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An Introduction to Sidecars (Extreme Length Warning)

Discussion in 'Bike Reviews, Questions and Suggestions' at netrider.net.au started by PatB, Jul 19, 2007.

  1. Just thought I'd post a little piece I wrote a while back on the joys of asymmetry.

    A long standing curiosity regarding the addition of third wheels to perfectly good two wheelers crystallised into something more concrete during the latter part of the summer of ’94 when I met Russ. Considering the utter irresponsibility that we talked each other into I should really change the name to protect the guilty but in the end I couldn’t be bothered.

    Russ and I were both skint, depressed to the point of being borderline suicidal (always a help when considering completely destroying the handling of your motorcycle) and interested in doing silly things with motorised vehicles. We’d also seen every film in the Mad Max Trilogy far too many times for our own good.

    It all started innocently enough as, under the influence of alcohol, caffeine, soft drugs and lack of sleep, we spent night after night in the garage, first getting our scruffy Suzuki 550s (GS for him, GSX for me) running reasonably well and then hacking the poor old GSX about to get it looking like the Australian post apocalypse device that I rather fancied. The GS had spent sufficient time as a London despatch bike that it had already suffered its own private apocalypse and didn’t need any modification at all.

    The air cooled Suzuki GSX lends itself rather well to this treatment. With the bodywork chucked away and a coat of grey primer on the tank and frame it’s halfway there already.

    The front mudguard went the way of the fairing, leaving just the fork brace, and its place was taken, rather inadequately, by half an old motocross guard bolted to the fairing brackets under the headlamp. The fairing frame also came in useful to support a rack above the headlamp, made from 10mm threaded rod, of which I had several hundred yards lying about at the time. The instrument pod was moved from the top yoke to mount on the rack in order to save weight on the steering. I don’t really know if it made any difference but the theory’s sound.

    Substantial, wrap around engine protector bars were welded together from an old set of crash bars off a CZ and various bits of tube.

    The tail end of the frame was trimmed right back, the existing seat cut in half and a structure consisting of more threaded rod and a few bits of plate welded together to support a tiny, raised pillion seat. A couple of Lucas tail lamps off a Hillman Imp tucked under this rather nicely and both looked good and provided a back up if a bulb went. There was now nowhere to put the number plate so a bracket was built out to one side of the pillion pillar to mount the plate and another Lucas relic to light it.

    In this state the bike turned heads and remained the fast, reliable, good handling machine that Suzuki originally designed. The motor was good and I’d not long rebuilt the Full Floater rear end with parts from a low mileage, crashed machine. By the early 1980s the Japanese were starting to get their handling sorted and, although there was plenty of room for improvement in the old twin shock bikes, I’m inclined to think that, with a few honourable exceptions, Joe Blow working in his backyard is very unlikely to be able to make enough difference to one of their later, monoshock offerings to make the effort worthwhile. Hence the engine and running gear were all left totally stock. Besides, I had other plans.

    These modifications were merely performed in idleness while I waited for my student grant cheque to turn up to finance stage two of the project. During the weird and wired nights Russ and I had hatched a plot to start building chop frames on a part time basis. We needed to practice building strong, straight, tubular structures but we both needed our bikes as regular transport so we couldn’t just tear one of them down to build a chop out of it. This , combined with the fact that I’d been interested in sidecars for years, decided us. We would turn my GSX into a chair puller.

    As soon as the cheque hit my bank account it was down to the steel stockholder to buy what seemed to be a ridiculous quantity of square and rectangular section steel tube and then we locked ourselves in the garage for a weekend. The GSX was put on its centre stand and I started running a tape over it whilst Russ had a go at welding our new steel together. It proved to be possible to produce a beautiful bead on the surface of any section without actually sticking anything together very well. We decided that all joints should be subjected to a combination of destructive and none destructive testing. In other words we’d hit them with a big hammer. If they broke they were crap, if they held up they were probably OK.

    Ground clearance for the chassis was determined by the simple process of hunting around the garage until we found three dud bike batteries of approximately the same height to prop it up on. Other critical dimensions such as sidecar wheel lead were guessed at based on half remembered and probably inaccurate magazine articles.

    We decided on a three point mounting. One strut from the left hand front corner to a mount on the left hand downtube just below the headstock, one from the left hand rear corner of the chassis to a mount on the rear subframe just aft of the rider’s left buttock and a single, substantial mount from the side rail of the chassis to below the left hand rider footpeg. The top two mounts would be single, 16 mm stainless bolts through a “knife and fork†arrangement of the chassis struts sandwiched between 3/16†plate brackets welded to the bike frame. The main lower mounting would be by a flange with the distance between the bike and the sidecar chassis adjustable by shims made from ¼†steel plate, thus allowing the degree of “lean out†to be adjusted in order to optimise the handling. That was the theory anyway. The square section frame members used on the GSX were a help in attaching all this assorted bracketry.

    That first weekend saw us with a complete chassis of welded square tubes, using an old MZ swinging arm and rear wheel. This arrangement allowed both easy toe-in adjustment-by way of the chain adjusters-and the facility to hook up a sidecar wheel brake if we decided it to be necessary at a later date. Suspension was by a pair of ancient and leaky Marzocchis nicked off an ex mate (but it was all right, I did leave him the equally ancient and leaky MZ shocks in exchange).

    The following weekend saw a marathon 24 hour garage session during which, sustained only by cheese sandwiches and coffee, we fabricated and fitted all the necessary bracketwork to the bike, bolted the chair into place for the first time and set it up with guessed geometry, sorted out a makeshift mudguard and rigged up a sidecar light.

    At one stage (about 4 am I think) Russ managed to blow away most of the front downtube while welding on one of the brackets. As he pointed out, none of the welding manuals tell you how to break the news to your large friend that you’ve just destroyed his motorcycle. Frantic repairs saw the damage made good but it was a nasty moment so we both drank lots more coffee in order to wake up and avoid more mistakes.

    We rolled Razorback, as this monster came to be known, out of the garage at 6 am on a cold, miserable early December morning. It was the first time either of us had even sat on a combo, let alone ridden one. Pushing it along it felt like it pulled to the right a bit but I’d heard about the vagaries of sidecar handling so I ignored it.

    Better take it for a circuit of the garden just to prove it works then time for some sleep before learning to ride it and starting the shakedown process. Me in the saddle, Russ perched precariously on the chassis I fired her up, snicked first and gently released the clutch. I was expecting to turn left to head across the lawn and round the house. Instead the outfit swung sharp right, hit a gatepost and stalled.

    Hmm. It does pull to the right a bit doesn’t it.

    Push it back to starting point, fire up again, a bit more left lock and… Whoops, hello gatepost.

    After another couple of tries we managed to get it to go left by both hanging as far to the left as possible whilst I applied all available muscles to stop the bars flopping over to the right. Shouting “Go left you bastard machine!†seemed to help quite a lot too. We made a mental note to reduce the amount of lean out before taking it out on the public highway. It would have been quite decent as a speedway/grasstrack outfit though.

    That evening, following a celebratory shot of tequila and eight hours sleep, we stuck an inch or so of shims in the lower sidecar mounting and wobbled off very slowly down the road to a local industrial estate where we could be fairly sure of remaining undisturbed by traffic for an hour or two.

    Howling around a deserted car park proved to be easy and fun. Once I’d got used to the steering, holding a straight line was no problem and gentle right and left handers were dealt with in the approved sidecar manner. Throttle on for left, throttle off for right. Brake applications were tried and I found that I could pull up in a straight line or, if I felt like it, snap the outfit through anything up to 360 degrees by slamming on everything and yanking the bars to the right. I’m not sure if Russ enjoyed this quite as much as I did, perched as he was on a plank tied to the bare chassis. More radical left handers lifted the chair wheel as expected but it seemed quite gentlemanly about it with a 14 stone mate on the platform so I decided not to worry about it. My most prevalent impression was the weight of the steering. I had to stop every few minutes to let my shoulder muscles recover.

    Heading home I was confident enough to really gun it round a roundabout and discovered to my delight that the whole machine could be set up in a glorious three wheel drift under power with the front of the sidecar touching down and striking sparks from the road. Russ was somewhat concerned as the considerable g forces developed by this behaviour were pushing him closer and closer to the unguarded sidecar wheel (or “bacon slicerâ€). He claimed to have been very relieved when I backed off.

    That was Sunday night. Monday morning and I was off to college to show off my engineering masterpiece. In the absence of my obliging human ballast I roped an old MZ engine to the chair, as far outboard as possible. Now MZs are excellent devices and they are built of nice thick metal but their engines do not weigh 14 stone.

    College was about 6 miles away over a mixture of rural A road and fast dual carriageway with a couple of roundabouts thrown in for good measure. The outfit was noticeably more responsive and more skittish with the lighter load and tended to run wide on left handers but I coped OK, if not brilliantly, until the first roundabout.

    Here confidence returned as I remembered my triumph of twelve hours previously and I sailed happily round until my exit approached. At this point things got rather entertaining. As I started to peel to the left I realised that I was going far too fast given my modest abilities, utter inexperience and lack of ballast in the chair. As a more experienced pilot I’d have either aborted the exit and gone round again or adopted the lean, gun it and hope approach of the dedicated three wheel nutter. However, part of being an experienced sidehack conductor is not to get into these situations in the first place. Instead the panic reactions took over and I momentarily froze, followed by, in spite of all my conscious brain could do to stop them, my fingers and toes squeezing the brakes. “Ohshitohshitohshitohshit†I said in the privacy of my full face.

    No matter how much you’ve read about the vagaries of sidecar handling and how many accounts you’ve heard from folk whose first (and often only) sidecar experience ended with them upside down in a ditch on the outside of a fast left hander, nothing will ever quite prepare you for the horror of that first time you bottle out and the sidecar lifts in earnest, leaving you hopelessly out of control.

    In my case I ended up heading for the end of the central reservation armco. Only the desperation borne of the forseen embarrassment of having to explain to the police how I’d ended up with the outfit straddling the barrier three feet off the ground allowed me to wrestle the thing back onto the road. We smacked the armco with the right hand engine bar and the number plate. I don’t remember doing so but I must have got my leg up out of the way and we came to a halt sideways on across two lanes, battered and shaken but still in one piece. A very chastened PatB rode the remaining 3 miles to college thinking “And they let learners loose on these things?â€.

    After a morning of lectures and an appraisal by my engineering peers it was time to take Razorback into Bristol to get a proper sidecar MOT. My confidence had built yet again as the unpleasantness of the morning wore off and I set a good pace for the first few miles.

    Then, on a climbing left hander I found myself closing up a bit on the van I was following so I gently backed off and the outfit duly started to run wide. Panic once again set in and I backed off further. The bike ran wider. I touched the brakes and ended up well out across the white line with traffic coming the other way. “Oh bloody hell†I said as the small part of my brain that deals with the survival reflexes made the decision to bolt for the opposite verge. I made it with a matter of an inch or two to spare, bounced up the kerb and came to a sudden halt with the front wheel in a ditch and the front of the sidecar tangled in the remains of what had, until a few seconds earlier, been a small tree. Getting it out again on my own came almost as close to killing me as putting it there had done.

    At our custom friendly MOT station it failed on a couple of mildly dodgy welds and a headlamp that aimed low. We were most impressed by the fact that, in spite of the rough handling of the morning, the wheel alignment was still set as it had been the previous night.

    Riding slowly home with a couple of hefty concrete slabs as ballast saw me reflecting on the peculiar paradox of the sidecar outfit. Everybody has at least one major moment on their first day out and yet I think I’ve only heard of one case of really serious injury resulting. Sidecars certainly were, and still are for all I know, regarded by insurance companies as the safest form of motorised vehicle bar none. I can only assume that the first day scares the shit out of everyone to the extent that the no hopers give up and the enthusiasts decide to learn to control such a beast properly.
    Make no mistake about it, a well set up combo is a very controllable, wickedly manouverable tool that, particularly on a loose or slippery surface, allows the rider to take liberties that would be suicidal with anything else.

    It’s questionable whether Razorback was a well set up outfit. For a start, as I became more capable, the limitations of telescopic forks became obvious and the front end started to behave like overcooked spaghetti when pressed hard. The steering was always too heavy due to too much trail and the front tyre didn’t really grip adequately. Nothing that a decent set of girders or leading links wouldn’t cure but I simply didn’t have the money to buy a set or the time to build some.

    The sidecar suspension was always too soft in spite of the fact that Marzocchi shocks are notoriously rock hard. We’d leant them way forward to meet mountings attached to a pillar on the chassis and consequently their mechanical advantage was seriously limited. The nose of the chair was always prone to touching down, although this didn’t seem to upset the handling. Building an adequately braced structure to mount the shocks more upright would have been difficult and so the problem remained for the time that I owned the beast. A solution that was considered-and suggested to the subsequent owner-was to attach a quarter elliptic (or, more likely, a half elliptic sawn in two) car leaf spring, upright, to the existing suspension pillar and run two struts from the eye of the spring to the shock mounts on the swinging arm. As we didn’t try this I can’t be certain that it would have worked but the theory seems sound.

    An incidental problem that we never really cured was blowing bulbs in the tail and number plate lamps. Mounting on several layers of old inner tube as a vibration isolator got bulb life in the tail lamps up to a level that was inconvenient rather than dangerous but the number plate lamp continued to last approximately seven minutes after each replacement.

    Interestingly, although the outfit looked pretty rough to the extent that nobody could believe that it had a valid MOT (passed with flying colours second time around), interest from the police was non-existent. This was in spite of my having negotiated at least one roundabout sideways having failed to clock the following unmarked car. And me with no number plate light too. I can only assume that combos are now sufficiently rare in the UK that noone knows much about the laws pertaining to them and so you get left alone.

    Another function of their rarity is that genuine knowledge of chairmanship is thin on the ground to say the least. Having ridden/driven a combo for a year I wouldn’t say that I was by any means an expert but I now know enough to recognise that about 95 % of everything that has been written about them in the mainstream motorcycle press in the last ten years is utter bollocks. Most pseudo factual articles in publications as the Used Motorcycle Guide now seem very obviously written by those who tried an outfit once, scared themselves rigid and then gave up but now pass themselves off as experts; a very easy con to perpetrate as most of the prospective audience will never have sat on a combo either. Alternatively, their outfits were very badly set up, although, since Razorback was set up by guesswork, followed by refinement on a trial and error basis, it can’t be that difficult. All you need is a pair of planks to do the toe in and a reasonable feel for what your machine is doing for everything else. The main theme of most of the articles concerns the typical “horrible left hander incidentâ€, treated as if it happened twenty times a day.

    I found that as I gained experience and genuine rather than false confidence the frequency of these sphincter twitching moments diminished and eventually became practically nil, even after I’d dispensed with sidecar ballast.

    The important points are to read the road well ahead, go into corners at the right speed and in the right gear and, above all, burnt into the experienced chairman’s soul in letters of fire, is the instruction to NEVER NEVER EVER TO EVER BACK OFF IN A LEFT HANDER EVER UNDER ANY CIRCUMSTANCES WHATSOEVER AND HOWEVER FOOLHARDY GIVING IT A HANDFUL MAY SEEM AT THE TIME. It may be scary but it certainly beats All Bran. I have to admit that I never quite stopped looking for a soft place to land in the opposite hedge but I’m just an old worry boots.

    Prior to actually building Razorback I’d found picking the brains of sidecarrists to be a frustrating and largely futile exercise. All seemed uncommunicative and unhelpful.

    However, after building an outfit from scratch, crashing it twice on the first day out and still being determined to carry on I found them to be very forthcoming with genuinely helpful advice about set up and riding/driving technique. It almost seemed as if I’d passed the initiation rite for entry into some kind of club for ageing lunatics; a bit like the Masons but ten times as dangerous and a whole lot more fun.

    Don’t all sidecarrists look old and boring in their Belstaffs and their Gold Top boots and their pipes and beards? Don’t believe it. It’s all a cover for what we get up to with our strange, asymmetric vehicles when no one is watching. Even the most staid of Gold Wing combos is just as capable (maybe more so due to the extra horsepower) as Razorback ever was, of performing a few left and right hand prouettes and then blasting off down the road sideways with two wheels in the air and the third one spinning. I guarantee that a powerful combo will bring out the hooligan in anyone who is not already dead.

    Spins and slides are so simple as to be not even worth a mention, while maximum head turning for minimum effort is to flick the chair into the air and hold it there for several miles. Balancing is child’s play and cornering is OK as long as you’re not travelling at stupid speeds. Be warned though, this can lead to oiling problems on some engines so don’t go too daft or you’ll chew your cams up or burn out your alternator. Honda and Suzuki owners take note.

    The wonderful thing, though, about the somewhat uncertain handling in the hands of the novice is that the thing becomes much less desirable to steal. All that stuff bolted to the side makes for a very difficult lift into a van and as for trying to ride it away, well… All the owner really needs to do is wait for the screams and then follow them to their source, before giving the would be thief trapped under the rolled outfit a damn good kicking to add to his woes. “Honestly officer, he must have hit his face on the ground when the combo rolled on this left hander.†Sometimes it’s really satisfying to own something that hardly any other bugger can (or wants to) control.

    Digressing a little, another means of avoiding theft by making things confusing is to own an old Indian with left hand throttle, hand change and foot clutch. Actually left hand throttles aren’t too difficult to improvise using a Japanese push-pull twist grip. Now that hydraulic clutches are reasonably common, it shouldn’t be hard to rig a left hand front brake as well assuming things like master cylinder bore and so forth were compatible. I don’t know about going to a hand change and foot clutch on a modern, revvy machine that needs lots of gearchanges but it has been done (usually to emulate Harleys, who ditched the arrangement quite some time ago for a number of fairly valid reasons) so who am I to say?

    I mentioned horsepower and I’d emphasise that what you need to have serious fun on a combo is a wild excess of power over grip combined with a good, strong torque curve. Ideally I would like sufficient power/torque to break traction at will on the throttle alone. I’d rather spin or go sideways than roll over and breaking the back end loose is one way to achieve this when you overcook the occasional left hander. Razorback was a bit peaky to manage this with any certainty and so left hand drifts were a bit iffy.

    I countered this by fitting the least grippy tyres I could get hold of. Roadrunners were good as such tread as they had never actually touched the road, the machine running on the centre, bald strip. A secondhand, square section Metzeler that appeared to be made from a shiny, cast iron like substance was superb and didn’t seem to wear much. Finally I put on a motocross tyre that came my way very cheap and which was brilliant apart from the fact that I had to shave the words “NOT FOR HIGHWAY USE†off the sidewall to make it (sort of) legal. Apart from the fact that the little rubber blocks that made up the tread would peel off and spang off the back of my helmet under hard acceleration and apart from the unearthly howl when used on tarmac, it was perfect and made the back of the bike look ultra macho as well. That howl was really something though. Even when the exhaust collector disintegrated I’m told that the tyre became audible first as the outfit approached.

    To prevent having to do such silly things with tyres, I would recommend using something like a V-Max as the tractor unit. Mind you, I’ve been looking with considerable interest at the Boss Hoss. With its single speed transmission, belt drive, car type rear tyre and immense torque it strikes me as being somewhere close to being the ultimate chair puller. After all it is, by all accounts, pretty unwieldy as a solo so why not adapt it for the use to which it’s so well suited in the first place. A set of ultra strong leading links like the ones the V8 trike boys use would sort out the front end nicely and the addition of sidecar mounted fuel tanks would get the touring range up. The huge battery necessary to swing all that iron from cold could also be stuck in the chair to improve the C of G and weight distribution situations. Yes it would be heavy as hell and yes it would be a bastard to reverse if such ever became necessary (although who, short of a fully laden roadtrain, wouldn’t give way to it?) but it would fulfil most of my parameters for the perfect sidehack. Pity about the $75,000 price tag before modification or I’d buy one tomorrow and chair it up the day after. Ah well, maybe when I’m a bit further up the ladder of corporate Australia.

    I must say, though, I’m not at all keen on the other extreme of the underpowered outfit. I’ve seen chairs stuck to practically everything from C90s upwards and even fancied a Jawa 350 outfit myself for a while but having ridden Razorback I’d incline to the view that anything under a 550 or so just isn’t enough.

    As a solo Razorback would do an indicated (and I would emphasise the indicated) 130 mph or a bit more with the right wind and plenty of room. With even a relatively light chair with limited frontal area (but, admittedly, probably lousy aerodynamics with all those turbulence inducing struts and what have you out in the airstream) and lowered gearing I could just squeeze an indicated 100 out of him given perfect conditions. That’s quite a cut in performance. Acceleration at real world road speeds also came down from very fast (for a 550) motorcycle levels to about on a par with a reasonably hot saloon car.

    Looked at in percentage terms, can a C90 or Yam XS 250 or Honda CB200 or what have you sustain such a drop in performance and still remain fun? I guess the answer is yes for a lot of people who run and enjoy such combos but I have to admit that from a personal perspective I’m much more into the idea of more capacity and horsepower rather than less.

    Running costs certainly went up. For a start the MOTs were more expensive but as that’s only once a year I suppose it’s not too bad. Average fuel consumption went from high 40s to low 30s per gallon. Chains didn’t seem to wear appreciably quicker for most of their lives (it ate them anyway) but went downhill more rapidly at the end, shedding rollers at about the point where previously I’d have thought about taking a link out. The larger rear sprocket fitted to drop the gearing seemed to be lasting well but front sprockets developed a severe dental problem every two chains or so.

    Rear tyres, with the exception of the aforementioned Metzeler which was well worn to start with, evaporated in about 5000 miles while fronts (Avon Supremes worked very well) lasted about 8000 before the deeper parts of the very peculiar wear pattern got down to a level that could only be described as bald. It was possible to get a few more miles out of it by turning it round, the Supreme being non directional. The sidecar tyre didn’t seem to wear much (presumably because it didn’t touch the ground much) and tended to be the last duty of worn out front covers, the sizes being interchangeable. Alternatively any old secondhand crap in approximately the right size could be utilized without noticeably affecting anything.

    Other than consumables, you have to remember that most of the components on a bike pulling a chair tend to be working very hard indeed, often in ways that they were never designed to cope with.

    For example, Razorback’s clutch took a hammering, particularly in the first couple of weeks before I’d got around to dropping the gearing and was having to slip it quite a bit on takeoff. Plates and springs don’t cost that much but they’d be a pain to fit if you have to do it more often than necessary. At the very least I’d put heavier springs in and build the muscles of my left hand to cope.

    The forks had a very hard life as well. To be honest I’m not sure how long they’d take the flexing and twisting to which they were subjected. The thought of the front end collapsing at speed due to metal fatigue or an undetected crack is enough to make me feel loose bowelled just writing about it ten years since I sold it. Leading links are even more of a must.

    I took the chair off just before I sold it and was expecting the bike to be fairly bent as a result of the stresses I’d subjected it to. Oddly enough the wheels still seemed to line up and there was no sign of the sidecar mounts having fretted in any way. Considering the tremendous punishment and spectacular overloading that the outfit suffered during my ownership (would you believe two MZ 250s on the platform?) this must be an indication that we did something right when we built it.

    And that is, more or less, that. I could go on forever about the rides I had on that machine, enjoyable, nightmarish, berserk, unlikely and what have you but there’s not much point. The sidecar is such an illogical device that, if you want one, you won’t be put off by anything and if you abominate them as a creation of the Devil on one of his more warped days nothing I can say will persuade you otherwise. If you’re tempted, have a go. If you survive your first day out you’ll probably be hooked for life.
  2. Brilliant story, thanks so much for posting! Pissed myself out loud at more than one stop. I've never had anything to do with sidecars other than watching chairman hoot about in his and damn nearly drop martyh into the bushes on a right-hander (chair was mounted on the left), but if I see one on the road now I'll be bloody watching closely, that's for sure. :LOL:
  3. Best piece of writing on Netrider this year, Pat, enjoyed it immensely!
  4. That was an incredibly long, but excellent read :LOL:
  5. can we get a Ktulu-esk summary?
  6. you. are. insane.

    great reading.
  7. Nah, the only really dangerous bit was setting the carpet on fire while welding it all together :p . Nothing like flipping up a welding mask, only to find yourself squatting in a puddle of flame. Boil in the bag

    Can't find any photos of the chair side, although I know I've got some somewhere. In the meantime, here are a couple of the right hand side of the beast.