This is another often asked question - ie which wheels to buy etc??
There are many on the market, some specific to certain makes and mostly very expensive. If you want to save a few £'s and have a go at making some then this is an easy pattern that I copied from my first SIB and have made three times since to suit various other SIBs. They are lightweight, adaptable and reasonably unobtrusive
These work great on regular design boats but Honwaves and similar types will need adapting.
The first ones I made from SS - much harder to work with (cut/file/drill) but 3mm thick aluminium box and channel works fine and is economical, more than strong enough and easy to work with normal tools. All you really need is a drill/bits, hacksaw and files.
All the materials are easily found on eBay UK and probably cost less than £40 for the last ones I made.
The pics illustrate but basically it's a piece of 'U' section (38mm OD, 32mm ID, 3mm thickness) with central M8 pivot hole one two M6 hole top and bottom for the sprung locking pins. This has the corners top and bottom rounded off. It is fixed to the transom with domed allen key SS bolts and spreader washers on the inner transom.
Main arms are 30mm OD square section, 3mm thickness. Inner end rounded off so it can pivot around the M8 hole and again a hole each for locking up or down. The pivot is just a SS M8 bolt with nylock nut, I just do this up finger tight although you could use a better pivot bolt from a chandlers. I only ever use the wheels to launch and then tie up the boat leaving the wheels in the car.
The wheels themselves are 4" wide solid as I've found these work much better on our local beaches compared to the smaller pneumatic type. 'Axles' are M10 SS bolts.
Pics here show wheels compared:
Obviously you need to measure carefully to calculate the right lengths/positions for the sections so the wheels clear the transom/tubes and are spaced as wide as possible.
And don't forget a tether between the locking pins or you'll invariably drop one in the drink!