Gravel bikes and tyre tread

I’ve been doing some pondering on tyre tread for gravel and unmade canal path type use

My cross bike came with WTB Nano tyres, which have a light tread. I’ve changed it to Schwalbe Marathon Plus tyres for commuting, purely for the puncture resistance.

I get the benefits of tyre tread for MTB tyres for slippery MTB conditions. I also get the benefits of slicks on the road and the fact that you don’t need a tread pattern to grip on a wet tarmac surface

All the gravel bikes on here tend to have tyres with quite a light tread pattern, often a file tread or something with very light knobbles

When its dry, how does that light tread pattern help? I’m thinking in everything from solid paths with loose stuff on top through to proper gravel fireroad type tracks. What are the benefits over something slicker? I sort of get it but can’t rationalise the logic – does the tread somehow deform over the dirt and let it grip? Does it penetrate around the dirt/gravel somehow and grip the surface underneath?

I can sort of see the benefits when it’s wet as I’m presuming that it’s to stop it slipping/spinning…?

On a similar vein, what’s the point of the tread in the Marathon Plus tyres? Doesn’t appear to be of any benefit on the road but does the tread pattern help in other situations? I bought them for the puncture protection above all else

Always thought the marathon tread was more to do with rain channels, but, it could be just to allow a bit of deformation of the rubber with varying surfaces. so a little bit of grip at the edges.

I’ve previously ran michelin world tour tyres as a light offroader. works very well on most non goopy surfaces and rolls alright too.

I have used all sort of tyres off road on CX and track bikes over the last 5 years and on narrower tyres (25c) I didn’t find the tread made much difference and the width of the tyre was the main stumbling block.
I also used “monster cross” tyres of around 45c which were much more secure feeling and the side knobs helped in cornering.

I used Marathon Pluses for a while too for same reason as you (puncture resistance). The tread is there to provide grip on surfaces that are not smooth tarmac as it is a touring tyres and not expected to be used 100% of good tarmac.

My findings on gravel and fire roads (and compacted single track) are that centre tread made little difference but side knobs helped a lot in corners.

Went back to an MTB at start of year as needed a change and the tyre grip is so great to have (didn’t realise what I was missing)

Marathon Mondials use the same tread pattern but more widely spaced and a bit deeper for handling a wider range of surfaces.

I use Challenge open tub Grifo’s mainly.

for gravel and unmade canal path type use

I can’t see past Conti Cross Speed 35’s. I also find they roll really well on tarmac, so well in fact that I leave them on for back road touring with panniers etc. Some folk seem to get a lot of punctures with them though, so I think it depends on the sharpness of the fragments or something… Personally I’ve had 1 puncture in over 2000 miles use

Nice to hear that iainc

I mullered a vittoria xmc in just a couple of weeks on the rear of my CX bike – ordered some Cross Speeds last night from Amazon – 40quid or so delivered for a pair.

Appreciate the responses but I’m still no clearer on the benefits of tread!

not much, easier to sell to those that don’t ask themselves the same question. lots of them, benp1. you try to ride big apples on gravel, it slides just like a kojak on the same. it’s there to show the punter when the tyre’s done, or for the shop to tell the customer the tyre’s done. but mostly. as earlier, easier to sell a thin tread rather than slicks.

It’s well accepted that bike tyres are too narrow to aquaplane, so tread on road tyres is there for looks/consumer reassurance. There is evidence that file tread can help grip in the wet. I can look for the link at work.

I doubt either matter much on dirt.

I ride mostly on gravel and really like Schwalbe Sammy Slicks.

They maybe not be the trendiest tyres but they work really well with plenty of grip in corners and are fast rolling.

Not sure if the file tread in the centre makes much difference, however the knobs at the side work well cornering.

On road my 38c Kenda SB8s are ace, not as good as road tyres, but good enough.

Off road they are really good.

I can’t see past them.

swalbe marathon pluses here – like the puncture resistance and bomb proof side walls plusngood rolling on more packed surfaces tried a couple of more knobbly tyres but didn’t really like on proper road sections so live with the knowledge that on loose bends the marathon pluses will slide out but predictably so

more gravel specific tyres are appearing as marketing people feed the experience, gravel specific gels will be along shortly, like the look of these reviewed over on road.cc http://road.cc/content/review/153812-panaracer-gravelking-32mm

don’t the grooves in tyres have no real function other than to make them look like they disperse water?

A shallow tread is useful on some surfaces. Maybe a thin layer of mud on a firm surface. Think of the difference between walking down a grass slope in smooth soled shoes or in trainers. For mixed surfaces I find an almost smooth tyre on the rear cuts rolling resistance while a bit more tread on the front helps with braking and steering when it gets loose or slippy.

Appreciate the responses but I’m still no clearer on the benefits of tread

If you mean tread such as Marathon plus and a surface such as fire-road or cancel path in the dry then there is no real benefit. I also used RibMos (slight tread) a fair amount as they are lighter than Marathon plus but still have pretty good puncture protection and they didn’t perform any differently. If fact I have also used Maxis Refuse (no tread) off road and they were fine too.
The width of the tyre is what makes a clear difference as more rubber to grip stuff.

Put some knobs on and there is definite benefit for cornering (front wheel) and climbing out of saddle (rear wheel). Even something like a Continental Travel Contact (smooth in middle but with side knobs) is noticeably better than just a treaded tyre. They were probably the best all round tyre in fact for puncture resistance, speed and a bit of grip for cornering.

(You may notice puncture resistance is a priority for me as with ‘normal’ tyres I get at least one puncture per week as where I live it is very stony and bits of sharp stone/flint cause punctures. The move to tubeless on MTB was the best thing I could have done)

I’m sure that the tread on Schwalbe Marathons has saved me from a few off – hitting patches of wet leaves and wet road markings in the winter, the tyre slips and then catches grip, slicks I’m sure would have seen me wipe out.

I can recommend the 38c Halo twin rail … used for a few gravel events and many long distance mixed surface training rides.

For Audax now I have the 29c twin rail fitted

I can see benefit of tread when cornering, and for having a different front to a rear

I was very kindly given a set of 26inch tyres by a member on here. They’re fitted to my wife’s bike, a pair of Continental Double Fighters. I think they looked like great tyres, though in fairness the amount and type of riding she does. Can’t really comment on their effectiveness on the road

The largest proportion of my riding is on the road so I need very road biased tyres. The Marathon Pluses are perfect for this but they’re a pain to get on and off the rim so there’s no chance of me changing tyres regularly. I need to do more gravel type riding with them to know how good they really are – puncture protection is key.

My use of them to date is fine but I’m not really doing anything challenging on them at all!

Think of the difference between walking down a grass slope in smooth soled shoes or in trainers.

It definitely applies to shoes, but it’s much wider area so there’s less pressure being applied. Analogy still seems fair though

Hmmmmm. I’ve been using Marathon’s on gravel and hard pack and they’re fine (mainly in the dry though for me). I also just changed a pair of Durano’s on the faux CX bike to Sammy Slicks and they’re fine on both gravel/hard pack and road. I was keeping up with the auld CTC fellas on their 23c shod road bikes OK yesterday (believe me, nothing to do with my ‘prowess’….).

Looks like it doesn’t make a lot of difference in the dry. lightly treaded Marathon’s, no treaded Durano’s or file treaded Sammy’s all do OK on and off road. BTW I’ve been using 28c road tyres and 35c Sammy’s. I also have a pair of 2″ (x 26″… gasp) Marathon’s on my expedition tourer and they’re bombproof on anything dry.

Not sure that the helps but conclusion is, it doesn’t really matter (IME).

Thanks – that’s the conclusion I was heading towards to be honest. In dry I don’t see there being much of a difference

I’m running 700×32 on my bike. Nearly went with 35s but they were getting very heavy very quickly!

I wonder how it changes in the wet…

On gravel, it doesn’t make a lot of difference. On mud, clay, hardback…. Well, errrm, it does. My fat Marathon’s seem to cope though.

On smooth solid surfaces (like roads), a slick tyre grips better because the entire contact patch is on the surface. A treaded tyre, on the other hand, has most of its contact between the tread and surface. Hence less grip. Water on the surface may affect the grip between tyre and surface, but it has this same effect on tread. Treaded tyres actually are worse off because they have less tyre in contact with the surface. Also, bikes don’t aquaplane (too slow, tyres too narrow, pressure too high).

On loose surfaces, a treaded tyre digs in generates grip; this includes the vertical profile of the knobs as they come in contact with dirt, roots, rocks, etc. A slick tyre can’t do this as well and it sinks in, generating its grip through its contact patch with the surface. This difference is also why lower pressures create less rolling resistance off-road: the tyre can deform and deflect more, generating greater contact with the surface.

Edit: I’d say it’s better to have tread and not always need it than to have fully slick tyres and find yourself in situations where you’d benefit from a little tread, which is the case with CX/gravel/whatever it’s called.