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Bonneville Motorcycle Speed Trials => Bville Motorcycle Speed Trials Rules Questions => Topic started by: Pippi2 on May 17, 2017, 08:49:10 PM



Title: BMST Rule Book 2017
Post by: Pippi2 on May 17, 2017, 08:49:10 PM
http://bonnevillespeedtrials.com/wp-content/uploads/2014/02/2017-AMA-BonnevilleSR-FINAL.pdf


Title: Re: BMST Rule Book 2017
Post by: Unforgiven on October 25, 2017, 09:31:05 PM
So, a 1000cc 2006 sportster would be illegal according to BMST rules. Since the rules state that the engine must maintain oem specs. Well that sucks. Legal for SCTA, but not the AMA ?


Title: Re: BMST Rule Book 2017
Post by: donpearsall on October 25, 2017, 11:14:15 PM
You are going to have to give more information. Do you mean illegal in the P-P Class? If you mean P-P, and your engine was originally 883cc and is now 1000cc, then yes, you could not run in the PP Class but you could run in another class such as the 1000cc (if it is under 1000 cc,) or 1300 cc if it is over 1000cc.  There are lots of classes you can still be "legal" in. Just be creative and match your bike to the class you want to compete in.

Not to denigrate the HD, but it could never compete with the 4 cylinder 1000cc bikes like Kawasaki and Suzuki.

Don


Title: Re: BMST Rule Book 2017
Post by: wobblywalrus on October 25, 2017, 11:25:33 PM
The bike would be in the pushrod class.  No four cylinder engines there.


Title: Re: BMST Rule Book 2017
Post by: Stan Back on October 26, 2017, 01:09:38 PM
Where do I run my 800cc Nimbus?


Title: Re: BMST Rule Book 2017
Post by: 4-barrel Mike on October 26, 2017, 01:19:02 PM
Where do I run my 800cc Nimbus?

What  color?   :roll:

Mike


Title: Re: BMST Rule Book 2017
Post by: Unforgiven on October 27, 2017, 11:13:11 PM
You are going to have to give more information. Do you mean illegal in the P-P Class? If you mean P-P, and your engine was originally 883cc and is now 1000cc, then yes, you could not run in the PP Class but you could run in another class such as the 1000cc (if it is under 1000 cc,) or 1300 cc if it is over 1000cc.  There are lots of classes you can still be "legal" in. Just be creative and match your bike to the class you want to compete in.

Not to denigrate the HD, but it could never compete with the 4 cylinder 1000cc bikes like Kawasaki and Suzuki.

Don

Not to disrespect the jap bikes, but they are ugly and cheap, and don't have pushrods, so thankfully I don't have to compete against them.  I just have to beat a XB9 Buell in both sanctioning bodies PP 1000cc class. 136 and change at BMST and the other Buell XB9 144 and change. 984cc to my BMST 883 or 984 to my SCTA 1000cc. I would have to build the bike twice in a matter of a month. Or less. So I have to build for one or the other. I believe with the right gearing set up, I could run faster than 136.


Title: Re: BMST Rule Book 2017
Post by: donpearsall on October 28, 2017, 12:36:10 AM
I guess I am not understanding what size your 2006 Sportster displacement is from the factory. No matter if you run in SCTA or BMST you can't change the displacement from stock if you want to run the production class. So there is no "rebuilding" as far as the size of the engine.  If it is 883cc you have to run in the 1000cc class. If it is a 1200 cc you have to run in the 1350 cc class. It is the same displacement class whether you go to BMST or SCTA.

So my actual point is, since the rules are virtually the same, you can run in both events with no changes to the engine.
Don


Title: Re: BMST Rule Book 2017
Post by: Seldom Seen Slim on October 28, 2017, 06:19:18 AM
Don said:  "...you can't change the displacement from stock if you want to run the production class. "

Yes you can, Don, at least in SCTA rules.  You can change the displacement of your engine as long as you stay within the size limits for the "natural" class of the engine.  Nancy's ZX14 left the factory displacing 1352 cc and ran down the long course at 1532 cc.  We had to stay UNDER the minimum size of the next class, which meant stay below 1650.  And it sat in impound at 1532 and got records at 1532.  You just can't exceed the size of the class the bike was manufactured in - and stay in production.


Title: Re: BMST Rule Book 2017
Post by: Unforgiven on October 28, 2017, 08:29:18 PM
Don said:  "...you can't change the displacement from stock if you want to run the production class. "

Yes you can, Don, at least in SCTA rules.  You can change the displacement of your engine as long as you stay within the size limits for the "natural" class of the engine.  Nancy's ZX14 left the factory displacing 1352 cc and ran down the long course at 1532 cc.  We had to stay UNDER the minimum size of the next class, which meant stay below 1650.  And it sat in impound at 1532 and got records at 1532.  You just can't exceed the size of the class the bike was manufactured in - and stay in production.

Yes, this is correct. And it is how the SCTA rules read. The BMST rules state...must maintain oem engine specs. I can accomplish the SCTA P-PP 1000cc  with a crank/rods piston head swap. And then put the 883 stuff back on for BMST, if I decide I can even get close to 136 and change. Makes it tempting, because I have ran fast enough on a basically stock 883 to think it may be feasible with some serious crank work and serious blueprinting.


Title: Re: BMST Rule Book 2017
Post by: AHG on October 29, 2017, 03:06:45 PM
All Stock 883 Sportster in 1000/P/PP class - at over 136MPH?
I will happily welcome you at impound. :-)


Title: Re: BMST Rule Book 2017
Post by: wobblywalrus on October 29, 2017, 03:34:20 PM
My 1000cc air cooled Triumph ran 146 mph at the BMST in 2014.  It had 87 horsepower on the rear wheel in Beaverton Oregon.  That is possible for a modified Sportster.  It had partial streamlining and was running under FIM rules.  That is roughly equivalent to AMA 1000 cc APS-AG which is 1000cc special construction, modified engine, gasoline.  The desired speeds are possible.  It will take some good aero and a modified motor. 


Title: Re: BMST Rule Book 2017
Post by: Unforgiven on October 29, 2017, 10:13:47 PM
All Stock 883 Sportster in 1000/P/PP class - at over 136MPH?
I will happily welcome you at impound. :-)

Allegedly all stock XB9 set that record. I have never seen an all stock xb9 run 150 mph. Just saying. No one has ever tried with an 883.  I have cyphered over it with a friend and we believe we can get close. I guess I will have to build two sportsters. One for the P-PP 1000cc class at WOS and a stock legal 883 for the AMA BMST. Far as BMST rules, the engine must meet oem specs. That is all it says.  Doesn't say anything else. Lot of hp left in that little 883. I have been learning and talking to the old heads, and it isn't all about hp. I hope we get to meet in impound soon.


Title: Re: BMST Rule Book 2017
Post by: Unforgiven on October 29, 2017, 10:20:07 PM
My 1000cc air cooled Triumph ran 146 mph at the BMST in 2014.  It had 87 horsepower on the rear wheel in Beaverton Oregon.  That is possible for a modified Sportster.  It had partial streamlining and was running under FIM rules.  That is roughly equivalent to AMA 1000 cc APS-AG which is 1000cc special construction, modified engine, gasoline.  The desired speeds are possible.  It will take some good aero and a modified motor. 

I have looked at that class too. Oh I know the evo sportster engine can make a lot of HP for it's size. I have been doing it for decades, I have built more than a few 100 hp sportsters. Folks would be surprised how much free hp resides in a evo sportster motor. The power to weight ratio isn't big jap power, but is respectable for the size of the motor.


Title: Re: BMST Rule Book 2017
Post by: wobblywalrus on October 29, 2017, 11:17:23 PM
Impound?  You will not see me there.  I need to throw my bike off of a bridge to get record speeds in my class.  I will see you at the meet.


Title: Re: BMST Rule Book 2017
Post by: Unforgiven on October 30, 2017, 08:56:23 PM
Not you Wally. Was quoting AHG's post about seeing me in impound if I put an 883 over 136 in 1000cc P-PP. We have been cyphering over this and although I would probably have way more fun building for another class, but I always liked accomplishing something no one else has. BMST rules say must look stock and engine be oem specs. Nothing said about pulley's or sprockets, etc. It would be hard, but I believe with some of John's heads some Darkhorse top secret crank work, etc, etc, I was raised by an NHRA Stock Eliminator racer so, I have been trained to look into every corner of the box. Ain't no way in hell  was a stock 1968 428 CJ mustang running in the 9's from the factory. I am going to be at WOS no matter what next year, BMST may be the run whatchya brung thing. Either way, I will have something: May have to slap together two sportsters.