Watts and MTB vs Road bike


Despite my age (44) i’m new to cycling (i’ve started in may). I ride a cheap / crappy MTB with 24 gears.

i realized that people with road bikes seems to go faster and climb easier than me. Of course road bikes are way lighter and these people are usally more trained than me but it doesn’t explain everything in my opinion.

i also notice (by checking people rides on Zwift or Strava) than they produce way more watts than me. It looks like i need to cycle like crazy just to go to 200 watts or something whatever gear i use.

So i wonder what are the differences between MTB and road bikes if we talk about power/watts, etc…

Is it easier to climb or go faster with a road bike or, after all, only our legs really matter?

ps: sorry for my poor English,i’m French :wink:

@David_Strappazon, first - no apology needed for your English. This is an international crowd and your English is excellent.

A mountain bike by nature will be slower in the real world because it is heavier, has more rolling resistance, and a larger aerodynamic profile. Zwift is using all that info to generate a virtual speed that you are travelling in-game. Thus for the same power output of two riders of the same weight, the mountain bike will be slower. Just because you ride a mountain bike in real life does not mean you have to configure to ride one in-game. Feel free to strap on the carbon road bike and get the benefit of extra virtual speed and ability to draft for example. What matters for your personal training effect is what your muscles are doing on the bike that is on the trainer, not what depiction it has on in-game. Unless of course you want to ride the MTB course, which will get poorer results on a road bike in-game.

Power output is what your body can produce. The fact that your may only be able to get 200 watts and someone else 300 watts is just your body and state of fitness. Let Zwift help you increase your body performance (muscular and cardio) by doing a training plan for example. If you are new to cycling, you’ll be impressed how much you can develop in a couple months.

You did not mention what your trainer setup with that cheap / crappy MTB is. What trainer are you using? Is it wheel-on or wheel-off. If it is a wheel-on trainer, did you replace the rear tire of the MTB with a smooth tread or are you running the knobby tire? If you have the knobby tire on a wheel-on trainer, is not recommended for the health of a wheel-on trainer, it will wear out the tire faster, and it likely is part of why you are seeing lower power numbers as a good bit of power it being wasted in friction ahead of what the trainer sees. Therefore the trainer is telling Zwift you are putting out less power. If not a wheel-on trainer, this is a mute point of course. This is all conjecture of what might be happening since we don’t know what your setup is. Let us know about your setup.

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only on the paved road surfaces, the dirt sections around Watopia, the jungle circuit especially, the MTB will be faster than the road bikes.

Gearing is also a factor. MTB’s usually have smaller gears for short bursts of power up and over features, rocks, logs, etc. But power is power, regardless of the gear you are in.



Thank you for your long and useful answer.

I use a Tacx Flow Smart with a Tacx training tyre. Of course in Zwift i ride a road bike.

I took a FTP test 2 days ago that I clearly failed because I didn’t understood how ERG mode works and I almost didn’t shift gear during the test. It gave me a FTP of 157 which is 2.5w/kg for me.

I know I need to increase my performance but globally I’m just surprise how people can produce output power very easily.
To give another exemple, it looks to me that 90 rpm is like cycling very, very fast but when I see people on their bike (on tv, youtube, etc…) 90 rpm look very easy and “slow” for them.

I’d say that my question is more: if I buy a road bike will it be easier for me to go faster and / or to produce more power ( in Zwift and in real)?

Is the weight / set up of a road bike clearly made to enhance performances compare to a MTB or even a very cheap road bike?

Hi @Joel_Larner

The issue here is the gearing of the mtb. The front chainring of a MTB is rather Small compared to a road bike.

I had to change my front chain ring to a 56 tooth when I still had my MTB on the trainer.


I might also add body position, having a more aggressive stance on a road bike. I don’t know if the science supports that, but I feel like I can put down more power on a road/gravel frame than on a MTB.

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Yeah, that’s what I was wondering.


It makes sense.

A FTP of 2.5 is very good.
You probably actually have a better FTP than that but as you said,it was the first time you took it.
To be accurate, you have to know how to perform a FTP test.
It’s not a pop quiz.

I agree with others, I feel like I can put out more sustained power more efficiently on my road bike than MTB, independent of aerodynamics or rolling resistence, etc… The configurations are designed for very different things. @David_Strappazon if you were to put an inexpensive road bike on that trainer you’ll find you can perform at a higher level in Zwift and have higher gears to ride faster for short sprints. I am using my 25 year old part aluminum, part carbon, 7-speed road bike on my wheel-on trainer (7-speed cassette won’t fly on higher end trainers). it is fine as I have a smaller cassette to get me the higher gears when riding, and when doing workouts in ERG mode your gear makes no difference.

To that point, you mentioned shifting during the FTP test. If ERG mode is working correctly, your gear should make no difference. Shift all you want, the trainer is going to hold you at the specified power. Spin faster, it relaxes the resistence, spin slower it cranks it up. Don’t shift, it has only a momentary fell good effect then the trainer is going to normalize back to the specified power.

As David and Tim point out, 2.5 w/kg is respectable for FTP, specially for a new rider. If you had a road bike on the trainer and did a new FTP test with what you know now, I’d bet it comes up a little. But as noted, don’t let FTP rule your life. You are who you are. No, you and I can’t put out 5 or 6 w/kg like the young stud racers, so what. We are riding at our level for enjoyment and training. I’ve been riding in the Colorado mountains for 35 years and am in well above average shape for a 58 year old (i.e. I leave all my friends in the dust) and am only 70 kg, yet my FTP is only 3.3 w/kg. I never had the racer muscle makeup and certainly won’t get it at my age. Use Zwift to improve your fitness over the winter, and enjoy riding indoors.

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I think I’ve read that Zwift turn off ERG mode during the 20mn of the FTP ramp test (but it’s on during warm up). If that’s the case then we have to shift in order to reach the desire wattage.

But I’m a newbie and I could be wrong…:grin:

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The “FTP Test” and "FTP Test shorter " both have the 20min free ride.

The Ramp Test and Ramp Test Lite (for lower FTPs) are both fully ERG controlled -you can check these out here.

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@David_Strappazon Just supporting the call for getting your gearing sorted - I’m a mtb’er focused mostly on aggressive downhill. I got my trainer to help with winter fitness etc and like everyone, put one of my mtb’s on the trainer first. That lasted about a week.

I’ve developed a bit through Zwift which has been super useful for my gravel riding and certainly helps with my mtb’ing but to really use Zwift to target mtb fitness, HIIT workouts are really good. Problem is that I developed a liking for Zwift racing so tend to focus on keeping “Zwift / RGT” race fit.

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Ok, thank you. I will know it now :wink:

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@David_Strappazon since you are new, realize that Zwift automatically sets your trainer to mimic the climb inclinations at 50%. In other words, if the incline is 10%, Zwift gives resistance equivalent to 5%. For downhills, it is cut in half.

Essentially, what this does is give big boys like me more gearing for the steep inclines. Since you are using a mountain bike, you should get all the resistance you can.

Once in the game (waiting on the road prior to start pedaling) go into Menu/Settings and in the middle of the page should be a 1-100% slider…go to 100%. That will tighten up your gearing.

2.5 w/kg is decent. No need to be disappointed with that. Particularly from your starting point.

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Ah, that explains it. I have done the Ramp Test and thus experienced it in ERG mode. Was not aware the other tests do not use ERG. Good to know.

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