Tech-stuff

This is probably my favourite bit coz I get to show off loads of useless information.



Dragpipes

I found running mutes stuffed up the exhausts of my Harley choked it to death, so I run open pipes. The problem with running open pipes (noise, what noise??) is the loss of mid-range power I picked up this snippet on the net somewhere. Get a 3/4 O/D washer and weld it to the head of a 1/4 bolt (I suppose metric equivalents will work), drill a 1/4 hole 1 inch from the end of the pipe and bolt it in with a couple of lock nuts. Now the washers can be rotated to alter the back pressure and allow you to fine tune. Apparently Harleys are best with the washer at 90 degrees to the exhaust flow (ie max back pressure)
This is supposed to be an old Honda factory works trick that works on Harleys (and who knows what else?) . I haven't tried it yet but will next summer, with luck. Any more info would be appreciated

23/4/00 NOTE:- I've now made a pair of these using M10 washers, and fitted them. I'll report any improvement (or otherwise) in a couple of weeks when I've put some miles on.

31/4/00 :- I've just come back from a longish run over the weekend and my initial impressions are that the mid range torque has improved, I have no way of measuring this or proving it, but I won't be removing this mod yet.

30/7/00:- I'm convinced now, this is the cheapest, easiet and most effective thing to get rid of that midrange flat spot (doesn't spoil the sound either)

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Suspension

Trike rear suspension falls into two categories, live axle and independent.

Live axle suspension means the wheel hubs are bolted solidly to a single axle With this system, when one wheel hits a bump, both wheels are affected.
With independent suspension when one wheel hits a bump that force is not transmitted to the opposite wheel. This design provides a more comfortable ride at low speeds.

Different suspension systems have different advantages and disadvantages. In this case the trade-off is low speed ride for high-speed handling. Independent suspensions work well on a car because it has two wheels at the front to stabilize the car in corners, unlike a trike.
When the rear wheel of a trike hits a bump at low speed, the reaction of the suspension will pitch the trike up on one side, causing rough ride. Independent suspension handles this job well and gives a superior ride at low speeds. As speed increases, the inertial effect of the rotating wheels make it difficult for the bike to be thrown off line (which is why your motorcycle does not simply fall over at speed). At this point (approx. 25 mph) the rear swingarm begins to move up and down in unison and the ride becomes increasingly smooth and more stable. The advantages of independent suspension are lost. This is also the time that the disadvantages of independent suspension begin to appear.

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The difficulty comes in cornering. When a unit with independent suspension enters a corner, the same independent action that provides a smooth low speed ride allows the trike to lean the wrong way in the turn. When the trike leans right, it wants to go right, and you are trying to force it left into a left corner. This is manageable in low speed turns buts gets progressively more dangerous as cornering gets more aggressive. Cars with independent suspension also lean the wrong way in the corners, but are stabilized by the outside front wheel, if you have ever driven a Reliant Regal you will know all about this!! (not that the plastic pig has IRS it just feels that way, in fact everything feels a bit independent in a Reliant)

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Detail of IRS rear end note size of roll bar used. (marked "A" on 2nd pic)

More info about Lehman Trikes at Trikes'R' Us , which is where I cribbed most of this article.


Then I found this article

True Facts About Independent Suspension
Many people have the strong belief that Volkswagen suspension is the same as D.F.T. Suspension. Wrong... D.F.T. Independent Suspension has four shocks instead of two. The wheels move straight up and down instead of at an arc as with Volkswagen. The early suspension trikes used the vw style and met much failure. At high speed a wheel acts as a gyro. Therefor you have two wheels in perfect alignment tow in tow out, acting as two gyros giving you perfect stability at very high speeds. Some manufacturers have you believe that independent suspension does not handle well at high speeds. On the contrary with both wheels acting in unison as gyros plus a 3/4 inch sway bar you can travel at any speed and get the same smooth ride with very easy steering (no need for expensive racking of the front end). With conventional suspension when the rear wheel of a trike hits a bump at any speed, the reaction of the suspension is telegraphed across the axle pitching the bike up on one side causing rough ride and hard steering. With D.F.T. Suspension when the wheel hits a bump the wheel only moves straight up and down and the rest of the bike does not feel the bounce effect. When you enter a corner with D.F.T. Suspension the unit does not lean the wrong way as with VW or Corvair. Since our wheels and sway bar work together in a straight up and down motion the trike will handle corners easier and better than a non-leaning system. Therefor you can actually make corners faster than two wheels. Remember: This unit was designed for a motorcycle not a car! Using the best engineering, t he best material available, the best machining equipment we have, designed and developed the best trike conversion on the market. In Plain Language Simply The Best "Trike It You'll Like It

C & J Trike Center
Johnny Beam
4920 Harrisburg Pike
Grove City, OH 43123
(614) 871-2456, (614) 875-7118
C and J Trikecenter


Now I'm totally confused, both articles seem to make sense.



Copper Gaskets

Before using copper gaskets they should be annealed.
To anneal copper it should be warmed up until it goes cherry red and then quenched to cool it quickly, Now most people use water to quench, but if you use methylated spirits you will get a much better finish. There is a possibility that the meths will catch fire, but it is quickly put out by smothering (or drinking, if you're that way inclined).



Gearing

One of the problems I have come across is getting the gearing right, working out the right combination of sprockets, diff ratios and wheel/tyre sizes has been a real headache. What you need to know is the original overall engine revs to roadspeed ratio of the donor bike and to get as near as possible to this on your Trike. This is usually expressed as so many miles per hour per 1000 rpm in top gear. I had this wrong at one time and had my Trike overgeared and suffered a a load of clutch slipping and overheating problems. A mate of mine has a CX500 Trike with a ford axle + 13" wheels, and it revs it's nuts off at 70mph.
You need to find out how many times the engine turns for one revolution of the back wheel and work out how many time the wheel goes round in a mile. All a pain in the arse really.



Reliant axles


A .PDF of the Reliant axle.

The good old Reliant axle comes with several different differential ratios
REGAL saloon = 8.3:1 (7.3:1 optional on van) according to the Haynes manual
ROBIN = 3.5:1
RIALTO = 3.25:1
I can vouch for the Robin and Rialto coz I've counted them myself, though not too accurately (see below)
I'm told that the Rialto 2 had a ratio of 2.77:1, but I can't confirm this and as I'm led to believe they were only made for one year they are probably as rare as rocking horse droppings
I received the following from Fox via the comments page:

Robin and rialto are 3.323:1
1984 rialto is 2.89:1 as we bought a batch from reliant years ago .
Fox :)

The largest sprocket that will fit into a Regal differential casing has 33 teeth

Be warned, trying to get wheels bigger than 13" to fit a Reliant axle is a problem, There are supposed to be some BMW wheels that fit the stud pattern but I don't know for sure. If you know better please email me.
I've had a couple of e-mails on this subject, Richard has 15" Vauxhall wheels on his Rialto based Trike. Ron sent the following info
Vauxhall 15" wheels will fit but you need to fit Metro wheel studs as they are thicker (stronger) then you can use metro alloy wheel nuts as I have on a few reliant axles..

Might do better to use a Ford axle, there are loads of ratio choices and more wheels than you can shake a stick at, though they are heavier.

Shortening axles
I had to shorten one side of the Regal axle for my mkII Trike. These instructions are based on how I went about it.
Remove the brakedrum, backplate and halfshaft, Scribe a line along the axle and acrosss the end casting so it will all line up later. By removing the 2 holding bolts and heating the casting (Ionly used propane so it wasn't that hot) I was able to pull the casting from the end of the axle. Saw off the required length, machine (or use a sanding disc like I did) the axle tube back to the correct diameter so it's suitable for shrink fitting the casting, then the casting can be re-heated and re-fitted to the shortened axle tube. (you did line up that scribed line didn't you?) Drill through the bolt holes and re-tap (5/16 UNF). that's the outer tube done. If the end casting comes loose you can tack weld it to stop it fretting (well it's held on mine).
The halfshaft takes a bit more work. I'll work on the assumption it'll be shortened by 50mm.

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Scribe a line along the length of the halfshaft. Mark the centre of the bit you want to remove. Using this mark as the centre, put centre pops 25mm either side, put another pair of centre pops a known distance from the centre line ie 100mm. The second set of pops will give you something to measure to so you know you've cut out the right amount (or you'll know how much you've cocked-up by always useful). Drill 8mm holes down through the middle centre pops and saw down through the middle of these holes. file out the 2 half holes to take a piece of 8mm square key steel. File the ends of the halfshaf flat checking that the distance between the remaining centre pops is correct (in this case 150mm). Turn up a sleeve to fit over the halfshaft bored out a couple of thou smaller than the shaft. I found the halfshaft I had was not round so I averaged the diameter and used that as the bore diameter for my sleeve. Re-assembly is best done with the halfshaft vertical in a vice. Weld around the end of the sleeve while everything is still hot. I put the shortened halfshaft in vee blocks and although I didn't clock it up the finished item seems to run true
Using this method the drive is not all transmitted through the welded sleeve.

NOTE - The above method won't work with Ford Sierra driveshafts. They are so hard that the centre punch gets flattened. I had to cut them with a 9 inch angle grinder. I didn't do the square hole thing. I still turned up sleeves that were a shrink fit on the shafts and then welded them.
They're still OK after 8000 miles.

DIY Sporty Tank


A fullsize .PDF of a DIY Sportster type tank pattern courtesy of Courtesy of Ron at Vision see:- Club Chopper forum thread

Be warned this will print out on an A1 sheet so you'll need to split it or take it to a print shop.
For reference the mid line of the tank top should be 16-5/8" long.

CLICK HERE




XS1100 Dipstick
The XS11 has a little window in the bottom of the clutch housing to check the engine oil level.
My knees are now past the point that allows too much grovelling around on the floor, so I have decided to make a dipstck. Having removed the clutch casing and taken a some measurements this is the design I have come up with.

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The two notches line up with the level lines on the outside of the casing.