Widest tire for 19mm rim 700c, assuming clearance?

aferrick

New Member
Region
USA
I just got a nice used 2014 Trek 8.5 DS, it has stock rims which are 19mm width 700c. The stock tires were replaced with some Chinese brand that says 700x38c but 40-622 for the identification number size, so they're around there.

Assuming my clearance can fit wider tires, which it looks like it can by at least a bit, is it safe to fit 29x2.1" tires or 700x45c etc on the 19mm rim? I've seen the fitment charts but if you guys have experience I'd like to hear it.
 
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Stefan Mikes

Well-Known Member
Region
Europe
City
Brwinów (PL)
I think you mean the inner rim width of 19 mm not in?
Some information first: 700c wheels come in several distinct flavours:
  • Narrow rims intended for road racing bikes. Another designation of these is 28"
  • Medium rims made for most of bikes for general use. These are designated as 28", too
  • Wide rims used for cross-country and mountain bikes. These are designated as 29" to indicate they take wider tyres.
All these wheels are of the outside rim diameter of 622 mm. The ETRTO designation for the tyre of 40-622 means it is for the 622 mm wheel and the actual tyre width is 40 mm (700x38c is somewhat imprecise French designation as such a tyre could be anything from 38 to 40 mm, depending on the manufacturer).

Now, it is the rim manufacturer intention to ensure the tyre profile is correct. Too narrow or too wide tyre would be improper. Your rims of 19 mm inner width are one of the narrowest in the medium 28" range, and the 40-622 tyre size was chosen intentionally.

WTB tyre-rim fitting chart reads you could use up to 50 mm (2") 622 mm (700c, 28") tyres. I would say you better limit yourself to 45 mm wide tyre max. Certainly, you should not install any 29" (wide) tyre on your bike. (Note: Contrary to WTB, Schwalbe doesn't recommend any wide tyres on a 19 mm rim although it recognizes wider tyres are allowed by the ETRTO organization).
 
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aferrick

New Member
Region
USA
I think you mean the inner rim width of 19 mm not in?
Some information first: 700c wheels come in several distinct flavours:
  • Narrow rims intended for road racing bikes. Another designation of these is 28"
  • Medium rims made for most of bikes for general use. These are designated as 28", too
  • Wide rims used for cross-country and mountain bikes. These are designated as 29" to indicate they take wider tyres.
All these wheels are of the outside rim diameter of 622 mm. The ETRTO designation for the tyre of 40-622 means it is for the 622 mm wheel and the actual tyre width is 40 mm (700x38c is somewhat imprecise French designation as such a tyre could be anything from 38 to 40 mm, depending on the manufacturer).

Now, it is the rim manufacturer intention to ensure the tyre profile is correct. Too narrow or too wide tyre would be improper. Your rims of 19 mm inner width are one of the narrowest in the medium 28" range, and the 40-622 tyre size was chosen intentionally.

WTB tyre-rim fitting chart reads you could use up to 50 mm (2") 622 mm (700c, 28") tyres. I would say you better limit yourself to 45 mm wide tyre max. Certainly, you should not install any 29" (wide) tyre on your bike. (Note: Contrary to WTB, Schwalbe doesn't recommend any wide tyres on a 19 mm rim although it recognizes wider tyres are allowed by the ETRTO organization).
Ha yes thanks, I meant mm. I edited the OP and title to reflect the units, was looking at too many numbers all day.

Thanks for the comprehensive answer.
 

Timpo

Well-Known Member
I just got a nice used 2014 Trek 8.5 DS, it has stock rims which are 19mm width 700c. The stock tires were replaced with some Chinese brand that says 700x38c but 40-622 for the identification number size, so they're around there.

Assuming my clearance can fit wider tires, which it looks like it can by at least a bit, is it safe to fit 29x2.1" tires or 700x45c etc on the 19mm rim? I've seen the fitment charts but if you guys have experience I'd like to hear it.
 

JRA

Well-Known Member
We used to mount the 2.1 700c WTB Nanoraptors on 19mm rims all the time and ride hard single track in the Rocky Mtns. on them. For around town use they should be fine. But you will probably end up with at most a 45c tire.....which also is fine.