Are the tires standard?

Yes, both the front (20") and rear tires (8") are standard. They can be easily found in most bike or skate shops.

The bike shops in my area don't carry the rear wheel sizes so I'm looking online. There appear to be different inner diameter versions of 200x50 tires. Which I.D. do I need? Are there any other metrics I should be looking out for?

Hi Elliot, The full I.D. of the rear tires that we use is > 8", Innova, 200x50, IA-2603-2 Or you could follow this link to our shop and order from us > halfbikes.com/shop/products/8wheel Cheers

The inner diameter must be around 4 inches. I cannot be greater than 8 inches as that is the outer diameter. I wasn't able to find information about the tire on Innova's website so I just ordered a whole wheel from Halfbike. More info about the necessary tire dimensions would be nice for future tire purchases as I won't need a whole wheel setup and the shipping is expensive for me here in the US.

Hi again Elliot, We've found similar tires in Amazon for future reference. The main difference is that we're sending out the whole package needed for the Halfbike: This one is for the outer tire > www.amazon.com/MBS-Roadie-Tire-ea-200x50/dp/B00E9E025G/ref=sr_1_6?ie=UTF8&qid=1542356595&sr=8-6&keywords=mbs+200x50 This one is for the inner tube > www.amazon.com/dp/B01ABM9VSS/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B01ABM9VSS&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=21517efd-b385-405b-a405-9a37af61b5b4&pd_rd_wg=6Ee2r&pf_rd_r=KT8DTWQ9JZBSEV5W2Z69&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=w5K6V&pf_rd_i=desktop-dp-sims&pd_rd_r=e15aed89-e978-11e8-b8bf-2d5ac68107a8 Cheers

I've saved the link for future purchase. Thank you!