Would these tyres fit?

[1982john]

Looking to change the tyres of my genesis longitude to something I can use for my urban commute.

It has these rims: WTB Scraper i35 27.5" Alloy Disc, 32H which I think have an internal measurement of 35mm.
With 27.5 * 2.8 tyres

I want to replace them with these which are 2.4
Schwalbe Super Moto-X MTB Tyre - GreenGuard

Is that too narrow?

[Brucey]

for riding on the road , not narrow enough, I'd say. Your rims have 584mm bead seat diameter so there are plenty of tyres labelled

xx-584

and/or

650B

and or

26 x 1-1/2" (NB not 26 x 1.5")

which will fit. Schwalbe marathons are pretty good for commuting; I suggest look at those and then find good reasons for choosing something different, if you can.

cheers

[1982john]

for riding on the road , not narrow enough, I'd say. Your rims have 584mm bead seat diameter so there are plenty of tyres labelled

xx-584

and/or

650B

and or

26 x 1-1/2" (NB not 26 x 1.5")

which will fit. Schwalbe marathons are pretty good for commuting; I suggest look at those and then find good reasons for choosing something different, if you can.

cheers

my bad I meant to narrow to fit on the rims not too narrow for road use.

[slowster]

I use 29 x 2.35 Schwalbe Big Apples with 45mm internal rims, and they are fine (although I would not try to fit a narrower tyre to my rims), so I would be confident that 2.4 Super Motos would not be too narrow on a 35mm rim.

However, the 1125g weight of the Super Motos would deter me. I would instead suggest considering the Schwalbe Big Ben or the Greenguard version, the Big Ben Plus (745g and 860g respectively). They are only available in 2"/50mm width in your wheel size, but I suspect they would probably fit given my experience with 2.35" Big Apples on 45mm rims, and you could buy just one tyre to begin with to try (and SJS are currently selling the Big Ben for only £10.99 plus postage).

If 2" tyres fitted, then I would see no significant benefit in using wider tyres like 2.4" for road use/commuting, and a big advantage of 2" over 2.4" tyres for commuting use is that it should be much easier to find and fit suitable mudguards with good coverage, e.g. like reohn2's Longitude here, which make a huge difference to user comfort and protecting the drivetrain from road spray, which should greatly increase the lifespan of the cassette/chains/gears and/or reduce the frequency with which they would otherwise need cleaning.

[Polisman]

I'd say, no way Hose.

[reohn2]

I want to replace them with these which are 2.4
Schwalbe Super Moto-X MTB Tyre - GreenGuard

Is that too narrow?

No problem fitting those tyres on those rims

[1982john]

So what's the lowest people think I could go? 2 inch would be great but that would seem unrealistic

[RickH]

So what's the lowest people think I could go? 2 inch would be great but that would seem unrealistic

There's a chart of ETRTO rim widths & compatible tyre widths on this page under "Which tire fits which rim?". This gives a minimum tyre width of 60 for a 35mm rim.

IIRC conventional wisdom states that tyres should be, ideally, 1.8 times the internal rim width. But MTBs have quite happily run much wider tyres. 1.8 x 35 = 63 but anything above 55mm/2.2" is unlikely to be a problem by my reckoning. The most recent trend is to run wider rims with narrower tyres (within reason).

[slowster]

I was quite sceptical about whether 2.35"/60mm Big Apples would fit on my 45mm rims, but there were one or two comments online from very knowledgeable people who said that it would be OK, so I took a slight gamble, and they were right. I'm not suggesting that I am as knowledgeable or that I would be equally confident that it would work in your case, but for £10.99 I think it would be worth trying. After all, that is the only way you will have a definitive answer to whether it works as far as you are concerned.

Schwalbe publish the ETRTO chart here, to which they have added their recommendations for wider rims and tyres than covered by ETRTO. According to that chart I should use at least a 70mm tyre with my 45mm rims, and you should use at least a 60mm tyre with your 35mm rims.

However, Schwalbe themselves say,

There are many additional combinations which are not listed in this table, but nevertheless, work out in practice very well. It goes without saying that you ride with these combinations at your own risk. Unfortunately, the ETRTO standard in reality often lags behind. For example, very wide rims become more and more popular these days. The usage of wider rims also makes sense, because they support the tire’s stability. You can reduce the inflation pressure, before the riding behavior becomes spongy.

In particular I think that for a given rim size it's likely that it's possible to use a balloon type tyre like the Super Moto, Big Ben and Big Apple in a wider size than would be satisfactory with a knobbly MTB tyre. People who fit knobbly tyres to rims that are significantly wider than intended for the tyre width often report that the tread is squared off, which can affect the handling/feel of the tyre and can also result in less traction when the bike is leaning over in a hard fast turn, especially off road on loose/muddy ground. It also means that the sidewalls are more likely when riding off road to come into contact with stones and rocks etc. and be damaged.

I think those considerations largely do not apply to balloon tyres with their lack of the pronounced tread and knobs on MTB tyres. In other words, the Big Apples on my 45mm rims have a round profile, and I have no qualms about grip when leaning over in a fast turn on the road (quite the opposite - the Big Apples have a huge contact patch and consequently loads of grip). I would not want to do likewise with my 2.4" Maxxis Ardent knobbly tyres on the same rims, because I would be riding just on the very outermost row of knobs).

FWIW, the ratio of tyre width to rim size of my Big Apples and 45mm rims is 1.33 (60mm/45mm), and 2"/50mm tyres on 35mm rims would be 1.43, which also suggests that you would be OK.

However, I would point out that my Big Apples do not have a very thick/noticeable puncture resistant strip in the tyre. They do have a strip in them which I can feel if I squeeze the tyre in my hand, but I am using the Performance Line version of the Big Apple which has Raceguard protection, and which is slightly dearer and rolls better than the Active Line version with K-guard protection. I suspect that the Greenguard strip in the Super Moto and the Plus version of the Big Ben may result in a bit more rolling resistance and/or a need to inflate the tyres a bit more (which may not be an issue, whereas a much narrower non-balloon tyre with a Greenguard or Marathon Plus strip in it might need to be pumped up very hard to avoid the tyre feeling draggy).

[reohn2]

So what's the lowest people think I could go? 2 inch would be great but that would seem unrealistic

I'd happily ride a 2inch(actual size*)tyre on a 35mm internal measured rim,but not much lower.
By the same token I happily ride 2inch tyres on 19mm int' rims over rough MTB trails and on tarmac

A wider rim means a tyre may even be wider than it's stated width,the 2inch(50mm) tyres I ride on 19mm int'l rims measure 47 widex47high.
If they were fitted to say a 35 int'l rim they'd be much wider but not as high,so if they increased to 52mm wide they may lose that 5mm in height.
My logical mind says that seems to be correct though I haven't actually done a physical test on it,but if I get the time I'll test out the theory tomorrow.

Thinks... ...many people ride loaded tourers on 32mm or even 28mm tyres on 19mm internal rims with no I'll effects

[reohn2]

OK,done some tyre tricks:-
The rims on my Longitude are 32mm internal.
The Conti Xkings fitted are 29(700C)x2.4inch and measured 59mm wide 55high @ 25psi
I fitted a Marathon Supreme 700C x 50mm on the same rim which measured 50wide x 49high @ 25psi,@ 40psi those dimensions increased to 52w x 50h,so the height actually increased with the width which surprised me.

Hope this is of some help

[RickH]

OK,done some tyre tricks:-
The rims on my Longitude are 32mm internal.
The Conti Xkings fitted are 29(700C)x2.4inch and measured 59mm wide 55high @ 25psi
I fitted a Marathon Supreme 700C x 50mm on the same rim which measured 50wide x 49high @ 25psi,@ 40psi those dimensions increased to 52w x 50h,so the height actually increased with the width which surprised me.

Hope this is of some help

If you assume that the tyre & rim bed form a circle (approximately), then using a wider rim increases the circumference of the circle. Therefore both width & height should increase.

This will be constrained slightly be the thickness (& therefore stiffness) of the tread area so one dimension may increase more than the other - a thicker tread will probably result in a bigger relative increase in width, whereas a thinner more supple tyre will probably increase more evenly in both width & height.

That's my theory anyway.

[reohn2]

OK,done some tyre tricks:-
The rims on my Longitude are 32mm internal.
The Conti Xkings fitted are 29(700C)x2.4inch and measured 59mm wide 55high @ 25psi
I fitted a Marathon Supreme 700C x 50mm on the same rim which measured 50wide x 49high @ 25psi,@ 40psi those dimensions increased to 52w x 50h,so the height actually increased with the width which surprised me.

Hope this is of some help

If you assume that the tyre & rim bed form a circle (approximately), then using a wider rim increases the circumference of the circle. Therefore both width & height should increase.

This will be constrained slightly be the thickness (& therefore stiffness) of the tread area so one dimension may increase more than the other - a thicker tread will probably result in a bigger relative increase in width, whereas a thinner more supple tyre will probably increase more evenly in both width & height.

That's my theory anyway.

I think that's a good and now proven analogy,I was wrongly thinking that increasing the bead seat width would cause a more elliptical shape,obviously I was wrong as the experiment showed.
One thing it did prove was that a 2in/50mm tyre on a much wider rim 19mm compared to a 32mm is no detriment and the tyre looked good to ride

[slowster]

One thing it did prove was that a 2in/50mm tyre on a much wider rim 19mm compared to a 32mm is no detriment and the tyre looked good to ride

I wonder how the following would compare in terms of comfort and performance:

1. 19mm internal width touring rim with 50mm tyre, e.g. Marathon Supreme or Almotion

2. 25mm internal width MTB rim with a narrower version of the same tyre, e.g. 40mm.

If 2 gave a similar ride to 1, and assuming that the increased inflated width might be in the region of 43mm-45mm, then that might offer a way of getting the equivalent performance of a 50mm wide tyre in a bike which doesn't have enough clearance for it.

[reohn2]

One thing it did prove was that a 2in/50mm tyre on a much wider rim 19mm compared to a 32mm is no detriment and the tyre looked good to ride

I wonder how the following would compare in terms of comfort and performance:

1. 19mm internal width touring rim with 50mm tyre, e.g. Marathon Supreme or Almotion

2. 25mm internal width MTB rim with a narrower version of the same tyre, e.g. 40mm.

If 2 gave a similar ride to 1, and assuming that the increased inflated width might be in the region of 43mm-45mm, then that might offer a way of getting the equivalent performance of a 50mm wide tyre in a bike which doesn't have enough clearance for it.

Answer to No1 with Supremes is very comfortable and a fast tyre,I'm impressed with them.
Now would work clearance wise,comfort factor wise I've no idea but I'm tempted to fit and ride the 50mm Supremes on the the 32mm int'l rims on my Longitude.