how big should the increase in avg speed be?

Mar 21, 2009
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Hello,

so recently I've bought a Scott Speedster S30 bike as my 2nd bike. Until now I've been riding a Mongoose crossbike and I've been hitting 32km/h avg speed on a flat course, 30km. This course has few corners and basically no stops, so its "pedal to the metal" (well the other way round) action all the time. Obviously the avg speed was altered occasionally by strong wind, but the 31-32km/h mark was pretty constant. I got pretty slick tires on the crossbike, but they are still a bit fat and around 3-4 bars pressure max. Also got TT handle bars on them (amateur ones)

Now, its was my 4th or 5th time on the same course with my Scott bike and ... I got the same times. Almost identical. At first I thought it was the pressure, I pumped 5 bars, which was much too low (6-9 suggested on the tire), so I pumped to 7 and had no significant improvement.

What is wrong, is it me or the bike? I know I shouldnt have expected that all of the sudden I would hit 40km/h marks, but come on, at least 3-4km/h more?

Also Mongoose has now like 10k done, its been serviced, but it doesnt go so smoothly either way and Scott is brand new basically, it was a demo.

Suggestions? Should there be an increase at all? I mean 32km/h avg on a road bike on short course is quite bad, isn't it? I was happy with it on the crossbike.
 
Mar 21, 2009
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King Boonen said:
Did you get new legs with the Scott? There's your answer ;)
No, but, I think there is a reason, why Contador didn't win Giro on a crossbike, isn't there?

Also, the other year I had my first amateur race on the crossbike. Globally (including both road bike and other bikes) I was like in the 300s of 1000 riders and excluding roadbikes I was 11th...
 
Re: Re:

TaBaixo said:
King Boonen said:
Did you get new legs with the Scott? There's your answer ;)
No, but, I think there is a reason, why Contador didn't win Giro on a crossbike, isn't there?

Also, the other year I had my first amateur race on the crossbike. Globally (including both road bike and other bikes) I was like in the 300s of 1000 riders and excluding roadbikes I was 11th...
There is, it's because he didn't ride one :). If he did and they could get it down to the right weight and geometry he probably would still win on it. If you went out and spent £8000-10000 on a new bike it might make a bigger difference, but probably still not as much as some people think.

You've bought a lower-end road bike that's probably a fairly similar weight to your cross-bike, both on fairly cheap wheels? The differences really won't be that much. Unless I spin the gear out I'm actually about as fast on my singlespeed as I am on my geared bike, even with climbs included. It really is true that it's not about the bike.

Lots of guys in my club ride cross-bikes through the winter. The bike makes very little difference to their speed, it's the conditions that make the difference. There are guys who have several different bikes too, from old steel to fancy carbon with electronic shifting. It still doesn't make a huge difference to their times, especially over a short course. Maybe if you hit out on a 80-100+ km ride you'll see a bigger effect. at 30ish kph only just at the speed required to feel any aero benefits the new bike might have, so that's unlikely to have much of an impact.

I'm not sure what relevance the second sentence has? You did well in a race?

Make sure you get your position right on your road bike though, it'll let you put more power through the pedals and that will make a difference.
 
Mar 21, 2009
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Re: Re:

King Boonen said:
TaBaixo said:
King Boonen said:
Did you get new legs with the Scott? There's your answer ;)
No, but, I think there is a reason, why Contador didn't win Giro on a crossbike, isn't there?

Also, the other year I had my first amateur race on the crossbike. Globally (including both road bike and other bikes) I was like in the 300s of 1000 riders and excluding roadbikes I was 11th...
There is, it's because he didn't ride one :). If he did and they could get it down to the right weight and geometry he probably would still win on it. If you went out and spent £8000-10000 on a new bike it might make a bigger difference, but probably still not as much as some people think.

You've bought a lower-end road bike that's probably a fairly similar weight to your cross-bike, both on fairly cheap wheels? The differences really won't be that much. Unless I spin the gear out I'm actually about as fast on my singlespeed as I am on my geared bike, even with climbs included. It really is true that it's not about the bike.

Lots of guys in my club ride cross-bikes through the winter. The bike makes very little difference to their speed, it's the conditions that make the difference. There are guys who have several different bikes too, from old steel to fancy carbon with electronic shifting. It still doesn't make a huge difference to their times, especially over a short course. Maybe if you hit out on a 80-100+ km ride you'll see a bigger effect. at 30ish kph only just at the speed required to feel any aero benefits the new bike might have, so that's unlikely to have much of an impact.

I'm not sure what relevance the second sentence has? You did well in a race?

Make sure you get your position right on your road bike though, it'll let you put more power through the pedals and that will make a difference.
About the race - globally I was faaaar away in the ranks, because road bikers were ahead. Excluding the road, I was almost top 10. I thought it was also an argument for higher speeds on road bikes. It was 100km, but purely amateur, so maybe like top 50 had expensive, high-end bikes. Now Im thinking that I should stay on the crossbike this year also (I registered at 50km and road bike this year) because, at least in one ranking I will be high up there.
Look from my perspective. I got a crossbike (its also cheap), I start in my first race and, hey, the hard work pays off, Im 11th within my group (non-road bikes as a separate group in the official results). Great. Im happy.
I start this year on road bike, I rank similar to last year, but on the road bike and Im just in the 200s or 300s. Terrible. Disaster.

Scott is about 9kg I think, Mongoose hm... well its very heavy with the aerobars, metal bottle cages etc., >12kg for sure. Scott has standard wheels, so I imagine they are cheap.

Now Im pretty confident that I would have the same avg speed on an MTB bike as well. Just mount the aerobars and it's pretty much the same.
 
I can kind of understand but I think you're looking at it the wrong way for the race. I'm guessing the number of people on cross bikes was pretty small? At the end of the day whether there is a 3 in front of that 11 or not you still rode the race in the same time, 11th is still 311th no matter how you look at it. I'd ride the road bike, not care much about your overall position and just see what time you get.


Also, you might have to explain what you have done to your cross bike. Have you stuck clip-on TT bars?
 
Another item is that if you are fairly large, the weigh of the bike and the type of tires has less effect on overall speed.

At the avg speed that you mentioned, aerodynamics plays a big role. The TT bars on the XC bike and regular bars on the roadbike is part of the equation.

Jay Kosta
Endwell NY USA
 
Mar 21, 2009
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Actually no, it was around 50/50, the other category was just "other", so cross, mtb, you-name-it bikes included.

I've fitted the crossbike with tires that are better for road than terrain, but hardly you can name them "road tires". I dont remember exactly, how thick they are, but its pretty standard crossbike size.
TT bars are from decathlon and they've costed like 40 euro and despite that I couldnt really imagine they'd be better, aside from the weight.
The TT bars are actually pound for pound the best investment I've done in regard to the avg speed. Without them, I was like 3km/h slower.
I was thinking about sticking them to the road bike, but after all, by definition road bike position is more aero, especially on down grip and you have to remember that the crossbike with the TT bars still dont give proper TT position, because of how the frame is formed.
 
Right, other explains it. However you look at it, it's the same result though. It's the overall one that really matters. I definitely know that lower placings can be disheartening (and that's only on Strava) but I've got used to just ignoring it.

Ok, so you've sped up your cross bike by lowering your cross sectional area, but you've not done that on the road bike, even if it is a slightly more aero position than the cross bike (although some cross bikes can be quite aggressive).

Of course, it's extremely hard for us to really know without seeing your position on both bikes but you're very big for a cyclist so the TT bars are likely to have a big effect. In fact, your road bike is 3-4 kph quicker if you remove the TT bars from the cross bike right?
 
Mar 21, 2009
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Indeed, but without the TT bars the position on the crossbike is very non-aero, not far from a city-bike.
On the other hand, in that race year ago I couldnt use the aerobars and had 34,5km/h on 100km course (flat). I was wheelsucking a lot.

Also, I find it much easier to reach my PB max speed with crossbike for some reason. Lol, I can't even get to 50km/h on 8% downhill, which makes me angry having in mind Wiggins had 54 AVG on flat :)

Other observation (that you mind find silly) that despite my course is one way and then back, I sometimes feel like I got headwind. Generally I feel like Im more prone to wind conditions on road bike. Maybe its too light for my weight?
 
Mar 21, 2009
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No, I haven't. I was thinking about doing it post-purchase, but locally there are no bike fitting services, I found one, but it is very expensive and they're doing it with sth called TREK precision fit
 
Oct 22, 2009
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TaBaixo said:
No, I haven't. I was thinking about doing it post-purchase, but locally there are no bike fitting services, I found one, but it is very expensive and they're doing it with sth called TREK precision fit
Put the aerobars on your road bike, and work on your positioning. Your body accounts for the vast majority of total resistance. If you can get lower and narrower, you will go faster. the bike itself makes very little difference: it is mostly in the positioning.
 
Re: Re:

momotaro said:
TaBaixo said:
No, I haven't. I was thinking about doing it post-purchase, but locally there are no bike fitting services, I found one, but it is very expensive and they're doing it with sth called TREK precision fit
Put the aerobars on your road bike, and work on your positioning. Your body accounts for the vast majority of total resistance. If you can get lower and narrower, you will go faster. the bike itself makes very little difference: it is mostly in the positioning.
This. In a related note, assuming decent slick tires on your cross bike, any difference from going from cross to road bike should be negated by going from TT bars to drops. I'm actually surprised you're going as fast.

Anyway, don't extrapolate from your cross-bike-filtered results. Guys doing road races on cross bikes aren't always killing themselves (especially if you're actually referencing a Gran Fondo/Sportive-type deal). On the bright side, 32kph means there's definitely room for improvement. So, in the words of Eddy Merckx, "don't buy upgrades, ride up grades." Or just ride.
 
Jul 17, 2009
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unless you are on a velodrome, Average Speed is a precise measurement of nothing. What's the average depth of the ocean?
 
Mar 21, 2009
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So, I've been riding some more on road bike, on longer routes, today I've done 55km and it wasnt so painful (only to my legs), so I guess Im getting more comfy with the position. Although the avg speed wasnt a killer, 27km/h, but I climbed 5 times a punchy climb, like 8%, 800m (we dont have many of those around here).
On the plus side the climbing was going pretty well considering my (over)weight. There was a couple of semi-pro/strong-amateur looking guys training there and I could hold the wheel for the most part. And, maybe its silly, but I hit my all time best of max speed, 70km/h, which was a great feeling and encouraging to keep digging and not giving up on the road bike.

Maybe Im overthinking the whole cross/road bike thing, putting to much pressure on myself. Also the route to clock my avg best is boring as hell and not very motivating.
Today on the flats I could go 33km/h on upper grip and wasnt killing myself.
Still dont know if I should start on the roadbike in the race tho.

Thanks for all the inputs.
 
Aero bars definitely make a huge difference. On the 20k Time Trial course I ride riding with aero bars typically drops 30+ seconds off of my times.

It's easy sometimes to get obsessed with stats. Sometimes on rides I find myself sucked into pushing hard to top my average speed for the route on previous rides, or constantly staring at the RPMs to maintain a certain range. While pushing your limits can be fun and rewarding, it is also nice sometimes to ignore the numbers and just enjoy the ride.
 
Apr 6, 2015
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Blakeslee said:
Aero bars definitely make a huge difference. On the 20k Time Trial course I ride riding with aero bars typically drops 30+ seconds off of my times.

It's easy sometimes to get obsessed with stats. Sometimes on rides I find myself sucked into pushing hard to top my average speed for the route on previous rides, or constantly staring at the RPMs to maintain a certain range. While pushing your limits can be fun and rewarding, it is also nice sometimes to ignore the numbers and just enjoy the ride.
Agree. Unless you are training for races, you should enjoy the riding. Not caring too much about the figures. Or you will forgot why you love cycling in the first time.
 

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