If I change my 26x2.10 MTB knobbies by 26x1.95 slick tires, will I feel any difference on my speed on paved roads? or is it going to be the same? I am kind of confused about how much I should change the width of my tires to notice an improvement in my speed. The reason: I will be using my MTB to commute.

  • 1
    Narrower tires can help a little, but unless they're a lot narrower, the difference is fairly small - especially when compared to the speed gains from replacing the knobbies with slicks. The misconception that bike tires need tread at all is a conspiracy set up by Detroit, to slow us all down. Aug 16, 2012 at 2:14
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    The change in width is probably not enough to make much difference. But changing from knobbies to (relatively) slick tires and upping the pressure will make a significant difference. Aug 16, 2012 at 12:04
  • Like what was said, when I switched from knobbies to slicks (well, more just road tread) I felt a noticeable difference, but pumping it up to 100 psi was HUGE!
    – BillyNair
    Aug 17, 2012 at 8:30
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    Duplicate: bicycles.stackexchange.com/questions/1952/…
    – ttarchala
    Aug 17, 2012 at 22:56
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    PSI will make the biggest difference with any tire even knobbies. I have a semi-slick touring tire on my bike and the rolling resistance I see in coasting increases drastically with even a 10 PSI decrease which is why I always check my tires before a ride to ensure I'm around 80 PSI (max rate for my tire). Change to a road tire and ride at max PSI and you'll think you've become [place your favourite road racer name here]. Aug 20, 2012 at 18:51

4 Answers 4


If you run your knobbies at typical MTB pressures, and you run your slicks at higher pressures, you should experience less rolling resistance, which could translate to higher speed.

I don't know what tires you're talking about exactly, so it's hard to say how much of a difference it will make. I run some pretty aggressive knobbies on my MTB (Panaracer Fire XC Pros) and with <35 PSI in them, that makes for some noticeable rolling resistance. On my vintage no-suspension MTB, I run slicks with 60-65 PSI in them, and those are halfway to being road-bike-like. Even with the MTB gearing, I can hold 15-16 mph on that bike for a decent amount of time.

You did not indicate what kind of suspension your MTB has. With any suspension, you're probably going to get a little pedal bob, which will rob you of some energy. That, combined with the upright riding position, will hold you back a little. But the engine (your strength) is more of a factor than tires, suspension, and bike weight.

Once upon a time a friend of mine-- road bike rider, likes Italian bikes, pretty fit at the time-- used to regularly get passed on a local muni trail by this little guy on a vintage mountain bike who was dressed in street clothes and riding to/from work. These roadies would be doing a paceline at a good speed, and the little guy on the mountain bike would just roll right past them, comfortably holding 2-3 mph faster. I wasn't there, so I can't tell you if the mountain bike guy had modified his bike or what. But he used to say "good morning" or something similar, every time he passed them, with a big smile.

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    That guy on the MTB? I love that guy. Aug 16, 2012 at 2:13
  • I do too, and I respect his strength as well. It's the engine more than the bike. Aug 16, 2012 at 2:45
  • ...If one is running downhill, I would say that there is something else than just the engine. Uphill, I agree with you, though.
    – iamamtb
    Aug 16, 2012 at 11:41
  • I was that MTB guy one morning when I smoked a roadie. Raining, uphill, pulling the kid trailer (unloaded but cheap and sturdy), in shorts and a t-shirt. He was on the shoulder and I was taking the lane.
    – BPugh
    Aug 13, 2014 at 13:54

I've made this change myself. You won't notice a speed improvement, but there will be a very slight effort reduction that might lead to a tiny bit more speed. You'll notice that you don't slow down as fast when coasting, meaning it takes a tiny bit less power to maintain speed when pedalling. But not enough to go noticably faster.

The biggest improvement will be the noise reduction :-) And fast cornering (on the road) will feel more secure.


I think you will notice a difference, but if/when you go back to knobbly mountain bike tyres, you will notice a huge difference. It will be much more noisy, going round corners at any speed will feel strange and insecure and you will not coast anything like as far when you stop pedalling. From all this, I think you can conclude that the effort for the same speed is reduced with slicks. You will also start to think that mountain bikes with 2.1 inch tyres look like they have doughnuts for wheels.

You will also probably notice that your tyres last longer too. Long distance commuting on knobbly types wears out the central knobs, leaving them unsuitable for much at all. If you commute in the wet, the knobs also throw up more water from the sides that lands on you.

I have used unbranded back street bike shop 26x1 and Specialized 26x1.5 road tyres (with tread, not slicks) on my mountain bike for all weather commuting and both lasted for ages.

Make sure you pump the tyres up to their recommended pressure.

Good commuting.

  • I too have noticed the amount of wet that knobbies throw up compared to street tires. When switching to those narrow tires, didn't you have to change the rims?
    – BPugh
    Aug 13, 2014 at 13:56
  • @BPugh, No, I didn't bother. But it was a while ago. Tires might be made to tighter tolerances now, or standard rims might be wider as I think the standard mountain bike tires are wider. I would still just try myself. Aug 13, 2014 at 14:59

I did this a few years ago on an old mtb when I started to use it for commuting.

However going to 1.95 hardly seems worth it - I bought a pair of Conti Gatorskins at 1.25. You'll need new innertubes with these too, but you'll find your ride a lot easier and faster.

  • While I agree, going to a 1.25 tire might not fit on his current rims. With a 1.95+ tire, the rims are probably 1.50
    – BPugh
    Aug 13, 2014 at 13:49

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