Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: Sam on January 30, 2015, 09:55:27 AM
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My Team and I are building a bike in the special construction streamliner class, we are aiming to reach between 200 - 230 mph. The vehicle will weigh approximately 500kg or 1,102 pounds. the Goodyear Eagle land Speed tire was recommended; however it is a square profile I know you can get the tread cut to add a bit of camber but the Bridgestone BT003 was also recommended. The Bridgestone is a proper motorbike tire and I was told by an SCTA member they are rated to 230mph but I spoke to a dealer and he stated they were only rated up to 180mph.
My question is to anyone who was run a motorbike, Are the more square Goodyear Eagle tires more or less stable than a regular cambered motorbike tire for the Bonneville Salt Flats?
Is the increased weight a problem for the standard motorbike tires?
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Sam, welcome to LSR. I'm a streamliner guy not bike liners but the advice will cross over. You need to design & build a liner around the tires & you need to chose a tire that is capable of going way beyond where you think you might run because once you have a taste $hit you will want more. The Mickey Thompson LSR tires don't have the square-ish type shape to them like the Goodboots do & I agree, I don't think that would be too desirable on a bikeliner.
Sid.
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Sam,
It might help if you indicated the wheel size you will be running under the streamlined shell.
As a car person I had to turn to the motorcycle pages of the SCTA rule book I had to hand - you need "special tires for racing" if 200+ is the target. You also need reinforced wheels.
The information will be available here I am sure.
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The BT 003 is good to 265mph. What class are you going to run? If youy are running a 17in wheel they do not need to be reinforced.
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Goodyears are not all that square edged when inflated on the correct rims , been used on bikes without buffing the edges
i think they are a viable option , as is the 003 up to your 230 or so
What motor are you planning, good streamliner does not need a real lot of power to do 200 , are you sure your not underestimating the potential
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We've got a decent amount of space in our design both front and back could fit up to 25 inches both ends. I'm not the suspension guy I do the Aero dynamics but I'll try and get him in on this conversation, would probably help. Where first timers to the salt and we've got engine that supposedly puts out 200-210bhp I'm doing windtunnel testing this month with my university. If I've got everything right we should have a very low drag coefficient 0.2-0.3 but time will tell. We may be able to run beyond 230 but costs are a big factor and we need to enter manufacturing stages.
I would like to run the Bridgestone's but don't know if they'll handle the increased weight well?
On a normal bike I imagine from an engineering point of view pushing them beyond their recommended limits by about 30% sounds about right most manufacturers give a decent safety margin. but with the weight doubled it's going to become an issue i think?
Please feel free to correct me if I am wrong in my assumption.
But thank you all for your help so far is helping clarify a lot of things
P.S I think I may have two ask use about rims as well I was looking and they couldn't find any that would fit the good year tires
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Hi Sam,
Are you the Sam from Project velocity? Giving the guys here some context will help with their advice... :-D
http://projectvelocity-bonneville.com/
:mrgreen:
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Yes i am the Sam from Project velocity thanks for the plug. Where actually getting all geared up to begin manufacturing so if you follow our Facebook you'll see your comments in action and I'll make sure to give everyone a big thanks for their help. Without the support we have had so far the project would still be a rubbish sketch on my bedroom wall.
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What engine are you going to use?/
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Great project Sam, nice to see some younger participants, great project for your education / prospect career!
If the bike works out a slippery as your design, I think you may need the LSR Tyre! :cheers:
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Sam -
200++ horsepower is a baseline target to get a "regular" street bike (fairing and such) to 200. In a liner you'll have enough potential to go way over 2 bills if you bring that much HP to Wendover.
I don't have the rulebook in front of me right now -- but if memory serves correctly "square" edged tires are specifically prohibited on bikes running SCTA/USFRA rules. The rule was aimed at putting car-type tires -- whether street legal or maybe drag race tires -- on a bike.
You do have a rulebook or four in hand during your build, right? Whatever -- you should think about getting one poste haste. The '15 book will be available within a month or so, but in the meantime -- get a '14 rulebook and use it and the updates and changes that ware listed elsewhere on this website. You'll then be privy to all the pertinent rules for bikes this year.
Welcome to the Forum. Visit often -- and please post photos whenever possible. We all are interested in seeing what you're doing. :-D :-D
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The Buddfab liner went 145mph with a 50cc Aprilia engine ... 24 horsepower. Demonstrates what efficient aerodynamics can do.
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I am not sure if it helps much but I have been doing some research and planning on a motorcycle streamliner for a while. My plan is to use the engine in my 650 APS-BG bike at first but build it for twin turbo 600s. Anyway I emailed Goodyear about their land speed tires and this was the response I received.
"I received your request about land speed tires for your streamliner build. The tires we currently offer are all rated at 300 mph and come out of a square shoulder mold but with the inflation pressures recommended for land speed use the tire becomes fairly rounded. "
My plan at this point is to build the bike to fit two engines running land speed tires but run it in the mean time with one engine and run BT003s or hard compound R10s until I can swing twin engines and custom wheels to fit the land speed tires since they fit a 15" rim. I am panning on making the wheels fit the current axels and ceramic bearings if I can. My understanding is the "race" tires specified in the rule book, including the BT003 and R10 should be fine, as far as the SCTA is concerned up to the 265mph range. Hopefully this helps some, if anyone else has some input I am sure It would help both of us.
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We do have rulebooks, currently working off the 2014 and 2013 books and the rule changes over the last two years. Our understanding is the most that has changed is the chassis tube diameters and wall thickness. Working on getting a 2015 rule book asap. The engine we are using is a Kawasaki ZX-10. my figures are coming from a computer simulation we did last year, it was pretty conservative so going beyond 230 is probably possible. I will defer to those who have more experience on the salt than myself. Our biggest problem was trying to model the surface at the salt flats. We are beginning our construction on the 14th of February. will try and update our website but most stuff gets posted to the Facebook page https://www.facebook.com/pages/Project-Velocity/405910939554934
Here's a photo of our front suspension https://www.facebook.com/405910939554934/photos/pb.405910939554934.-2207520000.1422725733./429182210561140/
Couldn't figure out height two post directly. Were using a hub centre steering setup which needs approved by the SCTA.
As I said were aiming to run between 200-230 and our bike should weigh about 500kg or 1100 pounds.
Will try and keep you all up to date.
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....As I said were aiming to run between 200-230 and our bike should weigh about 500kg or 1100 pounds.
Will try and keep you all up to date.
Great project. :cheers: :cheers:
One thing to keep in mind and I know this applies to cars but think also bikes is that if you are running in a class where the record is currently very high you have to build the car (maybe bike also) to the same safety requirements as the record speed at the time. You might be able to run with less safety gear and such if you have an understanding with them that you will only run up to an agreed speed. Not sure if this could effect you but maybe something to consider,
Sumner
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Bikes too!