Speed variations between bikes

[lulubel]

I usually ride a road bike with drop bars, 25mm tyres pumped up hard, that weighs about 10kg.

Since my road bike was destroyed in a crash a few weeks ago, I've started doing road rides on my hardtail MTB. This is obviously a lot heavier (although I haven't weighed it), has suspension forks that can't be locked out, and fat knobbly tyres that are pumped up by hand without a gauge because my OH took the schraeder side of the track pump apart and lost the bits!

I've been surprised to find my average speed on the MTB is less than 3mph slower than on the road bike over similar rides. (I read on a thread in the beginners forum that you should expect about a 3-4mph increase in average speed going from a hybrid to a road bike, so I thought the difference between MTB and road bike would be bigger.)

My average heart rate over the same rides is 3bpm higher on the MTB, but my perceived effort is quite a bit lower. The only difference I can see in my riding style is that I'm spinning a bit more on the MTB because my legs are still in a bad way, and I'm trying to be kind to them.

I was expecting the MTB to be an awful hard slog, but it's actually OK, apart from me not liking the flat bars and it being a tiny bit small for me.

Am I weird or is riding a MTB on the road actually easier than I've been led to believe?

 

[VamP]

Maybe you're tapping into efficiency gains with a different riding position? Perhaps you position on the road bike was less than optimal.

I get about 3mph between my road bike and cross bike (same weight, same position) which is almost entirely due to the knobblies. I would therefore expect the difference for you to be greater.

Obviously, a lot depends on the actual tyres that you have on your MTB.

 

[lulubel]

Maybe you're tapping into efficiency gains with a different riding position? Perhaps you position on the road bike was less than optimal.

I get about 3mph between my road bike and cross bike (same weight, same position) which is almost entirely due to the knobblies. I would therefore expect the difference for you to be greater.

Obviously, a lot depends on the actual tyres that you have on your MTB.

That's what I thought. I don't know what the tyres are, but they're very wide and knobbly, and there's still a lot of give in them after I've pumped them up as hard as I can. And they must be cheap. (The whole bike cost less than £250 new, compared to over £50 of tyres alone on the road bike.)

The difference in position hadn't occured to me - other than to assume being more upright would create more wind resistance and should slow me down - but I wonder, now that you mention it. The more upright position seems to engage more of the muscles I use when I'm running, so maybe I'm actually more powerful in that position.

I'll go and study my Garmin Connect data and see when the speed losses are happening.

 

[BSRU]

Maybe it is affected by the terrain, my hybrid and road bike basically have the same tyre but the hybrid is heavier and has a more upright position. There is little difference going up and down hills but a significant difference on the flat, especially into a headwind.

 

[HLaB]

It could be that the terrain is better suited for your MTB gears so its less of a difference.

 

[WychwoodTrev]

During the worst weather I used my mtb and found the time difference to be very small but the mtb was quite a bit slower up hills. And nowhere near as comfortable on 15 plus rides

 

[totallyfixed]

Average speeds are funny old things, to non cyclists it is meaningless to talk in 1mph increments, yet 1mph is a lot if you are riding close to your limit and 3mph is out of sight. Most club rides average around 15-17mph and if your average is about 12-13mph you would find it near impossible to ride 3mph faster over any distance. Your difference in speed is about right but could be greater on longer rides as the differences in weight will become more of a factor.

 

[lulubel]

It could be that the terrain is better suited for your MTB gears so its less of a difference.

Again, this is something I hadn't thought of, but it does make sense. One thing I am really enjoying about the MTB is having lower gears. I actually decided while I was out today that I'm going to spend the extra to get a wide range cassette and long rear mech for my new bike, so I can have lower gears. I deliberately chose a route today that has a nasty, steep climb on it, but is otherwise lovely. I'd normally avoid it on the road bike unless I was feeling really good (which I'm definitely not at the moment), but I knew I could just put the MTB in a really low gear and spin up it.

Anyway, the speed difference seems quite evenly distributed over my rides. The timing graph for the same stretch of road is the same shape for both bikes, just lower for the MTB.

 

[Broadside]

Average speeds are funny old things, to non cyclists it is meaningless to talk in 1mph increments, yet 1mph is a lot if you are riding close to your limit and 3mph is out of sight. Most club rides average around 15-17mph and if your average is about 12-13mph you would find it near impossible to ride 3mph faster over any distance. Your difference in speed is about right but could be greater on longer rides as the differences in weight will become more of a factor.

This.

3mph average speed difference is huge. When I first got my road bike my average was about 15.5mph, 2 years later I have managed to get that upto 17mph and on good days up to 18mph. As TF says go out for a long distance ride on your MTB and then you will really notice the difference.

 

[Crackle]

3mph an hour is a lot. I would expect that, put slicks on and it might be 1 to 2 mph but the effort to bring it to the same speed as your road bike won't be linear which is what makes the gap bigger than it appears.

 

[lulubel]

A normal ride for me is 1.5-2 hours - I'm just covering less distance in that time on the MTB. There is a long ride I could do at the weekend that doesn't involve any boring long stretches of main road, but I'd probably get the silent treatment from my OH if I did that when I'm still far from being recovered from my crash (currently on antibiotics because my right shin is infected), so it might have to wait a couple of weeks, and by that time I hope I'll have the new bike built.

To be honest, I don't think a long ride in terms of time would feel any different. I feel like I'm taking it pretty easy at the moment, and have plenty left in the tank when I get home. Covering the same distance on the MTB would obviously be a different thing because it would take me longer at the lower speed.

Anyway, these comments are quite reassuring because I expect my new bike to be heavier than the old one, and I was quite concerned the extra weight would mean a big difference in average speed.