Wednesday, May 29, 2013

Working through..........!

     As the title states I am working through a few issues.  The wheels I was hoping to use are not quite what I had hoped they would be.  The rear wheel with the disk brake will not fit in the swing arm with the belt drive and the other rear wheel is not interchangeable with the drive side carriers of either wheel.  The GS450 wheels based on specifications are supposed to be 18 inch wheels.  Surprise they are in fact 19 inch front and 17 inch rear.  I am not sure if this a result of the seller not knowing year or just a screw up in the online specs.  Either way they are not what I need.  They could work but why go to the trouble to make them work when there is no real benefit.  The outside diameter of the stock wheel with a 140/90-15 tire is 25.5 inches the same as a 130/70-17 wheel and tire.  The center of the wheel is still 12.75 inches of the ground.   I have order a set of tires that will fit the stock wheels.
    I ordered and received a set of air shocks from a seller on ebay.   I know they are not Ohlins but they look really cool on the bike and they feel really good.  They are way better than the stock shocks and for $100 I just could not pass them up.  The shocks are 13 3/8 inches from center to center.  The shocks really change the way the bike feels and looks.  That length is also the limit that can be used on this frame.   I had to change the top bolt on the drive side to a button head verses a socket to avoid belt rub. 
      I also ordered a pair of 1 inch club man bars with mirrors from an ebay seller.   The club man verses the clip-ons give me a little more adjust ability and the $40 price is hard to beat for bars and bar end mirrors.  I have also decided on EMGO's Cafe Muffler in black, 19 inches long. 
    I am still waiting on the seat pan my fabricator has had a few problems with his equipment and is pretty busy with his businesses main projects.  At any rate  I keep working on the bike.  below is the bike as it currently sets and a couple of finish ideas I am toying with.

Original drawing I made before I started the project.

 
Bike as it sets right now.

 
Finish design #1.

 
Finish design #2.
 
     The more I look at it, I really like the fat rear tire.   Time will tell.

Tuesday, May 21, 2013

Whoa!

     Well that was positive if less than spectacular.  I survived the test ride.  The positives first, the bike cranked right up and the new shifting mechanism worked flawlessly!  There was not any smoke from the bike and no unusual noises.    The seating position was comfortable as well.  So other than the oil leaks the engine seems to be serviceable.
     Now for the bad!  Brakes were practically non-existent.  The handling was non-existent.  I don't like the handle bars in this configuration.  So over all cranking and moving at varying rates of speed OK!  Handling , turning, STOPPING, Holy Shit that was scary!  I'm going shopping.
     First I have to figure out what I need to do.  I am thinking I will attempt to copy what RYCA does to their Cafe frame.  After all from what I understand one of those guys really is a "Rocket Scientist"!  Drop the front fork by 2 inches, Raise the back with longer back shocks by 2 inches, and change to 18 inch wheels front and rear.  Below I have taken a photo of the bike on the stand and imposed a stick bike over it, I can manipulate the frame and see what changes I can expect.
     From the reading I have done front wheel trail seems to be the key factor in how a bike handles.  A trail of somewhere between 2 and 4 inches seems to be the number for a neutral handling bike.  Meaning stable at speed in a straight line and easy and steady in a turn.  Trail is determined by drawing a line through the center of the steering column to the ground in front of the axle, and a vertical line through the axle and its corresponding end point on the ground beneath the axle.  The distance between these two points is the trail.   I have tried to keep all measurement to scale but I feel sure that the resulting number are just an approximation.  The stock trail is over 4 and the resulting trail after the modifications is 3.67.  I was hoping for a number closer to 3 but this should be acceptable.  The drawings below are as close to accurate as I can achieve with my current drawing programs. 



 
 
 
     After searching the forums for compatible wheels and shocks I have ordered a set of cast wheels for a 1983 Suzuki GS450. Wheels are 18 inches, the front rotor will have to be machines down to the same size as the Savage but that should be doable. The rear hub may be a problem.  Both hubs call for the same brake shoe when you reorder parts, but that can be misleading.   One source on the forum quoted this change over as plug and play, another said that it would require some machining of the hub.  I guess I will see.   Waiting on the wheels to arrive.  I have also ordered clubman bars and bar end mirrors.  I am still researching the shocks and I am considering rear shocks off a Suzuki GS550.  I still have to determine a few measurements. before I order.
     In the mean time I have taken the measurements and my local machine shop is fabricating the sub frame for my seat pan support.  It is very similar to a design I found on one of the forums for a scrambler build.  On my build the frame will be under a seat cowl that I plan to construct myself.  I am also having him add a plate to provide a location to attach my tail light and tabs for my rear turn signals.
     Speaking of turn signals, I had stated earlier that I wanted to re purpose some old turn signals I had left from a GS500F I had a couple of years ago.  I have taken the mounts from what was left of my old rear turn signals and used them to mount the front turn signals.  First I drilled out the center and threaded it to match the stubs on the GS turn signals.  These fit in the mounts for the front turn signals and now the signals screw right in.   The rear signals will mount to the tabs below the sub frame.
 


 
Next time I will begin to work on the fabrication of the rear seat cowl.
 
 

Saturday, May 11, 2013

Rear Set Installation

I picked up the parts from World Precision today.  He did a great job on the bracket.
 
 
      I went to great lengths to secure the bracket in the correct position before I took it to welding.  It was worth the effort because it fit perfectly!


 
I used the Handi-Grinder  to clean up the holes and mounted the rear sets after reinstalling the belt drive and cover. 

 
The decision I made to change the connecting post from a 1" square tube to the solid 1/2 stock was also a good decision.   Plenty of clearance in both directions for the belt and the swing arm.

 
A check of the seating position looks pretty good.  I am estimating about 85 degree knee bend.
 

The connecting rods were giving me a little trouble.  Deciding what to order and what length as well as the bends and the threading  are not a simple decision.  Online makes it a little harder as well.  My decision was a simple one, make it myself.  I went to my local hardware store and purchased 2 36 inch by 1/4 inch aluminium rods, 5 6M metric nuts, a 6M metric thread cutting dye, and the proper carrier handle.  Total $23.66.


 
     I measured for the shift rod and settled on 930 mm.    Aluminum is a joy to work with.  Reminds me of the old rule: "Light, cheap, durable, pick TWO!"  In this case I can add easy to work with.  I probably will have to rework these out of steel but for patterning and test purposes this is the way to go.  Usually you can do 1/4 turn and back up half a turn with steel, this is more like 2 turns and 1 back.    At any rate this was really easy and fast. 


 
Nice fit huh?

 
   I started bending the brake rod by inserting it into the rear brake arm, then flipping and inserting from the opposite end and bending in the opposite direction.

 
Length estimate and cut to length.


Looks pretty good.


When I threaded this piece I added 4 to five times the amount of threads to the hub end as I had on the lever end. 



 
Am I amazing or what?

 
This is my no means street legal at this point.  But being that I bought it without riding it, for $500, I have got to ride this thing.  I have to go through the gears and just see how it feels.  I have access to a parking lot across the street from my shop.  I have cobbled the muffler back into place and fashioned a rudimentary seat.  This is why test pilots get the big bucks.  Goggles on white scarf around my neck!  This is literally a wing and a prayer as I cross my self and say a little prayer.  Not catholic but at this point every little bit helps!    So tune back in Bat Fans!  Same Bat channel!  Same Bat Time!  Dating myself just a little.  If you are under, I'm gonna say 45, you have no point of reference for that comment.   Just check back hopefully there will be further post.
 

Tuesday, May 7, 2013

More Fabrication: Rear Sets Bracket


Moving the foot controls back to the center of the bike, is to this point the most daunting and important step.   I had originally thought I would use the rear motor mount brackets and make some sort of bolt on setup.   See rough drawing below.
 
 
I had a hard time working this out and decided to use the same design as the kit I had found online.  So with the rough patterns I had made earlier I set out to a local metal fabrication shop, Piedmont Metal Processing.  I also took the extra set of rear motor mounts I had bought on ebay to make sure we had the right hole spacing in the brackets.  Fortunately they were not very busy and had time to set down with me and draw up the parts I needed on their CAD system. 
 
 
A short walk down to the shop floor and the plasma cutter, a little set up, push a few buttons.
 
 
Voila! Brackets! I mean in about 5 minutes I had a complete set of brackets for my build.

And they bolted right on when I got back to the shop.

 
I then simulated the belt position and worked out the placement of my connecting bar.
 
 
Cut to length with the chop saw.

 
 
 
 
Checking the length and width with my drive belt pulley cover installed.

 
    A few things I had to work out because I was not completely happy with the clearance between the swing arm and the belt with the 1 inch square rod I had used in the original set up.  I changed to a solid 1.5 inch X .50 inch solid steel bar.  This gave me greater clearance tolerances and added strength.  I had hoped to use .25 inch steel plate for my brackets.  I found that I the clearance between the frame and the swing arm on the non drive side was too small to allow me to use the thick plate.  I went back and had them cut the inside plate out of 10 gauge steel plate.  I then needed to add the steel rod pictured below between the two plates to help solidify the whole unit.  I cut a threaded rod to the proper length and used nuts to lock them in place for the exact width of the motor mounts on the bike.   I positioned and clamped the entire unit together and took it to another local machine shop, World Precision Machine and Tool,  to be TIG welded together.  Hopefully I will have it back in a few days.  I met a guy there that does some custom bike building as well.  If I decide to cut down the tank he can do that for me as well.


 
I sourced my rear sets from a company I found online, "Fast From the Past". http://www.fastfromthepast.com
 
 
The Universal rear sets come in several configurations.  Once I get them mounted on the bike I can get the proper measurements and order the connecting rods from the same vendor.  I am starting to get excited as we get closer all the time.  Hopefully in the next week I can fire the bike up and ride it around the block.