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Side car & tug alignment

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This is a very consistent problem and there is a lot of foggy knowledge being offered. the knowledge is good but the real application is not clearly defined. there is no mention of any actual measurement points merely things like back wheel or front wheel etc and this leaves much up to individual interpretation.

It would help if we defined certain points as being the true datum points. 

Maybe we could say the back axle and like with a Harley you have the brake disc which is a true indicator of the wheel direction  which can be projected to a point on the ground say at 90 degs to  the middle of the front wheel footprint. Now when you set toe in you have a std and with a little further effort you can find a set of datum points one on the front motorcycle frame and one on the side car frame that could be measured to establish the toe in for reference without having to use beams etc. I have a threaded adjustor at my rear hard point that I can measure the adjustment and if I move the adjustor 3/16" it will change the toe in 1/16" I also have a zero mark for reference

Now about lean. We talk about 1 deg.  1 deg. from  what. The road surface/camber or 1 deg to vertical as shown with an angle finder and that again is a moving target as the camber can change depending on the particular road/area you are in.  I gave up and just made me an electrical camber trim so I can make periodic adjustments to my lean to get near neutral steering as I go down the road. I lift or lower the side car and that tilts the bike

This is all vital knowledge and varies from a set std according to brand and model etc, but it can develop some good methodologies that can be applied by anyone with a few tools if they have a problem in that area

Nobody is telling anybody to do this or do that . You are merely telling what you have learned or know and its up to the individual as to what they do with your experiences. They worked for you maybe they work for him .    Chuck

 

 

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John Holbrook

I hope this might be of use to you.

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Thanks Tom. I will try to up the front tire pressure to see if it helps with head shake.

My heavy steering is due to the damper so I am looking at the possibility of taking a suitable air cylinder going hydraulic with light oil and putting in a bypass valve that I can adjust to apply just sufficient damping to stop the head shakes. I have the steering bearings pretty snug but that did not really help much. I would love to get rid of the damper, so I keep trying. I have got sufficient miles on the rig to find everything that comes loose and have pretty much done the blue loctite or nylock thing to cure that That check list is really a good piece of info.

Question is a little occasional head shake normal or can it be completely eliminated         Thks Chuck

The rain stopped for a bit so I went out and checked front pressure 35 lbs so I took it to 40 lbs and I am going to ride tomorrow out to a job I have. The tire says it can go 49 lbs Its a Shinko back tire running backwards and has a very rounded profile  Chuck

I'd like to see toe-in measured in degrees, rather than inches, since an inch measurement is dependent on where the measurement is taken.

If measuring in degrees, what would be your base line for measuring from?

Actual toe in measurements are not all that critical as long as you get it very close. Measuring by the angle you would need to establish a base reference point, no different then using straight edges and a tape measurement. You need base points you agree on. Would you be able to tell the difference between 2. 01 degree's and 2 degree's most likely not with measurement equipment people are likely to have. When we measure we take the reading from just behind the rear wheel and just ahead of the bikes front wheel. Adjust the numbers we are looking for based on how long the bike is. For instance a Goldwing is about a foot longer then many other bikes, so we look for a larger number. Riding the bike I doubt if you would be able to tell the difference between 1 3/16 inch toe on a Goldwing and 1 1/4 inch. As long as you agree on the measuring methods it simply does not matter.  Two straight edges and a tape measure are tools most people have or can get and can figure out how to properly use. They also work good enough. Reminds me of a saying. Measure it with a micrometer, mark it with caulk, cut it off with a chain saw. The numbers you get are only as good as the tools you have and the skills you have to use these tools and at the end of the day close is good enough most people would never tell the difference nor would tire wear be much different +/- 1/16 of an inch.

Jay G
DMC sidecars

http://www.dmcsidecars.com

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1bmwmcsmitty901John Holbrook
Jay G DMC sidecars www.dmcsidecars.com 15616 Carbonado South Prairie RD Buckley WA 98321 866-638-1793 Hours Monday - Thursday 6-4:30
Quote from CCjon on March 29, 2021, 8:59 am

If measuring in degrees, what would be your base line for measuring from?

Doesn't matter. As long as you know the front measurement, rear measurement, and distance between where you took the measurements. The difference in the measurements, what we call toe, divided by the distance between measuring points, is the tangent of the toe angle. The inverse tangent of that number will give you the toe in degrees.

Jay that is a classic.

"Reminds me of a saying. Measure it with a micrometer, mark it with caulk, cut it off with a chain saw"

I  watched as Hannigan mounted the refurbished sidecar on the new bike. Even with the changes they made to the mounts it was seemliness.

Bolted it up  looked at it. Took it out side ran it around the buildings brought it in adjusted toe a bit. Handed it to me. I took off for an hour test ride came back happy. They checked it again and then checked all was tight. There is a difference when you have experienced people doing the work.

This is good, I suppose that my way of using a adjuster at the back is probably doing it by degrees tho I  have no real idea of what the actual is it seems to work. Its like changing side "a" on a right triangle to increase or decrease the angle. My bike is very short wheelbase and the measurement taken with beams using the back disc at the datum point was 5/8"  I have put a little more in but I am mostly playing with the electric lean adjuster right now. Saw the trimmer on Helge Pedersons bike courtesy of DMC and copied that sort of. I am getting to like it a lot

I tend to agree that every rig is different and we mostly have to start using ball parks and going from there by trial and error.  My bike is very camber sensitive and I am almost able to predict which way its going to drift looking at the road ahead and so I am forewarned. I do not trim for these changes just when a condition persists for a while. I think that right now my biggest problem is Head shake at low speed and I am working on that. I am looking at putting a little positive torque on the neck bearing adjustment. I have no indications of looseness when I jack the front up and shake the thing but loading could possibly introduce a little side play into the top race. Anybody  know anything about this and have any suggestions as to how much torque to apply. I did not find any improvement when I upped the front tire to 40 lbs

I am also thinking of moving the car wheel axle a little closer to the back axle to  lessen the steering resistance to turn Its running about level with the center of the back tire right now. Any advice???                         later   Chuck

I'm thinking to mark what you measured with caulk might be a bit messy. Especially in the chain saw teeth. To each their own but I think in this case I'd rather use chalk... Smiling as I write that.

Without work on the front end rake and or other mods you will have some front end shake at low speeds All adjustments will do is maybe mover the speed it happens a little in either direction.  In most case keep hands on the bars it is not an issue really.  Raising front tire pressure can cause faster wear and less surface contact .

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John Holbrook

Mucho Gracias Senor Smitty. So we just live with it.  I will no doubt ask a lot of questions because this is my first sidecar rig tho I have been riding 2 wheels since 1957. If it is the nature of the beast I can live with it. By the same token if it can be corrected I want to do that too. I do not want to waste time or resources chasing windmills either so that is why I ask a lot of dumb questions.

I started this endeavor around the end of July and have learned a tremendous amount mostly by screwing up and learning that that is not the right way so back to the drawing board and do it again. Right now I believe that except for a few items I believe I have a very nice rig that is a lot of pleasure to ride in fair weather and foul. It must look good because I do get a lot of complements from total strangers. My bike has a very retro look and the Ural car is an ikon in the side car world so they do go together very well. It is going to be my last build so I am sparing no effort to make it as good as I can. I have been making several trips from Travelers rest SC to Columbia SC where I have access to a pretty large stash of Harley parts and also a lot of good company. This is also my shake out and I am not having any problems . Really the rig runs very well. I have no real yardstick to measure against so things like how heavy can the steering be and such things is where my inexperience is showing because I do not have anything to compare to        Later Chuck

Can you or have you posted a pic of your outfit? I would like to see it

 Now get out and ride it learn to use the  pull and push natural to a sidecar to your advantage. Watch tire wear for any need adjustments. And Have fun.

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John Holbrook

Oh I am riding as much as I can testing my mods etc. Its been a case of lots of work and ride a bit but the ride is getting more And the work is going down. The only thing left is to cut the neck and alter the rake angle and I really do not want to go there unless it becomes very necessary. I am running 0 deg. trees and short fork tubes leaving the bike with about 5" clearance and pretty much level front to back. Later Chuck

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John Holbrook
Quote from Neville L Te Brugge on March 31, 2021, 12:05 pm

Oh I am riding as much as I can testing my mods etc. Its been a case of lots of work and ride a bit but the ride is getting more And the work is going down. The only thing left is to cut the neck and alter the rake angle and I really do not want to go there unless it becomes very necessary. I am running 0 deg. trees and short fork tubes leaving the bike with about 5" clearance and pretty much level front to back. Later Chuck

 Please do not cut the neck. You can get raked tress that work so much better and easier. Once you cut the neck bike is trashed and no going back.

I spent a few days down in Columbia with my son and we worked on the front wheel etc.

I put in a set of progressive front springs. and put a little preload as well to handle the extra loads when braking and "lemmetellya" it works.

Then we went to work on the front wheel itself. First we took the calipers off and using spacers centered the front wheel up in the forks then we worked on fitting the calipers to the front lowers so its a natural alignment and its very normal looking. Now we are looking for a way to fit the speedo drive in. We have some options but its a matter of deciding which way we will go with it its very crowded at the left side on the axle. Then we did a bit of programming on the Ultima digital programable ignition single fire ignition system and now the bike is getting 36mpg @70 on the interstate. It is geared like a long legged camel but has boocoo passing power etc and will come out the hole like a scalded cat if you get on it. At about 2700 rpms its right in the power band which starts to come in at about 1500 rpms. 

I have noticed that as the speed goes up the tendency to go right goes up too from the higher wind drag on the car. so my question is should i set the toe in for about 70 mph and use my electric lean to trim it to my running speed for lower speeds etc???. My left elbow starts to feel it after about an hour on the slab. I have enough stick time to have a subconcious push/pull on the handle bars and I am getting more comfortable with getting into sharp turns like in city driving

I am now at the point to where I have time to start on some of the cosmetics where I just fitted temporary expedients like my headlight trim at the front of the batwing etc. I have other things as well and hope to have them all done by the end of the summer when i am going to get all the sheetmetal like tanks fenders and the tub done with black Imron and I will do an undercoat job on the sidecar frame.  I have a HD black spoke back wheel mag that I am going to fit into the sidecar. I am wondering if I should put an auto tire (175-60-16) just like I have on the back wheel of my bike or just put a stock tire on there. ??????????. the actual conversion is not too difficult the Ural axle is 20mm and HD is 19mm so I will just buy a Ural axle or use a gr8 bolt for the axle material. I may or may not move the wheel back an inch or 2 at that time, I need some advice on that. My understanding is that the relationship of the car wheel to the tug wheel is a major factor with regards getting the steering easier to set up for tighter turning as well as making decreasing radius turns easier when you get to the hook. At my age this has become very important because I am starting to loose muscle mass and strength.

By and large I am very glad I decided to go sidecar and not to a trike because I have reached the point where I just cannot pick that heavy SOB up any more at all and I am too broke up anyhow                        Later Chuck

Like I said previously i have no previous experience to fall back on with side car driving so I may have some very optimistic ideas of what would be normal when it comes to steering resistance of a rig.

It seems that most of the stuff I see comes down to somewhere around 15% of measured wheelbase would be a ballpark for lead and that sounds reasonable to me. Mine is about 11' vs a 62"wheelbasewhich is mas amenos 18% . I find my hand bumping the fairing mounted mirror some times when doing a sharp low speed turn like when I take off on a tight left hander. I do not think this is quite right, it should need less effort. My handle bars are using polymer vibration dampers at the top tree so they are not yielding over much. My bars are 32" wide with 10" pull back risers. I know my bike is quick but I try not to do much power at that time and really use the power to flatten out hills and for passing/lane changes etc.

I am wondering what would be the minimum safe lead for a bike like mine the rig has a 50" track so its almost Square and it is very stable in reducing radius right handers tho like I said hard to steer. I cannot ever recollect  flying the chair. which is a Ural about 250 lbs. I do not want to end up with a flighty back wheel in left handers at speed. My travel speeds always reflect the traffic speed and I like using the Interstates when I am travelling and I am not a twisty adrenalin junkie. I like long distance and generally only make gas stops about 140 miles apart. I used to ride an ST11oo and I used to go from Greenville SC to ST Augustine Fl with 1 stop at Savanna GA. That scooter was a real roadrunner

                                                                                          Later Chuck

 

 

Is there anybody who has a Ural car on a Harley and has normal for a side car rig steering so I can find me  a ball park to work in. I can take my front attachment to an extension of the back engine mount and move the points on the sidecar frame forward to move the car back. this is a lot of work and I would like to have something to go on before I do that. so that is why I  keep asking to find something that works and I can use that for my guide. Its vitally necessary to have sufficient lead to keep the tug back wheel down solidly on the road when in a maximum braking situation.  when that back wheel comes off the road like in a stoppie with 2 wheels its ok but with a car you are going to twist and that is going to be a very hairy situation. Right now I can go to my traction limits without lifting that wheel so I know I can move the car backwards but I do not want to cure a problem and make a really big problem to bite me when things go to hell and I need to stop Mucho Pronto. Unpredictable motorcycles will kill you and good handling makes predictability

  Anybody with a Ural car on an American motorcycle or any other big inch ride that does slow turns well and handles well in a braking situation you have the Data that I am looking for. Please Chuck

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