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Bonneville Motorcycle Speed Trials => Bville Motorcycle Speed Trials Rules Questions => Topic started by: Chris V on January 22, 2017, 02:17:29 PM



Title: Hump on back neckline
Post by: Chris V on January 22, 2017, 02:17:29 PM
searched forum for this and in June 2015 this was asked and no real answer that I could get out of it.
So is anyone have the hump on there leathers behind the helmet in a class other then "Partial Streamlining"
After being at Bonneville the last 6 or 7 years and never rode the mile I'd like to try out.


Title: Re: Hump on back neckline
Post by: DRW on January 22, 2017, 04:19:38 PM
My Alpinestar suit has the hump, I rode in BMST Run What ya brung class with it, No problem ,  But if you run that class
Your stuck on the Short 3 Mile track !!
 


Title: Re: Hump on back neckline
Post by: Koncretekid on January 23, 2017, 08:21:07 AM
At BMST, I had thought that the use of a speed hump in all but partial streamlined was not allowed, but having re-read the rules about 3 times last night, I can find no mention of it.  The only possible rule that may apply is as follows:

5. J. OPEN CLASS
Open class motorcycles do not permit streamlining. Streamlining is anything that has the perceptible purpose of directing or controlling the airflow around the motorcycle and/or rider, thus reducing drag.

So it may be a judgement call by an inspector, and a written request to the tech committee may be the only way to confirm that the speed hump may be used in other classes.  I, too would like to know the answer so I don't end up with two sets of leathers to run open and PS classes.

Tom


Title: Re: Hump on back neckline
Post by: Calkins on January 23, 2017, 09:13:10 AM
If you 100% do not intend to set a record, you should be able to run a speed hump in any class.

My friend got teched at Speed Week (SCTA) and Van Butler allowed him to run his RR leathers with a hump, since he was just planning on getting his license.  AMA/FIM may be different, it all depends on the tech guy.  If you enter a class, and tell them you are just going out for kicks, you should be fine.


Title: Re: Hump on back neckline
Post by: Seldom Seen Slim on January 23, 2017, 09:20:19 AM
A couple of comments offered for whatever they're worth.

The hump in my Z Leathers is removable - sort of.  That is, the lump itself is stuffed inside a zippered pocket on the back - so the stuffing can be removed to (theoretically) make the leathers okay for classes where the hump ain't kosher.  HOWEVER - and it's a big HOWEVER - the "pocket" that remains when the stuffing is taken out ain't very supple, so either yoou'll need to give up lots 'cause it's so ugly to the wind as it flutters and flaps - or you'll have to tape it down like hell's hounds are chasing you for that loose leather.

And I've gone through tech a few times with the hump all there and standing proud - with nary a question about the suitableness for class.  That's what's to be expected.  But there hasn't been a re-inspection after I qualified/backed up a record -- to see if that hump is there and if it's legal in my class.

That that for what it's worth.  By the way, all of my runs have been SCTA/USFRA.


Title: Re: Hump on back neckline
Post by: Chris V on January 23, 2017, 10:16:04 AM
Thanks for the reply's I'm going to contact BMST rules committee and forward my concerns


Title: Re: Hump on back neckline
Post by: Seldom Seen Slim on January 23, 2017, 10:23:35 AM
That's ALWAYS the best way to get the answer you need.


Title: Re: Hump on back neckline
Post by: Pippi2 on March 25, 2017, 09:42:17 PM
Thanks for the reply's I'm going to contact BMST rules committee and forward my concerns

Tech@bonnevillespeedtrials.com

See you on the Salt,
Linnea


Title: Re: Hump on back neckline
Post by: Freud on March 25, 2017, 11:33:35 PM
The way the SCTA stresses safety it seems

they would be hard pressed to consider the lump

as streamlining. Safer to run in one class than

another because of the way the leathers are made:

preposterous.

FREUD



Title: Re: Hump on back neckline
Post by: Chris V on March 26, 2017, 10:38:47 AM
I've forwarded my concern to Tech BMST twice beginning 01/23/17 havn't heard anything yet 
would like to know for sure so as to enter proper class


Title: Re: Hump on back neckline
Post by: Pippi2 on March 26, 2017, 12:01:42 PM
I've forwarded my concern to Tech BMST twice beginning 01/23/17 havn't heard anything yet 
would like to know for sure so as to enter proper class

I emailed them for you just now….
The main home office has moved and is in the process of setting up shop again.
Thank you for your patience.
have a great weekend. -Linnea


Title: Re: Hump on back neckline
Post by: **RP** on September 05, 2017, 10:30:10 AM
Did anybody get an official answer on this?  I see online 2017 photos of the 3000 A-PBF record breaker in AMA and FIM with the hump?


Title: Re: Hump on back neckline
Post by: TheBaron on September 05, 2017, 11:20:05 AM
My understanding in SCTA is that "Humps" are legal for "Partially Streamlined" classes ONLY....

Robert in California


Title: Re: Hump on back neckline
Post by: **RP** on September 05, 2017, 04:22:51 PM
I am asking about BMST event rules.


Title: Re: Hump on back neckline
Post by: RansomT on September 05, 2017, 05:12:56 PM
Just have butt implants surgically inserted high on your back and make the leathers to fit. Anything for speed!


Title: Re: Hump on back neckline
Post by: stay`tee on September 05, 2017, 06:52:41 PM
The "hump" has stuff all affect on speed, however, "standing"(flattening your back) can make a significant improvement  :-)


Title: Re: Hump on back neckline
Post by: AHG on September 06, 2017, 11:49:50 AM

#1 - The comments regarding SCTA rules serve no purpose on the BMST page, as that speed meet is strictly involved with the AMA and F.I.M. regulations.
The same would pertain to motorcycle rules inquiries for the Cook Shootout.

#2 - Leathers with the hump on the back are allowed in all AMA and F.I.M. LSR classes, except for streamliners naturally


Title: Re: Hump on back neckline
Post by: Pippi2 on September 07, 2017, 09:27:57 AM
Page 23 of the BMST Rule Book:
2. O. (IV) LEATHERS
Suits made of synthetic material are not permissible. The use of stretchable Kevlar and perforated materials in non- critical areas are permissible. Leather suits shall be one- piece design or joined by a full circumference zipper at the waist. Leathers cannot be too big or loose. Critical area (knees, elbows, forearms, shoulders) armor or 2-layers of leather is highly recommended. Due to invisible flames, riders’ of motorcycles burning fuels of Methanol content are recommended to wear Nomex underclothing or something of similar nature.

We do not have a rule on leather humps. It's the machine that gets classified for records, not what you are wearing.
The BMST has different rules than the SCTA.

Stay fabulous,
Linnea


Title: Re: Hump on back neckline
Post by: comet on September 12, 2017, 10:39:44 AM
Chris it was brilliant to see you running the bike this year. Can't tell you how much Dawn and I enjoyed flagging you both off. Well done to you both.
Best wishes.



Title: Re: Hump on back neckline
Post by: Chris V on September 13, 2017, 09:33:27 AM
Comet, we are off topic here but anyway I am looking forward to next year :-D, Sandy not so much :cry:


Title: Re: Hump on back neckline
Post by: comet on September 13, 2017, 10:16:08 AM
It was a hot one this year for sure. It must have been hard work sitting in leathers.
I have read elsewhere (previously) that the race humps in leathers do not have much of an effect on performance until higher speed numbers are reached, over 125ish. Not sure if that is correct or not. But I have also heard they offer a safety benefit. A local hospital in Kent was doing research a couple of years ago into accidents with and without speed humps. I never found the outcome which would have been very interesting.


Title: Re: Hump on back neckline
Post by: Doc B. on November 20, 2017, 10:46:10 PM
For what it's worth, the late Dr. John Hinds wrote about speed humps and in particular their hindrance of getting an injured rider safely on their back in the case of spinal injuries and for the difficulty added during intubation. His experienced recommendation was to roll the patient on their side and cut the hump off with a scalpel so you can get the patient in a natural supine position without their head tilting back.

http://motorcycleminds.org/2017/03/24/the-hump/ (http://motorcycleminds.org/2017/03/24/the-hump/)

Note that this article does not deal with whether or not a hump is more safe than no hump in a crash. But Hinds pointed out that they are an aero feature, not a safety feature. My impression is that back armor and a neck brace (or one of those awesome inflatable MotoGP suits) are going to be more effective than a speed hump in preventing injury in that area of the body. Seems pretty clear a speed hump is for, well, speed. Hinds was a really entertaining lecturer and I highly recommend his Cases from the Races lecture that is posted on youtube.


Title: Re: Hump on back neckline
Post by: noboD on November 21, 2017, 07:25:16 AM
Just a semi-related question from the cheap seats. Are the new helmets with the point in the back considered aero? Seems to me if the speed bump is so should the helmet.


Title: Re: Hump on back neckline
Post by: maj on December 25, 2017, 02:50:11 PM
I am looking at the airbag suits now , and in one brand at least if not more of them the hump is used as the storage for the electronics and CO2 cylinder ,
 That will be a bit harder to remove for SCTA