Author Topic: 25c tire on a A719 rim  (Read 684 times)

velosam

  • '.....you used to be an apple on a stick.'
25c tire on a A719 rim
« on: December 14, 2018, 08:27:47 pm »
My marathons are getting scrappy and I have not got a replacement and need a tire for Monday.  Can I fit a 25c durano on the rim?

I can't see any specific size on the rim or the invoice.

Thanks

mattc

  • n.b. have grown beard since photo taken
    • Didcot Audaxes
Re: 25c tire on a A719 rim
« Reply #1 on: December 14, 2018, 08:33:42 pm »
The Mavic site is full of useful info of this sort - try there?

(as it happens, I believe I rode nearly 1000 miles of german audax with the same combination you describe - albeit a lighter tyre, still 25c. Purely cos that was the rim that was attached to my only dyno-hub!)
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

velosam

  • '.....you used to be an apple on a stick.'
Re: 25c tire on a A719 rim
« Reply #2 on: December 14, 2018, 08:40:20 pm »
Sorry it just occurred me to check and they recommend a minimum of a 28, so it may not be wise to run the 25 for commuting.

Re: 25c tire on a A719 rim
« Reply #3 on: December 14, 2018, 09:43:45 pm »
some manufacturers of rims with a similar internal width do allow 25mm tyres on their rims.  It is something of a modern fashion in some circles.  Myself, I'm not right keen on a tyre that narrow on that sort of rim, but I'd use it as a front tyre for a while, if I had nothing else.

cheers

velosam

  • '.....you used to be an apple on a stick.'
Re: 25c tire on a A719 rim
« Reply #4 on: December 14, 2018, 09:53:32 pm »
cheers will give it a shot till I get a new front

Re: 25c tire on a A719 rim
« Reply #5 on: December 30, 2018, 11:28:29 pm »
I ran durano plus 25c on those rims for about 2000 miles without any problems.

Re: 25c tire on a A719 rim
« Reply #6 on: December 31, 2018, 10:44:46 am »
Observe the maximum pressure and err on the cautious side.  Wired-on Duranos will blow off at about 120psi even on narrow rims, and I think they are only rated for about 110 or 115psi.  A narrow tyre on a wide rim increases the risk of it blowing off.  I wouldn't go higher than 90psi on a wide rim, which may not be enough depending on your weight and the number of sharp-edged potholes in your area.
Never tell me the odds.

mattc

  • n.b. have grown beard since photo taken
    • Didcot Audaxes
Re: 25c tire on a A719 rim
« Reply #7 on: December 31, 2018, 05:22:02 pm »
Are people still riding on tyres over 110psi on UK roads?!?

 ;)

Meanwhile, re this:
some manufacturers of rims with a similar internal width do allow 25mm tyres on their rims.  It is something of a modern fashion in some circles.
There's a slightly interesting artlcile in current Cyclist mag - some design engineer states that rims that sit "proud" of the tyre (i.e. their outer width is wider than the inflated width of the rubber) give a lot less drag than traditional arrangements. So that was his excuse for putting wide rims and 23mm tyres on the new bike.

How many riders this will *actually* benefit is perhaps less certain ...
Has never ridden RAAM
---------
No.11  Because of the great host of those who dislike the least appearance of "swank " when they travel the roads and lanes. - From Kuklos' 39 Articles

zigzag

  • unfuckwithable
Re: 25c tire on a A719 rim
« Reply #8 on: December 31, 2018, 06:32:47 pm »
there are wind tunnel tests that show the most aerodynamic rim/tyre combo is when a rim is 5% wider than a tyre. practically though, such setup makes the rim vulnerable to scratches from the curbs etc.

to answer the original question - i've ran a719 rims on my hack bike for a decade, always with a 25mm tyre, never had any problem. i also have 25mm tyres on 21c internal rims at around 80psi, also no problem.