Landracing Forum
Bonneville Motorcycle Speed Trials => Bville Motorcycle Speed Trials Rules Questions => Topic started by: Cereal KLR on February 02, 2014, 06:01:02 PM
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Hot off the press, changes are highlighted with an * :cheers:
Six months and counting...
http://www.speedtrialsbybub.com/2014_event/AMA-BUB-SR-2014.pdf
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Much closer to SCTA,
And better defined than previously
Looks like i am still FIM only , but at least i go there knowing that :cheers:
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The most controversial parts of the rule book have been addressed. Now we have in writing that you cannot use a stock frame in the A class (unless you chop it up and radically modify the seat height and/or the fork rake angle.
On the other hand, now the rear wheel can be streamlined like in SCTA.
So they gave some and took some away. I wonder if this mean they will have less entries because of the A class frame issue.
Don
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Ok so as I read it my bike passes as a special construction bike .....I have a stock Hayabusa frame raked 10* a specially constructed sub frame ( which lowers the seat hight ) ...extended swing arm 10" and a wheel base well over stock ....does this pass as an A class bike ??? .....asking now before I start a new rebuild project which will extend the wheel base at least another 20%
cheers
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Big Thankyou to those responsible for getting these out so early, :cheers:,,
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125 minimum for the 5 mile course? My little 500 needs two miles to get to 106 mph. If it is about keeping traffic flowing, I don't think it is the sub 125 bikes that slow things up as much as the "no bikes running" time. Karnac the Great sees legendary lines at the short start.
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Now that I read the rules for the A class frame, I can't see why a "purpose built, non production" frame is all that is needed to qualify for the class. But even if you build your own frame, it still has to meet the other criteria such as seat below the wheel rim height or have two engines.
If you build your own frame, it can't have a "wheelbase exceeding factory O.E.M. dimensions by more than +10%" or "Altered steering head angle". So that just leaves seat height or two engines to qualify.
So if I build a completely purpose-built custom bike with single engine and the seat height above the wheels, it will not qualify for the A class. But it will not qualify for the M class either, since that is for factory bikes. Crazy.
Don
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Don,
I think you are reading it wrong. it says you must have a minimum of 2 of the following:
2 engines with a combined displacement not to exceed 3000cc.
Seat base
is lower than an imaginary line drawn between the
tops of the rims.
Altered steering head angle.
Center hub steering.
Purpose built Non production frame.
Wheelbase exceeding factory O.
E.M. dimensions by more than
+10%. Measurement will be taken at the most forward axle
setting. It shall be the participant’s responsibility to provide
proper documentation listing specifications.
So as I read it all you can still run a factory frame as long as you have an altered steering head angle and an extended wheelbase which is pretty easy to do.
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Yes, I know you can run a factory frame if you modify it. BUT if you build a custom frame, that by itself does not qualify the bike for the A class. It still needs to meet 1 more criteria, such as seat below rims or two engines.
Don
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If it is a custom frame then what would you base the swingarm length or steering stem angle off of? Think about that for a minute and you will see that if there is no stock frame to compare it to then it would automaticaly qualify as an "A" bike would it not? Don't try to overthink things.
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I am not over thinking, just reading the rules as they are written. If a custom frame by itself qualifies, why wasn't that in the rules? Instead they included a custom frame as ONE of the TWO criteria. It is an assumption that it qualifies by itself. If the rule makers intended any custom frame to qualify the bike as an A class, the working would be a lot different.
Don
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ok Don,
If that makes you happy to get all tied up in the interpretation of the rules then so be it. I on the otherhand can understand that a custom frame automatically WILL make it an A bike as any custom frame automatically qualifies it for the altered steering head angle and wheelbase so it immediately has met 3 of the criteria.
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If an altered steering head angle is a qualifier for the "A" class, how do they do the measurement of the angle when on the salt?
How much angle from OEM is enough to qualify as altered?
What/who determines that it is a "Production" frame?
If you have a 2008 GSX-R 1000 frame with a 1990 RM500 engine installed is "Production" based on the GSX-R or the RM?
What if there are no identifying markings or VIN on the frame, can is still be qualified as "Production" just based on how it looks to the inspector?
Lots of questions that i would guess will be up to the Tech inspector to add their "interpretation" to. Looks like a lot of Grey area up for grabs.
JW
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I do hope somebody in the know does answer the above question about steering head angle. Would a set of offset triple tress that gave say 2-3 degrees more rake angle qualify or do you need to actually cut and modify your steering tube if using a stock frame?
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I do hope somebody in the know does answer the above question about steering head angle. Would a set of offset triple tress that gave say 2-3 degrees more rake angle qualify or do you need to actually cut and modify your steering tube if using a stock frame?
I may not be the "in the know" guy, but - :-D
Since no minimum or maximum change in steering head angle is specified, one would think that whatever additional degrees you added would qualify as a changed "steering head angle"
I personally would NOT consider raked trees as being the same as changing your "Steering Head" - Fork trees are a totally different structure then the "Steering Head" :-o
As for a "custom built" frame - I would tend to think that would fall into the "Purpose Built" terminology.
I am with ya Dan as far as sometimes you can over think something. :cheers:
Sure we have to be prudent with the time on our builds. I like to just dissect the line and focus on the key words.. :cheers:
When in doubt pm the Tech Steward, he's right here at Landracing .com - & a nice guy, or e-mail the AMA and ask Ken. :roll:
Have fun
Jimbo
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I applaud the changes for 2014, especially the change in APS to agree with SCTA and others. And I really like the cap on the "Classic" bike year at 1981. I think this will get more people interested in building a nice Classic bike knowing that later (after 1981) water coolers will never be allowed. Let's see, Suzuki Katana 750cc dual overhead cam, 4 valves per cylinder, 82 hp comes to mind! I wonder how big that motor is physically?
As for the distinction between Modified and Special Build, I think they are just making things a lot more difficult than they need be. I would say just let any bike run that meets the safety specs. If somebody wants to run a supercharged Hayabusa in "A", let 'em go. The only person that will not be happy is the guy who held the "soft" record before, and that's just an additional challenge. Unlimited in design should be unlimited.
I am disappointed that there are some records that were set in 2013 (at least 3) that there was no class for, but their records were allowed to stand. I'm talking about Production class bikes that ran in "Fuel" class or in "Production Blown" class with "non OEM superchargers", as these are specifically prohibited by my interpretation. I wrote for clarification of these rules (not specifically pointing out the offenders) in the hopes that they would be rectified. Maybe I'm interpreting the rules wrong, and if somebody can straighten me out, I would appreciate it.
Tom
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I applaud the changes for 2014, especially the change in APS to agree with SCTA and others. And I really like the cap on the "Classic" bike year at 1981.
Tom
The cap on the year was an good idea - But - Why limit engine class size to 1000 cc :roll:
What about the Knuckles, Shovels & Pans 1200 cc bikes ? Why would the 74 cu. in. pre 1981 Knuckle, Shovel & Pan Heads be excluded? I would have hoped that the engine size classes for the Classic Class would have followed the same engine size classification for all other classes.
Stay happy, healthy & warm -12 deg. last night, 9 deg. for our high today
Jimbo
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I have been informed by somebody in the know that triple trees does not qualify as altering the steering angle. you must physically change the frame.
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I have been informed by somebody in the know that triple trees does not qualify as altering the steering angle. you must physically change the frame.
Maybe you can ask your guy how they determine that the stock steering angle has/hasn't been altered. Do they use an angle finder on the steering head as it sits ready to race or some other method?
As I understand it, steering head angle is measured by the angle that a line through the center of the steering head intersects a horizontal line running front to rear of the motorcycle. If that is correct wouldn't changing the front or rear ride height effectively alter the steering head angle?
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that is a question I would recommend you ask one of the officials personally.
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A simple way to measure Steering head angle (rake) is with a simple tool called a saw protractor. Works excellent, used properly you can dial in right to the exact degree.
I'll attach a picture of the type we use - hope it uploads for ya. :cheers:
Jimbo
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I'll see if I can find an answer from the AMA Tech guys.
A simple way to measure Steering head angle (rake) is with a simple tool called a saw protractor. Works excellent, used properly you can dial in right to the exact degree.
I'll attach a picture of the type we use - hope it uploads for ya. :cheers:
If using the Saw Protractor, what are us using for the horizontal axis, a bubble level?
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"If using the Saw Protractor, what are u using for the horizontal axis, a bubble level?"
A good 4 ft. level works fine. you can use it for a horizontal or a plumb fixture. I have checked rake angle both ways just to verify the first measurement.
Its really kind of simple and quite accurate.
I tried to up load a picture of how we do ours, but the file came back as too large - sorry -
Jimbo