Viewing 13 posts - 81 through 93 (of 93 total)
  • F1 style Bike Maths
  • nemesis
    Free Member

    And to F1, I don’t think it’s a very good analogy. F1 is actually a much simpler model despite the many tracks, etc. A closer equivalent would be rallying but with bigger jumps, logs rocks, etc

    Come to think of it, that could be pretty thrilling! 🙂

    bennyboy1
    Free Member

    Just to throw it into the mix I was curious so did some Strava segment comparisons in recent weeks – ‘tested’ my new 23 lb 120/100mm carbon full sus 29’er versus the times from my previous 21 lb 120mm carbon 26 HT.

    The segment conditions were pretty much identical even though on different days – a local dry, dusty wooded and slightly rooty 1.5km singletrack section with a gentle rise and fall and 17m altitude difference. Legs were pretty fresh on both days and I managed to give both efforts what felt like 100% gas with no interuptions.

    29’er – 3mins 08 secs – ave speed 29.5km/h

    26 – 3mins 26 secs – ave speed 26.9km/h

    Make of that what you will. 🙂

    nemesis
    Free Member

    If you trust strava to be accurate to any usable degree, you may well be able to prove that a rigid shopper is faster that a top of the range bike 🙂

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    amedias
    Free Member

    Make of that what you will

    full sus is quicker?
    the course favours one bike over the other?
    you were less tired on one day than the other?

    this is the problem with limited sample tests…

    You’d need to do back to back, same day, and multi day, multiple runs, multiple riders etc before you start to get any thing that resembles data rather than anecdote.

    FWIW, my fastest ever times on my local loops have been clocked up on the bike I would least expect to be fastest.

    njee20
    Free Member

    How about we just arrange to get two 2014 Specialized Enduros, in 29er and 26er flavour and attach some gps gear to them before sending them around a short circuit. After the first lap you swap the riders around and then do two more laps with another two riders with a half time swap each?

    As Al alluded to earlier Matt Page did just that with 3 Focus bikes a couple of years ago, complete with power meters.

    amedias
    Free Member

    ^ Njee, and that test was actually really interesting, would be waaaay better done with a lot more runs, and more riders, and on more trails though.

    It’s also still very hard to deal with the variable power aspect of the human though, even with a power meter and good self control, lots more you could do, but where do you stop in tests like this…

    fibre
    Free Member

    I don’t think you could rule out rider input\feedback or normalise things like tyres pressures. The bikes interact with the riders in different ways and would effect the energy input as would what tyres and pressures complement the different wheel sizes.

    This year I thought I’d get a 29er and see for myself the difference.

    My unscientific thoughts…

    I found I was able to lower pressures before feeling roots etc (rolling over easier rather than compressing on the square edge hits sooner?). Use tyres with a lower tread height for lower rolling resistance but with the longer contact patch and lower pressure I found I had the same grip with a less aggressive tread. A change in technique helped the issue of tight corners and accelerating out of them. Accelerating from a stop involved slightly more effort until somewhere between 5-10mph then the larger wheels gained momentum faster and retained more speed with the same effort as the surface got worse.

    Overall I’ve found the 29er quicker as whole (on or off road) and more comfortable and less fatiguing on long rides (rider fatigue\comfort has to effect energy expenditure?, we are the power source after all).

    The bike is great fun, which is the most important bit 🙂
    Just to poop on the science, it just depends on what bike\wheels work for the rider\trail.

    oldnick
    Full Member

    By the time the 26er lost enough weight it would be so fragile and skittish it would be unusable IMHO.

    The doubters always harp on about wheel weight and the increased effort to accelerate them, but in my experience the 29er corners better on the same tyres than the 26er, thus needing less accelerating to be done post corner. Then the lower rolling resistance kicks in and bingo, Kryton buys a new bike.

    JCL
    Free Member

    I suspect 29 is theoretically faster than 26 for most real trails hence why XC racers are all on 29. When the trails get seriously gnarly it seems to swing in favour of the smaller wheels, but not sure for how long? In theory I would have thought 29ers should be killing the DH too, but maybe the practicalities e.g. wheel stiffness have not got there yet. Plus the current crop of DH riders are used to 26 of course.

    As travel increases so does stability which is the main benefit of 29″. The argument is 180mm plus bikes don’t need the added stability of 29″ BB drop. However, there is also lower rolling resistance of 29″ so I think the wheelsize has huge untapped potential. Even bikes like the E29/TF01 are compromised to appease traditional views.

    njee20
    Free Member

    ^ Njee, and that test was actually really interesting, would be waaaay better done with a lot more runs, and more riders, and on more trails though.
    It’s also still very hard to deal with the variable power aspect of the human though, even with a power meter and good self control, lots more you could do, but where do you stop in tests like this…

    Of course, I find it surprising no one’s attempted to do something similar since AFAIK.

    Nobby
    Full Member

    Obviously more than anyone (including world champions factory teams) is willing to spend to achieve.

    End of.

    Nino Schurter would disagree – he had his bike a few years before Scott even had a production 650B.

    Surely the main (if not only) reason manufacturers get involved in racing is to promote their brand and, more importantly, the products they want to sell us?

    Kryton57
    Full Member

    oldnick – Member
    By the time the 26er lost enough weight it would be so fragile and skittish it would be unusable IMHO.

    The doubters always harp on about wheel weight and the increased effort to accelerate them, but in my experience the 29er corners better on the same tyres than the 26er, thus needing less accelerating to be done post corner. Then the lower rolling resistance kicks in and bingo, Kryton buys a new bike.

    Not better. It carrys the momentum of the weight/size. Which on a tight corner could have it under steering thus invoking braking therefore loss of speed. Vis a vis, the rider has to learn to get the best of each wheel size, it’s not a magic answer.

    Oh and I’ve bought a 650b. 🙂

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