Sidecars, I love sidecar outfits, they're fun, they don't fall over on the ice, you can bring lots of crap with you and they're fun.
yes, I know I mentioned that they're fun twice, but they're so much fun it was worth mentioning twice!
ah, but they're only fun if they're set up right, if not, they can be bloody terrifying and downright dangerous, you are, after all, adding a lump of weight which works much like a pendulum onto the side of a machine that was never designed to have something extra on the side!
Of course, that observation is a huge generalisation, back in ye goode olde dayes many bikes came with lugs already attached to the frames for sidecar use, manufacturers such as Panther (oh how I would LOVE to own a Panther model 100 or 120) even supplied their bikes with forks that could be reversed to provide different amounts of trail for solo or sidecar use (more about the importance of trail in a bit!)
Ok, so how do you set up a sidecar correctly?, honestly, there is no single definitive answer in terms of settings, there are too many factors involved, tyres, the bike , the size of the sidecar, its intended purpose, weight, geometry and personal choice to name a few.
What I hope to do with this post is give a few pointers for the benefit of those starting out, tell you what has worked for me (which may not work for you, personal preference again) and address some of those grey areas
What I am NOT doing here is attempting to write the definitive 'how to' guide for sidecaring.
choosing a bike and sidecar that compliment each other
So, let's start with the basics then, firstly, choosing a bike and sidecar that compliment each other.
In essence you are adding a pendulum to the side of your bike, you are expecting your bike to cope with the extra, uneven weight and depending on your choices, it will either do it well, or ruin the bike you are using and send you to the lunatic asylum! (one such place being the
kawasaki GT550/750 owners site on Facebook!)
It's pretty obvious that buying a huge four seater sidecar and expecting it to work well attached to a 250cc bike is not going to work, the bike won't be able to pull it, the frame wont cope with the extra weight, nor will the suspension, the clutch or the steering.
What a lot of people don't consider is that having a sidecar that is too light and fitting it to a large capacity bike is also very bad.
For instance, I have seen a lot of big cruisers like Road Kings, Valkyries etc mated up to Velorex sidecars or similar.
For those that don't know, Velorex sidecars are Czechoslovakian made lightweight sidecars that were designed for small capacity lightweight machines, and were often sold mated to Jawa motorcycles from the factory.
why is it a bad mix?, well, that sidecar was built to be light and designed to be used with a small capacity, low powered machine (less than twenty hp) , now, the bike is going to be putting a lot of force and weight against the sidecar, especially when turning, a bike designed to cope with that little Jawa is simply too flimsy to bear the weight of a fully loaded goldwing.
The stub axle is too weak, the wheel bearings aren't really up to it, the frame itself is going to flex, the tyre is disproportionately skinny and the suspension on the sidecar wont cope well to say the least.
Plus, it's going to lift off the ground with the smallest effort when the bike pulls against it (more of that tomorrow)
yes, there are people who will point out that they have managed just fine for years with such a setup, but they aren't getting the best experience they can, and there's a very good chance that it will fail badly at some point (I managed to bend the stub axle on a velorex when it was fitted to a Honda 500, just to put things in perspective, and it wasn't being ridden particularly hard, either)
So, think about what your needs are, then pick a bike that will suit, pretty much any bike can be used for sidecaring, some are better or easier to adapt than others and a sidecar to match.
As a rule of thumb, the bigger and heavier the bike, the bigger and heavier the sidecar)
When selecting a bike, torque is more important than outright power, a peaky engine makes for hard work with the added weight of a sidecar so a highly tuned engine with little low or mid range isn't the best idea.
the easiest bike to attach a sidecar too generally speaking is one with a traditional full perimeter frame rather than one that uses the engine as a stressed member (it can be done with a stressed member frame, but it is more work, I've never been a fan of making unnecessary work for myself!)
Chain, Belt or Shaft?
There are advantages and disadvantages to each, I prefer shaft drive, it's more robust, doesn't need regular adjustment and needs less maintenance in general, the disadvantage is that it is more expensive to alter the gearing (it is a good idea but not essential to lower the gearing on most bikes by 10 percent or more depending on size and engine size etc to allow for the extra weight).
if the bike has wire spoked wheels this becomes easier as the wheel can simply be rebuilt with a smaller rim.
Chain, very easy to play with final gearing by swapping cogs, however it is getting a harder life with the extra weight and the chains and sprockets will need replacing more regularly than on a standard machine.
belts, much the same as chains, but it is often harder to obtain different sized belt sprockets.
Both chain and belts will need regular adjustments to allow for stretch too, which means you are altering the relationship between the sidecar wheel and rear wheel of a bike, ideally something that you don't want to do once you have a set up that works for you.
Nailing It All Together And Not Killing Yourself!
Ok, so you now have your dream bike and sidecar, but you need to attach them to each other in a way that will be safe to use and fun to ride.
the things you need to understand to get the geometry right are lead, lean out and toe in, for each of these I will list a good starting point, you will need to make many adjustments to find what suits you well.
The points where you mount the sidecar to the bike are very important too, get it wrong and you will have a very bendy outfit as the sidecar and bike flex with each other, get it right and it will be nice and rigid.
If you are an impatient person, go away, find someone who is calm, patient and obsessive and get them to set it up, there is a lot of trial and error involved, and you can't hurry the process!
It is much, much easier to do the initial setup up with two people.
The key is to set it up loosely then make the adjustments to the various angles etc, tighten it up, ride the bugger, scream in terror, return to garage, re adjust and repeat until the screaming is no longer apparent
Mounting Points
The most common method is to use a four mounting point system, the ideal places are as close to the headstock as possible , near the front lower engine mount, near the swinging arm mount and near the rear suspension mount (assuming your bike has dual rear shock absorbers)
The reasons for this are that it spreads the mounts and stresses created over the widest practical area which helps keep it nice and rigid and minimises strain on the bike frame plus these are all areas where the bike frame is braced across it's width, by attaching the sidecar at these points, the cornering stresses generated are transferred to both sides of the motorcycles frame rather than just the nearside.
Better engineering, stronger setup, less flex
people that have particularly large outfits often add a third lower mounting, again, this helps disperse the stresses involved.
It is also possible to use a three point mounting, but this is generally only ever seen on smaller, lighter machines (and a few vintage set ups)
The lower mounts take the majority of the weight, the upper mounts provide triangulation and prevent the bike and sidecar from flexing toward and away from each other.
Ideally at least one, but ideally both of the lower mounting arms should be rigidly mounted to either the sidecar frame or the bike frame.
If you use clamps to attach all the arms at both the motorcycle and sidecar ends of each arm, the whole thing can flex like a parallelogram, allowing the bike and sidecar to move in relation to each other-very nasty and potentially lethal!
Toe In
This refers to the amount that the sidecar wheel is angled towards the bike, get it too tight and the tyres will scrub and wear out rapidly, with negative toe in (toe out), the sidecar is pulling away from the bike constantly.
either can cause steering wobbles
The way to measure it is to put two parallel lines on your garage floor, line the bike up so that both wheels follow the first line (make sure bikes wheels are perfectly in line with each other) and the wheel of the sidecar follows the second
using a plumb line or similar, make a mark on the first line that you drew that lines up with each spindle on the motorcycle.
from these points, draw two lines that are at 90 degrees to the first line you made so they meet the second line that you drew, creating a parallelogram.
Now, measure the length of the two lines that go from the line under the bike to the line under the sidecar.
the front one should be 20-40 mm less than the rear as a starting point.
This is your toe in measurement
Lead
lead refers to the amount that the sidecar spindle is ahead of the rear wheel spindle, that diagram you just drew on the floor come in hand again here, with a mark on the ground directly below the sidecar and rear wheel spindles it is relatively simple to measure , roughly 230 mm is a good place to start.
Lean Out
this refers to the amount that the bike leans away from the sidecar (the sidecar should be perfectly level when viewed from front or back)
This is generally measure using a line down from the centre of the headstock to the floor, where it meets the floor should be about 25 mm outside of the line that the bike wheels are sitting on.
On a personal note, I have never really felt comfortable with lean out and have always managed just fine with the bike sat upright.
As I mentioned, the above is just a guide, and should provide you a good place to start when setting up for the first time, there will be plenty of trial and error until you find a set up that works well for you.
Suspension Set Up
Now you have your lovely bike n sidecar set up to perfection, you also need to consider uprating your suspension to deal with the additional weight.(the heavier your setup, the more important this becomes)
In an ideal world, this would involve smaller wheels which utilise car tyres, lowered rear suspension with stronger springs and hub centre steering.
This is, for many, prohibitively expensive and compromises have to be made.
at the least, it is a good idea to notch the suspension up to a harder setting, if you are using telescopic forks without any in built adjustment then you should at least get heavier duty springs, ideally have the forks re machined in terms of damping too.
A good suspension specialist such as
Hagon Sock Absorbers will be able to advise you on what would be best suited if you give them details of the vehicles weight etc
Which Front Forks?
Telescopic
Nearly all modern bikes come with telescopic front forks, these can be used perfectly well in most cases (although you wouldn't want to go back to them if you have ever used either leading link or hub centre steering)
The advantages are that you probably already have a set on your bike, and it's relatively cheap to adjust the springing and rebound to allow for the added weight of the sidecar.
The disadvantages are that they provide relatively heavy steering, dive when braking (brake too hard and you can cause the rear wheel to lift, leaving the outfit teetering on the front and sidecar wheels ) are more prone to head shake and will try to flex or walk around each other when turning causing shakes.
The effect of walking can be counteracted to a degree by the addition of a fork brace and the heavy feel of the steering can also be aided by the use of wider handlebars giving more leverage.
Raked Yokes (for telescopic forks)
Buying a set of slab yokes from an engineer (or making them) will help with those telescopic forks, having them made with six or seven degrees of inbuilt rake (not strictly an accurate description, but it will suffice) will give more trail and lighten the steering noticeably, also, the yokes will be stiffer than the original items, helping keep everything taught.
They are a good compromise if you can't afford or don't want a leading link front end
Leading Link or Earles Type Forks
This is like adding power steering to your outfit!
A good set of these will give you more trail in the steering (trail is worked out by a line in line with the angle of the headstock to the ground and a vertical line from the front wheel spindle to the ground, the difference between the two at the point they meet the ground is the trail) which makes the steering much lighter, in addition to this they do not suffer from fork dive under heavy braking, in fact some lift under slightly braking, which can take a little getting used to!
Also, because of the design, there is no fork walking that you can experience with telescopic forks, making the steering feel much more stable.
They also allow for the fitting of a wider front tyre, again adding steering and stability
The disadvantage is price, typically a new professionally manufactured set by a company such as
Unit Sidecars will cost well over a thousand pounds
Hub Centre Steering
Holy grail or overkill?
look at the front suspension of a naked Reliant Robin (phwoooaaarr, sexy, isn't it?), this is about the simplest hub centre steering setup you will find.
It provides very neutral steering and very little reaction under braking and like leading link forks it will allow the fitting of a much wider front wheel if desired.
It is even better than leading link suspension because the square part of the tyre (always use square profile tyres on the front of an outfit!) is always flat on the ground
I am not convinced that the extra complexity and cost involved compared to a leading link set up is really worth while.
Hub centre steering recquires a lot of fine adjustments to set up, and you will almost certainly need to alter the bikes frame to allow for its fitting.
It is also very, very expensive!
Upgrading The Brakes
should you upgrade the brakes?, the answer would seem obvious, you are adding more weight, therefore you need more brakes.
It's not quite so simple, your braking is only going to be as efficient as your tyres, not to get into the physics of it too far, you need to consider the co efficient of friction or 'stiction' as it's also known.
Your standard bike tyre has a relatively small contact patch on the road, the bigger the braking force, the more likely that the tyre will simply slide on the road rather than grip, a sliding tyre will not slow down as fast as one that is gripping effectively.
Or, to put it another, way, put a huge brake on a wheel without fitting a wider tyre and it will simply lock up quicker rather than stopping faster!
Adding a sidecar brake is a good although not essential idea, and of course, if you can afford wider wheels with wider tyres, then it makes perfect sense to upgrade the brakes as well
Ok, anyone still awake?, you there at the back, stop snoring!
Tomorrow, riding the bugger, what you can expect and why
