What size of road tyre for my Old Mountain Bike ?

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TimFromLondon
Posts: 6
Joined: 18 Jun 2020, 9:47am

What size of road tyre for my Old Mountain Bike ?

Postby TimFromLondon » 18 Jun 2020, 10:07am

a short history: I have an old mountain bike brought in Malaysia back in the mid 1990s, its been used sporadically since but kept dry so its in pretty good shape especially after a good clean and a few replacement parts being fitted.

The problem I have is that I brought the bike to suit riding on logging tracks in north Malaysia so the tyres are pretty knobbly to say the least. Now I'm old(er?) I'm not really going to do that kind of cycling so I want to replace the bike but of course no stock, anywhere, anytime soon. So my solution is to keep plodding on with this bike but try to change the tyres to suit road and light trail use.

Tyres are 26" x 2.3" and I can't find anything that's road like to suit this size BUT I don't understand the variation in width that I can fit to the existing wheels.

Can anybody point me towards a tyre that would be better for road use (at a reasonable price given this is a temporary fix) or an online resource so that I can understand what I need to determine the range of tyre widths that my existing wheels will accommodate?

Many thanks in advance!
Tim
Last edited by Graham on 18 Jun 2020, 10:39am, edited 1 time in total.
Reason: Title

RobinS
Posts: 162
Joined: 9 Apr 2015, 10:01am

Re: What size of road tyre for my Old Mountain Bike ?

Postby RobinS » 18 Jun 2020, 11:03am

If you do a google search on "MTB 26 slick tyres" it will come up with plenty of choices from about £8 up to £20.

slowster
Posts: 1721
Joined: 7 Jul 2017, 10:37am

Re: What size of road tyre for my Old Mountain Bike ?

Postby slowster » 18 Jun 2020, 11:14am

TimFromLondon wrote: I don't understand the variation in width that I can fit to the existing wheels

Measure the internal width of the rim as per the image below and refer to this table (from this website).

Image

TimFromLondon
Posts: 6
Joined: 18 Jun 2020, 9:47am

Re: What size of road tyre for my Old Mountain Bike ?

Postby TimFromLondon » 18 Jun 2020, 1:05pm

Thanks folks - very helpful!

Brucey
Posts: 41444
Joined: 4 Jan 2012, 6:25pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby Brucey » 18 Jun 2020, 1:05pm

26x2.3" is usually also known as 58-559 or 60-559 in ISO sizing.

ISO sizing uses tyre width (in mm) and rim bead seat diameter (BSD in mm) as the designation. Multiple different tyre widths will fit to the same rim provided the BSD value is the same. The biggest problem when buying tyres is knowing for sure that this is the case.

The usual convention is that 26x ** sizes all fit to a 559mm provided the ** number is in decimals. If it is a fraction (eg 1-1/2" rather than 1.5") then the rim probably isn't 559. But to be certain it is always a good idea to check the ISO size, because not all tyre manufacturers are bright enough to stick with the usual labelling conventions.

all the tyres here

https://www.sjscycles.co.uk/tyres-26-559-rigid/

will fit the same 559 rim diameter. However some won't be a good match for the rim width and some won't be a good match for the bike because the overall wheel diameter is too far different. Both these things will vary with the bike/wheelset.

However in your case I'd suggest 50-559 Schwalbe big apples might be a good choice.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Jamesh
Posts: 1554
Joined: 2 Jan 2017, 5:56pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby Jamesh » 18 Jun 2020, 2:58pm

I have used land cruiser tyres on my steel MTB without any issues.

Good price and roll ok for cheap tyres!

So long as your tyre is as wide or wider than your rim you should be ok.

Cheers James

Chris56
Posts: 37
Joined: 3 May 2020, 9:30pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby Chris56 » 18 Jun 2020, 3:54pm

+1 on the Schwalbe tyres. They offer excellent grip and puncture resistance. If you do want to spend as much then the Decathlon do some good trecking tyres that are really cheap. I had them i n 26 x 1.75 on my old mtb and, although heavy, they did roll quite quick and never punctured in 2 years of daily use

mattsccm
Posts: 3521
Joined: 28 Nov 2009, 9:44pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby mattsccm » 18 Jun 2020, 8:36pm

Modern trenddsare for wider rims for a given size of road tyre. I have happily run 25mm tyres on old MTB rims that were around the 20mm mark.


TimFromLondon
Posts: 6
Joined: 18 Jun 2020, 9:47am

Re: What size of road tyre for my Old Mountain Bike ?

Postby TimFromLondon » 19 Jun 2020, 10:48am

Many thanks for all the replies - very helpful!

But...

I've taken the tyre and inner tube off and found the following:

- The rim is marked 26 x 1.75.
- The inner rim distance is 20mm
- The outside of the rim is 25.2mm
- From the outer edge of the rim to the bead landing inside the rim is 7.5mm
- As best as I can measure the bead diameter is 565mm
- As best as I can measure the outside rim diameter is 580mm

So I've added to my confusion with the tyres marked 26 x2.30 the rims marked as 26 x 1.75 and the rim and bead sizes don't seem to tally with either. I have an engineering degree and so I'm used to standards but bike tyre and wheel sizing seem to be very unruly and understanding them very elusive! :lol:

Do these dimensions mean anything to you much wiser bike folk?

Thanks
Tim

Jamesh
Posts: 1554
Joined: 2 Jan 2017, 5:56pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby Jamesh » 19 Jun 2020, 11:23am

Anything marked 26 / 559 will fit.

How easy it is to fit on your particular rim us another matter.

A decent set of tyre levers will help.

1.25 / 1.5 or 32/35mm width should be fine.

If you want better performance go for folding Kevlar tyres as they are lighter and more puncture resistant.

Cheers James

markjohnobrien
Posts: 323
Joined: 4 Oct 2007, 8:15pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby markjohnobrien » 19 Jun 2020, 11:27am

TimFromLondon wrote:a short history: I have an old mountain bike brought in Malaysia back in the mid 1990s, its been used sporadically since but kept dry so its in pretty good shape especially after a good clean and a few replacement parts being fitted.

The problem I have is that I brought the bike to suit riding on logging tracks in north Malaysia so the tyres are pretty knobbly to say the least. Now I'm old(er?) I'm not really going to do that kind of cycling so I want to replace the bike but of course no stock, anywhere, anytime soon. So my solution is to keep plodding on with this bike but try to change the tyres to suit road and light trail use.

Tyres are 26" x 2.3" and I can't find anything that's road like to suit this size BUT I don't understand the variation in width that I can fit to the existing wheels.

Can anybody point me towards a tyre that would be better for road use (at a reasonable price given this is a temporary fix) or an online resource so that I can understand what I need to determine the range of tyre widths that my existing wheels will accommodate?

Many thanks in advance!
Tim


Schwalbe Big Apple are great.

Bmblbzzz
Posts: 3640
Joined: 18 May 2012, 7:56pm
Location: From here to there.

Re: What size of road tyre for my Old Mountain Bike ?

Postby Bmblbzzz » 19 Jun 2020, 12:10pm

I'm pretty sure 565 isn't a standard rim diameter, so most likely it's 559 slightly inaccurately measured (not a dig at you, tricky to measure). A lot of people seem to like Schwalbe Big Apples. I used to have Vittoria Randonneurs in, I think, 40-559, and didn't particularly like them.

Jdsk
Posts: 3885
Joined: 5 Mar 2019, 5:42pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby Jdsk » 19 Jun 2020, 12:13pm

TimFromLondon wrote:I have an engineering degree and so I'm used to standards but bike tyre and wheel sizing seem to be very unruly and understanding them very elusive!

https://sheldonbrown.com/tire-sizing.html

!

Jonathan

Brucey
Posts: 41444
Joined: 4 Jan 2012, 6:25pm

Re: What size of road tyre for my Old Mountain Bike ?

Postby Brucey » 19 Jun 2020, 2:43pm

TimFromLondon wrote:
So I've added to my confusion with the tyres marked 26 x2.30 the rims marked as 26 x 1.75....

Do these dimensions mean anything to you much wiser bike folk?


as per my reply upthread the decimal sizing for width on both the rim and the tyre suggests 559mm BSD. Normally one or both would also be marked with the ISO size; I suggest you check that again, because your measurements are ambiguous; there is another rim size that uses 571mm BSD so your measurements are neatly between two sizes. I happen to think that you will probably have introduced an error using most methods of direct measurement such that your rims are 559 not 571 but you need to be sure. Other than finding markings, some ways of being sure(r);

- try to fit a known 559 tyre
- offer up a 559 rim alongside your wheel
- measure the rollout of the bare rim on the floor and calculate the diameter (this is intrinsically more accurate for several reasons).

hth

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~