650cc A-BG build TDR

[MTABike]

please delete

[Old Scrambler]

Good start and lots of room to work (play).  Think about ground clearance, exhaust clearance, air and carb clearance, future turbo clearance, and then think about ground clearance all over again. If you plan to run in partial streamline, you will need it.  No front brakes and think about a narrow wheel / tire combo.  Don't set your pegs until you've tried the ride.

[Dr Goggles]

Good to see Billy nice get on the R6's looking forward to seeing what you build.............I have a photo that Simon took of you two leaning against the back of the Gal at Salt Talks, you looked fragged......I was clean, and hassle free but believe me I have been that guy covered in grease leaning against something that I wouldn't bet 5 cents was going to get me home without more grief.

[Vinsky]

Looks like you got a good start there.  I agree, that chain length could be a real problem. You will want a good chain guard as well as some real good chain guides.  I would almost be tempted to run a jack shaft just to reduce the chance of a wild chain comming out of there.

John

[Peter Jack]

Is it worth running at least the top run through say a length of 1 X 2 tubing? That should prevent it from getting away and causing too much damage.

Pete

[bak189]

Did you ever think of putting the engine behind the rider.....makes for a shorter chain, and also puts more traction on the rear wheel......just a thought.......(that's the way we build many of our sidecar outfits)

[bak189]

IF...you run a bike/sidecar on the salt/dirt with todays high powered in-line engines traction is always a problem.....How about putting the engine behind the rider....build a cradle for the engine that includes the engine and rear wheel assemble, put the swing arm pivot in front of the engine (not unlike today modern scooters) we now have all the weight directly on the salt/dirt for better traction.  Build the front part of the frame out of light weight 4130.....The rider rides in a kneeling position....using a elec. shifter on the left handle bar...a master cyl. on the right bar for the single disk on the rear wheel....no foot controls....The rider is just about the same profile as the top of the engine....low frontal profile....race the BUB event and use a Dustbin fairing and tail made by Airtech (as per AMA/FIM rules).........I understand BAKKER MOTORSPORTS is building a bike like this for a customer....
will be interesting to see how it works............................
.

[Koncretekid]

At the rate you're going, you'll be finished in a couple more days!  You only started this diary 2 days ago.  Anyway, it looks great (kind of familiar, at that).  Nice bends and looks to be good stiff design.  I like the perimeter frame as it allows lots of space to work on the top end.

The only thing I don't see so far is some lower frame members under the motor.  Maybe the motor is designed to be a stressed lower member, but who knows for sure?  You might want to add lower frame members to be sure. 

You said you thought you might be going at it a bit backwards.  I will paraphrase a well respected member of this forum and say "It doesn't matter how you start your build, it's how you finish the build that counts".

Tom

[Stainless1]

Scott, one of your earlier mock ups showed you over the gas tank.... the tank will hold you into the air and not let you get behind the stem.  You are running efi so you have a pump, build a tank and mount it low in the frame for ballast and aero. 
Do overs are common, even for old farts, so you kids shouldn't worry about them.
I'm putting a M4 on a suzuki 1 liter... I think they will do revs to 15000, which should be about your redline.  My plan is to use coil over plugs and the AEM coil driver.

[Seldom Seen Slim]

Unh, Scott -- turning 30 is a stressful event?  Dang, sir, you're in for one heck of a rough time if that's the case.  but take heart - many of us here have managed to survive that and even older anniversaries.  Oh, to be 29+++ again.  I could save bunches of $$ on those Viagra pills.

[Seldom Seen Slim]

What?  Why the heck do you think that way?  I'm in the mid-60s and haven't allowed myself to act like an adult 'cept in extreme cases, and I'll say it without fear of being corrected - that many of the folks on this forum are like me (well, not necessarily in age) .

[Glen]

I'm, 76 and still think being an adult looks pretty boring watching lawn bowling or bingo like most my age do.Some play golf. There are a lot of street rodders in Southern Utah and they always have fun.

[55chevr]

Land speed racers grow old without growing up ... Slim - I think you already said that


Joe

[wobblywalrus]

Scott, work = force x distance.  Force = mass x acceleration.  Acceleration is changing the velocity or direction of travel of a mass.  It can be deduced that a part of a system that flaps or flops around uses work to do this.  The work on our LSR bikes is supplied by the engine.  The sum of this is reducing flappy and floppy things leaves more engine energy available for going fast.

A long chain is relatively heavy and when it oscillates it travels further - compared to a short chain.  It can create a significant power loss and a little 600cc engine does not have horsepower to spare.

These may be performance benefits to driving two jack shafts with short toothed belts and having a rear chain of normal length.  The belts are lighter and they flop for shorter distances.  Less energy loss.

Another concern is the loads on your power transmission system.  A long chain weighs more - even if it is restrained.  Chains do not wear evenly.  They have what we call "loose" and "tight" spots.  These are more pronounced with longer chains.  This uneven wear causes variations in the chain tension on the sprocket and transmission system that was not considered in the original design.

Last, all chains hang in a catenary shape.  Long chains more so.  It can take a lot of tension make a long one straight enough to not rub on anything.  This puts a load on the power transmission system it was not designed to handle.

Anyway, some things to consider. 

[55chevr]

I wouldn't concern myself with symmetry.  The engines are assymetrical and if the frame hugs the engine profile it will be similar. The center of gravity would be a greater concern.  The steering neck should be plumb, the rear axle level and the wheels in alignment.