Why you should ride your road bike on unsealed roads

There are few more enjoyable things as a road cyclist than riding on a freshly laid patch of super-smooth hotmix bitumen. You glide over the silky surface with seemingly neglible rolling resistance, getting maximum value for each pedal stroke. Indeed, a smooth road surface can be the difference between feeling like you’re fighting for every metre and feeling like you’re flying across the landscape.

But as satisfying as smooth road surfaces can be, I’d argue there’s just as much fun to be had at the other end of the spectrum: riding a road bike on unsealed roads.

If you’re new to road cycling and/or have tended to stick to sealed surfaces on your road bike so far, taking that first pedal revolution on the dirt can be a nerve-wracking experience. But it doesn’t need to be. Here’s what you need to know about riding your road bike on the dirt and why you should give it a go.

Upper Coonara Road in the Dandenongs.
Upper Coonara Road in the Dandenongs.

One of the most appealing things about taking your road bike off road is the sense of adventure that comes with doing so. It feels like it shouldn’t be possible to traverse small, gravel-strewn roads on thin tyres, but when you realise it is, it’s a real light-bulb moment. All of a sudden, so much more of the map is within your grasp.

If you’ve lived in any one area for a while, you’ll probably be familiar with all the great sealed roads within your reach. Chances are you aren’t as familiar with the unsealed roads. Being willing to leave the bitumen opens up so many more possibilities when it comes to ride options, creating loops that wouldn’t otherwise be possible and generally just seeing different parts of the world around you.

The great thing about unsealed roads is that they’re almost always smaller and with less traffic than their sealed cousins. I can’t ever remember being disappointed at having a road to myself while riding. There’s a real tranquillity in heading off down some unexplored stretch of road just to see where it goes; even better when it’s just you, your bike, maybe a couple of mates, and the birds in the trees around you.

Warwick Road in the Dandenongs.
Warwick Road in the Dandenongs.

The first question many people have when considering an off-road ride for the first time is: “won’t I get lots of punctures?” There’s little doubt that your chances of getting a puncture increase when you leave the sealed stuff behind — largely due to pinch flats — but there are steps you can take to reduce that risk significantly.

With that in mind, here are some tips for riding your road bike on unsealed roads:

Tyre selection is important

Standard road bike tyres are 23mm wide with 25mm tyres becoming increasingly popular as well. I’d recommend something in a 25mm option if at all possible — the extra width seems to provide extra grip on the rough surface. If your frame will allow you to fit tyres even wider than 25mm then that’s not a bad option either.

Bear in mind that the wider your tyres, the less efficient you will be (UPDATE: Turns out this isn’t necessarily the case!). This is more of a problem if your ride is a mixture of sealed and unsealed roads. Ultimately it’s a compromise between efficiency and comfort/handling. Do what feels right to you.

Arguably as important as tyre width is the thickness of the tyre. I know many guys that happily ride unsealed roads on 23mm Continental GP4000 tyres. If you’re going to stick with a 23mm tyre, go for something that’s a little thicker and/or grippier than your regular road slicks.

You can get away with 23mm tyres on most unsealed roads, but it doesn't hurt to go for 25mm and/or something a little more grippy than slicks.
You can get away with 23mm tyres on most unsealed roads, but it doesn’t hurt to go for 25mm and/or something a little more grippy than slicks.

In the past I’ve used 23mm Continental GP4000 tyres on unsealed roads and had no problems. I currently use 25mm Challenge Strada open tubular tyres when riding off-road. I’ve also used 25mm Schwalbe Marathons which are absolutely bomb proof but at a cost — they’re quite heavy and they’re tricky to get on and off your rims.

Consider lowering your tyre pressure

It’s not a bad idea to let a bit of air out of your tyres if you’re going to be riding a lot of gravel. This will allow your tyre to “stick” to the road better, providing you with better grip, particularly when cornering. It’s a trade-off though — let too much air out and you’ll make it harder for yourself when you get back on the bitumen.

I tend to run my tyres at around 110psi when I’m riding exclusively on sealed roads. I’ll often drop that to 90-100psi if I’m going to be throwing some gravel into the mix. You can get away with lower than that too; ultimately it comes down to personal preference.

Pack an extra spare tube or two

Even with appropriate tyres you are more likely to get a puncture on the gravel than on the tarmac. Be prepared for this — take an extra spare tube or two. And while it might sound obvious, be ever-vigilant when picking your line through the gravel. Hitting sizeable stones at speed isn’t the best option if you want to remain puncture-free.

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When you’re starting out, be cautious in the corners

It sounds obvious, but cornering becomes a little more tricky when you’re riding a road bike on the dirt. You don’t have as much traction and if you get it wrong you can easily send the back wheel sliding out.

Take it slowly to begin with. Really concentrate on putting pressure on your outside leg when cornering, keeping a low centre of gravity, and paying attention to how the bike responds. After a little while you’ll feel much more confident and you’ll probably realise that you can push the bike a lot further on the gravel than you might have expected.

Try to stay in the saddle when climbing

This is one you’ll work out pretty quickly on your own but if you get out of the saddle while climbing a steep, unsealed surface, your back wheel is going to start slipping. Your best bet is to stay seated when climbing on gravel, concentrating on keeping your weight nice and balanced — too far forward and the back wheel still might slip; too far back and the front wheel might lift up, especially when the road is super-steep.

Do your research

Feel like trying out some unsealed roads on your road bike? A good option is to do a little bit of research before you set out on your ride. Google Street View can sometimes give you an idea of the road surface and whether it’s passable on a road bike. Sometimes and old street directory can come in handy as well — here in Melbourne the Melways shows which roads are unsealed; perfect for planning your little off-road jaunt.

Mapping out your ride isn't a bad idea.
Mapping out your ride isn’t a bad idea.

If you’re planning out a specific ride be sure to allow more time than you might expect for the gravel sectors. It will be slow going — give yourself enough time to enjoy it without pushing yourself to get back on time. For me personally, I count on an average of 23-25km/h on sealed roads (depending on how hilly it is); on unsealed roads I’d expect 15-20km/h, again depending on the climbing.

Leave the bling at home

Got a $10,000 aero-optimised road bike with $5,000 carbon wheels? Probably best to leave it at home when riding on the gravel. Take your back-up bike or at least take off those expensive carbon wheels. All you need is something sturdy and comfortable — you’re going to be going slow anyway so your 80mm deep profile carbon wheels probably aren’t going to help all that much.

Be bold

While research and planning is obviously important, be willing to check out that interesting-looking unsealed road you just spotted out the corner of your eye. Some of the most memorable rides I’ve ever had were when I said “what’s down there?” and went and checked it out.

You might discover a nice alternate route to where you were going, a challenging little climb or an amazing strip of road you would never have found otherwise. Explore!

Be willing to turn back

You’ll be surprised just how bad the road surface needs to get before you can’t ride it on a road bike. But there will be times that it simply isn’t rideable. Just bear that in mind, particularly if you’re exploring a road for the first time. Better to retrace your steps and stay out of trouble than come a-cropper on a 25% gradient rock-strewn descent in the middle of nowhere.

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Let someone know where you are

If you’re going way off the grid, take a mate with you or at least let someone know where you’re going to be. The advantage of riding reasonably busy sealed roads is that if something happens to you, you’ll normally be spotted quite quickly. If you’re on some narrow, winding gravel road, deep in a national park away from anyone, assistance is likely to be a little further away.

If you’ve got the option, considering riding up on the gravel and down on a sealed road

This won’t always be possible, but just bear it in mind when planing out your routes. Climbing an unsealed road might make for slow going, but the low speed makes it very unlikely you’ll get a puncture. Bombing down a gravel descent is far riskier.

One good example is the unsealed climb up to Mt. Donna Buang (see links below). It’s totally possible to do that climb on 23mm road tyres — probably even on slicks — but coming down it is another story. A popular ride involves riding up on the dirt to the summit then descending the sealed road back to Warburton. As an added bonus you can jump on the Lilydale-Warburton Rail Trail to get back to wherever you started.

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I’ve been fortunate enough to do a number of great rides on unsealed roads in the past few years. Here are some links if you’d like to read more about specific rides and roads:

So, what are you waiting for?! Get out there and enjoyed riding your road bike on unsealed roads!

What have I missed? Are there other tips you’d offer to riders trying unsealed roads for the first time?

40 Replies to “Why you should ride your road bike on unsealed roads”

  1. Thank you Matt for the excellent article. Been riding (road bike) now for about 12 years after retiring and find it both a relaxing activity and gentle on the body.
    As a 72 year old and after playing fooball, cricket etc. etc. cycling does me good!!
    I find I am relaxed and my mind is both focussed on riding yet also able to enjoy a variety of scenery, animal life and so on.
    I have always kept fit and this has held me in good stead during these more “mature” years.
    I encourage the older generation to take up this fabulous sport.
    Keep up the good work!!!
    Roger.

  2. Hi. A great read. Thanks. I’m reading it now in 2020… Are the thoughts you’ve written about 25mm tyres being good for gravel still relevant today? Thanks

  3. Hi there, Matt!

    Thanks for this informative article. I’ve been your avid reader in your blog. Anyway, I used to ride bike on the roads, gravel or even in dirt. I am riding my VIMANA Premium Build to all of my adventures.

  4. More than 3 years on this article is still so relevant. My contribution would be to try lower pressures with stronger tires.
    I’m running a Specialized Armadillo 25mm on the back wheel of my road bike at 72-80psi, & I weigh in at 73kg/160lb.
    Not only more comfortable & more traction especially off road, but yes: faster.
    Seems counterintuitive but there’s science to explain it.
    Congrats & glad I found this site, greetings from tiny Malta!

  5. Might need to revise this “the wider the tyre the less efficient you will be” given current research and that many pros are now riding 28mm tyres

  6. Ride off road all the time on my cx bike..great fun and even with 50mm carbon wheels..just have to pick your line and tyre pressure..

  7. Great write up Matt! We’ve just put a team of 6 female roadies together to do our first randonee in December and one of the girls sent this article around. You’ve summed up all the important bits really well. It makes me a bit nostalgic for Melbourne too (I live in Sydney now).

  8. Hi Matt,

    Thanks a lot for the article. Of course touring in countries where most of the roads are bad is another issue. I have, on my tourer, the widest tyres I can possibly fit which are only 28s. And I really want to go to some adventurous countries like Romania, Albania, Macedonia, Montenegro etc. (haven’t decided exactly where yet) which I think have bad roads all over (on the roads which don’t have masses of traffic) and I was beginning to think that’d be impossible. Your article reassures me that it might be possible. Do you think it would? I’ve ridden it on unsealed bike tracks in Scotland but not for days on end. I don’t mind discomfort and being realistic about distance, just want to at least be able to get somewhere.

  9. Hi Matt, I used your article to talk a mate in to a little dirt road adventure yesterday. Of our 70k loop Collector – Gunning – Collector NSW there’s 20k ish stretch of dirt road. Hard work as it climbs most of the way. We had a ball, both on road bikes. Me on 25mm and my mate on 23mm. Love your work. Cheers Matt.

  10. Thanks for another great article Matt. I don’t mind a bit of gravel on my roady.
    Have to agree about Donna up the dirt. Rode from Healesville two years ago not realising a/ dirt after about 7 km, and b/ closed June-Oct. Magnificent climb on 23mm tyres and the cold not a problem as kept me working. Good surface even with recent showers, only occasionally muddy but little gravel risk. Descended the same way to get back to the car. Obviously no other traffic, but am told bugger all anyway and you hear cars coming out bush (so yes, tell someone where you are!). Last year did the Warbuton side in the snow later in the season, but by then too wet on the road to chance the Healesville descent with slicks.

  11. Don’t forget to think about your gearing. A 53/39 crankset is not going to cut it on the dirt roads I frequent. A cassette with a large tooth count sprocket is also handy. My preffered dirt road bike has a low of 34×34 for tackling supersteep gravel climbs where getting out of the saddle is going to result in wheel spin.

    1. Thankfully most dirt roads are not super steep. If they were, they’d get washed away in winter and you’d be better of on a MTB to navigate the ruts.

      If you have to stand up, you have to get the weight distribution right to maintain traction. Mostly that means not leaning over the front wheel. For example, last year I enjoyed Skyline Rd around the back of Sugarloaf Reservoir, which has some dirt hills over 15%, and on a road bike with slicks (27mm on the rear) and 39×23 as the lowest gear.

      1. Incidentally, Strava reckons the steepest bit was just on 20%, and I was managing a little over 9km/h. Yes it was steep.

  12. ‘the wider your tyres, the less efficient you will be’

    There’s a whole article in…wait…there’s a whole magazine called Bicycle Quarterly that begs to differ.

  13. Interesting and insightful write up. I have a commuter bike with 26 inch rims which had road / thin hybrid tyres and on the dirt around our home they were constantly slipping so I swapped the road rims for a couple of mtb rims and tyres and haven’t regretted it at all.

  14. Don’t forget the flexibility and speed that a CX bike will provide also. With some nice Conti CX Speed 35mm tyres you can do just about any road passable by 2wd vehicle and they roll quick enough on the tarmac. Great write-up.

  15. Great writeup. Ill just add, dont get to comfortable with the quietness of the roads, all too quickly you can have a car fly around the corner from the opposite way, giving you little time to react with slower stopping distance often found on the dirt for both parties.

    You dont expect it as much, and neither to the cars so both tend to use the middle of the road in these cases. Always try and keep to the left of the road where possible.

    Some of my favorite road rides include some gravel.

  16. I don’t mind a bit of dirt road now and again. I do everything, including road racing, with Michelin Pro4 Service Course tyres, 25mm on the back. The 25mm actually measures 27mm across, and I have relatively narrow rims. These are fine for me even down around 80 psi. More traction in the wet too, cause you get more rubber on the road – and ever so much more comfortable than 23mm tyres pumped up over 100psi.

  17. Agree it’s a lot of fun but last time my garmin took me via the unsealed scenic route I damaged the rim. Any hints on using specific wheels apart from using cheapies?

  18. This is my favorite gravel route close to Melbourne. I like it so much that I’ve ridden it about 5 times this season. I’ve done it on 32mm, 38mm and 40mm adventure tyres. The fatter the better I reckon. Yellowdindi Road would feel like a rock garden on 25mm tyres. http://ridewithgps.com/routes/6263953

  19. Thanks for the comprehensive overview. I was wondering if Tyre pressure would be dealt with, and there it was.

    Lowering tyre pressure is good for comfort and grip, what about avoiding punctures? One train of thought is that less pressure makes the rubber more accommodating, sharp things wont pierce it. On the other hand, higher pressure can also resist some punctures.

    Likewise on tyre width there can be conflicting arguments about the impact rolling resistance. It is brand and situation specific or can you pinpoint attributes and show a measured effect on performance?

    1. The tyre casing usually dictates rolling resistance. A supple casing consumes less power than a stiff casing. Of course as tyre width increases much beyond the rim width, so does wind resistance, but I can honestly say I don’t notice any extra drag from the 25mm tyres I use on the rear, that measure 27mm in practise.

      1. Thanks for the input. In windtunnel tests with different tyres it is fascinating to see what does and does not significantly affect aerodynamics.

    2. Hi Chris,

      I’ve found that punctures from foreign bodies penetrating the tyre are close to zero on gravel. All the punctures I’ve had on gravel have been from pinch flats and as Matt said, usually on downhills when getting a bit excited. At speed you can’t change your line as quickly/safely so inevitably you’ll hit a larger stone or rock from time to time and that’s when it can happen. That is also the trade off with lower tyre pressures – pinch flats are more likely. I’ve done rides where the I got a puncture on 32mm tyres on my cross bike and a mate was riding 25mm road tyres and got none.

      1. I’ve got three words for you…

        1. Tubeless
        2. Tubeless
        3. Oh, I can’t remember. Oh that’s right. Tubeless.

  20. Can’t agree with you more that there is so much great riding down the roads less travelled! Great write-up

    1. The same set of 35mm semi-slick Schwalbe Marathon Supreme tyres survived several of those rides (2013 Jam 300, 2014 Jam 400, 2013 Grand Ridge, Gippy Gold twice)…with at least 6000 km of commuting in between…and they still have plenty of life in them. A bit slow on asphalt but worry-free on gravel and definitely worth a try.

      1. Yeah, I’m not sure whether I’m tempting fate here, but I’m yet to get a puncture on gravel. I run Clement X’Plor MSO 40mm or Challenge Gravel Grinder Race 38mm tyres. Tyres are everything.

        I did Gippy Gold 2015, Grand Ridge 2014 and Jam 2014. Mind you, I bailed at 291km on Jam. I’m not the least bit embarrassed by this. It is such a tough ride, it deserves a failed attempt. Next year, I won’t fail.

        Congratulations on completing Jam 400. Only a handful of people are tough enough to tackle that bitch and succeed.

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