Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: tauruck on February 09, 2013, 06:54:33 PM
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The Honey Badger is a tough little animal and I like it's attitude so I'm calling this build by that name. I'm doing a bike powered by a Sportster motor. The bodywork will be a streamliner similar to the Burt Munro bike. On this one I have all the bits and pieces so it should go along very nicely. I put some pipe in the jig today but had to figure out how it works. I haven't used it in two years. I was thinking rigid but Wobblywalrus advised a sprung rear would be better so I'm going to do my first monoshock swingarm. I'm trying to figure if I should go with 21" wheels front and rear. Does anybody have any advice or ideas on wheel size. Some pics of some of the stuff I use. Dummy motor, jig, sprockets.
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Some more images.
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Tauruck, that picture you sent me of Haskeen Pan reminds me of the alkali flats we have here in the west and especially the Alvord. My experience with them is not with LSR but as a desert racer. They get muddy in the winter and folks drive on them. They make ruts that harden when the mud dries in the summer. They can be a problem, and as I mentioned in a PM, one of our local racers got caught in one at ELMO and flipped. He was on a rigid framed Suzuki four. In response to whether or not suspension is good, it is probably not needed at the Bonneville for most years, although the salt can be choppy every now and then and suspension will give a person a competitive edge during those times. My bike would have suspension for alkali lakes, for sure.
The reason I am posting this is I do not know all that much about running a LSR bike on alkali lakes, although we did not waste any time crossing them during dez races. Some of the folks on this forum do. They can give a lot better advice on how to set up a bike for those conditions.
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it might be difficult mounting the bodywork with any type of swing arm.
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I'll heed your advice and lets see how it goes once I have the frame done. :cheers:
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Getting bike tires with speed rating is tough when you use bastard sizes ... I suggest you stick to conventional sport bike size tires ...
Joe
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+ 1 on the tires.
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Thanks. I've got all different sizes here but I'll have to check on the stock Sporty mags I have. I know the front is a 19" but the rear might be a 16" I think. I do have an 18" rear that's an Akront wheel with a 180 Michelin Superbike tyre on it. Then I have a bunch of new Avon Venoms but they are all 21". I welded a few more tubes today so I have the bottom rails welded to the up pipes. I should have the neck, backbone and rear engine mounts fried on by tomorrow evening. Don't ask me about rake because I've already called the bike the eyeball special. I'm going purely on gut feel here. Pics of some Sporty stuff I have in stock.
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Some exhaust parts and front motor mount.
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Some work came in putting this project on hold for a while. I've only got a few pipes in the jig but I should have a few pics by Friday.
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Tauruck, we were in top form at BUB last year. All sorts of speed wobbles and crashes. It was so bad that the event was on hold cause both of the meat wagons were hauling folks to the hospital. The head guy, Denis Manning, came down to pre-stage and gave all of us a lecture on bike building and set up so we would not speed wobble. This is what he said.
First, make sure the wheels are in balance and true.
Second, be sure the wheels are in line with each other.
Third, the bike needs to be in balance. In other words, it should not want to fall to one side or the other 'cause one side is heavier.
Fourth, the aerodynamics should be the same on either side. One side should not have more drag than the other.
He might have said more and I forgot about it. This definitely is something to think about during the build.
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Point taken. I have no Patella (kneecap) and so much steel in my left leg my surgeon said if I break my leg once more he's going to have to weld it back together. :-D About balance, my buddy Lefty has a Bourget frame with twin cam motor in it. It's worn the left side of both tires and you have to work to keep it upright in a straight line. I won't be going that route. Bo, tell me if I'm wrong. I set up all the motors I fit to frames by having the centreline of the backbone in line with the con rods. It's the same as the factory Sportster. I THINK! :-D :-D :-D The frame in pic is not the race one.
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T-
Frame jig looks good. Sportster engines work well in a frame type that you describe. The frame that you show in the photo looks like a Paughco chopper frame. They work well for a cruiser and Scott Stites used one on his LSR Sportster/Buell project that ran very well. I would suggest a longer frame. I like 72" wheel base bikes as they run straight. If you rake the neck 35* to 40* it will go straight as an arrow. This is the link to Scott's build.
http://www.landracing.com/forum/index.php/topic,2333.0.html
This link is to my Sportster/Buell build. This bike runs 150 mph without a wiggle on the salt flats. It has a neck angle of 37*
http://www.landracing.com/forum/index.php/topic,4876.0.html
Joe
Joe
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Thanks Joe, yes the frame on the jig is my loop frame for my Bobber. The one I'm busy on is loong and the rake is at 38* but the forks are a set of leading edge upright old style I had lying around. What's your take on them?. Shouldn't make too much difference once they've been cut to size.
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The tire-size / speed limitations are directed by your class speed-record. I run a set of 21s on my little Triumph Cub with full suspension set at quite stiff levels. I have yet to get into the 90s but the bike rolls very easily and is straight as an arrow. I am not afraid to lift my left hand to open my face-shield while I am slowing down at the end of a run. My wheelbase is about 57-inches. One potential problem is rear-wheel clearance at maximum suspension compression.
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Mike, I know nothing about Harleys except that they are asymetrical. That is why I made the post, it is something to consider. The folks that are responding know a lot more about them than me.
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It's all good Bo. I've built a few frames and they run straight. Hard but straight :-D The rigid theme never really caught on here. I'm going to put in some serious hours on this one tomorrow. I was having trouble with my mig torch. It fed then stopped and it went on for quite a while so I decided to get a new torch. I'm used to the handle on the one I have but the new one never felt quite right so I never mounted it. I opened the torch one and found lint in the trigger contact. After I cleaned it it was fine, better than ever. I'm putting in the double backbone and the neck tomorrow. I used to use hole saws to fishmouth tubing but now I use a marker and employ the plasma cutter. Once it's a "closish" fit I use the belt sander to finish. I had a 38mm roller made for it so it cleans the slag off beatifully. I had lots of these necks machined in 07 so I haven't got a problem with inventory. Bearing cups are in the freezer tonight. It helps slightly when pressing them in.
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The forks are a bit different. I usually warm the neck and freeze the bearing races. I use aluminum cups that I machined to catch the lip on the races. Hole thru the middle and 3/4" all - thread rod with a 1" nut top and bottom and ratchet them together.
Joe
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Yup, I also have an installation tool of sorts. Two thick bushings with a step, threaded bar and an air wrench. The cups go in easy. Lots of guys tap them in using a hammer and socket. I'm just busy on a custon truck that needs to be out of here by 3 and then I can get into the interesting stuff. Never fear, I'll be bugging you guys for info in the very near future. Thanks man.