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Fitting a sidecar to a CB400A Hondamatic

5014 Views 13 Replies 4 Participants Last post by  dtsmjr8dan
hello everybody ;)

A few moons ago there was a very nicely turned out 400A with a sidecar fitted, turned up on this forum ( see below)

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What I am looking for is some guidance regarding the fixing points used on the CB400 frame. A few pictures would help and I am sure that I can transpose them into the UK driving side without much problem.;) I have quite a bit of sidecar driving experience and I cannot see any reason why the Hondamatic should not give a good account of its self.
It is just an interesting thought at the moment but I think the torque charicteristics of the Hondamatic should work quite well although I would not expect it to be a motorway rocket.

Food for thought perhaps

cheers from the UK
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No help with this one but I remember that bike. There's been a couple of side car rigs posted over the last few years, fairly rare. All of them have been the A model
Hi Steve9e; you can use the front engine mounting bolts for the bottom front fixing; a clamp round the front down tube would also work; toe in and lean out as per the diagrams should suffice; but I'm not sure about the rear fixing to the frame on a 400Hondamatic. Try this link:
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That's some good information, thanks for posting this
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Hi Gixxer,
Thanks for the info. I do have some pics of a sidecar fitted to a 400 which looks the same period as my 1979 400A which I had forgot about. They were taken off ebay a year back from a guy selling a sidecar?

The front two are normal practice, but only shows one at the end of the gearbox using one of the rear footrest hanger bolts. I attach these pics for the benefit of our colonial friends just in case someone else fancies having a go? Do not be fooled by the crude steering damper connection which at a glance looks like a sidecar connection.
I rode a Chang Jiang 750 flat twin outfit for a couple of years and a look through my records might be worth a look as the connections were awesome, very Panzer like?;)

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feels like a winter project coming on if I can locate a sidecar to my taste ?????:oops:

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It looks like the rear mount is going up to the middle of the curved tubing section of the frame, right behind the left side cover. Hard to see if there's also another pickup point from the left passenger peg mount, not sure I'd trust the cast aluminum for that loading.
hi LDR :D

I think the lower rear connection fixes to the Rear fork pivot bolt? I am not so sure that is a good idea.:???: Someone somewhere in the UK must have come across this period of Honda with a sidecar.
at the moment this is a passing fancy on my behalf but you never know what turns up? ;)

I've toyed with the idea of a sidecar, have to get a special license here in Washington state for that.
Mechanically there shouldn't be any problem with using the swingarm bolt location for a mount since it's one of the more rigid points on the frame, much longer bolt needed and the mounting point would need to have a bushing to space the mount out a bit for clearance. As for the viability of the rear mount being so close to the front mount I have no idea.
hi LDR :D
I thought about the fix to the rear fork pivot bolt and you are right of course . It is the strongest point and care would have to make sure the fork is not "crushed" and remains free. On this type of frame there is not much choice really. Bikes such as BSA Golden Flash, Triumph Thunderbirds etc all had twin shock rear suspension and were popular sidecar bikes, so I will have to have a look at few examples at Vintage Club meetings.
i am sure I will turn something up.;)
The way that bolt is set up is that the dust covers for the swing arm bushings actually tighten up against the end of the bushing leaving the swing arm free to move. What would be needed is a thin bushing on the outside of the dust cover to space the bracket away from the cover to ensure free swing arm travel. If the cover gets pushed in against the swing arm it'll bind and restrict suspension movement.
hi LDR :D
I talked briefly to Watsonian Sidecars in the UK and they have a design and could supply a fitting kit. First of all I will keep my eye open for a suitable period 1970-80's single seater sidecar to restore as that is the high cost item and my budget will be low but enthusiasm high?:(
I wonder what will happen next?
Interestingly enough a sidecar just popped up on the local Craiglist for $995. Goldwing brackets for it. I'm almost tempted to get it just for grins and giggles
hi LDR :D
Why not, the price of the one on offer seems very reasonable, and you could carry more sandwiches?;)
The pic below was taken last Sunday at the Allenheads lunch stop of the Beamish Trophy Trial which in its present form has been running annually in my neck of the woods since 1972. Needless to say I took part in the first one riding a 1949 600cc Scott t/s twin.Not the sort of event for aging knees and a 400A. There is a very nice pre war 1000cc JAP engined Zenith parked just behind me.

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On my Ride for MS last Sunday, there was a sidecar rig for a wheelchair. Ramp and all. Handicapped kid had the time of his life.

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Check out what he had printed on the
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