Widest Tire for 19mm Inner Width Rim?

[rpr]

I have an LMT’D in order which comes with 19mm inner width rims and 2.4” hybrid tires, which are already near the extreme end of what’s considered to be compatible with 19mm rims, at least according to WTB charts. There are other charts out there that don’t even consider the 2.4” OEM tires to be compatible with 19mm rims.

Regardless, I’m going to change the hybrid tires out with knobbies as we ride mostly on gravel trails and forest service roads. I would really like to go with a slightly wider 2.5” or 2.6” tire though. There are a couple LMT’D owners who have reported doing this with no problems.

What are the the thoughts on these WTB charts? I assume a wire bead would be a safer bet than a foldable bead if pushing the width limits?

 

[Nvreloader]

Rpr
This may help, see information here:
https://www.bikecalc.com/wheel_size_math = wheel/tire diameters
Tia,
Don

 

[rpr]

Thanks but I think that chart is just for calculating wheel circumference when wheel and tire diameters are known. It’s not really a guideline for determining how wide of a tire you can fit in a given rim width.

There’s some good forum discussions out there in this question, mostly on MTB (non-ebike specific) forums though. Lots of different opinions but after reading through a lot of threads it seems there are two consensus opinions:

1. Some of the manufacturer recommendations that have been “shrinking” acceptable ranges for rim widths based on tire width are self serving. There’s almost no real data to back up this trend of shrinking acceptable rim width ranges for wider tires, and it’s almost certainly biased by marketing desires to sell more rims (with limited to no benefit) to some degree.

2. Most folks who actually post undesirable performance characteristics are complaining of issues with rims that are too wide for their tire widths (rim strikes, side knobs being pulled up too high from wider rims creating squarer profiles, etc). There are comparably much fewer complaints about undesirable handling characteristics associated with pushing the envelope of wider tires on narrower rims. Some posters refer to pro riders and downhill competitions where 2.4” to 2.6” tires are still being used on 19mm - 23mm rims to cut down on weight, and there are really no reports of issues. Apparently this was a much more common practice years ago before the manufacturers started to push and expand the market for wider rims, but it’s still not all that uncommon today.

I can’t personally back any of this up, but there’s quite a bit of discussion out there on this with a fair degree of consensus on the above two points if you dig a bit. This makes me feel a bit better on trying 2.4” - 2.6” width tires on 19mm inner width rims for our rather mild riding, assuming there’s adequate frame and fork clearance.

 

[scrambler]

2.4" on a 19mm is already stretching it indeed...
So it will depend what you do with it, but if we are speaking of off road riding with an off road tire that grips the ground, it is the worst case scenario, so what will matter is how aggressively you ride and how bumpy the trails are....
There is not a lot of risks associated with trying it though, and if you are doing fine with the 2.4", going 2.6" is a very small increase, so you may be fine.

 

[Nvreloader]

Rpr
Sorry, got the wrong chart, see here:
https://www.wtb.com/pages/tire-rim-fit-chart

Hth's
Don

 

[linklemming]

Lots of variables in this.

In the old days, 19mm rims were standard and we ran wider tires. I recently ran 2.35 Johhny watts on a 20mm rim and had no issues

Correct tire/rim(wider) choice is more critical if you are running tubeless and lower tire pressures.

Different tire manufacturers have different charts. They are close but differ at the limits as expected. Published sizes are not always what is seen in real life. An example is that schwalbe tires run narrower than expected and maxxis tires are pretty spot on and their recommended charts differ accordingly.

A narrow rim on a wider rim, makes the tire profile more 'pointy' in the center. The effect I have observed is that the bike tends to fall in the corner on initial turn in. It can scare you for a second if your not expecting it but you quickly get used to it (at least I do). Of course different tires can affect this.

Personally 2.4 is about as wide as I would go on a 19mm rim given a choice. You can always try it and see if you like it.

I ride with a friend who has both extremes on the same bike (2.35/19mm on the front and 2.1/30mm on the rear...not ideal but its what he currently has...long story). He is the fastest gravel rider I know. Go figure

 

[rpr]

I’m trying to convince myself I can go 2.5” or 2.6”, especially considering Ride1up ships the LMT’D with 2.4” WTB’s, but unfortunately it sounds like that would really be stretching it.

Thanks for all the feedback.

 

[PedalUma]

19 can do 50 or 52 safely. That is just over 2". It would be pushing it. Consult this chart. I hope this is helpful.

Tire & Rim Fit Chart

WHAT IS IT? The WTB Tire & Rim Compatibility Chart is used to determine what tire and rim width combinations provide optimal performance and compatibility. By matching your tire section width to your rim width you can determine optimal, compatible, or not optimal fitting options to ensure the...

www.wtb.com