Recumbent - Sourcing a strange 20" rim size

Hi - I'm undertaking the restoration of a Pashley Trike - not exactly a recumbent but I thought since y'all use small wheels you might have some clue here... ;)

Basically - one of the rear rims is pretty badly buckled. Too bent—I fear—to be saved by re-truing.
Naturally with these things, it has a strange rim size - somewhere between BMX (406) and most old UK folders (451) that I cannot seem to find a stockist of, called 440 (500A).

Does anyone have any clues as to any stockist of this size - Ideally UK but EU or worldwide for a lead would be useful. It needs to be drilled for 36h.

If I can't sort it I might be persuaded to switch out to 451 or 406 but then problems with the brake calliper reach may come into play.

Many thanks in advance to anyone that can offer any leads.
Best
Huw

What have the dealers said?

Once you fix the rim, where are you going to find tires?
Anyhow... A 451 will only offset the brakes by 5,5mm.
Do you have that much in adjustment?
You can also get rims with pretty wide brake surfaces.
Good luck.

http://www.sjscycles.co.uk/category-20-(440--500A)-343.htm

Yes - I'd already found that SJS have the tyres (they are the online gods!) but not rims - or at least not on their online catalogue;

@ megaman - haven't really spoken to anyone yet - at christmas people seem too busy for complicated requests - so my 'no-one has anything' comment is really based on trawling of online catalogues. I plan to ring around Pashley / Moulton resellers in the new year - I suppose I thought asking here might save a few calls...

Happy new year cumbent peeps btw!
Huw :)

I agree with Shaman - a 451 rim has a bead seat diameter of... 451mm. While a 500a rim has a bead seat diameter of 440mm. Using the 451 rim would mean moving the brake pads up about 5mm, which should be pretty do-able. Since the 440 size isn't meant for performance machines, I suspect the 451 size would let you use faster tires, too.

I intend to have a go at saving the buckled rim - if I can get it off the blimmin rear axle!
But yeah - if it's really not a goer then plan b might be to rebuild the rear with the 440 from up front and then have a new 451 up there. It'd have mismatched tyres then but I'm on some sort of budget and it might be the best plan. I'm slightly worried about adding to the ride height though - the trike is going to be for my somewhat diminutive mum and every few mm I add to the height will make a difference on this adult sized trike.

If I do go for 451 - can anyone steer me in the direction of a UK supplier. I only really know of Gaerlan in the US and the shipping for just one rim is going to be a bit silly cost wise. UK/EU - don't mind really...

How did Pashley do? If you are absolutely fixed on finding 500A rims, there is the option of custom rolling a rim to size. I've done that before, usually for high bicycles. Checking with older French retailers (it is a French size) would be a sensible option also.

Thanks for your replies people. I swapped out the bent rear for the front over the christmas break and had it on my truing stand and I've pretty much managed to unbuckle it; Needs a few more tensioning tweaks but it looks like I'm not actually going to have to replace it after all which is a major headache avoided. Thanks for the input though. It might not have been so easy - it looked pretty unsalvageable before I got it off the hub.
Best
--Huw.