[Closed] Power loss on full sus' bikes compared to hardtail's

Look at the results of the XCO World Champs. Only one hardtail in the top 10.

Wasn't a full sus in the top 3 of the olympics xc race? Might have been 650b too.

Wasn't a full sus in the top 3 of the olympics xc race? Might have been 650b too.

Kulhavy won it on a Specialized Epic 29er full sus.

But the xc bikes will have a lockout so they aren't losing any power, just carrying more weight.

The answer is it depends.

fat blokes lose power on full sus.
dont think there is a full susser really suitable for fat blokes.

Any power you would lose would have to end up as heat in the shock. Does your shock get warm when you ride XC? No.

I don't think you would lose speed anyway. If you ride rigid the rough stuff slows you down more than any theoretical energy loss. On a FS some of your forward momentum ends up in the shock; on a HT some of your forward momentum gets converted into up and down momentum instead.

What Molgrips said plus the extra climbing traction, cornering traction and lower fatigue.

In short, hardtails are shite.

Useless to compare an xco bike to a normal susser. They are using things like electronic lockouts now which is why full suss has become an option again. When climbing you can see there's no bob at all.

On a normal bike I can't see how the saddle bobbing up and down as you peddle can be anything but bad.

Do you suppose in a another 20 years, someone will pose the wheel size question?

In short, hardtails are shite.

I'd say full suss bikes (unless they lock out) feel slower up most hills than a hardtail. Much less direct when you stand and pump. Similar when you sit and spin. They're also generally heavier, which doesn't help. Most people would probably make any time lost back up on the downs. I think Ton is right in that the weight of the rider is also a factor.

Useless to compare an xco bike to a normal susser. They are using things like electronic lockouts now which is why full suss has become an option again. When climbing you can see there's no bob at all.

They've been pretty viable for about 10 years now. Some riders use them religiously (Kulhavy) some do so rarely if the course necessitates (Schurter, Absalon), some never do (Emily Batty). Personal preference. One isn't better than the other.

Molgrips I'm intrigued you don't think there's [i]any[/i] power loss? So if you outfitted a V10 with some 23c slicks, and hung some weights on a road bike they'd climb Alpe d'Huez the same? Can guarantee the shock won't be getting warm!

I don't think there's no power loss, I think it's negligible.

Re the v10, I think riding position, wheels and tyres are most of the slowness.

Hence you fit some 23c slicks in my hypothetical test. It's a climb, so negligible aero gains, position needn't be an issue. Frankly plenty of modern road bikes are just as upright anyway!

I think like the wheel size thing you can answer the question for a rider on a course

But as the relative amounts of climobing and different surfaces change you get a different answer

I'm also unconvinced that comparing bike swith the same tyres is fair. It might be that the Fs lets you run a thinner tyre or a higher pressure for the same level of comfort or traction

If I was dumping 10W into my shock is that negligible? What it cause a noticeable heating effect?

Over a shorter course I don't think there is much in it.

But after 3 or 4 hours of riding the full suspension is quicker because the rider isn't so battered about.

And yet marathons (up to and including 24 solos) are won on hardtails.

There is no 'better' or 'quicker', it's not that straight forward!

I am so much faster on my hardtail - and it can't be all down to weight. Although it is a good 9 lb lighter than my full suss, as a percentage of rider + bike weight the difference is bugger all.

On my local trails I always go for the easiest and smoothest ascents and the techy DH. So I don't loose any traction on the climbs. If I have to ascent rocky climbs then the difference is much less maybe even quicker on the full suss.

So yes - depends what your riding.

Use to be that you'd see the FS bikes ridden to please a sponsor and the shock would just be pumped up and locked out so that it was pretty much a HT. Think they are more prevalent now that the shocks are getting better, lockouts easier to use, and everything is getting lighter. Aren't the WC XC courses getting more technical too (maybe why bars seem to be getting wider too.)

Also tend to see more of the men on FS bikes than the women. Maybe any efficiency loss is more significant for the women as a percentage of overall power, or maybe a weight thing or speed down the rocky stuff?

Are you lot talking about pedalling bob, or thekinetic energy lost to the damper?

It's a climb, so negligible aero gains, position needn't be an issue

I think position has a lot more to do with it than aerodynamics.

i think the terrain makes the biggest difference. From my own experience on my local climbs, there's definately a correlation between roughness/ technicality and amount of suspension.

The two local 15 min fire road climbs im significantly quicker on my CX bike than either hardtail or full sus, the singletrack slightly rocky more technical route out of the village, my top few times are all on the full sus, i dont think i could clean it on the cx.

down or along, my anecdotal experience is that im quicker on the full sus, i stay off the brakes more and can keep the power down pedaling easier in the rough stuff on a full sus. once again, flat fireroad non rocky trails, the cx is quickest

got it logged on strava? do a raceshape to see where you are losing time.

http://blog.strava.com/whats-your-best-effort-see-how-it-compares-8480/

It's probably been covered already, round Cannock that might be the case, but up here in Cumbria my hardtail was (with the exception of tarmac) slower and had poorer traction, up, along and down, than my 6" AM full susser. Same rider, same trails, different bike.

I won't be buying another hardtail.

the terrain makes the biggest difference

njee20 - Member

Hence you fit some 23c slicks in my hypothetical test. It's a climb, so negligible aero gains, position needn't be an issue. Frankly plenty of modern road bikes are just as upright anyway!

I've done recent rides on 3 various bikes. All road based all on my 'TT' circuit which is 29km with some climbs/flats

My times are for a Carrera TDF(road rubber), Charge Cooker(commuting rubber), MetaAM29 (Ralphs)

There's 3 mins difference between the 3 bikes overall. Interestingly I make up any gains on the flat section of the TDF, uphill I'm less than 2s difference between the 3 bikes. Downhill I'm quickest on the Cooker (confidence thing).

That's for me....

Any power you would lose would have to end up as heat in the shock. Does your shock get warm when you ride XC?

My mate's squeeks and squeels like a stuck pig - that energy harnessed would make him awsumz

Are you lot talking about pedalling bob, or thekinetic energy lost to the damper?

I think course designers in XC are under pressure to keep courses rough enough to prevent bikes from being too much like flat-barred CX bikes.
A higher UCI weight limit would mean more suspension too, if that's what the marketeers decided was important.

Is their a comparative approximate industry figure of power loss?

Yep, a full suss loses roughly 5-10 Glimbarts in comparison with a hardtail.

I don't think pedalling bob is an issue on XC FS bikes tbh.

down or along, my anecdotal experience is that im quicker on the full sus, i stay off the brakes more and can keep the power down pedaling easier in the rough stuff on a full sus.

This.

Also, on the more difficult climbs you have to be moving around on the bike more to keep the bike moving. This costs energy.

All and any power that doesn't get transferred to forward motion I guess.

This also includes energy absorbed by the shock over bumps. The question is if this energy is preserved if you are on a ht.

This also includes energy absorbed by the shock over bumps. The question is if this energy is preserved if you are on a ht.

Except when there's pedal bob (or honking bob). Then the shock absorber is working directly against you.

The shock does absorb forward motion, of course it does. If you coast along the flat on a bumpy trail, the shock moves and does work against the damper fluid - where's that energy come from?

The swingarm might be moving vertically but only due to the forward motion of the bike and the leverage of the wheels against bumps.

I've logged various rides on a number of hardtail (FF29 and Solaris) and full-suss bikes (Five, Trance and Gyro) over the past few years, including lots of attempts at the same segments different bikes. I've made a few attempts at trying to analyze these to see which bike is faster in various segments and I'd have to say that it is really hard to come up with any definitive conclusions. It does look as though the HT has an edge on smooth climbs (and roads) and the full-suss has an edge on rougher climbs, but the differences are much smaller than the day to day variation in my fitness/enthusiasm etc. So, I can find examples of smooth climbs where my fastest time was set on a full-suss (or rough ones where a HT wins), simply because I was feeling good that day.

Make of that what you will, but personally I'd say that, if you sit and spin up climbs (as I do), there is not much in it. The HT should win (if only because it is slightly lighter) up a road or smooth trail. The full-suss probably wins if it gets technical.

Racers do tend to stand on the climbs though.

I used to ride with a really quick bloke. Couldn't keep up with him with both of us on rigid. I stood more chance with bounce. This was racing on really rough tracks.
So you may lose power but it's quicker.

The shock does absorb forward motion, of course it does. If you coast along the flat on a bumpy trail, the shock moves and does work against the damper fluid - where's that energy come from?

The swingarm might be moving vertically but only due to the forward motion of the bike and the leverage of the wheels against bumps.

For me gains of a full suss on the rough stuff far outweigh any gains that might be had on a hard tail for the smooth bits. If I just ride canal towpaths I might come to a different conclusion.

Not for Winching and plummeting

If you ride smooth climbs, technical descents and no flat (which most people do where I live because of the geography) then the time you gain on the climbs far outweighs the time you loose on the descents simply because you you spend about 4/5 of your time going upwards.

The descents are no more or less fun on the HT, slower certainly but more challenging. I don't prefer one over the other - its nice to have a change - but I can definitely get more in on the hard tail.

What Molgrips said plus the extra climbing traction, cornering traction and lower fatigue.

Makes sense to me. I think in almost all cases a well set up and applicable FS will do a better job of covering the ground than a HT, especially loose or nadgery climbs when you want that rear wheel on the dirt not bouncing about..

In short, hardtails are shite.

False. Hardtails are great fun and I find I can't be bothered with the maintenance overheads and endless technology churn of FS.

Covering ground as fast as possible isn't the aim of MTB for me.

HTs for me.

This thread has inspired me to take out my hardtail (which hasn't been offroad since it was rebuilt in June) and ride back to back with my full suss. I feel a Strava coming on...

I don't think pedalling bob is an issue on XC FS bikes tbh.

Then why aren't they used by everyone in a competitive situation?

I'm quicker just about everywhere on my 29er hardtail than on my 26" FS of the same weight.

What about maintaining speed through less fatigue?

I'd be interested to hear what part people feel that has to play. Purely for selfish reasons I guess.

I find my HT is my go to bike (as was my previous HT) but my body carries a fair few injuries so although my fitness is ok I find the jarring, especially over repeated rutted ground for eg gets fatigue kicking in. Both the HT I mention are 29ers for reference.

I have a FS (120mm 26er) but have a love / hate relationship with it and the only time it was ever my go to bike was when it was new. But that was due 1) new bike love and 2) it was lighter than the 26er HT I had at the time but then that wasn't hard as it weighed over 33lb.

I'm quicker just about everywhere on my 29er hardtail than on my 26" FS of the same weight.

Could be wheel size.

I think in almost all cases a well set up and applicable FS will do a better job of covering the ground than a HT,

Hmm.. what I said about FS only applies if it's rough. If it's not, then the lower weight would be a benefit of HT.

Pedal bob/power loss is IMO quite minimal these days. The speed differential between my two bikes on a typical xc ride (some ascending/descending) is fairly minimal between my Covert and Bfe and IMO entirely due to weight differential as Covert is set up quite heavy.

@Normal - definitely get bashed around more on the HT which is actually deliberate as it's more fun on my typical trails. On an all day ride with lots of descending I would definitely be quicker on the FS due to less fatigue as well as more outright speed downhill.

What about maintaining speed through less fatigue?

I'd be interested to hear what part people feel that has to play

I did a couple of 5 hour rides on my Five earlier this year; just stringing together landrover tracks over shooting estates with logging roads, windfarm access roads etc. So, nothing really technical, just a few rough tracks with loose rocks etc.

I ended both rides feeling tired but happy. In both cases I then went back a week later with my Solaris. The logic being that there was nothing too technical, but lots of climbing and even a few road sections. So, it should be easier and more fun on the hardtail. In fact, in both cases, I got so fed up with the jarring on the landrover tracks that I cut the rides short after around 3 hours. I was marginally faster over those 3 hours, but mainly because I wasn't enjoying the ride and just wanted to get it over with.

Not sure that really answers your question, but for a ride of more than a few hours (even if it's just bimbling along on simple tracks) I tend to go for the full-suss these days.

When a rigid bike hits a bump some of your forward energy is used to lift the bike and rider up not forward. With suspension its only the unsprung weight that that gets lifted up. Same reason why tubless tyres with lower pressure that can deform over rough surfaces roll quicker.
A previous poster noticed his fast mate was quicker than him on a F/R but not as much with suspension. A skillfull rider will absorb a lot of bumps with his body, rather than loose the the forward motion energy.

Anecdotaly I reckon my rigid bike gets away with a 2t bigger chainring than my HT, and about 6t over the (32lb #enduro) FS.

So assuming the rigid bike is 100%, the HT is about 95% and the big FS about 80%. IME an efficient ~100mm FS would be quickest of the lot up any kind of long rough climb, the added traction and unstopable-ness adding more speed and energy saving in not having to constantly lose speed and re-accelerate over rocks/steps/ruts makes up for the pedaling losses.

120mm proabbaly doesn't climb much worse (less eficient, even more traction), probably past the peak but no worse than a hardtail, just different, but....

150mm+ bikes tend to be designed to be great at being shock absorbtion first, and just enough comprimise to allow them to pedal up to the top. Similarly some 120mm bikes are aimed at being technical 'XC 'bikes so are close tot heir 100mm cousins, and others as short travel 'enduro' so only pedal marginaly better than their 150mm+ siblings.

Hmm.. what I said about FS only applies if it's rough. If it's not, then the lower weight would be a benefit of HT.

Isn't that at odds with my argument you refuted about riding on the road? If you're losing negligle power (in your words) surely there's negligible difference? The shock gets hotter on a really rough climb, which again is completely at odds with your 'if the shock doesn't get hot you're not wasting power' argument.

Having spent years riding FS and gone back to hardtail, you can't argue that if you get out of the saddle for a sprint up a climb, irrespective of rough or smooth, a hardtail feels far more responsive. Not having a power meter on my bike I can't quantify efforts, but thinking >500w. If you don't ever climb like that (and plenty don't) then you're likely losing what is the single biggest area where a hardtail excels. I'd seriously consider going back to a 29er FS if I could get one without too much of a weight penalty, but to say that x or y is faster just isn't true.

Isn't that at odds with my argument you refuted about riding on the road?

Well no because in your scenario the weights were equal. In real life a FS will be heavier.

You are right about the sprinting of course. Feels much faster, but is it?

Also, there's FS and FS. My XC racer only has 63mm travel, you barely notice it. My results speak for themselves 😉

The shock gets hotter on a really rough climb,

Wow, that surprises me.. Still.. The question is, is the energy lost made up for by the other gains?

Thanks for the comments regarding my fatigue post chaps.

2 days in a row that I'm on the same page as you RP, should I be nervous 😉

It is indeed the 'link up' sections where I find the fatigue kicks in. Those rough road / landrover tracks type of thing. Unfortunately where I ride (often dictated to by time/opportunity) the fun singletrack is linked by either road sections or towpath or cross country tracks already mentioned.

I don't want to drag this in to a wheel size thing or a what bike for me thing but I do think I need to persist more with FS. I saw a lovely looking Epic for sale yesterday on clearance. The thing is I'm not excited by the prospect of owning a 100mm xc bike. I'm drawn to the glamour of the longer travel stuff I see being ridden on YouTube / Vimeo vids in midweek mini movies! After years working in marketing I should know better!

LOL .... whoever said "In short, hardtails are shite.

#science " obviously can't ride for toffee

Full sus riders who eschew hard tails are shite riders coz they don't have the proper riding skills to get the max out of the bike

We know who they are. Typically male, carrying a few too many pounds, more money than sense thinking that buying the most expensive kit makes them a better rider and they spend more time pimping their bikes in the car park than riding on the trails

.....recognise yourself?

@markrh, the trails at Cannock were specifically designed to suit hardtails hence the reason you find your faster. in fairness we don't like to talk about it too much for fear of impacting on local bike sales.

I'm drawn to the glamour of the longer travel stuff I see being ridden on YouTube / Vimeo vids in midweek mini movies!

I own an XC race FS and a 7" travel Patriot. After owning the latter for years it is now finally dialled in, and let me tell you - it's [b]not[/b] just marketing.

It's an absolute blast on my local trails. I can't get over how much fun it is. Ok so I'm not doing 30ft gaps, but I'm going way faster and getting more air than I have in my life. Brilliant.

So good that I am going to use it as my everyday FS and I'm changing the 5 for.. a fully rigid 29er 🙂

Everyone talks about pedal bob as a disadvantage on FS, but what about all the energy absorbed effortlessly by the shock when riding over rough ground. On a HT that's energy your legs are having to absorb which leads to fatigue too. So really depends on the ratio of rough v smooth trails as to which would be fastest. If you take somewhere "flat" like Thetford you might think a HT would be fastest, but for me at least I'm quicker on FS because of the endless rolling bumps.

I suspect for most average riders on an average trail a modern short travel FS would be fastest overall in most cases. Especially on a longer ride.

Thetford is a strange case. When I did a 100km there I took a longer travel fs and set it up with really slow rebound, so I could stay sitting down and pedalling through the bumps. The suspension compressed in the dips and extended nice and controlled on the ups so I didn't get chucked into the air. Worked nicely too.

2 days in a row that I'm on the same page as you RP, should I be nervous

You certainly should 🙂

I know you don't want a what bike thread and that we've already done it on the other thread, but I wonder if this is where the "nu-skool" 29ers will shine. Bigger wheels for efficiency over rough ground, geometry for the fun bits and just enough suspension to get by.

[*]The shock gets hotter on a really rough climb,[/*]

Wow, that surprises me.. Still.. The question is, is the energy lost made up for by the other gains?

Bumps don't generate energy. They just lie there looking all mean and moody. If you are climbing then the only source of energy is you. If some of that energy is being used to heat the shock then it isn't being used to propel you forwards. Of course, without the suspension it may have been "lost" somewhere else.

So what's the difference between a warm shock and the job a shock is meant to do in normal operation - i.e absorb energy?

I still don't get this shock getting hot thing.

What I meant was that a warm shock would indicate that a significant amount of energy is being lost, since that's what we are talking about. However, njee's shock gets warm so maybe it is!

But a hot shock does not mean that pedalling energy is being absorbed.

Indirectly it does - the heat in the shock is being subtracted from your kinetic energy, which in turn comes from pedalling.

So what's the difference between a warm shock and the job a shock is meant to do in normal operation - i.e absorb energy?

Nothing - it's absorbing energy that's come from your legs, and is turning it into waste heat.

I still see it as a complete red herring.
If you were riding along a completely flat road, and your shock got hot, then I would see the theory as having merit, but a shock functioning over rough ground isn't analogous. It could well be reducing the amount of energy needed to overcome obstacles.

If you were riding along a completely flat road, and your shock got hot, then I would see the theory as having merit,

What do you think my theory is?

I'm saying you DON'T lose much energy from suspension.

roverpig - Member

You certainly should

I know you don't want a what bike thread and that we've already done it on the other thread, but I wonder if this is where the "nu-skool" 29ers will shine. Bigger wheels for efficiency over rough ground, geometry for the fun bits and just enough suspension to get by

I've been compared to a lot worse so don't worry! Anyway you seem like a decent enough chap.

True enough. The chaps at my LBS recommended a Camber Evo to suit my needs. The only thing that put me off (other than the purchase of my Solaris just a few months ago) was the fact that the 26er FS I have and rarely 'go to' is indeed a Camber 😳

That's the joy of the internet. None of use are who we appear to be online 🙂

What is it that you don't like about your 26" Camber?

What do you think my theory is?

I'm saying you DON'T lose much energy from suspension.

I just think that shock temp is irrelevant when it comes to judging this.

But it probably had something to do with JCL agreeing with you - I like to take an opposing view to anything he says 😀

I'm saying you DON'T lose much energy from suspension.

Exactly. You lose some energy in unwanted pedal bob (not much of an issue these days anyway with efficient geometry, platform shocks, lockouts etc) and you gain some in not having to use your legs to absorb bumps in the trail. There's also a small weight penalty of course in like-for-like bikes.

Personally I'm quite happy to carry 6" of plush and reasonably efficient rear travel around most trails. Might not be the fastest solution on most UK trails, but easy on the old bones and still a lot of fun - especially on the downhills.

I just think that shock temp is irrelevant when it comes to judging this.

Think you are getting hung up on this point for no reason. All he said was that your shock doesn't get hot simply from pedal bob, hence 'probably' not a lot of wasted power. But yes, it is irrelevant as even a loss of say 10 or 20 watts might be significant on a long ride. But then of course there are benefits of FS too.

@ RP.
I couldn't say I don't like it as such. I just preferred the 29er HT's to ride. Firstly a Carve Expert and more recently the Solaris.

That pushes it towards a wheel size thing but can't help but feel that is only part of the equation. I like the propedal, for example, for smoother sections but then find it isn't active enough when hitting a rutted / jarring section.

It does have a lever for 'on the fly' adjustment but sometimes you just want to ride, others the terrain might change frequently (ie parts of a towpath) plus I find with gloves on I once moved the rebound dial at the same time which was my fault but annoying nonetheless.

On the plus side, the mods I've made 50mm stem instead of stock 90mm and slightly wider bars have been great. The stock tyre set up is excellent too.

Given that "work" is being done within the shock then it is likely to heat up but since the shock has a small volume relative to its surface area then this heat will dissipate quite quickly.

I think you'd need to look at a bike through a thermal imaging camera shortly after it's been ridden down something like a World Cup DH course to see anything significant change.

I don't know what people are talking about regarding XC racers locking out rear suspension. Sure they usually run a remote lock-out but Niño wasn't using it much in those last two World Cups he won. You could clearly see the suspension was active on the climbs.

If those guys can win on FS on those limited tech courses then the argument for a hardtail is over. Unless you ride around on bridal ways but that's hardly mountain biking is it.

Hardtails, halfway to cyclocross. Shite.

Has anyone thrown in the use of SPDs and proper pedalling technique to remove pedal bob? 😉 (obviously not as much help when out of the saddle).

My 29 FS feels less fast/responsive than my 29 fully rigid, or my 26 HT I had before, but I can ride further without acheing and hit technical stuff much faster. I feel a nice flexy (steel) 29 HT would be the ideal inbetween, but I'm liking the comfort of the FS right now.

I'm sure there's no one corect answer here though, each to their own and all that.

molgrips - Member

Any power you would lose would have to end up as heat in the shock.

Eh, no, it mostly gets lost in vertical movement.

Eh, no, it mostly gets lost in vertical movement.

good point. If you had no damping at all, then the vertical movement would be increased and yet the spring wouldn't heat up as a result. So yes it's really a red herring. In practice a shock is not going to get hot from just pedalling a bike up a hill.

Yes. Wheel goes up, gas gets compressed, wheel goes down, gas expands. In theory the energy spent pushing the wheel up comes back when the wheel comes back down again. Except for two things:

1) when the gas is compressed it gets hot. Whilst it does cool back down again some of the heat is lost because that energy is conducted to the atmosphere.

2) The damper oil slows the piston down, taking some energy away and turning it into heat.

Njee's shock probably gets warm due to 1 I think.

In practice a shock is not going to get hot from just pedalling a bike up a hill.

THAT WAS MY ORIGINAL POINT!

@NN

I know what you mean about the simplicity of the HT. It's probably what I like best about the Solaris. I just get on it and ride. I've even set it up 1x10 and the fork is always left open, so there is very little to think about. Unfortunately that just means that I have more time to think about how sore my poor old back is getting 🙁

Maybe what you need to look for is a full suss that you don't have to fiddle with. It may just be marketing guff but I notice that Transition talk about their Gidy Up suspension being designed for people who just want to get on and ride and don't want to mess about with flicking switches. So there you go. Get yourself a Smuggler and let us know how you get on 🙂

😀 sounds like a plan RP!

I love my Solaris BTW, also 1x10. Although I'm currently over thinking saddles 😉

You don't have to fiddle with suspension once it's set up. It's never been a big issue for me. Set sag, ride. However if you want to fiddle with it you'll get more out of it.

In practice a shock is not going to get hot from just pedalling a bike up a hill.

THAT WAS MY ORIGINAL POINT!

My issue was that you're using this as proof that FS doesn't waste energy. You then backtracked and said you only meant rough ground, where the shock would be working harder and thus more likely to get hot. I see now how you get into so many stupid circular arguments.

Gah.

First, I said that energy loss was negligible. A possible indication of significant energy loss would be a warm shock. I'd never experienced this, but njee has so I may be wrong.

However given the other things pointed out on here about energy wastage fs might still be more efficient on rough stuff for more indirect reasons.

I'm not after a big hit-athon, relax!

People timing themselves and showing themselves faster on a HT. There may be some element of self for-fulling prophecy here. You expect to quicker on a climb, so the extra effort you think you need to 'thrutch' over a rock or whatever propels you faster up the hill anyway.

There are really very places places a FS has a definite advantage, really long extended flat is rocky sections, where you really can't pedal on a HT, is one that springs to mind.

People timing themselves and showing themselves faster on a HT. There may be some element of self for-fulling prophecy here. You expect

Self fulfilling.

Perhaps. My comments are based on a year of hardtail riding following 3 years of Strava data on FS. Including race courses and casual riding. Not as in going out on a brand new bike and sprinting everything and saying "see, its faster". It's far from impartial, but it really isn't as clear as FS = better. We can all post scenarios where one bike excels over t'other. That doesn't change anything. Different riders will go faster on different bikes on the same bit of trail.

This is as retarded as a wheelsize debate.