Ok. Here's my dilemma: My grandfather is around 63 years old and seriously overweight. He's having problems getting around and as a result is not happy. My grandmother has been searching frantically for a three wheel bike to support his weight with no luck; the cheapest she can get one here is $1200 Canadian. So, I'm kind of wondering about a custom job. Can anyone even build me a trike frame? Here's what we'd need:
-Steel preferably, weight is not a big issue but strength is essential.
-Should take 29" mountain bike wheels
-Lots of clearance for big tires
-Being able to take a suspension fork is a huge plus
-Disc brake mounts
-Upright positioning, fairly slack, comfortable geometry.
-Needs to support around 300lbs
-And, finally, it should be able to take most stock bike parts without too much hassle.
If there's anyone who can do this, PLEASE get in touch with me via PM or email. This would help a lot

In the US, trikes usually mean recumbents and tricycles are heavy, slow industrial movers such as Worksman There are quite capable of carrying heavy riders. In the UK we still have high performance upright trikes in racing, touring and MTB styles. One of the best builders is Longstaff with their Cyclone model at £750.

Uprights trikes generally use smaller wheels, esp in the rear. 26" MTB wheels are ideal for this purpose and there is no advantage in using 29".

I don't know if Sun Bicycles (https://www.sunbicycles.com/) get imported to Canada, but their Atlas Cargo Trike has a capacity of 500 lbs (specs say 250 for the rider and 250 for cargo.

The Worksman PAV3 (a recumbent with scary-looking tiller steering that probably works great as long as you don't go too fast) has a 550 lb capacity. It probably also weighs 550 lbs.

The Worksman is likely to be indestructible, the perhaps Sun less so.

Worksman medium-duty executive trikes have a weight capacity of 300 lbs. https://worksmancycles.com/shopsite_s...ml/page13.html

Good luck.

The above recommendations are the way to go. A custom trike frame would be more work than two regular frames for a custom builder, and they would price accordingly. I doubt any pro would touch that job for less than $2000US.
Good luck.

He needs something like this:

https://www.trailmate.com/adultTrikes.cfm

They claim these dealers:

AGAR ENTERPRISES, INC. BOX 333, ONANOLE, 204-848-2535 Web Site
ATKINSON SPORTING GOODS, LTD 512 MAIN STREET, SWAN RIVER, 204-734-4760
BELLE RIVER SPORT 481 NOTRE DAME STREET, BELLE RIVER, 519-728-3717
BRAUN'S BICYCLE 27 SCOTT STREET, KITCHENER, 519-579-2453 Web Site
DIXIE LAWN & CYCLE 27 ERIE STREET NORTH, LEMINGTON, 519-326-4572 Web Site
GOOCH'S BICYCLE & HOBBY SHOP 185 SHERBROOK STREET, WINNIPEG, 204-956-6571
VELO ADVENTURES QUAI DES CONVOYEURS, MONTREAL, 514-288-8356
WALK AND ROLL 98 LAKESHORE DRIVE, NORTHBAY, 705-474-5619 Web Site


I don't know where you get this kind of bike, though I see people on such things from time to time. Try a local bike shop, here in ontario you can try:

https://ucycle.com/index.php

They should be able to direct you.

Our local Pickering shop occasionally has these also, it is called Bay Cycle.

Norco makes one, they are everywhere in Canada:

https://www.thecyclepath.ca/pages/bikes/adult_trikes.htm

Or try this:

https://trektoronto.ca/itemdetails.cfm?id=3420

www.supersizedcycles.com

Damn! It sounds like your Grandpa is getting into downhill trike racing! That's pretty cool! If I were looking for a trike for an older person, I'd probably be looking at something lightweight that was designed to operate on roads (skinny high-pressure tires, rim or coaster brakes, etc).

I have been trying to talk my father into one of those trikes for years. He lives where the land around him is mostly flat. Other people use them but he still thinks they are kiddie tricycles.

I've had experience with a few of those Trek trikes and they aren't half bad! Pretty weird to ride on if you're used to a 7kg bike, but still pretty damn cool!