Welcome, Guest. Please Login.
rbent - Recumbent Bike Enthusiasts of North Texas
Mar 29th, 2024, 12:24am
News: Want to join the rbent Forum? See this thread.
Home Help Search Login


Pages: 1 2 
Send Topic Print
2017 Hotter 'N Hell Hundred (Read 7029 times)
MrWizard
Five Star Member
*****


bonus mile sponge

Posts: 671
Re: 2017 Hotter 'N Hell Hundred
Reply #15 - Sep 5th, 2017, 10:08am
 
CF is partially metallic ..  Enough so that it kills radio signals ..   A cellphone inside the shell of a velo typically won't get signal ..  neither will a GPS ..  Thats part of the reason I have that re-rad box on the velos, to move the outside GPS signals, inside.  
 
with RFID  putting the tag outside on the shell  doesn't work ..  there's a phenomena called "electromagnetic reflectivity " that distorts the transmitted signal making it unreadable.     RFID works by a small transmitter that is charged up by the loop (similar to those contact-less chargers on some cell phones)    The "loop"  transmits energy which charges the on-chip transmitters capacitor which, when charged enough, causes the ID signal to be transmitted which it then reads via a receiver in the loop.      The shell reflects so much of that energy that the charge-to-transmit timing is off and the transmit signal itself becomes distorted.  
 
 
 
Quote from Action Lad on Sep 3rd, 2017, 7:20pm:
Quote from MrWizard on Sep 3rd, 2017, 9:39am:
Carbon fiber velomobiles and RFID don't mix .. There's a newer chip design that works better, but HH100 isn't using it.
Oh, is it that the CF doesn't let the signals get through?  I don't know what they look like, but is it possible to have it on the outside?  Does it fall off/jounce off easily?   Smiley

Back to top
 
 
Email   IP Logged
MrWizard
Five Star Member
*****


bonus mile sponge

Posts: 671
Re: 2017 Hotter 'N Hell Hundred
Reply #16 - Sep 5th, 2017, 10:09am
 
Yeah .. even then it missed two of my loops at the TTTT ..    Angry  We had to put it fairly high on that plexiglass to even get it to read.  
 
Quote from rmillay on Sep 4th, 2017, 9:37pm:
We had the same problem last year at TTTT.  One carbon fiber TT bike we had to arm wrestle the rider to put the chip where it was away from the frame.  Doug's velo was trickier, as there isn't much in the way of things sticking out to put the tag on.  I think we finally stuck it to his plexiglas windshield.

Back to top
 
 
Email   IP Logged
Pages: 1 2 
Send Topic Print