Correlation between Rim Width and Max Tyre Width

[FrikkieMeyer87]

I would have thought that this would have been discussed in much detail already, but I could not find any solid reference to the topic at hand: How does rim width correlate to tyre width? Is there any concrete limits for certain widths at all, or does it differ from one rim/tyre combination to the next?

 

Here's some context to that question;

 

I have 26" Alex Rims DM18's (559x18) on my bike fitted with 26 x 2.25 Maxxis CrossMark UST Tubeless tekkies front and back. The previous owner of this bike did a lot of road riding with these tyres, and as a result, the rear is worn to a point where it does not provide the grip it's supposed to (on that note, these tyres don't appear very grippy even when new). This together with the fact that they've got a bunch of dry sludge in and showing some age cracks on the sidewalls prompted me to look for new tyres. Obviously, my first place to look was the hub. Lo and behold, a set of 26 x 2.4 Continental Mountain King II tyres, brand spanking new!

 

Some quick searches suggest that fitting a 2.4 to a 18mm rim will not work so lekker. I thought I'd try and understand where my limits lie when looking for tyres for this rim.

 

Aaaaand go!

[Fat Boab]

Look up the Sheldon Brown table, and use that and his comments as a guide.....

[Fat Boab]

Sorry - forgot the link.....


 

http://www.sheldonbrown.com/tire-sizing.html

[FrikkieMeyer87]

Look up the Sheldon Brown table, and use that and his comments as a guide.....

 

Are you referring to THIS?

 

Based on that, I should be good with a tyre width of anything from 24mm to 40mm. My current tyres are 26 x 2.25. If this is in inch, then 2.25" = 57.15mm which baffles me immediately and completely, as technically that tyre should not be riding on that rim and yet I'm having a blast with my current setup. What am I missing? Is the 2.25 the tread whereas the 40mm perhaps refers to the bead, and if so, where would I get the bead measurement?

 

Thanks for the help, and sorry for all the questions

[The Bike Brew]

there is alot of confusion on this point --- most people think going to WIDER RIM is the solution to their TRACTION/COMFORT problems - not true.

 

some of the wheels/rims on the market are just too wide for the average 2.1/2.2 tyre and when matched to these WIDE RIMS results in the tread no longer sitting where it was designed to be ...

 

this makes alot more sense : https://www.notubes.com/technology/wide-right

[FrikkieMeyer87]

there is alot of confusion on this point --- most people think going to WIDER RIM is the solution to their TRACTION/COMFORT problems - not true.

 

some of the wheels/rims on the market are just too wide for the average 2.1/2.2 tyre and when matched to these WIDE RIMS results in the tread no longer sitting where it was designed to be ...

 

this makes alot more sense : https://www.notubes.com/technology/wide-right

 

That makes sense and is, I suspect, the opposite of what I'm trying to do. I've got what I believe to be a fairly narrow rim, and want to fit what is regarded as a wider tyre to it. I'm currently running 2.25, and was interested in fitting 2.4 but I'm not convinced that my rims (or my frame) can take it.

[Fat Boab]

Are you referring to THIS?

 

Based on that, I should be good with a tyre width of anything from 24mm to 40mm. My current tyres are 26 x 2.25. If this is in inch, then 2.25" = 57.15mm which baffles me immediately and completely, as technically that tyre should not be riding on that rim and yet I'm having a blast with my current setup. What am I missing? Is the 2.25 the tread whereas the 40mm perhaps refers to the bead, and if so, where would I get the bead measurement?

 

Thanks for the help, and sorry for all the questions

 

I'll pull the roadie card here (  ), but the Sheldon Brown table is a guide and his comment under the table applies. It's often exceeded...

[Jewbacca]

I think the point of wide rims is to run bigger volume tires without tire roll and burping?

 

Getting 2.1's to fit a 30mm ID rim is going backwards.

[Fat Boab]

I think the point of wide rims is to run bigger volume tires without tire roll and burping?

 

Getting 2.1's to fit a 30mm ID rim is going backwards.

 

Best check the rotation direction arrow on the tyre then.......  

[FrikkieMeyer87]

I think the point of wide rims is to run bigger volume tires without tire roll and burping?

 

Getting 2.1's to fit a 30mm ID rim is going backwards.

 

Agreed, that makes as much sense as these guys driving Mk1 Citi Golf's and putting those super wide rims with wheelbarrow wheels on 

 

But in the case of a narrow rim with a wide tyre, I don't fully grasp how the 2.25 width of the tyre correlates to the 40mm max width mentioned on the Sheldon Brown table because if it is in fact inch vs mm, by that reasoning, I have already exceeded what he deems the maximum and I'm riding with no problems at all other than my lack of traction.

[El Nino]

From the table below it would appear that your 26x2.25 (57mm) tyre is a little too wide for your 18mm rim. You would need a minimum 19mm rim.

 

 

[popcorn_skollie]

The rims are quite narrow and I personally would not go wider than 2.1 tyres.

But a fair question is also how far you are pushing those wheels? 

 

The wider the tyre. The more aggresive its intended purpose.

The same can be said for rims too.

Anything over 2.25 is going to feel sketchy on flat corners and off camber sections anyways.

 

So you could get away with 2.25 tyres until you indulge in some more aggressive riding.

Then the wheels limitations will present itself. At which point you should probably consider other wheels rather than be concerned with finding a narrower tyre.

[FrikkieMeyer87]

From the table below it would appear that your 26x2.25 (57mm) tyre is a little too wide for your 18mm rim. You would need a minimum 19mm rim.

 

Tyre width.png

 

Yes, from that table it would seem that 2.2 is pretty much the max that I should be looking at, although I suspect that the additional 2 mm I currently have with the Maxxis won't quite be the straw that breaks the camel's back in this case as it's still in the low reaches of the 19mm recommended rim width. But yes, 2.4 will definitely be a bit too much. Pity.

 

The rims are quite narrow and I personally would not go wider than 2.1 tyres.

But a fair question is also how far you are pushing those wheels? 

 

The wider the tyre. The more aggresive its intended purpose.

The same can be said for rims too.

Anything over 2.25 is going to feel sketchy on flat corners and off camber sections anyways.

 

So you could get away with 2.25 tyres until you indulge in some more aggressive riding.

Then the wheels limitations will present itself. At which point you should probably consider other wheels rather than be concerned with finding a narrower tyre.

 

I've been cycling for about a month now and have done exactly two (2) local trails. While I like to believe that I'm gooing it out there, my GoPro footage tells another story; one where the likelihood of me being overtaken by a veteran postman on a strawberry bike with a basket and whitewalls does not seem that far fetched. I came off my bike (See: "Fell over") whilst crossing a wet wooden bridge on Sunday because instead of opting for speed, I went for a low gear and tried to pedal over and my next level, road worn rear tyre simply went "BZZZZZT" and I came to a standstill and slowly toppled to the side and off the bridge. It was this that prompted be to rethink the suitability of my existing tires.

 

Buying new wheels would be awesome, but then so would buying a new bike. At this point I'm trying to spend as little as possible, whilst learning as much as possible and making as much as possible of what I have at my disposal. For my current riding ability and style I'd say that had the current tyres been new, they would have been more than sufficient but sadly that rear tyre is at a point where it's going to continue giving way and I will continually spend my afternoons standing in front of the mirror, bloodied and bruised, trying to convince myself that it's the bike's fault and not mine     

 

http://i.imgur.com/uTH82YB.jpg?fb

[El Nino]

Yes, I think you would be better off buying new tyres than new wheels at this stage. Only problem you have is that you are quite limited with tyre choice for 26" wheels.

[popcorn_skollie]

I've been cycling for about a month now and have done exactly two (2) local trails. While I like to believe that I'm gooing it out there, my GoPro footage tells another story; one where the likelihood of me being overtaken by a veteran postman on a strawberry bike with a basket and whitewalls does not seem that far fetched. I came off my bike (See: "Fell over") whilst crossing a wet wooden bridge on Sunday because instead of opting for speed, I went for a low gear and tried to pedal over and my next level, road worn rear tyre simply went "BZZZZZT" and I came to a standstill and slowly toppled to the side and off the bridge. It was this that prompted be to rethink the suitability of my existing tires.

 

Buying new wheels would be awesome, but then so would buying a new bike. At this point I'm trying to spend as little as possible, whilst learning as much as possible and making as much as possible of what I have at my disposal. For my current riding ability and style I'd say that had the current tyres been new, they would have been more than sufficient but sadly that rear tyre is at a point where it's going to continue giving way and I will continually spend my afternoons standing in front of the mirror, bloodied and bruised, trying to convince myself that it's the bike's fault and not mine     

 

http://i.imgur.com/PJiIu8l.png

 

I would grab two of the 2.2's. Mountain Kings offer decent amount of grip and are fine to run front and rear. With some luck and patience the pair could land here for around R600. Good deal imo. 

[El Nino]

Is the OP not running tubeless? I'm assumimg this because his existing tyres are Maxxis UST.