Wednesday, September 12, 2012

Fitting a sidecar to a Royal Enfield Bullet

The Bullet I've had for years and is an old warrior and faithful friend. She's a 1997 model, originally a 350, now a 500 and veteran of a ride back from India and down to the Sahara in Morocco as well as MCC trials and numerous UK and European road trips. The sidecar was an ebay buy and is a sixties Watsonian Monza. I had previously bought an Avon Super Sports but when I thought about it, it was way too heavy so passed it on. The Monza is an ideal weight for a Bullet and looks right with it. I was worried that fitting the chair would ruin a good bike. Did it? Read on....

1997 Royal Enfield Bullet with Watsonian Monza sidecar.
The starting point for fitting the chair was two buckets full of sidecar fittings bought from a local auction for a tenner. As I went on to find going the mix and match route for fittings is a difficult one for a sidecar rookie but buying a set of new, ready to go, fittings can be very pricey.

The story has a part one and a part two. The part one fitting picked all the most apparently suitable bracketry and lined the chair up to the bike as per instructions from an old handbook and used straight edges to get all the angles right. Problem was though that the rig was un-rideable. Even from the lowest speeds the steering shook terrifyingly. Knowledgable folks said ride through it and it will settle down. Sadly this wasn't the case. I'm pretty sure the sidecar geometry wasn't to blame and it seemed like the front end needed a rebuild as on examination there was wear in all moving parts.

The forks were taken off, new steering head bearings fitted and then the whole lot was re-assembled with new stanchions, a steering damper from a Redditch Bullet (see earlier post) and a fancy Hitchcocks fork brace.
Another angle. The Monza is surprisingly comfortable even
for a tall adult.
Next step was to put the chair back on. I decided to throw the handbook away and go for the 'if it looks right, it is right' approach in the hope that I would learn more on the art of sidecar fitting. The Monza chair is almost the same length as the Bullet; whereas fitting it by the book the rear of the chair sat further back than the rear of the bike I decided to put it right alongside. This looks a lot better and given that you can find recommendations to place the sidecar wheel anything from parallel to the bike's rear wheel to a foot in front it is still within the acceptable range.

The other two adjustables for fitting a sidecar in terms of handling are: 'toe-in' for the sidecar (the angle to which the chair's wheel points inwards to the bike) and 'lean-out' of the bike. The toe-in will steady the handling, too much and steering will be heavier, too little and it will be skittish. Go the wrong way and point it out and handling will be pretty wild! Too much toe-in will also give heavy tyre wear. Against expectation the bike must lean out from the sidecar rather than stand upright. Without lean-out the bike will steer in to the sidecar, too much and it will pull away.
I think this is the best angle on the Bullet combo. Bullet trials
interloper in the background.
The second fitting of the sidecar seemed ok and off it went for an MOT test. Job done, it steered nicely and passed. Then first ride with a passenger in there was some movement on the fittings and the nose of the sidecar ended up meeting with the tarmac.

Some re-thinking was needed on fittings. For the front upper fitting I had gone with a straight bar, I had been told that this wouldn't work and only a 'swan neck' would be rigid enough. This didn't quite sound logical to me as it is the two points of attachment that are important, the shape of the fitting arm is irrelevant. If a short, straight bar is rigidly attached it should be better. What had moved and caused the sidecar nose to drop was the upper front bike frame attachment. It had just one clamp bolt as well as the spade bolt to fit to the arm. I swapped it out for a sturdier one with two clamp bolts. Also the rear lower ball joint was suspect. This was exchanged for a slightly stronger, if more cumbersome, set up.
Rear fittings with ball joint and rear swan neck.
The rig was now definitely rigid. I rode it around the block. It looked right and it went right. I then loaded the sidecar up to go off to the Royal Enfield Owners Club 'Fossil Rally' weekend the next day. What a revelation camping with a sidecar, I could even carry a barbecue, firewood and a sack of charcoal. Brilliant. Then I set off and it handled like a pig with a definite affinity for the gutter. I realised that, whilst the rig had been set up ok with the suspension unloaded on bike and sidecar and it rode ok on a low speed jaunt around the neighbourhood, as soon as there was weight on it the geometry all went to pot.
Front fittings, not by the book but seem to work fine.
The ride to the Fossil Rally took nearly three hours, it should have been just over one. Some time was spent sheltering from a thunderstorm and some on trying to start a waterlogged bike after. Also the steering damper came loose at one point and those violent shakes returned. It's not often I don't enjoy riding a bike but this was one of those rare times and a definite low point in my motorcycling career!

At the rally the morning after was spent re-adjusting the chair. Thankfully I had thought to add extra ballast in the form of several massive spanners, adjustables and a two foot long stilson. The handling was improved though still not perfect but the ride home approached enjoyable at times.

Once home more adjustment was possible and on the next test ride I finally got the appeal of sidecarring. When set up properly the bike should run straight on a fixed throttle, steer away from the sidecar on slowing and in to it on acceleration. Riding the outfit feels like a skill worth learning and with satisfaction to be had. Plus it adds a new dimension to motorcycling and provides heart stopping thrills at moped pace speeds..

1 comment:

  1. You appear to be missing a third part of the story - the test drive where some of your womenfolk were placed in the sidecar to have their bottoms dragged down the road whilst the chair sank like the titanic.

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