This sidecar was built to transport my 3 year old son on the local cycle paths. It was constructed from a steel angle frame, with a wooden bodywork and plastic screen. It was designed to pivot against the bicycle frame so the cornering and riding were less affected by the addition of the car. The design was reminiscent of sidecars which were commercially available in the 1940's. Sidecar From Wikipedia, the free encyclopedia
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This sidecar was built to transport my 3 year old son on the local cycle paths.
It was constructed from a steel angle frame, with a wooden bodywork and plastic screen.It was designed to pivot against the bicycle frame so the cornering and riding were less affected by the addition of the car.The design was reminiscent of sidecars which were commercially available in the 1940's.
For details of the sidecar design please see the previous page.
The CAD sketch on the right shows the proposed wheel and frame design.
Frame Plan
First the angle iron was cut to the required lengths and all the ends were squared off.
Areas to be welded were cleaned with a grinder and then the frame was assembled on a flat surface with some wooden right-angles to set things square. Cable ties were used to hold everything in place.
This image shows the frame after welding.
Click for larger image
This image shows the basic frame completed.
The wheel support had a slot to enable the sidecar to be height adjusted for different bicycles.
The outer wheel frame was a piece of bent 25mm strip steel (4mm thick). The bends had to be made fairly accurately to ensure the wheel would be a good fit between the mounts. This outer frame was bolted to the main frame rather than being welded, to make the wheel removable.
The outer wheel support was located on the axle and the clamped to the outer frame, ready for welding.
This photo shows the outer wheel support welded in place and everything assembled so far.
The sidecar bodywork was made with a 12mm plywood base and top. The sloping back was also 12mm ply and a hole was cut to allow access to the boot.
Softwood stand-offs were used to set the height and then a 4mm plywood skin was glued and tacked in place.
Bodywork with one outer skin in place.
Some waxed string was laced though the ply skin panels at the front to pull the two halves together. Screws were added to hold the top and bottom corners in place.
A section of the top panel was cut out and the sides were shaped, to form the passenger compartment.
A plywood piece was glued to each side to give the cut edge some strength and a grab handle was added at the front.
The 2 images below the bodywork resting on the wheel frame tp give a feel for the final set up.
Basic bodywork box
This photo shows more progress.
A dimension check with the young passenger showed that the hole in the top was a bit tight.
So the windscreen was moved 40mm further forward and the back of the compartment was moved back as much as possible.
This photo also shows the wheel arch, which was made from 2 semicircles of 12mm ply with a 4mm thick curved top. This assembly was only secured to the inner frame so that the wheel could still be removed by unscrewing the outer frame.
Body filler was used to blend the wood joints. The front seam was covered in a thin fibreglass layer and also smoothed in with body filler.
The boot lid was cut to shape and secured with 2 flush hinges.
The bodywork was painted in an army type colour. Actual NATO Paint was expensive (and toxic) so some domestic wood paint was mixed at the local hardware store to get a karky type colour.
The sidecar bodywork was attached to the frame using some springs at the rear and some rubber stand-offs at the front to act as a pivot.
Since writing this page I have received a number of questions about the pivot, how it is designed and how it is fixed to the vehicles. Hopefully the photographs below will help.
Two clamps of bicycle pivot Detail of sidecar pivot. The block with 2 mounting bolts had slotted holes to allow
the tracking to be set,
Assembled link from the front Assembled link from the rear.
This photographs show the bicycle clamp parts
Another view of the assembled pivot without the bodywork in place.
Other people who have build similar sidecars have used a piece of threaded rod for the pivot which also allows the fore and aft position of the car to be set.