Tyre size

iain_j Posts: 1,941
edited August 2008 in Workshop
Sorry if this is a been-asked-100-times-before question...

Last year I bought a Claud Butler Dalesman tourer, and it came with Schwalbe Marathon Plus tyres, 700x35C. I've done over 1000 miles on it no trouble, a couple of centuries included, but can't help feeling the tyres are a bit big for what I'm doing.

All of the miles so far have been on tarmac, though several miles have been on some pretty poor roads - mud, grass, gravel, non-existent surfaces. I'll probably take in some towpaths, forest tracks, un-tarmacked cycleways, that sort of thing, along the way. Usually a lot of climbing too - flat roads aren;t challenging enough for me :P Haven't gone fully-loaded yet - had a well-stuffed rack bag a few times but hoping to make good use of the panniers I bought with it too.

The Marathon Plus's have been great so far, no slips on wet and/or muddy roads, and no you-know-whats even after riding over broken glass and hedge clippings. Can anyone recommend a tyre size for this sort of riding? Is 700x28 more like it, and will going down to a size like this have much effect - on speed, comfort, climbing, etc?


  • alfablue
    alfablue Posts: 8,497
    I think you could do all that on 28's, you would lose a little comfort, and possibly it would be slightly trickier to control on very bad surfaces, but not drastically so. My girfriend has 700x25 marathons (regular, not plus) and she does fine on similar rides. (I think 28's would be better but her bike doesn't have the clearance for 28's with mudguards).

    Marathon Plus's are heavy tyres so you save proportionately more weight by reducing the size, climbing may be marginally improved as a result (probably by a very small degree). They should be faster, pressures will have to be higher and you will feel the bumps more and ride quality may be slightly poorer. Pinch flats would in theory be more likely, but properly inflated this shouldn't really be an issue. Grip on tarmac should be just as good, on rough surfaces the tyre will conform less to irregularities so there is a slight compromise there.

    For me the biggest difference is a psychological one, staring at a fat front tyre when I am struggling up a hill, thinking about the excess weight I am carrying is a bit demoralising.