Tyres for 17mm rims

[lowrider]

I have a Dawes Horizon fitted with 37mm tyres fitted to 700c 17mm wide rims I wish to fit narrower tyres to get a bit more speed out of it. I think in theory I should be able to fit 28mm tyres I intend to use the bike unloaded and forB & B touring carrying maybe up to about 10kg.

I was thinking of using schwalb Marathon 28mm tyre the bike is a small 2005 Aluminium framed version of the Horizon.

Does anyone have actual experience of running with this tyre on that size of rim on a similar bike.
What will it be like in terms of harshness
Will it cope with the weight and is that tyre size the optimum for speed /proposed use.

[meic]

I use 28mm ultragators on 19mm Sputnik rims for lightweight work. including touring. I whizz along in comparison to my 1.75" Marathons.
They have no problems except that the Marathons have invincable sidewalls and the ultragators can suffer sidewall damage with big sharp gravel.

[EdinburghFixed]

Unless you are very heavy, then 10kg of luggage is no issue at all (and maybe not even then).

Think about it this way - if you weighed just a stone and a half more than you do now, nobody would tell you not to get a certain 28mm tyre because it wouldn't hold up!

My closest experience to yours is the 25mm Marathon Plus tyres that I used over the winter. I found them to be squirmy on wet roads, less comfortable than the 23mm racing tyres they replaced and *very* heavy to boot. However, they were never punctured during the whole of this dank winter (at 150 miles a week) so they did the job I bought them for. this is quite good).

I hear that the non-Plus Marathons are considerably more easygoing and if you want a blend of puncture resistance with other ride qualities it's not a bad place to start.

[lowrider]

Thanks for the replies this confirms what I had suspected I was told by a local bike shop that 28mm would be too narrow for a touring bike, I thought that was rubbish. i think I will give it a try now although I am not certain about the Marathons yet but puncture resistance will be high on the list of priorities.

I have heard that if you try to go too narrow somtimes the ride ios so harsh you actualy go slower than say the next size up anyone come across that effect.

[PW]

A 17mm (internal) rim is just about perfect for tyre sizes from 25 to 32mm, I've used that combination since the late 70s.
28mm tyres are fine for on road touring, though I wouldn't use them for bridlepath bashing. My wife and I rode the coast to coast, Whitehaven to Robin Hoods Bay version, with camping gear, on 28mm Paselas. No bother from the tyres at all, including Hardknott and the disused railway track from Robin Hoods Bay back into Scarborough.

[lowrider]

Thanks
That sounds good to know the paselas were an option I was concidering

[EdinburghFixed]

Thanks for the replies this confirms what I had suspected I was told by a local bike shop that 28mm would be too narrow for a touring bike, I thought that was rubbish. i think I will give it a try now although I am not certain about the Marathons yet but puncture resistance will be high on the list of priorities.

To be fair, it might be too narrow if you weighed a lot, and were going to have front and back panniers plus a rack top bag, on something rough like a Sustrans trail.

I have ridden my fixed-wheel bike (on 23mm slicks) on a few unpaved surfaces around Edinburgh and the Lothians (with at least a 10kg pannier). It was quite entertaining and nothing dramatic happened - apart from some exciting "freestyle" skids on the muddy hills - but if I wanted to build a 'go anywhere' bike it wouldn't have those tyres! (I weigh roughly 12 stone for what it's worth)

I have heard that if you try to go too narrow somtimes the ride ios so harsh you actualy go slower than say the next size up anyone come across that effect.

I think like so many things, this is grounded in fact but the every-day rider need not be concerned. I daresay if you were running 18mm tubular tyres at 150psi, you would notice jarring compared with a normal tyre. But I have tried many 'normal' tyres of widths between 23 and 32mm and at pressures between 80-120psi and never found anything other than a pleasing improvement in handling going down the scale.

I am doing my LEJOG attempt on the same 23mm slicks at 100psi.

[lowrider]

To be fair, it might be too narrow if you weighed a lot, and were going to have front and back panniers plus a rack top bag, on something rough like a Sustrans trail.

I have ridden my fixed-wheel bike (on 23mm slicks) on a few unpaved surfaces around Edinburgh and the Lothians (with at least a 10kg pannier). It was quite entertaining and nothing dramatic happened - apart from some exciting "freestyle" skids on the muddy hills - but if I wanted to build a 'go anywhere' bike it wouldn't have those tyres! (I weigh roughly 12 stone for what it's worth)

I think like so many things, this is grounded in fact but the every-day rider need not be concerned. I daresay if you were running 18mm tubular tyres at 150psi, you would notice jarring compared with a normal tyre. But I have tried many 'normal' tyres of widths between 23 and 32mm and at pressures between 80-120psi and never found anything other than a pleasing improvement in handling going down the scale.

I am doing my LEJOG attempt on the same 23mm slicks at 100psi.

I note your points, I am about 13.5 stone, it was my intention to use these tyres on tarmac only or in a worst case a smooth ash surface anything else I would stick to the current tyres. I thought about front panniers but more as ameans to redistribute weight. The idea of using the 28mm size comes from seeing Audax bikes on the web these all seem to have 28mm tyres anything less than that I would steer clear of as they seem a bit too narrow to me.

[Freddie]

I have heard that if you try to go too narrow somtimes the ride ios so harsh you actualy go slower than say the next size up anyone come across that effect.

I think like so many things, this is grounded in fact but the every-day rider need not be concerned. I daresay if you were running 18mm tubular tyres at 150psi, you would notice jarring compared with a normal tyre. But I have tried many 'normal' tyres of widths between 23 and 32mm and at pressures between 80-120psi and never found anything other than a pleasing improvement in handling going down the scale.

I am doing my LEJOG attempt on the same 23mm slicks at 100psi.

I think you're wrong in saying the every-day rider need not be concerned. I assume by "EdinburghFixed" that you are a hard rider(like to go fast) and probably put little weight on your rear(largish drop to the bars).

As the bars go up and speeds go down one is certainly grateful for the extra comfort and easier tracking of larger tyres.

[EdinburghFixed]

Sorry, I referring to the phenomenon where high pressure tyres 'jitter' on the road surface and reduce speed, not the comfort issue.

Of course the wider the tyre, the more comfortable it may be. My MTB is like a sofa with almost 50mm tyres... of course it's also as fast as a slug!

[CJ]

Sorry, I referring to the phenomenon where high pressure tyres 'jitter' on the road surface and reduce speed, not the comfort issue.

Actually, power losses are not confined to "jittering" of the tyre and can be related to comfort. The muscle and fat tissues of the human body have visco-elastic properties. Jiggling them about is not merely uncomfortable but also diverts energy from forward motion of the bicycle. How this works if when the bike wheel rises up a bump the force between wheel and bump is increased by displacing wobbly bits of the human body. If that body were perfectly elastic, the same size force would push the wheel back down the other side of the bump and no power or speed would be lost. But the body is more or less viscous (internally sticky) so the recovery force is less, more or less energy is absobed and the wheel doesn't get all of its speed back when it rolls down the other side of the bump.

Bicycling Science has a section on "bump losses" where it's noted that they may amount to several watts. The American millitary, apparently, have sat soldiers on hard vibrating seats and measured from at little as 2.7W up to a staggering 2KW, which is reckoned to be the limit of human tolerance!

Raising yourself from the saddle, using the elastic tendons and lean muscles of the arms and legs to isolate more viscous and hence lossy tissues from vibration, will minimise bump losses. But a less athletic or more fatigued rider, who sits on the saddle and gets jiggled as a whole, will absorb more energy.

So whilst harder high-pressure tyres are of benefit to one who has the athletic abilty to minimise bump losses, they may actually cause a less fit rider to esperience more drag and go slower - even when freewheeling!

It really is a matter of different strokes for different folks.

[andrew_s]

I have heard that if you try to go too narrow somtimes the ride ios so harsh you actualy go slower than say the next size up anyone come across that effect.

Yes, if you go on rough tracks, you can go much faster on fat MTB-size tyres than you can on road-sized ones, and there's a fair difference between 25 and 32 road tyres. I've verified this from both sides - me on 26x1.75 shooting past people on road bikes, and me on 700x28 taking almost twice as long as a mate on 26x1.75 (ish). It's not so much the power loss, as remaining in control of the bike when the wheels are only on the ground half the time. The difference in speed is most on downhill sections, but it's still there on the flat.