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What makes one bike faster than another?
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roverpigFull Member
OK, I think we can all agree that the number one factor in how fast you go on a bike is you. After that I’m guessing that we’d all agree that total weight is most important. But what comes next?
In my ongoing mission to compare and contrast my old (2006) Five and my new (2012) Trance I’ve started to look at times. I’ve loaded a load of rides into Strava and defined a number of segments (mostly, but not all, climbs). The nice thing about this is that I didn’t know at the time that these segments were being timed, which should remove some of the operator bias that always plagues these tests. What I’m finding is that my best time on the Trance is consistently faster than my best time on the Five. A one-sample t-test on the percentage difference give p<0.01, which for the non-stats-geeks (i.e. you normal folk) means that we can be 99% confident that the difference is real and not just a fluke. The average difference in speed is around 10% (varying from 5% to 18% for the 8 segments I’ve analysed so far).
Now, I know that the total weight of both bikes is pretty much the same (both are almost bang on 30lb all up weight). I also used the same wheels (and pedals) on both bikes. In fact, for most rides, the bars and stem were the same too).
So, the rider was the same, the total weight was the same, the wheel weight was the same, but there is still a 10% difference to account for. What else could cause that difference?
stilltortoiseFree MemberSame tyres too? Tyres and tyre pressure can make a big difference. Fit/geometry is critical too. If the bike fits you well you’ll be in a more efficient riding position. I took my new bike out at the weekend and just sliding the saddle back by 10mm or so made a MASSIVE different to comfort and hence my efficiency. Small things for small gains all add up. It’s the entire British Cycling strategy 🙂
thisisnotaspoonFree MemberAfter that I’m guessing that we’d all agree that total weight is most important
Surely that just come’s under ‘rider’?
Dirt used to do group tests with timed runs. Interestingly downhill the bikes (anything from 5-6″ trail bikes to DH bikes) were almost always within seconds of each other (on a 2min DH track), but uphill they either managed it in the same time as the reference hardtail or failed miserably (so the times for example would be 5:00, 5:00, 5:01, 5:02, 10:30) with not many inbetween.
I’d say you’re just better than you were 6 years ago, and therefore the 6 year newer bike is faster.
D0NKFull Memberyou are fitter. HTH.
unless you’re riding the 5 and the trance back to back, I’d have thought the chances are you’re fitter and more skilled – unless you’ve covered that elsewhere.
edit
Fit/geometry is critical too.
maybe that too, was just thinking the other day, I wonder how many 29er/650b/rigid/FS/whatever converts have actually just by fluke have ended up with a bike that fits them 100% perfectly and that’s the difference, not the wheel size or other niche.
worsFull MemberDoes it matter? I’d have thought fun was the major factor comparing those 2 bikes?
roverpigFull MemberSorry, I wasn’t very clear there. Although the Five is an old model I only got it recently and all the rides were done over the past year.
My first though was some kind of bias to do with my fitness or weather conditions, but even selecting rides that were done on the same route within a week of each other there still seems to be a consistent advantage for the Giant.
Of course, speed is only one factor and may not even be that important to some people, but I’m surprised by the size and consistency of the difference.
Fit might be part of the difference. The Trance is a large (20″)and the Five a medium (18″) and the Trance does seem to fit me better. I’m surprised that makes such a big difference though.
Stiffness is something that I thought might be to blame too. The rear of the Trance feels very solid whereas just riding the Five down a trail it feels looser. What I need now is a new Five with a (stiffer) maxle rear end for comparison 🙂
martinxyzFree MemberIt’s how efficient the maestro design is. It blows the five design away and as efficient as the five feels, it’s not a patch on the maestro system. Not to mention how torsionally stiffer it is through the entire length of the frame.
Maestro giants are rocketships. They remind me of my Turner with DW. A different league.
plyphonFree MemberIf you really want to get into it you have to consider things like spoke tension, bearing wear, frame design (flex and stress points specifically), and so on and so forth.
ToastyFull MemberGood inch and a half extra length in the Trance top tube, I’d definitely say it would be a factor. Sizable difference though!
rickonFree MemberMaybe it’s because you care too much about figures and time than riding the bike 😉
The big question should be… which is more fun?
ads678Full MemberAre you using the same forks or do they have different amounts of travel?
I have a 2005 Five and would say that most new FS bikes would be better going up hill, unless i drop the front end travel to 120mmish. I’m talking long slog fire road type stuff here, technical stuff I think it’s decent but the Five is not a bike for going up hills fast IMO.
Conditions would be a major factor for me as well.
ToastyFull MemberIt’s how efficient the maestro design is. It blows the five design away and as efficient as the five feels, it’s not a patch on the maestro system. Not to mention how torsionally stiffer it is through the entire length of the frame.
Given the bulk of riders top 10 in races like Megavalanche are on single pivots they must be hella fast then. Imagine how fast they’d go with Maestro! 🙄
njee20Free MemberMaestro giants are rocketships. They remind me of my Turner with DW. A different league.
They’re not though are they, otherwise in a race situation nothing else would get a look in.
roverpigFull MemberYes, it could be the forks. Fox 125mm on the Trance vs 150mm Revs on the Five(actually 120/150 dual position, but I rarely bother to knock them down to be honest). Not sure I understand why though. Seat angle is pretty similar, so my position relative to the cranks is the same. Most of the climbs I’ve looked at aren’t steep enough for the front to be lifting, more steady drags and often done with both forks locked out.
Conditions could be a factor, but I’ve done quite a few back to back (a few days apart) rides, to try and limit the effect of trail conditions.
To be honest, I expected the variability to be so high that I wouldn’t see anything statistically significant, so was surprised to see such a clear and significant different. It could still be something unrelated to the bike though.
To those that say it doesn’t matter and I should stop worrying about the numbers, that’s fine. Nobody says you have to care how fast your bike is. I’m not even sure how important it is to me, but I would like to try and understand what might have caused the difference. At the end of the day, a more efficient bike allows me to go further for the same effort, which usually equals more fun for me.
Steve77Free MemberIf you still have the 5 try a back to back test with the same tyres and pressures
martinxyzFree MemberIt won’t be dead accurate,toasty but a hell of a lot more accurate than what you posted above. :OD
Megavalanche top 13 2012
Remy Absalon (not) on a single pivot ~ http://world.endurotribe.com/2012/08/remy-absalon-wins-2012-megavalanche-in-lalpe-dhuez/#toparticle
nicolas Lau – a cube stereo with a horst link
Dan Atherton – another single pivot? no.His GT.
Greg Doucende – Trek,not a single pivot.
BAILLY MAITRE Francois – a single pivot Scott? No.
Jerome Clementz – Cannondale , not a single pivot. http://www.wtb.com/catching-up-with-jerome-clementz/
Olivier Giordanengo – yeti sb66? If you could call it a single pivot.
Lucan Anrig – santa cruz (and it wasn’t a Chameleon ;O)
Nicolas Quere – Commencal – not on a single pivot for mega
Gustav Wildhaber – Santa cruz (nomad possibly)
Karim Amour – kona.
Franck Parolin – Giant (and it wasn’t a tcr composite ;O))
Cameron Cole – Lapierre
nickcFull MemberYou’re trying harder on a new bike ( that subconsciously you want to be faster to reinforce your purchase decision) that fits you better.
Stop worrying about it
roverpigFull MemberSteve77If you still have the 5 try a back to back test with the same tyres and pressures
The rides I’m comparing were all done with the same wheels, tyres, etc and in most cases it was the same trail ridden on the two bikes a few days apart. I just swapped the wheels over from one bike to the other to try and keep things as consistent as possible.
thisisnotaspoonFree MemberRemy Absalon (not) on a single pivot ~
martinxyz – Member
It won’t be dead accurate,toasty but a hell of a lot more accurate than what you posted above. :ODnicolas Lau – a cube stereo with a horst link
Dan Atherton – another single pivot? no.His GT.
Greg Doucende – Trek,not a single pivot.
BAILLY MAITRE Francois – a single pivot Scott? No.
Jerome Clementz – Cannondale , not a single pivot. http://www.wtb.com/catching-up-with-jerome-clementz/
Olivier Giordanengo – yeti sb66? If you could call it a single pivot.
Lucan Anrig – santa cruz (and it wasn’t a Chameleon ;O)
Nicolas Quere – Commencal – not on a single pivot for mega
Gustav Wildhaber – Santa cruz (nomad possibly)
Karim Amour – kona.
Franck Parolin – Giant (and it wasn’t a tcr composite ;O))
Cameron Cole – Lapierre
Ohhhhhh dear
Commencal – SP
trek – SP
Cannondale – SP
Yeti – definately not a single pivot
Kona – SP (unless it was a magic link?)frosty87Free MemberAs OP says you and total weight are the 2 biggest variables.
After wheel/ tyre combo and pressure I would say drive train resistance would come next. A small amount of pedaling power is lost to friction in the drive train and the smoothness of the bearings.
Sounds like a fun project, I’ve got no head for stats!
bigjimFull MemberI went from a trance frame to an ASR5 (mostly same components) and I couldn’t believe how much faster it was. The geometry is very different between the bikes which I think must be the main thing – the ASR5 encourages you to throw it into corners, and has a much lighter, stiffer rear end, just encourages you to go faster. The trance was a good bike but much more ‘safe’ a ride than the yeti.
roverpigFull Membernickc[/u]You’re trying harder on a new bike ( that subconsciously you want to be faster to reinforce your purchase decision) that fits you better.
Normally I’d be with you on that one. Operator bias plays a huge part in these tests and (in my mind) pretty much invalidates any bike comparison I see written online (including those 29 vs 26v s 27.5 ones). However, I bought the Five (from ebay) after the Trance and if I’m honest I really wanted the Five to be better. I prefer pretty much everything about the Five, right down to the frame colour. But even I’d have to admit that (based on this very limited sample of two specific bikes) the Trance is consistently faster.
Stop worrying about it
OK then 🙂
martinxyzFree MemberRover, there’s a few lightweight bikes out there with poor design that will feel slower than a bike with a well thought out design/spot on pivot placement that can be around 3 pounds heavier than the other bike, but still climb quicker.
I’m not talking about the Five when I say that, I had others in mind.
aracerFree MemberAfter that I’m guessing that we’d all agree that total weight is most important.
No, we don’t – or at least only to the extent that that already comes under “you”, bike weight certainly isn’t the next most important thing. For a start using your evidence, there’s no way the difference in weight between your two bikes makes 10% difference in speed. Though I’d have also suggested that tyres make more difference than bike weight.
ToastyFull MemberHehe at the Mega thing 🙂 Quite a few single pivots in there, you see a lot on the bigger beefier models. If you’d looked at 2011 results there were even a couple of Orange in there.
2x Orange and the Commencal top ten at very least. Most of the rest being 4 bars, which are plusher than single pivot if anything. Completely the opposite direction to the VPP/Maestro setup.
Not that it makes a difference anyway 🙂 Which was pretty much my original point.
roverpigFull MemberOK, I guess we don’t all agree that weight is the second most important factor 🙂
Total weight (you plus bike) is pretty simple to understand though. Work done in climbing a hill is weight times height, so time taken to do the climb is weight times height divided by the power that you produce i.e. speed up a hill is directly proportional to weight and if you double the (total) weight and put out the same power it should take you twice as long to get up the hill.
But I’ll concede that letting all the air out of your tyres might have a bigger effect 🙂
It’s all irrelevant in this case as we are talking about the same weight and same wheels under the same rider.
D0NKFull MemberCommencal – SP
trek – SP
Cannondale – SP
Yeti – definately not a single pivot
Kona – SP (unless it was a magic link?)don’t most of those have a single pivot between the frame and the back wheel but a multitude thereof elsewhere? Might not be 4bar, vpp or DW but still (the possibility of being) a fair bit more sophisticated than the orange single single pivot?
(I do own an ssp and very nice it is too, but clever it is not)
klumpyFree MemberSo, the rider was the same, the total weight was the same, the wheel weight was the same, but there is still a 10% difference to account for. What else could cause that difference?
Well, at the risk of being controversial; I went along with a mate on a Five test ride, and everyone agreed it was an utterly terrible bike in every situation.* Everyone agreed the Trance someone else brought was great. Maybe the Five is rubbish? That’d do it.
That said, where exactly is the Trance faster and do you care about that bit? For example, I ride up hills to ride back down them, so uphill performance isn’t important to me.
*It was so bad the attendant bike geek was convinced it had somehow been “put together wrong”.
uwe-rFree MemberI would guess the significant factor would the suspension set up.
Suspension design is not the issue it is the amount it bobs and sucks up the effort put in. An unsophisticated ssp with a big and plush stroke is going to eat up that effort, as would a flexy frame / wheels components.
If you locked all the travel out on both bikes you might even them up on the climbs but I assume you don’t just climb and then walk down! So its not really the bike being slower its just set up for different things.
roverpigFull MemberI’ve been thinking about this a bit more. The numbers don’t lie, but I still don’t believe them 🙂 I just don’t believe that there is anything fundamental in the Five that would make it 10% slower than the Trance on average. Maybe a few percent, but not 10. Ten percent is a huge difference. I’m guessing that there is either some selection bias in the data I chose, or something different in the setup of the two bikes.
Of course, there are none so blind as those who will not see 🙂
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