What are the smallest bicycle tires I can fit on my rims?

[PapaMoorhead]

Recently purchased a 2020 CTY 1.1 Hybrid bike.

It came with 700 x 40 tires and I am trying to determine the narrowest tire I can use on the wheels that came with the bike.  Would like to go down to a 700 x 32 or 700 x 35.

Will the wheels that came with the bike work with either of those tire sizes.

I am currently putting about 200 miles a week on the bike.

Any tire suggestions?

Thank you.

[REI-JohnJ]

@PapaMoorhead Thanks for reaching out!

You should be fine going down to a 700 x 35 tire on your bike. We'll have to check with the Co-op Cycles team to find out the rim width of the wheel to see if a 700 x 32 tire will fit. We'll circle back with you here when we find out. Thanks!

[pliang21]

Hello John,

I was wondering if you were able to get the info on thinnest width we can use on our rims. 

Thanks!

[REI-JohnJ]

@pliang21 

Thanks for reaching out!

@TomV's gives great advice, but we wanted to add that it looks like the 2020 Co-op Cycles 1.1 bike came with rims that have a 22mm internal diameter. Based on the equation that TomV used, that would mean you may be able to go down to a 33mm tire. Depending on the tire you would like to use, there can be variability in compatibility. As such, we recommend visiting your local bike shop and speaking with a bike tech to be sure.

Hopefully this helps, thanks!

[pliang21]

Hello John,

Thank you for your expertise! I will definitely stop by my local rei for a better judgement.

[TomV]

Your rim should have a sticker/designation on it, like 622 x 21, where the 622 just tells you its for 700c while the 21 (or whatever number it is) tells you the rim's internal width where the bead sits. Aim for tire widths to be anywhere from 1.5-2.5x the rim's width. So for my example of 21, we'd have a tire range of anywhere from 32 up to 50-ish. Going outside of this range, tires will still fit the bead, perhaps with difficulty, but the handling characteristics of the tire will suffer.

Although you're looking to downsize so this doesn't apply to you, for completeness of others reading this, when going larger, while the rim may accept the tire with a good profile to it, you have to also make sure the frame (and sometimes brake calipers) have sufficient clearance, a 4mm gap on all sides for road or 6mm for mountain/offroad bikes.

[pliang21]

Ah i was wondering what that sticker was on the rim, mine says 622-14. Thanks for the information it helps a lot!