Vulcan 88 Trike stretch & rake...

[Prof]

Latest project is this Vulcan 88 trike. Owner has built it over a number of years having put 500 thousand k on it as a solo and then as a sidecar. Sidecar was not to his liking, so he picked up a trike kit from the US. Motor is interesting. Looks air cooled but water cooled, twin plug heads and develops good power, which I could feel when I took it for a quick jaunt.


Very robust set up with wishbone independent rear suspension and a quality diff...


And now we are at the next stage... obtaining some extra trail. Trike is quite nice to ride at low speed, but very frisky by second gear. Badly affected by unevenness of road, steering feels too direct. I would worry about the consequences of even just running over a rabbit and the resulting speed wobble and crash...


Trail tested at 4" which is a little surprising. I thought it would be much less. Thinking is to increase trail to 6-8" and also to stretch the neck by around 4 or 5" to get a longer wheel base and more stability...


One of our WA members has built a lot of trikes commercially over the years and knows his stuff, so I will call him in the next day or so and see what he recommends. Trike is quite high and we can get the front down but no height adjustment on the rear. Would be nice to be able to drop the whole thing by a couple of inches, but does not seem an option.

This machine will be engineered using Motiv Engineering. I really like Phil, straightforward, no superiority and always keen to find the simplest solutions. I'm sending photos through to him with my proposals and he'll tell me what he requires.

I was not expecting this job so soon, but the owner ended up with a short window of opportunity and basically just rocked up from interstate. He'll be marching in the Adelaide Anzac Day march and then will start pulling down the bike on Thursday.

He'll stay until it's done, so expect some feverish activity.

Meanwhile Victor will be here tomorrow to machine up some bits for his new shovel project and complete frame build and new style... not allowed to show any pics til its done though... damn!

[Prof]

Trike's owner spent yesterday and this morning stripping the front of the trike. I measured up the headstem bearings which were worn out and pulled read the serial number of the top one and was able to pick up a new set from CBC this afternoon.

Yesterday while the trike was being stripped, I did up some diagrams and sent them through to our engineer and also to Mick, my WA contact. Was able to speak to both this afternoon and have a plan for stretching and raking the neck which will begin tomorrow with machining up a new steering head. Engineer was happy with my structural proposals and gave me a bit more understanding on the why's and wherefores which was good.

Mick suggested 42-45 degree rake as ideal for trikes with around 2" trail. He also said he'd not done a lot with motorcycle trikes, more with VW and Subaru engines and used springers or girders on them. He wasn't all that sure how well telescopics would work. I have spoken with an HD trike owner who'd had handling troubles until he raked his trike out to 40 degrees extending the telescopics to keep it level. Said he could ride hands off at the ton.
Mick also cautioned about taking the steering head too far forwards because of instability due to the narrower track of a motorcycle trike's track. With the telescopics we will end up with about 8" of trail which may make the steering a bit heavy, but finances play a part here, so it will be one step at a time.

So I will suggest to owner that we try 42 degrees with his current forks and stretch the steering head forwards 4". See how well it handles and if necessary later replace the telescopics with a springer or girder.

Tonight I levelled the trike. Actually the front of the frame is ½" higher to allow for the forks to sink 1" under the weight of the trike. A big dividers is really good for this sort of measurement...


I reassembled the forks and front wheel and here have them set up at 42 degrees. The existing forks have previously been extended 4". 42 degrees allows the new steering head to be at the right height. Any more rake and the forks would need to be lengthened or the steering head swooped lower, which would not look so good on this machine...


Close up showing the increase of rake from 32 degrees to 42 degrees.


If I am not too stuffed by tomorrow night, I will get some progress shots up.

For your interest, the engineering progress on this trike is that firstly, we have spoken with engineer to ascertain what and how the work needs to be done and what materials to use. I photograph the whole procedure for the engineer. When we are done, the trike will be final assembled and he will come down and take photos and we will do a sound test, steering test and braking test. He will then send in the photos and paperwork. That will be looked at by regio folks who will then make an appointment for the trike to be inspected. Once passed it needs to be registered in SA for 12 months, after which it can be registered in NSW.

[Prof]

Now that is is all worked out, I need to machine up the steering head.. I have picked up new bearings on Friday. The bottom bearing is larger than the top and the hollow bar I have for the steering head is sadly about 3mm too small in diameter. I have to make the steering head in two parts. The bulk of the steering head carries the top bearing. A 31mm piece is added onto the bottom to carry the larger bottom bearing...


Hollow bar from which I make the bottom 31mm section. Heavy man!!!!...


Ready to press the two pieces together. Interference fit. Top and bottom bearing races will be installed once the steering head is final welded into place...


Pressed together...


Frame number needs to be transfered to new steering head with letter and number punches. I have found the most effective way to get a straight line is to tack a piece of 30mm angle to the steering head. This allows me to produce a straight line and also keeps the punches square...


I have suggested 3" stretch and draw up a patern to provide the stretch plus angling out to 42 degrees...


Steering head has to be aligned so... trike is levelled...


Rear wheels chocked to prevent movement...


A pair of bottle jacks are used to help with levelling and also to allow removal of the scissors jack so we can...


Measure half way between the rear wheels...


and create a centre line. The front measurement is worked out using my alignment laser in the existing head stem....


Stretch plate is tacked to back of steering head and this centre finder used to square it up before adding some extra tacks...


We now tack steering head to front of existing steering head. Owner (Fred) thinks it looks a bit long and we cut off the plate and using an odd leg caliper mark a 30mm line to cut along and shorten it...


Double check of rake =42 degrees as required...


Owner likes it...


Here's how it looks...


New steering head now attached. I have used this method a number of times for stretch and rake. Benefits are that it is much quicker than cutting off the steering head on Jap frames because of the complexity and liberal use of thin pressed metal around the steering head. I also makes alignment very simple to do. Finally it adds an extra point of contact with long weld runs. Once side gussets are added this is a very strong set up...


Aluminium pattern fits both sides so while Fred cuts out the 3mm steel pieces, I...


cut the top of the original steering head so we can tie in the side gussets...


Right hand gusset is fitted and then left is cut out identical using G clamps...


Gussets tacked and a flat piece shaped up to lock the whole lot together. Holes are for plug welds into the top of the old steering head. This should prevent any side movement under the heaviest of stresses...


Double check on steering lock. Necessary because the increased angle of rake can cause the top triple tree to foul. But plenty of lock available... much more than it originally had. Tank is far back enough to clear forks, so we will make sure our new steering stops all us to use full available lock...


Tomorrow we'll finish boxing in the new steering head. Steering stops will have to be made as well as a top radiator mount. We'll fully assemble the front end and then the engineer needs to see it as well as the photos I have taken so far...

[Prof]

Steering head now complete except for fork stops.

Plate that locks new boxing into old steering head is plug welded and a small piece of 3mm bar is welded in to finish the job. Two triangular pieces are shaped and welded in. Tails poking up at the back allowed me to hold them while shaping and to do initial tack weld...


Finished top...


Underside now to be done. I want to do the boxing in three parts. Firstly plate the bottom of the original steering head to make it strong. Then two triangular side pieces welded into the bottom of the steering head. This way the whole kit and kaboodle will be structurally rigid. Main issue is to


Steering head plated with 3mm plate. Curley piece welded to it is a piece of scrap used to hole it for first couple of tacks...


Cardboard pattern of first half of 3mm plate...


Finished job...


Side view showing available steering lock. We will use most of it for ease of manouvering although with 42 degrees rake and telescopics giving us 7.25 inches of trail the steering is a bit floppy. A springer would work better as we could adjust the trail by varying rocker length. Maybe something to do later. We'll see how it rides as is. I met a triker some years back who's Harley trike was raked out and used telescopics and he was very happy with it...


Fred trying it out. Likes it!


Side view...


About to send a link to engineer so he can comment and we can proceed to next step.. Tomorrow morning we will do fork stops and a top radiator mount which had to be removed.

To get the trike registered,it has to be inspected by the engineer and comply with current regs (18 pages for this type of trike LEM-1). Regs include 94 decibel max, so some big mufflers will have to go on. Needs a handbrake which Fred made by putting a ball valve in the front brake line... works well. Have to sort out labels on controls. Rims are max of 200mm and these are exactly 200mm. Will let you know what else we need to do to comply as it comes up.

[Youngblood]

Very interesting, looks good.

[Prof]

Fred got everything painted and reassembled and then the electricals decided to play up. He spent a day trying to sort it out with no success, so we are in the process of rewiring it. Lots of connections are quite dirty/corroded and the wiring has had quite a few mods of poor quality over the years. We are simplifying the wiring as much as possible, as the loom thickness was insane. Will be a day or so before it is done. Still pullbacks to be made.

Meanwhile engineer thinks it can be inspected as a modified vehicle rather than a current build. This means just a brake and lane change test and a general roadworthy. Mufflers although original are loud and will need quietening.

More news and pics as there is something to see for our more recent efforts.

[Prof]

Wiring has taken a number of days as original is fairly complex and pretty battered. Will be done shortly. In the meantime a couple of catchups plus a new set of stainless pullbacks.

Fork stops weld to the bottom of the gooseneck and are made from 6mm plate cut out to 25mm deep. They will hit the back of the bottom triple tree so are substantial enough to resist a very solid bang...


Welded in...


Top radiator mount was cut off and a new one now made to replace it. Easiest way to make right angle and U shaped brackets is to find a matching piece of RHS or angle iron. Saves bending and inaccuracy that often comes with it if you can find a piece of RHS the right wall thickness and size... which in this case we were able to...


Nut bronzed to one side saving the need for two spanners and three hands when mounting or demounting!...


Now for the pull backs. Western bars are not suitable for longer forks and rake. Main disadvantage with them on any bike is their width which slows steering response time, ok under normal circumstances but not when quick reactions are needed. Also the longer and more raked the front end the narrower (within certain parameters) and further back bars should be. Best leverage and in this case reach is at or just below shoulder height and with the thumb width on the bars approximating shoulder width. That is what we aim for on this machine.

A pair of threaded bungs are machined up to slide inside the bars and attach to the top triple tree. With all bungs I like to include a lead in to prevent cross threading. These bolts are M12 so I cut in a 12mm x 12mm lead. Doing this is also beneficial for threading... hard to run the thread tap in crooked...


Next set up Biscuit on the trike. Get him to relax and sit as he would while riding. Then close his eyes and set his hands in the position and angle he finds most comfortable. I bend up a piece of fencing wire to approximate the position and when we are satisfied with the position, I then bend up the two pieces of the pull backs out of 1" stainless. Because they are so tall, I slip in some 7/8" tube before bending to reduce flex. Once bent we set them up on the bungs. To keep the bars in the position that is most comfortable, I use a spare set of risers bolted to a piece of 23mm x 6mm bar.


Biscuit tries them out and we cut an inch of the bottom of the bars. Width is good. Bars are twisted around in various positions until we are sure they are right.

The bars will be stabilised with a piece of 3mm stainless flat welded between them. top is curved for better looks and to keep the whole speedo within Biscuit's vision. Easiest way to make curves is to trace around a round object...


Bars are now checked for square and alignment...


Pull back on both sides is measured with a tape with the bars lying on a flat plane...


There is a fair amount of drop as the front end is turned to full lock and reasonable leverage needed at rest to pull the forks back into line. This is one of two reasons we add a cross piece to the bottom of the bars that will be welded across the bottom of the bars and stop twist. The other reason is that even under normal conditions, 3mm plate will flex under the pressure of acceleration as well as moving the bars side to side. This bottom bracket will stop this happening. Texta marks on the top tree show approximately where strengthening ribs are situated. Our bolts need to avoid these enough to get a spanner on them. Red arrow shows the spot chosen for the left hole. It is marked as an 'x' on the stainless piece and then taken to the marking table where both holes are marked and drilled...


Set up ready to weld. The bottom plate keeps the bars the correct distance apart as well for welding...


A couple of 10mm holes are drilled in the bars and plug welded. I drill the holes in a position so the welds even though polished will be hidden...


Missed a photo of the finished bars but will add some in tomorrow. The bars are welded ground back and then polished. Polishing is a 6 step process and takes longer than the initial manufacturing. Stainless polishing is unforgiving. Where mild steel is chromed, a coating of copper fills in any small blemishes. With stainless nothing can be hidden.

Bars on and fit is perfect. Biscuit is surprised that even with the extra 10 degrees of rake and extra lock, the pullbacks make turning the front end easier than his old western bars. A very happy chap...


Now that the bars are done I can finish the wiring up front. Pics of the finished job when Biscuit comes back Monday week. I'll include some of the wiring with an explanation of why a couple of things were done.