Bike Forums

Go Back  Bike Forums > Search Forums
Reload this Page >

Search Results

Register
FAQ
Calendar
Today's Posts
Search
Vendor Directory
Notices
Search: Posts Made By: JohnJ80
Showing results 1 to 14 of 14
Search took 0.02 seconds.
Forum: Road Cycling
06-20-21, 07:07 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

“Best” meaning they have top end bike handling...

“Best” meaning they have top end bike handling skills. Ever see the time Peter Sagan bunny hopped his bike over a rider that fell on the cobbles in Paris Roubaix? That = best.

So if you think...
Forum: Road Cycling
06-14-21, 08:52 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

its unknowable because it’s a complex system and...

its unknowable because it’s a complex system and everything interacts. There won’t be an intuitive answer because it’s going to a take deep dive into the math. That’s my point.
Forum: Road Cycling
06-13-21, 07:06 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

Do you really think Trek engineering didn’t think...

Do you really think Trek engineering didn’t think of that and simulate it before they committed huge money to molds for the frames? If only it where that simple.

Again, it’s unknowable until all...
Forum: Road Cycling
06-12-21, 08:53 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

My point is this: it’s unknowable without...

My point is this: it’s unknowable without knowledge of the entire system at resonance at that instant in time and without some knowledge of the impulse that set the system into resonance.

None of...
Forum: Road Cycling
06-12-21, 11:56 AM
Replies: 134
Views: 18,455
Posted By JohnJ80

I don’t agree. If anything the damper would limit...

I don’t agree. If anything the damper would limit oscillations of the frame and change the mechanical resonance. Think what happens if you were to put a rubber piece in the middle of a tuning fork.
...
Forum: Road Cycling
05-05-21, 07:02 AM
Replies: 134
Views: 18,455
Posted By JohnJ80

There are probably some things you can do with...

There are probably some things you can do with tires, tire inflation, tire balance etc… Some frequency related to road imperfections, tire rotation sped, and/or hitting some bump is causing the frame...
Forum: Road Cycling
09-26-20, 06:27 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

Sure, I think I can. I should be clearer on...

Sure, I think I can.

I should be clearer on the frame thing - it could also be an imperfection in the layup but the geometry is ok. At any rate, I doubt the Felt engineers did any actual testing...
Forum: Road Cycling
09-26-20, 05:59 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

I stepped through this slowly trying to get frame...

I stepped through this slowly trying to get frame by frame. What you see is that she has her weight down in a tuck and the saddle is relatively lightly loaded. As she gets the impulse input, you...
Forum: Road Cycling
09-26-20, 04:06 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

sure looks like it is to me. She looked like she...

sure looks like it is to me. She looked like she hit either a road imperfection or something on the road when the bars jump. That’s a classic “impulse response” from control theory and it looks to me...
Forum: Road Cycling
09-09-20, 04:09 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

Very good point about wheel balance. If the...

Very good point about wheel balance. If the system is underdamped or resonant and that wheel imbalance hits the right frequency, it would probably set off the wobble behavior. Silca makes some...
Forum: Road Cycling
09-07-20, 06:27 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

Here’s a long discussion by Lennard Zinn on bike...

Here’s a long discussion by Lennard Zinn on bike geometry issues related to wobble and mechanical resonance.
...
Forum: Road Cycling
09-06-20, 10:00 AM
Replies: 134
Views: 18,455
Posted By JohnJ80

I’m an electrical engineer with a background in...

I’m an electrical engineer with a background in control system and semiconductor, but the concepts in a mechanical system are the same (and so is the math). Basically, any time you have an...
Forum: Road Cycling
09-04-20, 10:14 PM
Replies: 134
Views: 18,455
Posted By JohnJ80

correct. I don’t agree. the range of uses...

correct. I don’t agree.

the range of uses is so wide, the variance of users also so wide, the virtually infinite variation of road surfaces and conditions are impossible for a manufacturer to...
Forum: Road Cycling
09-04-20, 11:51 AM
Replies: 134
Views: 18,455
Posted By JohnJ80

Not sure I agree with that. It’s a classical...

Not sure I agree with that. It’s a classical mechanical resonance or under damped issue where some repetitive frequency at the right frequency sets up the wobble. Depending on what’s wobbling - top...
Showing results 1 to 14 of 14


 
Forum Jump

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.