Landracing Forum
Tech Information => Aerodynamics => Topic started by: joe-r1 on February 03, 2013, 02:21:54 PM
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Hi! First i would like to excuse me for my bad english!
I'm new to LSR and i would like to have some info on what to do and not to do...
To begin with, my bike is a 08 yamaha r1 stock motor that i use on the street and on the strip for fun. I know its not the best bike in the world for dragracing or LSR but that my bike for now...
I'm tinking about aero and i would like to have advice...i put a link a the end so you can see my bike and what i'm talking about...
I would like to start with the front...it is better to get the bike lower as possible so it can reduce the frontal surface (big hole behind nose and fender)? i put some picture of my bike stock, then lowered 3/4 in and then 3/4 in lower and strapped...i would like to know in which configuration it will be best to put my bike for top speed.
For back of the bike, it is better to get the bike also low as possible or like stock form? I don't know if it will affect the front, front lower and back up so the nose of the bike will point down...Maybe bike geometry (steering)...
Also i know its the aero section but do extended swingarm as benefit for a strock motor bike? i already have extension...
If you have other suggestion to get my bike better for LSR without a full bodywork feel free to share!!
http://s1302.beta.photobucket.com/user/Joe-r11/library/
Thanks
Joe
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Three places to start.
Rulebook: http://www.scta-bni.org/
Fiberglass options: http://www.airtech-streamlining.com/landspeed/landspeed.htm
Go thru old Build Diaries on this forum, anything bike, especially starting with APS or MPS. Do NOT miss this one: http://www.landracing.com/forum/index.php/topic,9341.0.html
Have fun!
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your English is a lot better than some people that live here.
getting the front and rear of the motorcycle lowered is probably the best bet.
most of the rulemakers have a percent limit on total bike length from stock, depending on class and organization.
strapping the front end might not be a good idea . can the fork tubes be extended through the top triple tree ? can you get shorter fork tubes?
bf
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You're on the right track. There's nothing wrong with strapping the front. Many have done it. I would just lower the rear as much as the front to keep your front geometry the same. Then, get rulebooks for where ever you want to run. :cheers:
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if you strap that front end enough , you're going to have little or No suspension.
then what?
or is it just me?
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The main thing is to work with the bars, pegs, and seat to get yourself down low on the bike with all of you gear on. Then, have someone take pictures of you on the bike from the front, back, and side. Next, make a copy of the pictures, cut out you and the bike's silouettes, and enlarge or reduce them enough so you can transpose them onto graph paper. Then you can start to design stuff.
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Thanks saltwheels262!
i don't strap the front too tight...even on the drag strip i get speed wobble if i tight it too much! And yes i can slide the fork tube more than 3/4in.
Thanks wobblywalrus!! That a really got idea that i never think of!
An other think also is i will need some info on suspension tuning... right now it set like a drag racing...(an other tread in suspension section?
Thanks!
Joe
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On the subject of a lengthened swing arm, many of the fastest, and sometimes the fastest, sit-on bikes at the BUB meet have production frames with standard length swing arms. A lot of these folks say more length is not needed and they have the records to back them up. A lot of other fast people lengthen them. There are some advantages. It is easier to get a good streamlined shape on a longer bike. An experienced racer told me a 6-inch extension would be right for my 1000cc bike. Geez. Its hard to figure out the hot set up when two groups of people get good results doing things completely different ways and they have totally logical reasons why they do it. It is like that with suspension, too.
It is nice to see a big Yamaha four on the salt. Those R-1s are great bikes.
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Reducing the height by the same amount front and rear retains the original rake (caster) angle, but reduces trail.
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I've always preferred long motorcycles. with a good 1 inch rake.
street, strip or land speed.
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Reducing the height by the same amount front and rear retains the original rake (caster) angle, but reduces trail.
Reduces wheelbase
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Salut Joe:
Loring posts the rules on the web: http://www.lta-lsr.com/Pages/default.aspx. I assume you're planning to be there in July? Let me know if you have any questions and we can get them answered. It's a lot of fun!
Frank
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if you strap that front end enough , you're going to have little or No suspension.
then what?
or is it just me?
IMO it's just you... :evil:
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Thanks guys!
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Whatever you do, make it and you the smallest hole that can be put in the air, then carefully close the hole.
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Joe you are a member of the R1 forum correct ? Your bike looks familiar. What event are you planning to attend ? I would love to know what speed you do, as I hope to run either my 2006 or 2012 R1 at Ohio Mile in June,July or Sept. Gearing used could also be a great benefit as well. Good Luck and go fast !
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Yes i'm a mender on R1-forum...i will try to go at the Loring event if i can get time off!...i have done 186 on stock form and gearing on GPS with some tire spin and in the rev limiter so yes probably good gearing will help me a lot! That an other thing i will try this summer, some gearing...
Good luck with your's and get me some news!!
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When is the Loring event ? Ohio is much closer for me in Pa. I'm quick kurt on the R1 forum.
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From the Loring section of the forum here: http://www.landracing.com/forum/index.php/topic,12068.0.html Tech July 11-12-13. Racing July 12-13-14.
Link to the LTA is on this site's homepage, upper left side.
Ed
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Joe,
I hope to see you in Loring in July. It's just too close to you to miss it! I plan to be there early to help with tech inspection. Regarding making changes, you might want to try it with the stock set up to see if you have any problems at 186 mph. If you do lower the front without lowering the back, it will reduce the trail which could make your bike more prone to a tank slapper.
In my opinion, sport bikes are designed to turn easily and quickly, not especially to run flat out in a straight line. I would advise to take the headstock bearings apart, clean, and re-grease, but don't overtighten them on replacement. Any resistance to steering inputs can set up a weave. The steering damper is still required because it is designed to restrict larger motions which happen in a wobble or tank slapper.
Check the LTA rules and make sure you're bike meets them, including tires less than 10 yrs. old, a metal battery hold down, and safety wire to prevent your oil filter from unscrewing (ask me how I know that one!)
Tom
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Hey Tom! Thanks for the advice, I really appreciate!! I don't know if my bike will be ready for the loring event but one of my friend will try his turbo zx14 probably so i will be with him for shure! If i can get my bike ready i will go, if not i will do some testing this summer and probably next year it will be ready!
Thanks and i hope to see you there!
Joe