Boston who brought this dimension to my attention. He kept this angle to around 81* for his handling goals (and not discounting other frame dimensions and their effect on handling).
Steering geometry and handling is far more complex yet trial and error simple then most are willing to take on competently. Andy
Last edited by Andrew R Stewart; 11-13-17 at 12:13 AM. Reason: Totally messed up posting attempts
11-13-17, 09:41 AM
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11-13-17, 09:42 AM
#72
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Wow, my computer's freeze up really effected my posting here. So here's the post that was lost-
Some bike builder/designers call castor the angle between the horizontal and a line connecting the point on the ground that the steering axis intersects and the front axle. Attached is a freehand drawing from nearly 45 years ago showing this, in the red. It was Bill Boston who brought this dimension to my attention. He kept this angle to around 81* for his handling goals (and not discounting other frame dimensions and their effect on handling).
Steering geometry and handling is far more complex yet trial and error simple then most are willing to take on competently. Andy
Some bike builder/designers call castor the angle between the horizontal and a line connecting the point on the ground that the steering axis intersects and the front axle. Attached is a freehand drawing from nearly 45 years ago showing this, in the red. It was Bill Boston who brought this dimension to my attention. He kept this angle to around 81* for his handling goals (and not discounting other frame dimensions and their effect on handling).
Steering geometry and handling is far more complex yet trial and error simple then most are willing to take on competently. Andy
11-13-17, 09:59 AM
#73
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