Mountain Bike Reviews Forum banner

Does a lighter bike mean it's "faster"......some non-German test results here.......

3K views 24 replies 11 participants last post by  nino 
#1 ·
Does a lighter bike mean it's "faster"......some non-German test results here.......

Unfortunately this is not as good and scientific as Nino's German test results, but I think it does prove something.....what? You can make that decision.

I was doing a comparison test between two race bikes last night, you can see here for the complete posting http://forums.mtbr.com/showthread.php?t=22118

.......anyway, the "main" difference between the two bike was the weight, one was about 23.5 lbs and the second was aproximately 1-1.5 pounds heavier. Both are race bikes, using the same wheelset, tires, psi and fork. The rest of the components were very similiar.

What I noticed was that I could ride each bike pretty much at the exact same speeds, but it was my heart that had to work a little harder riding the heavier bike, not much but a little. So the next time someone tells you that they can ride their heavier bike just as fast as your light one, that may be the case, but have them hang with you for about 3 hours and see if they are still hanging, or just breathing a heck of a lot heavier.

KMan

Test results:
Lap #1 Trek Fuel
Distance 4.78 miles
Time: 22.34
Average Speed: 12.5 mph
Average/Max Heartrate: 173/190
Max Speed: 23mph

Lap #2 Titus Racer X100
Distance 4.76 miles
Time: 22.40
Average Speed: 12.4 mph
Average/Max Heartrate: 178/191
Max Speed: 23.5mph

Lap #3 Trek Fuel
Distance 4.78 miles
Time: 23.16
Average Speed: 12.1 mph
Average/Max Heartrate: 173/190
Max Speed: 22mph

Lap #4 Titus Racer X100
Distance 4.76 miles
Time: 22.39
Average Speed: 12.4 mpg
Average/Max Heartrate: 176/192
Max Speed: 22.5mph
 
See less See more
#2 · (Edited)
KMan said:
Test results:
Lap #1 Trek Fuel
Distance 4.78 miles
Time: 22.34
Average Speed: 12.5 mph
Average/Max Heartrate: 173/190
Max Speed: 23mph

Lap #2 Titus Racer X100
Distance 4.76 miles
Time: 22.40
Average Speed: 12.4 mph
Average/Max Heartrate: 178/191
Max Speed: 23.5mph

Lap #3 Trek Fuel
Distance 4.78 miles
Time: 23.16
Average Speed: 12.1 mph
Average/Max Heartrate: 173/190
Max Speed: 22mph

Lap #4 Titus Racer X100
Distance 4.76 miles
Time: 22.39
Average Speed: 12.4 mpg
Average/Max Heartrate: 176/192
Max Speed: 22.5mph
Attach some 5 lbs weight to one bike and repeat the test. I think 1-1.5 lbs difference is not that much of a difference.

Also I did some similar tests and I found that if I performed 2 such tests in a day I'd be slower on the second run because the first took it out of me no matter how much I rested in between. I might just post my results too:


My tests in question were on 9th and 17th of Jan where on one of the runs up this hillclimb on each day I ran with a 4kg weight added. I was looking to confirm that 4 kg would slow me down about 20 seconds for every run and that was shown reasonably accurate across all 4 runs.
 
#3 ·
There's a lot of variability in your scores that doesn't seem to correlate with the bike weight. I would be interested to see what the SD of these are, I bet your results fall within 1 SD of the mean and are not statistically significant. Doing a real study with multiple participants and some sort of system of hiding the weight from them so they don't know if they're on the control or experimental bike, and some real statistical analysis might be more meaningful.
 
#4 ·
mward said:
There's a lot of variability in your scores that doesn't seem to correlate with the bike weight. I would be interested to see what the SD of these are, I bet your results fall within 1 SD of the mean and are not statistically significant. Doing a real study with multiple participants and some sort of system of hiding the weight from them so they don't know if they're on the control or experimental bike, and some real statistical analysis might be more meaningful.
Didn't realise your reply was to me.

Anyway the only relevant runs are 2 on 9th and 2 on 17th. All the others runs were not part of the test but unrelated time trials. On 9th I rode with balast first and then without and on 17th I rode without balast first and then with, to minimise any differences in power from being tired. Also the 4 kg balast was on the rider (backpack) and not the bike.

Total for balasted runs = 12:01, avg per run 6:00.5
Total for unbalasted runs = 11:16, avg per run 5:38.00

Avg difference per run = 21.5 seconds. Good enough for me ;)
 
#6 ·
agree about cummulative effects

KMAN, why did you do this test? Are you only keeping 1 bike and trying to decide which is faster?

I think a good way to compare bikes is to ride the same ~2hr course, alternating bikes every 4 days or so (to ensure recovery) for ~3X each and measure the exact time to climb a hill at 30min, 60min, 90min and 120min into the ride. The idea is that the time to climb the hill indicates power and truly indicates race results. A heavier bike, as you say, can be ridden just as fast but at the expense of fatigue. Now at 90min and 120min it gets pretty difficult to mask that fatigue and power begins to drop - and my assumption is that riding the lighter bike would be faster further into the ride. I don't think measuring lap times is as good because there are too many variables.

When I get my new wheels, maybe I'll try something like this.
 
#7 ·
1 lbs VS Nokian NBX Lite....

you don't need to be a professor to tell which is faster...obviously a lighter bike means less work thus it's faster (everything beeing equal!).

BUT

i just had another testride with some Nokian NBX Lites. this time i not only did my usual "after-work-1-hour-ride" but a 2 hours ride with everything in it from smooth fireroads,technical singletrails and long steep climbs as well as some fast and some thight downhill sections....37 km / 850 meters dislevel

i did that same lap on a set of Schwalbe Skinny Jimmy (1.9"/435 and 460g) tires that i had mounted this winter on my wifes wheels (the exact same wheels as mine...). with these wheels and tires my time was 1:55:40 at 155 average heartbeat.

the same lap with Nokian NBX 2.0" Lites took me just 1:50:00 at an average heartbeat of 152 which shows i had to work less this time even though i was almost 6 minutes faster....

the trails were unchanged.temperature was also about the same so the difference is mainly the tires. 5 minutes 40 seconds that's ca. 5% REDUCTION in overall time! that's exactly the difference i measured on my 1 hour lap last year too.

now my bike is about 8-10 lbs lighter than your typical FS rig, i have Nokian tires mounted with Eclipse tubelesskit...i have to say it's a pretty fast rocketship. so it's really no surprise that when i try some nice FS bikes like a Epic S-Works or whatever they all feel terribly slow....
 
#8 ·
Correct...

I am only keeping one bike, kind of stupid for me to keep two bikes that have the same purpose. I did the test for two reasons, the first and main reason was fit, to see which bike I liked riding better, if one hurt my back more than the other (I have a bad back problem), and which I thought handled more to my liking. I also wanted to see if one bike was faster than the other under the exact same circumstances. Hence a test that runs the 2 bikes back to back under the same conditions. I wanted to run 2 more laps but it was going to get dark and the park would be closing.

Running test like this over different days in my eye is not a great way to do a comparison as some days you will feel better than others, trail conditions change, etc. Too many varables to change. Back to back multiple loops I feel is a better judge. Even one longer lap each is not really a good judgement as fatigue plays a part. Maybe if I have the Fuel next week and the time I may run a samiliar test, 4 laps but do a longer route like 7 miles.

KMan

Motivated said:
KMAN, why did you do this test? Are you only keeping 1 bike and trying to decide which is faster?

I think a good way to compare bikes is to ride the same ~2hr course, alternating bikes every 4 days or so (to ensure recovery) for ~3X each and measure the exact time to climb a hill at 30min, 60min, 90min and 120min into the ride. The idea is that the time to climb the hill indicates power and truly indicates race results. A heavier bike, as you say, can be ridden just as fast but at the expense of fatigue. Now at 90min and 120min it gets pretty difficult to mask that fatigue and power begins to drop - and my assumption is that riding the lighter bike would be faster further into the ride. I don't think measuring lap times is as good because there are too many variables.

When I get my new wheels, maybe I'll try something like this.
 
#9 ·
a mt. biking magazine did a test...

a mt. biking magazine did a test..was either "mountain bike action" or "mountain biking"

the results were obvious and conclusive: less weight is way faster, on climbs. the weight of rider has a larger factor than the weight of bike, of couse.

my answer is to:
1. lose body weight
2. gain more endurance
3. light 21# xc race al. hardtail with rs sid.
4. 27# xc trail steel hardtail with more fun componants, marz mx fork. (but most people would have more fun on a Blur or some other xs fs trail bike).
 
#10 ·
Nino

You are distinguishing apples to oranges with different tires, rolling resistance, tread patterns, etc. Good info, but not apples to apples. Even what I did was not apples to apples, two different bikes. Nor was it originally intended to be a weight comparison, just a comparison between two different bikes. The weight issue and the HR was noticed after the fact. If I would have used my NBX lites on one of the bikes I am sure that would have been the faster bike, but that was not what I was after.

"the trails were unchanged.temperature was also about the same so the difference is mainly the tires. 5 minutes 40 seconds that's ca. 5% REDUCTION in overall time! that's exactly the difference i measured on my 1 hour lap last year too."

Doing this on different days "can" result in biased results as some days you may feel better than others and ride much faster or even slower.

KMan

nino said:
you don't need to be a professor to tell which is faster...obviously a lighter bike means less work thus it's faster (everything beeing equal!).

BUT

i just had another testride with some Nokian NBX Lites. this time i not only did my usual "after-work-1-hour-ride" but a 2 hours ride with everything in it from smooth fireroads,technical singletrails and long steep climbs as well as some fast and some thight downhill sections....37 km / 850 meters dislevel

i did that same lap on a set of Schwalbe Skinny Jimmy (1.9"/435 and 460g) tires that i had mounted this winter on my wifes wheels (the exact same wheels as mine...). with these wheels and tires my time was 1:55:40 at 155 average heartbeat.

the same lap with Nokian NBX 2.0" Lites took me just 1:50:00 at an average heartbeat of 152 which shows i had to work less this time even though i was almost 6 minutes faster....

the trails were unchanged.temperature was also about the same so the difference is mainly the tires. 5 minutes 40 seconds that's ca. 5% REDUCTION in overall time! that's exactly the difference i measured on my 1 hour lap last year too.

now my bike is about 8-10 lbs lighter than your typical FS rig, i have Nokian tires mounted with Eclipse tubelesskit...i have to say it's a pretty fast rocketship. so it's really no surprise that when i try some nice FS bikes like a Epic S-Works or whatever they all feel terribly slow....
 
#11 ·
correct...

it's just that the advantage of lower weight is clear.

BUT i was pointing out that a simple tire swap has more influence on reduced lap times than 1 lbs alone.

that 2 different days aren't comparable is logical BUT seeing under the same circumstances (same trail condition, same temperature,same overall weight, same fitness etc) i beat the time by 5% AND have reduced heartbeate still shows a thing or two. i also have "better"days where i'm able to push a little more but that usually also shows on the average heartbeat.

you were tellling you wanted to try out which bike suited you better also position-wise...i'd say different body positioning might have more impact on your riding time than 1 lbs more or less.your power output greatly depends on your correct position on the bike so even a slight change in seating height or uper body position might change more than less weight.
 
#12 ·
"non-German" test results? Who are you kidding?

KMan said:
Unfortunately this is not as good and scientific as Nino's German test results, but I think it does prove something.....what? You can make that decision.
Who are you trying to fool with "non-German" test results.........

Everybody knows that ONLY Germans can do accurate testing on mountain bikes....

On this board we only accept tests and conclusions of German magazines, so unless you can get them to duplicate and publish your results, why bother?
 
#13 ·
Nino, you might be suprised on a FS...

If you get a decenlty light FS or ride one of those Scott Strikes at 19lbs, you most likely will be faster on a FS. reason being is very simple. On a FS you will allow you to use less energy as you body will not be as fatigued form be beat up like a HT does to your body or the wasted energy by standing up to avoid gettting beat up. If your HR stays lower, your able to tkae the best line, you should have more energy in reserve which might you faster in the long run.

The REAL would be to get a HT and a FS that are speced' the excat same then compare HR, times and speed. Now you must you a ratio or HT vs FS weight and HT HR vs FS HR then you will truly see which one is faster. I think in the long run, a FS that is no more than 1 1/2-2lbs heavier than a HT will be faster in the long run.
 
#14 ·
agreed...

agreed:
depending on the trail conditions you might be faster...we had that debate 100 times before.but that wasn't my point.

i was telling MY bike is so fast that a typical FS feels just plain slow.
 
#15 ·
KMan said:
Running test like this over different days in my eye is not a great way to do a comparison as some days you will feel better than others, trail conditions change, etc. Too many varables to change.
If you ran the test enough times the differences in how you felt on different days and varying trail conditions would filter out. I'm not sure what sample would be required to reduce that error but it's probably more than 10.
 
#16 ·
Good info....

I get your point now that reducing 1 lb in tire weight will have a greater effect than removing 1 lb of other bike weight. And I agree with that point.
Agree with the position as well. The one bike has a stem with a little more rise than the other and I could tell the difference.

I plan on taking the "best" of parts and putting them on the Racer X and calling it a week!

KMan

nino said:
it's just that the advantage of lower weight is clear.

BUT i was pointing out that a simple tire swap has more influence on reduced lap times than 1 lbs alone.

that 2 different days aren't comparable is logical BUT seeing under the same circumstances (same trail condition, same temperature,same overall weight, same fitness etc) i beat the time by 5% AND have reduced heartbeate still shows a thing or two. i also have "better"days where i'm able to push a little more but that usually also shows on the average heartbeat.

you were tellling you wanted to try out which bike suited you better also position-wise...i'd say different body positioning might have more impact on your riding time than 1 lbs more or less.your power output greatly depends on your correct position on the bike so even a slight change in seating height or uper body position might change more than less weight.
 
#17 ·
you got me wrong again...

it's not the lighter tires but the FASTER tires that make a bigger difference than 1 lbs of weight saved elsewhere.
the Nokians are almost the same weight as the Schwalbe tires on my wifes bike (overall 10g heavier!) but still make a huge difference because they are faster rolling.
 
#18 ·
Do you sweat? Don't forget you could easily sweat 1 to 1/2 pounds of weight off on a 5 mile loop, in addition to the water you're drinking on the bike. On a really hot day (about 100' farenheit at high humidity) I can sweat as much as 5 pounds an hour off of my body despite what I'm drinking. Just another variable to consider. So weighing yourself and your bike before each lap might be a good idea. Or you could just start on different bikes on different days.
 
#19 ·
Chester said:
Who are you trying to fool with "non-German" test results.........

Everybody knows that ONLY Germans can do accurate testing on mountain bikes....

On this board we only accept tests and conclusions of German magazines, so unless you can get them to duplicate and publish your results, why bother?
In that case here are the results of some similar tests that a firend of mine, Hans, performed. Hans and I train on the same hillclimb as in similar, but non related, tests I posted earlier. :)

 
#20 ·
KMan said:
Running test like this over different days in my eye is not a great way to do a comparison as some days you will feel better than others, trail conditions change, etc. Too many varables to change. Back to back multiple loops I feel is a better judge. Even one longer lap each is not really a good judgement as fatigue plays a part. Maybe if I have the Fuel next week and the time I may run a samiliar test, 4 laps but do a longer route like 7 miles.KMan
Hey, I think you should do another day of testing on the same track and suggest you take reverse of the protocol you took in these tests.

The reason is that if you did all 4 runs in one day you would have made progressively less power for each successfive run which would mask which bike is truly faster.

If you look at my tests on 9th and 17th, on both days I made ~20W less on the second run. This is btw with taking about an hour rest/easy riding between runs. Thats why I took 2 days and reversed protocol for the second day so that I had a result for me being fresh for both balasted and unbalasted case, and tired for both balasted and unbalasted cases. That way it all balances out and if you average all the run times for each bike they would be all close to the same power.

It is true also that you make different power overall on different days (on 9th Jan tests I made average ~325 W while on Jan 17th tests I made ~340 W avg) but as you do both bikes on each day it will balance itself out and result in less error than just taking results from one day of testing.
 
#21 ·
Finally some accurate German data that proves your point

Boj said:
In that case here are the results of some similar tests that a firend of mine, Hans, performed. Hans and I train on the same hillclimb as in similar, but non related, tests I posted earlier. :)

Ahh..........viel besser, ausgezeichnete daten

Yes, thats the kind of science a bike rider can actually trust.......not like that suspect data we saw in the earlier posts.
Now I'm convinced, its obvious everything you've said and every conclusion you have reached is proven beyond a reasonable doubt. Well done.

That Hans looks like a "pro" rider from those fast times. Probably rides Nokians :)
 
#22 ·
Nokian NBX 2.1

nino said:
you don't need to be a professor to tell which is faster...obviously a lighter bike means less work thus it's faster (everything beeing equal!).

BUT

i just had another testride with some Nokian NBX Lites. this time i not only did my usual "after-work-1-hour-ride" but a 2 hours ride with everything in it from smooth fireroads,technical singletrails and long steep climbs as well as some fast and some thight downhill sections....37 km / 850 meters dislevel

i did that same lap on a set of Schwalbe Skinny Jimmy (1.9"/435 and 460g) tires that i had mounted this winter on my wifes wheels (the exact same wheels as mine...). with these wheels and tires my time was 1:55:40 at 155 average heartbeat.

the same lap with Nokian NBX 2.0" Lites took me just 1:50:00 at an average heartbeat of 152 which shows i had to work less this time even though i was almost 6 minutes faster....

the trails were unchanged.temperature was also about the same so the difference is mainly the tires. 5 minutes 40 seconds that's ca. 5% REDUCTION in overall time! that's exactly the difference i measured on my 1 hour lap last year too.

now my bike is about 8-10 lbs lighter than your typical FS rig, i have Nokian tires mounted with Eclipse tubelesskit...i have to say it's a pretty fast rocketship. so it's really no surprise that when i try some nice FS bikes like a Epic S-Works or whatever they all feel terribly slow....
I agree with Nino on his NBX experience`s.
I wasnt able to get the NBX2.0 lites, so opted to give the NBX 2.1`s a go on my bike.
On my regular training rides I`ve found the time savings to be in the vicinity of 5 - 10%.
I put this down to the outstanding rolling ability of these tyres (this rolling ability and the ability of this tyre to corner hard and carry speed into and out of the corners certainly equates to a lower average HR)....and I`ll certainly be going for the NBX Lites for my next race tyre.
My lap times whilst racing have also confirmed that these tyres are returning lap times very close to 5% faster than any other tyre I`ve raced on ( I won my last race by a meagre 3 seconds and believe without a doubt I wouldnt of achieved this without the NBX`s on the bike).
Cheers
 
#24 ·
psychosomatic

You are getting more improvement than the test data seems to support. That said, I could not find numbers for the Skinny Jimmy, but they would have to be extremely slow for you to see that kind of difference. Obviously not just the % difference in rolling resistance, because that is just a fraction of the overall drag on a rider. In other words if rolling resistance (both tires) accounts for 20% of the total drag on a rider and you measure a 5% improvement in time then the tires would have 25% reduction in rolling resitstance. I think your style simply agrees with the NBX and that is why you go faster. It is a confidence thing.

On a related note, while looking at the data you posted it seems the Eclipse converted Racing Ralph is the fastest measured tire. Now, you assume that the Eclipse converted NBX would see the same benefit, but that is an assumption and given the already extreme compliance of the NBX it might not be so true. Also, in the more recent thest the NBX Lite achieved 21.2 Watts, but in the earlier test the NBX 2.1 only achieved 28.3. Why the big difference? The 2.25 Racing Ralph had lower numbers than the 2.1.

Anyway, your point that fast tires are more important than 1lb saved is probably true and is certainly something that guides the spending on my bike.

nino said:
you don't need to be a professor to tell which is faster...obviously a lighter bike means less work thus it's faster (everything beeing equal!).

BUT

i just had another testride with some Nokian NBX Lites. this time i not only did my usual "after-work-1-hour-ride" but a 2 hours ride with everything in it from smooth fireroads,technical singletrails and long steep climbs as well as some fast and some thight downhill sections....37 km / 850 meters dislevel

i did that same lap on a set of Schwalbe Skinny Jimmy (1.9"/435 and 460g) tires that i had mounted this winter on my wifes wheels (the exact same wheels as mine...). with these wheels and tires my time was 1:55:40 at 155 average heartbeat.

the same lap with Nokian NBX 2.0" Lites took me just 1:50:00 at an average heartbeat of 152 which shows i had to work less this time even though i was almost 6 minutes faster....

the trails were unchanged.temperature was also about the same so the difference is mainly the tires. 5 minutes 40 seconds that's ca. 5% REDUCTION in overall time! that's exactly the difference i measured on my 1 hour lap last year too.

now my bike is about 8-10 lbs lighter than your typical FS rig, i have Nokian tires mounted with Eclipse tubelesskit...i have to say it's a pretty fast rocketship. so it's really no surprise that when i try some nice FS bikes like a Epic S-Works or whatever they all feel terribly slow....
 
#25 ·
some answers...

Motivated said:
You are getting more improvement than the test data seems to support. That said, I could not find numbers for the Skinny Jimmy, but they would have to be extremely slow for you to see that kind of difference. Obviously not just the % difference in rolling resistance, because that is just a fraction of the overall drag on a rider. In other words if rolling resistance (both tires) accounts for 20% of the total drag on a rider and you measure a 5% improvement in time then the tires would have 25% reduction in rolling resitstance. I think your style simply agrees with the NBX and that is why you go faster. It is a confidence thing.

On a related note, while looking at the data you posted it seems the Eclipse converted Racing Ralph is the fastest measured tire. Now, you assume that the Eclipse converted NBX would see the same benefit, but that is an assumption and given the already extreme compliance of the NBX it might not be so true. Also, in the more recent thest the NBX Lite achieved 21.2 Watts, but in the earlier test the NBX 2.1 only achieved 28.3. Why the big difference? The 2.25 Racing Ralph had lower numbers than the 2.1.

Anyway, your point that fast tires are more important than 1lb saved is probably true and is certainly something that guides the spending on my bike.
i don't see where a tire can "agree with you" and make for a 5% time reduction.my riding doesn't consist of downhills, corners and braking only (where a tire could make a difference in how it feels) but the main part is going "straight" where grip doesn't play a factor at all. just those few corners where grip really counts won't gain you 6 minutes...the Schwalbe tires actually felt quite good to me and gripped well but they definitely roll slower which could be felt right away when i changed the wheels. the difference is really like you would have a brake dragging slightly all the time on the Schwalbe. they are by no means slow.the Conti Supersonics i used the last 2 years felt about the same... they are actually quite good but the Nokian is in another league.i have yet to ride a tire that is as fast.

i don't agree with you on the "Eclipse-Bonus" (saved watts). the Schwalbe RR was tested with and without tube and the difference they measured is due to the lack of the inner tube only.that has nothing to do with the sidewalls of the tires.so if you run any tire without a inner tube it will have about the same effect.

different tests done at different times,different temperatures,different pressures on different machines give different results....only logical.don't compare numbers from one test with those of another test! and those 28,3 watts you are talking about might be the numbers for the larger 2.1" but definitely not the 2.0" light.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top