LondonSkaters Speed Team - Speed Skating & Rollerblading Club in London

Mikey-two-Names · Joined: 24 Feb 2004 Posts: 4108

Karine raised some interesting points there. Why are bikes faster than skates, and why are they more efficient too?

I'm definitely much faster on my recumbent than on my skates, by a significant margin. I did very nearly the same speed on London to Southend on the bike as I did for Berlin on skates , and that was with atrocious tarmac, some hills, more than twice the distance, and no real drafting at all.

I think skates might have the advantage in two circumstances - the first 75m of a sprint from a standing start (and here I'd bet a runner would beat both the bike and skates), and on long steep downhills. Eddy reckons he can go a few mph faster than upwrong bicycles on a big downhill in Berkley simply because of a lower tuck. I'll bet no downhill skater will ever be as fast as a tandem or a sporty recumbent like mine though.

Fred_Paris · Posted: Mon Oct 24, 2005 1:26 pm Subject:

Do you think that as runners problem with skating is you have to carry most of the weight of your body? even if you carry less on skate than while running.

Biking look very confortable, and you don't have to carry your weight, so all the energy actually goes to the padling.

Might not be very clear or accurate, just the tought of the moment.

On short distance I'm definitely faster while running, the truth is I'm a runner more than a skater.

dan_b · Joined: 15 Jun 2004 Posts: 2428

Mikey-two-Names · Joined: 24 Feb 2004 Posts: 4108

I think the biggest losses on skates come from these areas:

* I think the primary loss in efficiency is because of the way skates are propelled. Some of the wheels are always scuffing during any turn, and each stride involves two turns of the skate. You have huge losses every time you pivot, mostly in the heel carve since that is the most loaded one, but also in the pivot out from setdown.
* Secondly, skates have small wheels and don't deal with rough roads nearly as well as bikes.
* Plus having so many more bearings, there is more loss there as well.

Yup, tucks are good for thigh burn LOL.

Xia · Joined: 06 Apr 2004 Posts: 874 Location: Geneva (Suisse)

Mikey-two-Names · Joined: 24 Feb 2004 Posts: 4108

You have power cranks installed in your skates?

Xia · Joined: 06 Apr 2004 Posts: 874 Location: Geneva (Suisse)

Mikey-two-Names · Joined: 24 Feb 2004 Posts: 4108

Just wondering how you knew the power output was the same. You seem awfully precise on the speed changes caused by the rough roads. I'm just trying to judge what accuracy they are worth.

Rick · Joined: 25 Feb 2004 Posts: 5914

Wa s silly program on Channel 4 called "No Girls Allowed" That had a race between a mountain bike, a race bike, a sprinter and Vinnie. it weas fdone in heats and was totally unscientific and over 100m in a straight line.

Vinnie went against the race bike and lost comprehensively though started much better.
Sprinter killed the mountain bike.
Sprinter false started in the final was was still just pipped by the race bike.

What lessons? legs accellerate fastest but have a limited top speed. Skates are legs with wheels and have a lower acceleration but a higher top speed. Race bikes are slower still off the line but have an even higher top speed.

What we didn't learn. Skates are faster on bends than bike as there is more acceleration and bikes are hard to pedal in bends.

I don't know how well recumbants accellerate compared to uprights. They have a better aerodynamic profile than uprights so they have a higher top speed but the power comes from leg muscles whereas much of the power in an upright is generated by bodyweight. It is possible to use muscles too when pedals are attached to feet to I would suspect that an upright would be first off the line but I have no real idea.

Rick · Joined: 25 Feb 2004 Posts: 5914

Rick · Joined: 25 Feb 2004 Posts: 5914

As this is a speed of skates versus bikes thread, it's horses for courses. If we take away ideal conditions, where you can just keep going at top speed with nothing in the way, such as in heavy slow moving traffic like we have in central London, skates are faster than all other forms of transport over a mile or so. They make better use of the available space as they are simply easier to get between vehicles and can hop on and off pavements, etc.

Xia · Joined: 06 Apr 2004 Posts: 874 Location: Geneva (Suisse)

Mikey-two-Names · Joined: 24 Feb 2004 Posts: 4108

Well, I think you're probably right that rough surfaces make you slower, but I very much doubt the specific speed differences since you're only guessing your own power output. You're being very precise about speed vs power for which you have poor accuracy.

I'd be amazed if the speed differences really were as big as that. I would expect a small difference from the rough surfaces, and a much bigger effect to come from your loss of technique on rough surfaces. Someone else's loss of speed through technique would likely be greater or smaller, depending on their ability as a skater.

Xia · Joined: 06 Apr 2004 Posts: 874 Location: Geneva (Suisse)

There might be a loss of technique but really there is that much difference from surface to surface.

Bad surface: tarmac with loads of embedded chipstone usually found on A road. Gliding on it is just not possible.

Normal surface: tarmac with no 'protuding bit', mostly everywhere in UK

Good surface: Smooth tarmac equivalent to marble (yes it does exist). Its usually shiny and really slippery when wet, ultra rare in Uk, a bit more comon in France everywhere in Italian town that I know off (unless its cobble in old towns).

KarineM · Posted: Tue Oct 25, 2005 2:03 pm Subject:

Ah yes cobbles slow me down too, which is very bad, because the only way to get past them is to keep my speed up. And it's not cobbles that are in short supply around here in Paris-Roubaix territory Wink

Seriously, bad surfaces are a killer for my speed. I don't know if bigger wheels, being a better skater or just being stronger would help, but I don't doubt the differences quoted.

Karine

PS. All the good skaters overtake me when the going gets tough Embarassed