Turbo Trainer average speed v road average speed

TJ1004
TJ1004 Posts: 12
edited February 2013 in Road beginners
Hi Guys,

Bit of a silly newbie question, but is there any correlation between the average speed I can do on my turbo and the average speed I should be able to maintain on the road.

The reason I ask is that I rode during last summer on the roads getting up to around 60/65 miles a ride. So during the winter I have been doing some base training on a turbo and find that I can ride for 2 hours doing interval sets but at a much higher average speed than I can reach on the road.

I know factors like wind, road conditions and hills come into it, just wondered if anyone has a rough guide to what they find themselves.

thanks

Comments

  • JackPozzi
    JackPozzi Posts: 1,191
    It varies hugely according to the resistence level of the turbo, but generally I'm faster on the turbo than road for the same effort
  • lc1981
    lc1981 Posts: 820
    Logically, there should be a correlation. If you're getting faster on the turbo, you should be faster on the road. There are obviously more variables on the road, but you should be faster when everything is averaged out. I sense from your question that correlation isn't what you mean, however. Do you mean should you be able to ride as fast on the road as the turbo? That's a whole different question (to which the answer is no!).
  • sungod
    sungod Posts: 17,142
    on the road you're subject to aerodynamic drag, the power needed to overcome drag is proportional to the cube of speed, i.e. to double speed requires eight times the power

    at low speeds the overall resistance is dominated by drivetrain losses and rolling resistance, which increase linearly, once you get to higher speeds, drag becomes the dominant factor and the brutal exponential relationship takes over

    on the turbo, the only thing really subject to drag is the rear wheel, which has relatively small effect, and the linear losses dominate, so for a given power you'll go 'faster' on the turbo

    ultimately it's power that counts, if you've got the power curve for your turbo you can use the indicated speed to get a reasonable estimate of power and use that to gauge training effort and progress
    my bike - faster than god's and twice as shiny
  • smidsy
    smidsy Posts: 5,273
    Only correlation is the fitter you get the more likely you arr to achieve a higher average
    Yellow is the new Black.
  • On my rollers I can happily do 20 miles at 21mph average, If I could do on this on the road I would be a happy man I usually hoover around the 16.5-17 mph on the road.
  • smidsy
    smidsy Posts: 5,273
    On my rollers I can happily do 20 miles at 21mph average, If I could do on this on the road I would be a happy man I usually hoover around the 16.5-17 mph on the road.

    Great can you cycle 20 yards in front of me and clear a decent route , bit gritty round here at the mo :D
    Yellow is the new Black.
  • Bobbinogs
    Bobbinogs Posts: 4,841
    I try not to get caught up in the speed thing when riding on the road. I concentrate on cadence and effort/HR (and then look at the speed when I get back to see what I did).

    I use the turbo for many reasons: recovery, intervals, HR zone work, etc., and none of those need me to be aware of speed, which is just as well because the speed remains 0kph. I think the main point though is that good turbo training/usage will help you get faster on the road.
  • Bobbinogs wrote:
    I try not to get caught up in the speed thing when riding on the road. I concentrate on cadence and effort/HR (and then look at the speed when I get back to see what I did).

    I use the turbo for many reasons: recovery, intervals, HR zone work, etc., and none of those need me to be aware of speed, which is just as well because the speed remains 0kph. I think the main point though is that good turbo training/usage will help you get faster on the road.

    This: All true. All reasons why I could do with one (and an HRM). With that said, my wheel upgrade plan has to happen beforehand, as they don't make 27" turbo tyres. :lol:
  • It depends on too many factors (like riding in the road does). Turbo type, tire psi, pressure against the roller, and so on.

    I'm generally faster on the road than on my current turbo setup at the same power output, but I can also change the conditions (mainly psi and pressure against the roller) to make me faster on the turbo if I wanted to. I don't do it because I don't care about speed on the turbo and my current setup is the closest to "road feel".
  • I have an Elite Supercrono Fluid trainer and it has harder resistance to the base model, so I usually run 4-8mph under what I can do on the road.

    I probably should have just gotten the base model but I compensate by using the little ring.
  • ForumNewbie
    ForumNewbie Posts: 1,664
    I've got a Elite Crono Gel Turbo with no resistance settings. The weight of me on the bike presses the back tyre on to the roller, which I think creates a similar resistance level to the road. Ceratinly my average speeds on a short turbo session are very similar to a short road ride with similar effort.

    I don't see the need for different resistance levels on turbos as you can just use the bike gears to get different resistance levels. People setting their turbo at low resistance levels can record much faster average 'speeds' than they would get on the roads, so I don't think it's a very realistic measure. Heart Rate seems to be the best way to assess how hard you are working on a turbo.
  • elderone
    elderone Posts: 1,410
    I find turbo speed is higher than road speed .I always ride the road by my hrm and try to do the same on the turbo but its hard to keep a high HR on the turbo compared to the road.My HR on the road is usually between 140-160 around here and can go up on the extra hilly bits.There is no way I can do 2 hours on the turbo at those HR,s.
    Im just hoping the turbo work will help with over all fitness and lower my road HR.
    Dulce et decorum est Pro patria mori
  • My turbo speed is a lot slower than my road speed for the same amount of effort (using my HR zone reading as a measure of "effort") - much lower. It feels like a steady 2-3% incline. But then, I do have the resistance set quite high. I'm sure if I turned it back down to 1 I'd go a lot quicker. But what's the point in that? It's not like I'm going to get to my destination any quicker; my thinking is "more miles equals greater wear on the rear tyre".
    They use their cars as shopping baskets; they use their cars as overcoats.
  • schweiz
    schweiz Posts: 1,644
    I use a set of Elite E-Motion rollers on which you can set the resistance to one of 3 choices.

    Position 0 - I can hold 250-270 W and I'm well over 45 km/h
    Position 1 - I can hold 250-270 W and I'm around 35 km/h
    Position 2 - I can hold 250-270 W but by cadence is down and my speed is about 25 km/h

    So position 1 is closest to a flat road in terms of compensating for rolling and wind resistance.
  • TJ1004
    TJ1004 Posts: 12
    Thanks for the comments.

    As i said in the original post, I am finding my average speed on the turbo much faster than on the road, somewhere between 4-6mph when at similar cadence and hr.

    Looks like some of the others have found the same sort of thing. i dont use a power meter so cannot measure output and I cant see me affording one anytime soon.

    So hopefully I will keep on at the intervals and see some fitness improvements which will help on the road in time.
  • ForumNewbie
    ForumNewbie Posts: 1,664
    my thinking is "more miles equals greater wear on the rear tyre".
    Not sure about that - if you have more turbo resistance with your tyre pressing harder against the roller, I would have thought that would wear the tyre quicker than if you have really low resistance, even although you are doing less turbo miles.