Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1437792 times)

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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3090 on: August 08, 2018, 11:52:09 PM »
A 2017 FIM rule change limits the height of the hump behind the seat to 150 mm above the lowest portion of the seat base.  The photo shows the height of the old hump and the lowered hump.  It was not enough to lower the hump, only.  The seat base is raised, too.

   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3091 on: August 08, 2018, 11:54:25 PM »
The total change from lowing the hump and raising the seat makes the hump less than 150 mm high.


Offline RansomT

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3092 on: August 09, 2018, 08:21:12 AM »
It is a steel belted radial.  Do they grow?

I thought they did .... I show a 2% variation in my gearing calculations versus actual speed.  I've only checked closely at speeds above 200 on hard surfaces. I just assumed it was growth, it could be another factor.  I currently run a Michelin RS with 40 psi (heated tire).

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3093 on: August 12, 2018, 03:36:11 PM »
The tachometers and speedmeters we use are almost always inaccurate according to the dyno operator.  That is whereI would look first if those instrument readings are used in the figuring.

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3094 on: August 12, 2018, 04:20:03 PM »
There are changes to the FIM partial streamlining rules since 2014.  Changes are made to conform to these.  Also, some aspects of the 2014 streamlining were very hillbilly.  These are upgraded to something respectable.  The wind tunnel guys need to evaluate my best work.

The rules say "No part of any streamlining may exceed below the visible inner circle of the tyre rim at its lowest position."  The tail could be lowered this far.  It seemed counterproductive to drop it lower than the bottom of the engine belly pan.  The fresh aluminum shows what is added.  It has a nice rounded edge on both sides.  The new metal also shows some added tail length.

Some school kids in Kelso, Washington, saved up their lunch money and gave it to me for gas to get to B'ville.  Somehow I need to bring the bike up there during the skool year so they can see it. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3095 on: August 12, 2018, 04:25:42 PM »
The top of the tail was lowered and seat pan raised to get less than 150 mm of height difference between the two.  Elevating my arse will help to level out my back.  This change might help the aero.  The tail was not lengthened out to the full 400 mm.  Some room is needed to account for chain adjustment and fitting a new or slightly larger rear tire.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3096 on: August 14, 2018, 12:46:15 AM »
The Triumph Bonnevilles have a main frame that connects the steering head to the engine and has the supports for the seat and rear fender.  There are two down tubes under the engine that bolt to this main frame and they also connect to the engine.   The swing arm connects directly to the back of the motor.  There are some brackets called outriggers that connect the swing arm pivot to the frame.  All of this bolts together and it must be properly aligned so the bike goes straight and true.

The first step is to tie the front of the bike to the work bench with four tie downs.  They will hold the bike upright during the alignment.  The nearside tie downs are shown in the photos.  One tie down connects lower nearside triple clamp to the far forward nearside corner of the work bench.  The other tie down attaches the nearside of the frame neck to an eyelet midway on the nearside of the work bench.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3097 on: August 14, 2018, 12:51:32 AM »
These fotos show the two offside tie downs.  The result is the front end of the bike is tied down to the workbench.  The back of the bike is not tied down. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3098 on: August 14, 2018, 12:56:43 AM »
A level is clamped to the side of the main frame tube near the steering head.  The tie downs are adjusted so the bubble is in the middle of the sight glass.  Now the front end of the bike is plumb. (The side of the main tube goes straight up-and-down.)

Tomorrow this procedure will continue. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3099 on: August 15, 2018, 10:48:45 AM »
Now a bottle jack is placed under the engine, a vertical bar is clamped onto the rear wheel, and another level is attached to the vertical bar.  These bolts are loosened:  the swing arm pivot, the three outrigger bolts on each side, the two front and rear upper engine mount bolts, the two cylinder head stay bolts, the lower rear engine mount bolt with its the two stay plate bolts on each side, the lower front engine mount bolt, the four bolts holding the lower frame tube bracket to the tubes (in front of the engine), and the eight bolts holding the lower frame tubes to the main frame.  There are 29 bolts, total, to be loosened.

All of these bolts go through holes that are larger diameter than their shanks.  The rear wheel can be tilted from side to side when all are loose.  There is enough slop in the system to allow this.  The important thing is to tighten all of the bolts when the rear tire and the side of the main frame tube near the steering head are plumb.

   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3100 on: August 15, 2018, 11:05:14 AM »
Some sort of way to hold the rear wheel in plumb is needed.  Two ratchet straps are used with the top ends connected to the top of the vertical bar and the lower ends attached to eye loops on either side of the work bench.  The straps holding the front of the bike to the bench and the straps to the bar are adjusted until the bubbles are centered on both levels.  Nw all 29 bolts are tightened in the sequence described in the Triumph shop manual.

The Bonneville has a square frame tube near the steering head that makes this trick possible.  Most frames do not have anything like this.  When I have a bent frame straightened I ask for a leveling plate to be welded on near the steering head do this operation.  It is easy weld it on in the correct alignment when the frame is in the jig.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3101 on: August 16, 2018, 10:20:51 AM »
A carpenter's stringline is wrapped around the front wheel and staked to the back of the work bench as shown in the pix.  The string should touch the tires, only, and be stretched tight.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3102 on: August 16, 2018, 10:27:40 AM »
The front wheel should be turned so the gaps between the tire outer edges at the back of the tire and the string are the same on both sides.  The string should just touch the forward edges of the rear tire.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3103 on: August 16, 2018, 10:50:54 AM »
The rear tire is moved in the chain slack adjusters until the gaps between the rear edges and the string are the same on both sides.  Some fiddling is needed.  The gaps between the rear edges of the front tire and the string should also be the same on each side, the string should touch the forward edges of the back tire, and the string on each side of the bike should be unbent.

Measure the distances between the ends of the swing arm and somewhere on the chain adjusters on both sides of the swingarm.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3104 on: August 16, 2018, 10:58:25 AM »
The end product is a drawing like this.  This procedure needs to be repeated every time the bike is put together.  The gap will change slightly.

This leveling plate near the steering head, two levels, and string procedure was developed so bikes could be aligned in locations without a frame building table, such as transit vans, parking lots, paddocks, etc.