Author Topic: Rear Fender Tailsection  (Read 5478 times)

0 Members and 1 Guest are viewing this topic.

Offline Marty

  • Full Member
  • ***
  • Posts: 67
Rear Fender Tailsection
« on: January 22, 2012, 02:01:12 PM »
Hey Fello Racers,
                         Very confused about the rule for rear fenders/tailsections. I understand it cant be located back behind rear tire(vertical line drawn) but its the part where it says cannot be lower than rear(wheel) does this mean at any point of tailsection or just the part near rear wheel.My FRP fiberglass GSXR tailsection is alittle lower at the front but not at rear wheel. And is it an unladen rule or laden rule meaning sitting on bike or not?
                         Another question. Can anyone tell me if an aerodynamic front fender is worth any mph,or is it more show, just need some things answered so I may continue my build.

Offline Old Scrambler

  • Sr. Member
  • ****
  • Posts: 721
  • Going Fast - Slowly
Re: Rear Fender Tailsection
« Reply #1 on: January 22, 2012, 02:56:43 PM »
Different rules for various classes..........What's Yours?

In Modified chasis, the tail cannot extend beyond the rear tire and must be no lower than the top of the rim (static) from the axle to the rear.  In Modified Partial Streamlined the length is the same but the tail section can include (cover) the upper rear portion of the wheel.

In A-Special Construction the tail can extend beyond the wheel...........and now its time to read the rule book. Always be specific to your class. 
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline ol38y

  • Sr. Member
  • ****
  • Posts: 686
  • When all else fails, gas it!
Re: Rear Fender Tailsection
« Reply #2 on: January 22, 2012, 03:22:02 PM »
At BUB a front fender is required weather it has an aero advantage or not. So, you might as well use one with an aero advantage...
Larry Cason
Bakersfield,CA    It's a dry heat!

2010 BUB 1350 M-PG record
2012 Speedweek  1350 A-PG record 169.975
2014 El Mirage Dry Lake  1350 A-PG  172.651

Offline Stainless1

  • Administrator
  • Hero Member
  • ***
  • Posts: 8968
  • Robert W. P. "Stainless" Steele
Re: Rear Fender Tailsection
« Reply #3 on: January 22, 2012, 10:36:00 PM »
Hey Fello Racers,
                         .....Another question. Can anyone tell me if an aerodynamic front fender is worth any mph,or is it more show, just need some things answered so I may continue my build.

We ran 3 different front fenders on the 1000, one was a stock busa, worth a little less than 2 MPH over the GSXR fender, and a streamlined Busa fender that I made with the front of the fender even with the horizontal plane of the front axle, worth 3 more than the busa fender.  So my opinion is they are just for looks and speed.  There is a reason for limits on how wide and how much fork coverage is allowed... aero advantage 
Start a build thread.. pictures
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Marty

  • Full Member
  • ***
  • Posts: 67
Re: Rear Fender Tailsection
« Reply #4 on: January 23, 2012, 08:11:27 PM »
Thanks for that reply stainless1. I have seen a few land race front fenders on airtech website.My build will be unfaired,so I am thinking an aero fender is a good idea,reason I asked is my bike does double duty as a dragbike ,just trying to keep costs down, but i am willing to spend alittle to get a little. Thanks again.

Offline Stainless1

  • Administrator
  • Hero Member
  • ***
  • Posts: 8968
  • Robert W. P. "Stainless" Steele
Re: Rear Fender Tailsection
« Reply #5 on: January 23, 2012, 11:26:09 PM »
SCTA doesn't allow the aero fender on open bikes, Bub still does but they have the very restrictive rules on tail sections.  Look at Scooters pictures, there is a thread here somewhere, lots of Bub bikes, and the Bub threads, it will help you understand the rules a little better.
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Marty

  • Full Member
  • ***
  • Posts: 67
Re: Rear Fender Tailsection
« Reply #6 on: January 24, 2012, 09:31:17 AM »
Hey Guys,
               Have another question. If running in A-AF class can I have a fiberglass reproduction fake headlight,It doesnt say anything about it in my rule book under that class. However in M-F it states not larger than 5" in diameter? is that also used for rules in other classes as well.This seems alittle vague to me as well.I have been using an SCTA rule book for all my rules.
               I understand all about the Aerodynamics of such a thing BUT at which point is it illegal??Thanks

Offline Stainless1

  • Administrator
  • Hero Member
  • ***
  • Posts: 8968
  • Robert W. P. "Stainless" Steele
Re: Rear Fender Tailsection
« Reply #7 on: January 24, 2012, 09:53:25 AM »
A bikes generally don't have headlights, special construction is normally purpose built race bikes, no headlight required or needed.  M bikes are modified production, not purpose  built race bikes.  Be careful using the SCTA book for Bub.  Bub rules (AMA) are on line I think and you can contact them through a link on this site for printed rules.
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline ol38y

  • Sr. Member
  • ****
  • Posts: 686
  • When all else fails, gas it!
Re: Rear Fender Tailsection
« Reply #8 on: January 24, 2012, 10:11:01 AM »
Marty, in SCTA you can have a headlight in M class but a definate "NO" in A class. As far as I remember in BUB you can have a headlight in either M or A. You can download BUB's rules online. Just remember they may change when this years rules come out.  Larry
Larry Cason
Bakersfield,CA    It's a dry heat!

2010 BUB 1350 M-PG record
2012 Speedweek  1350 A-PG record 169.975
2014 El Mirage Dry Lake  1350 A-PG  172.651

Offline nrhs sales

  • Sr. Member
  • ****
  • Posts: 976
Re: Rear Fender Tailsection
« Reply #9 on: January 24, 2012, 10:50:51 AM »
Yes you must build your bike specifically to either AMA (Bubs) or SCTA rules as they are very different especially in regards to bodywork that is allowed or not allowed.

Offline Marty

  • Full Member
  • ***
  • Posts: 67
Re: Rear Fender Tailsection
« Reply #10 on: January 24, 2012, 09:00:26 PM »
Hey guys,
                 I have read both AMA and SCTA rules over and over and since I am running in BUB it does not state I cannot run a fake headlight, BUT what size am i going to get away with, Hate to show up with bike all setup, just to have to take it off? Please help thanks

Offline 55chevr

  • Hero Member
  • *****
  • Posts: 2446
Re: Rear Fender Tailsection
« Reply #11 on: January 24, 2012, 09:16:44 PM »
most rules say 7"

Offline racer

  • Full Member
  • ***
  • Posts: 245
  • Impound 2009. sweetest spot at Bonneville.
Re: Rear Fender Tailsection
« Reply #12 on: January 25, 2012, 02:18:22 PM »
Once you decide what size head light to run, try mounting it backwards.
Might be a bit more aerodynamically friendly.

 
Hey guys,
                 I have read both AMA and SCTA rules over and over and since I am running in BUB it does not state I cannot run a fake headlight, BUT what size am i going to get away with, Hate to show up with bike all setup, just to have to take it off? Please help thanks
Ray C Wheeler

Offline Marty

  • Full Member
  • ***
  • Posts: 67
Re: Rear Fender Tailsection
« Reply #13 on: January 25, 2012, 02:26:07 PM »
Hello stainless1, I would love to start a picture thread BUT I am completely computer illiterate. I can barely turn one on, just use it for mail and 2 websites (landracing.com) and (Dragbike.com) If my grandkids can help me with it I will try, Thanks

Offline ol38y

  • Sr. Member
  • ****
  • Posts: 686
  • When all else fails, gas it!
Re: Rear Fender Tailsection
« Reply #14 on: January 25, 2012, 05:13:39 PM »
Once you decide what size head light to run, try mounting it backwards.
Might be a bit more aerodynamically friendly.

You'll never get away with that in SCTA tech and I doubt it at AMA either. Years ago you could but not anymore...
Larry Cason
Bakersfield,CA    It's a dry heat!

2010 BUB 1350 M-PG record
2012 Speedweek  1350 A-PG record 169.975
2014 El Mirage Dry Lake  1350 A-PG  172.651