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Ian Soady¹ said :-
First (short run). Needs some attention.
Finally I took the B'Zuki outfit intending a short run round local roads. Fortunately I started by going to the end of our road then down a local cul de sac with a turning circle at the end. It was awful! As soon as I set up there was a terrible flutter from the bars, getting much worse if either the sidecar or one of the bike wheels hit a bump. I never got out of second gear and was thankful I didn't venture onto the main road. Scared me quite a bit I can tell you. Of course my outfit piloting skills are very rusty!
I've checked tyre pressures at 34 bike front, 38 bike rear and 26 sidecar but not looked at anything else yet. My initial thought is that maybe it's due to the Roadrider front tyre which has quite a round profile. This can easily be changed. Second thought is that aligment is not right although I have checked it carefully. Toe in at 3/4", sidecar wheel lead 10", lean out when I'm on the bike about 1/4" at the tyre. I'll check again. Worst case is just that the bike geometry - trail especially - is just not suitable.
07/04/2026 11:25:57 UTC
ROD¹ said :-
I think you are correct about the front tyre, a square section tyre is always better with a sidecar.
Although it is treating the symptoms rather than the root cause, a steering damper may help?
07/04/2026 13:42:31 UTC
Ian Soady¹ said :-
I've had a lot of helpful comments from the Federation of Sidecar Clubs FB page. Suggestions include stiffening up the rear suspension (I have a spare pair of stiffer units); thicker oil in the forks; yes a different tyre although there aren't any sidecar tyres in 18" size that I can find; reducing front tyre pressure; increasing front tyre pressure. And as you say fitting a damper though I agree I should be able to get it better without. A last resort maybe.....
07/04/2026 14:06:32 UTC
Ian Soady¹ said :-
OK, have fitted the stiffer rear units (Falcons) and reduced the tyre pressures to 28 front and 32 rear (left the chair one at 25) and checked aligment carefully. The back wheel was about 5mm out of alignment with the front so have corrected this but toe in is still between 1/2" and 3/4".
so full of trepidation I tried it out. The shake has definitely reduced significantly but is still there. It's worse under power: coasting seems relatively OK although still only tried at 10mph and under. I feel there may still be some play in the steering head bearing so will jack the front up and adjust it.
Classic Bike Spares, my local shop, has a pre-unit BSA steering damper complete which may be worth adapting. I'll give it some thought.
So slowly getting there I think. I may try reducing tyre pressure by a couple of pounds or so more.
On the positive side, I was flagged down by a bloke who besides being very complimentary about the outfit wanted to show me his dismanted TriBSA that had been in the corner of his garage since he built it when he was 17 (now 77). It was a bit sad looking but complete. I did have to tell him that prices had plunged but he was in a position where he couldn't do anything with it and none of his potential will beneficiaries had the slightest interest. While we were chatting another old bloke stopped and loved the outfit and took pictures. Fortunately he'd gone when I wobbled off!
https://www.classicbikeshop.co.uk/triumph-bsa-norton-steering-damper-complete-ki...
09/04/2026 12:50:02 UTC
Ian Soady¹ said :-
Oh by the way, harking back to the previous conversation, as testing staions no longer actually ride the bike it could easily have passed the MoT despite being potentially lethal.
09/04/2026 12:51:10 UTC
nab301 said :-
I remember in the early 80's , my Em Zed was off the road waiting for spares , a local lad offered me a lift to a bike show in his Em Zed sidecar outfit in the sidecar , (on the R/h side...)
It handled exactly as you described yours Ian , i.e horrendously , it had a factory friction damper fitted , he'd ridden the outfit through Europe and seemed unperturbed by the wayward handling and by my uncomplimentary comments!
Maybe it's time for a Factory Harley Trike...
Nigel
09/04/2026 13:43:39 UTC
Ian Soady¹ said :-
I suspect if I was brave enough I could probably ride out the shakes - various people have said that they get better with speed. On the other hand it might get bad enough to end up in the ditch. It would be a shame to scratch the nice new paintwork let alone the damage it would do to me.
09/04/2026 15:21:21 UTC
ROD¹ said :-
Ian, do you have a large carpark local to yourself which is empty at weekends.
If you do that would probably be the safest option to set up the outfit.
09/04/2026 17:25:45 UTC
Ian Soady¹ said :-
Good point Rod, and I have identified such a car park which I will use to explore sharp left and right turns. However to get to it needs a couple of miles on fairly busy roads including a couple of roundabouts.
But now the good(ish) news. I filled in a query form on the Avon (now Goodyear) website and was very surprised to get a phone call in return from a very helpful chap. He stressed that he was calling rather than emailing as nothing he would say could be construed as "advice" for obvious legal reasons. Anyway, he was very helpful regarding tyre pressure / load combinations and it's clear that I've had the front tyre overinflated - and it still is, probably, at 28 psi. The unladen weight on the front wheel is 86kg - let's say that increases to 120 fully laden. According to my chap, this would correspond to a pressure of 21 psi (the lower limit to stop the tyre coming off the rim). I'd be very uncomfortable at that so will try the effect of 25.
I have been trying to work out the effect of front tyre pressures and it has struck me that lower pressure equates to a bigger footprint which would act to increase effort required to rotate around the steering axis - exactly the same as the effect of a steering damper. Like trying to steer a car with flat front tyres and no power steering. So I think I'm eventually on the right tack(!). Hopefully I'll have another short test today at 25.
I must say I've never bothered much about tyre pressures on solos, taking a starting point for most as 28 front, 32 back although these are for bikes weighing 180 kg or so. I seem to remember the Tiger liked 42 at the back but it was a big heavy beast.
10/04/2026 10:08:45 UTC
Upt'North ¹ said :-
Well done Avon/Goodyear. Good customer service is underrated. I had a similar experience at Doves Builder Merchants at Berwick-upon-the-Tweed this morning. There's some nice folk out there.
You included Ian....of course.
Upt.
10/04/2026 11:20:31 UTC
Ian Soady¹ said :-
I've just had another very short run and a great improvement. 25 psi in the front: much much better especially on smooth road surfaces. A biggish bump still knocks the bars but at least they don't start oscillating. I got up to about 20mph and felt relatively safe.... I may try even lower pressure but won't go below 23. Another long conversation with a passing couple who used to have bikes in their youth, and the postman who said he could do with something like the outfit to do his round. I did offer to sell it to him but he said he preferred to remain married.......
I have started to wonder about the back and sidecar tyre pressures - currently 30 and 25 respectively.
10/04/2026 11:54:11 UTC
ROD¹ said :-
Ian, Did you ask Avon if they still make the speed master rear tyre? These were the preferred front tyre for an outfit back in the day.
I believe some tyre manufacturers make small batches of retro tyres, like the TT100 from Dunlop ect.
The square section of the speed master rear would give the same properties as lowering the tyre pressure, giving a greater contact area.
10/04/2026 12:07:50 UTC
ROD¹ said :-
I have just checked the web but the speed master does not seem to be available.
The best I can find in an 18" is the Heidenau K28.
10/04/2026 12:15:35 UTC
Ian Soady¹ said :-
I think the rear was called the Safety Master (popularly known as the skidmaster)? As I remember the front (ribbed) was the Speedmaster. I have one on my Norton Electra with a TT100 on the back....
I've been having a chat with an ex aircraft engineer on a BSA forum and he tells me that nose wheel shimmy is a problem on aircraft. They had a special tyre to counteract it:
10/04/2026 12:24:51 UTC
ROD¹ said :-
Then this popped up!
https://www.aceclassics.co.uk/products/avon-sm-mkii-400-18-rear-tyre/...
10/04/2026 12:18:36 UTC
Ian Soady¹ said :-
Well spotted. A bit pricy though! And showing as out of stock.......
10/04/2026 12:21:28 UTC
Ian Soady¹ said :-
I can't see any availability on the Avon. However, I've used Mitas tyres successfully on other bikes and in fact have one on the sidecar wheel. The H-03 looks like a possibility and at £50 good value:
10/04/2026 12:39:17 UTC
nab301 said :-
Ian that's interesting re the tyre pressures , is the 21psi recommendation related directly to the unladen weight or just as you say the minimum pressure to keep the tyre on the rim ? I have a road rider front on my solo Enfield and the bars can flap about a bit when slowing down.. I better get out the weighing scales. Roadriders have fairly stiff side walls compared to some "classic" type tyres which could also be part of the problem , either way if you don't hear from me again you'll know lower front tyre pressure isn't a good idea! (currently 30psi approx)
Nigel
10/04/2026 14:38:22 UTC
Ian Soady¹ said :-
Interestingly, looking at the workshop manual the front pressure is 16 psi! Of course tyres used to be much stiffer then. I think I'll probably go for the Mitas although am feeling a little more confident now. Maybe a slightly longer test run at 24 psi is in the offing? I'm also still considering adapting the BSA steering damper.
Given the amount the outfit veers on acceleration / braking with 42 bhp I wonder how those with Gold Wings etc manage?
I have found a graph / spreadsheet showing weight / pressure relationships courtesy of Claude that I'll try to post.
10/04/2026 14:50:40 UTC
Ian Soady¹ said :-
Here you are:
10/04/2026 14:49:50 UTC
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