Cycling UK Forum

I purchased some Shimano RX31 wheels on eBay and they came with 23mm Schwalbe Durano tyres. Shimano say the recommended tyre width is 25-38.

Should I sell on the 23’s and buy 25’s or will it be safe enough to use the 23’s?

EDIT: I have found a website that states that the internal width of the rims is 17mm and another website stated that for a 23mm tyre the internal width of a rim need to be 13-16mm. Surely 1mm isn’t all that important?

there are 17mm internal width rims that are meant to be OK with 23mm tyres. It looks a bit wrong to me, especially if there is to be a substantial load. I think that a 'real' 23mm tyre will come up about 24mm on a 17mm internal width rim, but I'd be happier with 25mm tyres as a minimum on that size rim.

cheers

Brucey wrote:there are 17mm internal width rims that are meant to be OK with 23mm tyres. It looks a bit wrong to me, especially if there is to be a substantial load. I think that a 'real' 23mm tyre will come up about 24mm on a 17mm internal width rim, but I'd be happier with 25mm tyres as a minimum on that size rim.

cheers

Damn! I already spent £75 on 30mm mud guards to suit the tyres. :/

Hi,
I used 25 mm conti GP's on my tourer many years ago doing Audax's in Devon, T261 mavic x 20, I never doubted I would have a problem.
Probably because we did not have easy info at a nano second like today.
Maybe low pressures might be a problem

You selling the tyres and guards cheap
£75 what............

NATURAL ANKLING wrote:Hi,
I used 25 mm conti GP's on my tourer many years ago doing Audax's in Devon, T261 mavic x 20, I never doubted I would have a problem.
Probably because we did not have easy info at a nano second like today.
Maybe low pressures might be a problem

You selling the tyres and guards cheap
£75 what............

The tyres are 23 though...

I’ll post a picture of them when I get home after Christmas and people can see if they ‘look’ right.

If they’re not right I’ll sell the tyres but return the guards for a full refund.

Hi,
Brucey might have more to offer, but his advise will err on a point of manufactures recommendation and of course safety.
I was using 25's on a 20 mm rim, you 23's on a 17 mm rim.

NATURAL ANKLING wrote:Hi,
Brucey might have more to offer, but his advise will err on a point of manufactures recommendation and of course safety.
I was using 25's on a 20 mm rim, you 23's on a 17 mm rim.

Mentioned it to the bike shop today where I bought one of my bikes and they didn’t see it as an issue...

Mavic used to "worry" a lot more about rim widths and tyre size before mtb rims on which folk mounted a much wider range of tyre sizes on just one size/width rims. Then lo and behold they didn't. I've often mounted over or under sized tyres on rims with no problems.

Stuff them and stop fussing. Nothing bad will happen and it might makes those silly skinny tyres feel a bit like some nice wide ones.
Too much worrying about I reckon.

re heavy loads and skinny tyres; check the pressure limit on the rims and tyres carefully. This inflation chart

http://rcctulsa.org/filesSite/TireDrop.pdf

suggests that a load on one wheel of 55kg ought to require that the tyre is inflated to 130psi, if it is a 23mm one.

FWIW one of the concerns about skinny tyres on wide rims is that the rim is much more likely to be damaged.

cheers

If one rides up and down kerbs, maybe.

djnotts wrote:If one rides up and down kerbs, maybe.

no, just ordinary roads these days are quite sufficient.

cheers

You'll be fine with the 23s. Just ride.

I'm riding 23 mm tyres on 17C and 19C rims for years now, no problems whatsoever.
Tyres become wider with more volume and pressure can be lowered, the only disadvantage could be in the limitations of the frame.
Mavic is very conservative about rim and tyre width,. but the new Open Pro is 19C, so what tyre should we ride on them.....
Here some recommendations from the Yankees, not limited by ETRTO standards...they make really sense IMO, see lower half of the article.
https://intheknowcycling.com/2016/04/03 ... eel-sizes/

Brucey wrote:re heavy loads and skinny tyres; check the pressure limit on the rims and tyres carefully. This inflation chart

http://rcctulsa.org/filesSite/TireDrop.pdf

suggests that a load on one wheel of 55kg ought to require that the tyre is inflated to 130psi, if it is a 23mm one.

FWIW one of the concerns about skinny tyres on wide rims is that the rim is much more likely to be damaged.

cheers

I’m somewhere between 133 and 139kg.

How do I find out the pressure limit for the rims?

The tyres max pressure is 80psi.