What Size Spare Tire Fit on the Hollywood Racks SR1 Bike Carrier?

Updated 06/05/2026 | Published 05/23/2026

Question:

I cannot find anywhere Amazon, this website or the company’s website as to what diameter this rack will fit. We have a 37”x12.5”. Yes, it fits up to 15” but what about overall diameter? I see stuff about some sort of “U” needs to be 22”, but I don’t know what that is referring to. I’ve seen references to “oversized kits” as well, but I don’t find any info about an oversized kit. Will this work on a 37x12.5? If not, why not? If the straps are too short, I can get longer straps.

asked by: Steve

Expert Reply:

Hi Steve,

The 15" measurement is referring to the width of the tire, so if your spare tire's width from front to back is less than 15" it will work with the Hollywood Racks SR1 Bike Carrier part # HRSR1. In regards to the diameter, I reached out to Hollywood Racks, and they have only tested the # HRSR1 with tires up to 35" in diameter, so they don't recommend using the rack with wheels larger than 35" in diameter.

The reference on the Hollywood Racks website to an oversized kit is due to an update they made to the carrier. Previously, the carrier was not able to carry wheels as large as 15" in diameter. Hollywood Racks added longer bolts for wider tires to the kit to increase the maximum tire width to 15".

What vehicle are you looking to use this on? A 2026 Ford F-350 Super Duty was input into the question but the part # HRSR1 is not a fit for this year, make, model of vehicle. This is due to the size of the spare tire that comes with the truck.

expert reply by: Claire H

Steve

6/4/2026

I think there is some confusion in definitions regarding tire/wheel measurements. I do not think that the 15” that Hollywood Racks is talking about refers to the diameter of the tire. I think the 15” refers to the width of the tire. As I mentioned, the maximum tire diameter this rack will fit is not mentioned anywhere that I could find. Let’s ignore what type of truck I have. Yes, I own a 2026 F350. But the tire I am trying to put this rack on is a 37” x 12.5”. And what is this 22” U referring to?

Claire H.

6/4/2026

@Steve I reached back out to Hollywood Racks, and they said the rack hasn't been tested with tires larger than 35" in diameter and don't recommend using tires with greater than 35" diameter with the # HRSR1. The 15" does refer to just the width of the tire, so the width of your tire is okay, but the diameter is larger than what they recommend using with the rack.

Steve

6/5/2026

@ClaireH Okay, thanks.