Love it! Even if the sidecar is on the wrong side.
Any info on the front tyre. I have been unable to find an appropriate CT to run on my chair.
Al
I think the narrowest 17" CT you can get now is a 195/40/17 but it is still 45mm wider than your stock tyre. See at bottom.
Would it even fit between forks and on your R3's 3.5" Front rim width without fouling somewhere??
Long term the best option is a leading link front end to suit a better and common light sports car tyre range rim diameter and width.
I had a Melbourne engineered Suzuki GS1000 with leading link using VW steel rims laced to a Suzuki hubs and disc brake set up with 15" car tyres front and 18" rear flat car retreads on early radial m/cycle tyre carcasses

My '78 BMW DJP has leading link but stock R100RS alloy snowflake rims with Avon stiff sidewall sidecar tyres. I am pretty sure you can still get them but not sure about sizing.
See
@Seanii Plunkett 's set up he gave me the details for the Front end makers near Bathurst, Country NSW.
SRK Engineering aka Sean Kelly. 1994 -2014 Celebrating 20 Years
Now located in O'Connell NSW
PH: 02-63375705
Email:
Sean@srkengineering.com.au
Trading as SEAN & ROBYN KELLY S R K ENGINEERING | ABN: 47 260 834 611
Note: All prices are in AUD$
SRK Engineering | Welcome to SRK Engineering | Engineering, Site, Nsw, Srk, Services
VSCCS Modified Vehicle Licenced Certifier (NSW)
SRK also privide Certification of modified vehicles,
Motorcycle,Sidecar, Trike
Passenger cars inc Omnibus<=4.5tonnes,
Omnibus GVM >4.5 tonnes,
Light commercial
All Vehicles and Trailer up to 4.5Tonne
GVM Upgrades, seat reduction, motor Homes,
Individually constructed cars and Motorcycles, sidecars and Trikes.
SRK Engineering | SideCars | Sidecar, Custom, Have, Sidecars, Projects
Sidecars, Sidecar installation compliance.
SRK Custom Sidecars: Our services start from your basic sidecar installation through to a custom built sidecar. We also offer Leading link suspension units, wide and narrow formats. 13”& 15” Front & rear wheels, brake upgrades, custom sidecar suspension. Fibreglass repairs, Engine work and custom exhaust systems. Here we strive to provide a complete service for the sidecar rider. Whether you are new to the game or you have been riding for years. Call in and have a chat, have a look at some of the projects we are currently working on.
Link Removed
https://www.vredestein.co.uk/car-suv-van/tyre-finder/tyres/product/1/195/40/17/895-sportrac-5
https://www.vredestein.co.uk/car-suv-van/tyre-finder/tyres/product/1/195/40/17/895-sportrac-5
TYRE e.g. VREDESTEIN SPORTRAC 5 195/40 R17
SPECS
195 WIDTH
40 ASPECT RATIO
17 RIM DIAMETER
81 LOAD INDEX
V SPEED RATING
149 mph MAX SPEED
Yes RIM PROTECTOR
'E' ROLLING RESISTANCE RATING
'A' WET GRIP
70 NOISE (DB)
Yes EU LABEL