Opinions on a good MTB please

Discussion in 'Australia and New Zealand' started by Brenton Spear, Nov 16, 2003.

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  1. Jose Rizal

    Jose Rizal Guest

    hippy:

    > "Jose Rizal" <[email protected]_._> wrote in message news:[email protected]...
    > > > One of these would be fine for roads and your typical council bike paths. If you wanted to do
    > > > more bouncing around on off-road terrain, then perhaps a mountain bike with 26" wheels is more
    > > > appropriate?
    > >
    > > Cyclocross events show that 700c wheels can be used just as well
    > offroad
    > > as 26". 29" wheels are also now legal in MTB events (at least in
    > USA).
    >
    > "Just as well"? If that's the case then why do I only see 700C wheels in CX events?

    Cyclocross involves offroad cycling, therefore despite your question, your suggestion that 26"
    wheels are more appropriate for offroad events isn't valid.

    > Why don't the XC racers, the DH racers or for that matter most of the mtb riding population
    > use 700C?

    MTB events are regulated, with wheel sizes being specified. It was only recently that 29" wheels
    became acceptable to UCI for offroad racing
    (http://www.dirtragmag.com/features/news/index.php?ID=121). This indicates recognition of many
    riders' opinions that larger wheel sizes are as effective (or more so) as smaller ones, and
    therefore should be allowed in official events.

    DH is different from what's commonly referred to as "offroad". In fact, I personally think DH is
    not cycling as such, but rather an unpowered descent, requiring minimal pedalling. Why these
    events don't use larger wheels might be due to the severe loading involved, or the rules of the
    game, or both.

    > I don't disagree with the fact that they can be used, but I don't think they are _as good_ as the
    > smaller/wider wheels.

    Why not? Don't knock it till you've tried it. Gary Fisher put a persuasive case to the UCI and won.
     


  2. Tim Jones

    Tim Jones Guest

    "Jose Rizal" <[email protected]_._> wrote in message news:[email protected]ewsread1.news.atl.earthlink.net...
    > hippy:
    >
    > > "Jose Rizal" <[email protected]_._> wrote in message
    > > news:[email protected]...
    > > > > One of these would be fine for roads and your typical council bike paths. If you wanted to
    > > > > do more bouncing around on off-road terrain, then perhaps a mountain bike with 26" wheels is
    > > > > more appropriate?
    > > >
    > > > Cyclocross events show that 700c wheels can be used just as well
    > > offroad
    > > > as 26". 29" wheels are also now legal in MTB events (at least in
    > > USA).
    > >
    > > "Just as well"? If that's the case then why do I only see 700C wheels in CX events?
    >
    > Cyclocross involves offroad cycling, therefore despite your question, your suggestion that 26"
    > wheels are more appropriate for offroad events isn't valid.
    >
    > > Why don't the XC racers, the DH racers or for that matter most of the mtb riding population
    > > use 700C?
    >
    > MTB events are regulated, with wheel sizes being specified. It was only recently that 29" wheels
    > became acceptable to UCI for offroad racing
    > (http://www.dirtragmag.com/features/news/index.php?ID=121). This indicates recognition of many
    > riders' opinions that larger wheel sizes are as effective (or more so) as smaller ones, and
    > therefore should be allowed in official events.
    >

    My wheels on the MTB come out to the same size roughly as the road tyres anyway - they inflate to
    about 1/2" bigger than a regular road tyre making the riding circumference the same size.

    Cyclocross don't (from memory) use a real MTB tyre do they?

    I would think that moving to a larger wheel would have the following disadvantages (all other things
    being equal):

    1. Weaker
    2. Needing a longer bike - not as easy to handle round tight corners
    3. Slightly more weight
    4. Slightly less torque

    Having said that, I've never actually tried it as you said ;-)

    > DH is different from what's commonly referred to as "offroad". In fact, I personally think DH is
    > not cycling as such, but rather an unpowered descent, requiring minimal pedalling. Why these
    > events don't use larger wheels might be due to the severe loading involved, or the rules of the
    > game, or both.
    >

    I would think mainly the stresses involved, and you'd be surprised at the power some of these
    guys can do.

    I remember hearing an interview with one of the national level guys, and the institute of sport
    tested him for power for a lark - he came in above many of the elite road racers!

    > > I don't disagree with the fact that they can be used, but I don't think they are _as good_ as
    > > the smaller/wider wheels.
    >
    > Why not? Don't knock it till you've tried it. Gary Fisher put a persuasive case to the UCI
    > and won.
    >

    I would love to try it (and a bunch of other cycling stuff) - unfortunately I have to make do due
    to time and money with the equipment I have - and that the stuff I have does me fine for my solo
    jaunts ;-)

    If I was a serious racer (or even a racer full stop!) I would look into it a lot more.

    Tim

    Tim
     
  3. Hippy

    Hippy Guest

    "Jose Rizal" <[email protected]_._> wrote in message news:[email protected]...
    > > > Cyclocross events show that 700c wheels can be used just as well
    > > offroad as 26".
    > >
    > > "Just as well"? If that's the case then why do I only see 700C wheels in CX events?
    >
    > Cyclocross involves offroad cycling, therefore despite your question, your suggestion that 26"
    > wheels are more appropriate for offroad
    events
    > isn't valid.

    Well, given that the rules say wheels must be no bigger than 26 inches (except for the new 29" rule)
    I'd reckon that 26" would be the way to go - unless of course you had some perverse desire to be
    disqualified from every race you enter.

    I've ridden my old, 27" road bike off-road, but I'd much rather do it on my 26" mtb. How do we know
    which is the best size to take offroad? I'd love to hear some justifications for different size
    wheels.. until then, I'll stick with 26" and the wide varierty of tyre choices, ability to swap
    spokes, rims, tyres and tubes with other riders easily, etc.

    > It was only recently that 29" wheels became acceptable to UCI for offroad racing. This indicates
    > recognition of many riders' opinions
    that
    > larger wheel sizes are as effective (or more so) as smaller ones, and therefore should be allowed
    > in official events.

    So why weren't 700C wheels given a go along with 29"? Or were they?

    > DH is different from what's commonly referred to as "offroad".

    Seems pretty offroad to me :)

    > I personally think DH is not cycling as such, but rather an unpowered descent, requiring minimal
    > pedalling.

    You didn't see the Nationals on SBS last weekend then? Muddy as a very muddy thing.. lots of
    pedalling going on. Not that I'm all that impressed with DH. It always seems to be guys throwing
    themselves down mountains, but if 29" wheels are supposed to reduce loading on the wheel's parts,
    you'd think DH racers would be onto them in a shot?

    What's the amount of pedalling in an event got to do with wheel size anyway?

    > > I don't disagree with the fact that they can be used, but I don't think they are _as good_ as
    > > the smaller/wider wheels.
    >
    > Why not? Don't knock it till you've tried it. Gary Fisher put a persuasive case to the UCI
    > and won.

    Have you tried it? It would be unfair of me to try and ride a bike with my road-going 700C wheels
    and compare it to my mtb with 26" wheels. Are any companies making 700C wheels that take wide mtb
    tyres? No? Well there's another reason not to use 700C wheels on an mtb.

    hippy.. stickin' with 26 (for now..)
     
  4. Jose Rizal

    Jose Rizal Guest

    Tim Jones:

    > My wheels on the MTB come out to the same size roughly as the road tyres anyway - they inflate to
    > about 1/2" bigger than a regular road tyre making the riding circumference the same size.

    You need to measure that again. Having the same circumference means having the same diameter, and
    you'd have to be riding balloons if your MTB tyres inflate to the same diameter as your road tyres.

    > Cyclocross don't (from memory) use a real MTB tyre do they?

    Most use wider tyres than typical road tyres, in the high 30s width.

    > I would think that moving to a larger wheel would have the following disadvantages (all other
    > things being equal):

    > 1. Weaker

    How?

    > 3. Slightly more weight

    It depends on the rims and hubs used.

    > 4. Slightly less torque

    What torque are you referring to?
     
  5. Jose Rizal

    Jose Rizal Guest

    hippy:

    > "Jose Rizal" <[email protected]_._> wrote in message

    > > Cyclocross involves offroad cycling, therefore despite your question, your suggestion that 26"
    > > wheels are more appropriate for offroad
    > events
    > > isn't valid.
    >
    > Well, given that the rules say wheels must be no bigger than 26 inches (except for the new 29"
    > rule) I'd reckon that 26" would be the way to go - unless of course you had some perverse desire
    > to be disqualified from every race you enter.

    That's if you're going to race in official events. That is beside the point; the point is that you
    suggested 26" wheels are more appropriate for offroad than larger wheels, and it's not so.

    > I've ridden my old, 27" road bike off-road, but I'd much rather do it on my 26" mtb.

    We're discussing wheel sizes, not bicycle variations. If you took your road frame and put a
    straight handlebar, a typical MTB drivetrain, a wider saddle, suspension forks, wider tyres of
    38-40mm and compared that to your MTB, then you might be able to better evaluate the wheels'
    diameter's effect on ride.

    > How do we know which is the best size to take offroad? I'd love to hear some justifications for
    > different size wheels.. until then, I'll stick with 26" and the wide varierty of tyre choices,
    > ability to swap spokes, rims, tyres and tubes with other riders easily, etc.

    How often do you swap spokes, rims, and tyres with other riders? Except for tyre choice, these are
    ease of maintenance, not operability issues. These do not argue against the effectiveness of larger
    diameter wheels used offroad.

    > > It was only recently that 29" wheels became acceptable to UCI for offroad racing. This indicates
    > > recognition of many riders' opinions
    > that
    > > larger wheel sizes are as effective (or more so) as smaller ones, and therefore should be
    > > allowed in official events.
    >
    > So why weren't 700C wheels given a go along with 29"? Or were they?

    No one argued for 700c. The point is that the 26" wheel is not the ideal in offroad cycling.

    > > I personally think DH is not cycling as such, but rather an unpowered descent, requiring minimal
    > > pedalling.
    >
    > You didn't see the Nationals on SBS last weekend then? Muddy as a very muddy thing.. lots of
    > pedalling going on. Not that I'm all that impressed with DH.

    Most DH rigs these days resemble motorcycles without engines. These rely on gravity for most of
    their speed and travel, with the pedals required seemingly only to make minor adjustments to the
    rider's position towards the best downhill path.

    > It always seems to be guys throwing themselves down mountains, but if 29" wheels are supposed to
    > reduce loading on the wheel's parts, you'd think DH racers would be onto them in a shot?

    Who said that 29" wheels are supposed to reduce loading on the wheel's parts?

    > What's the amount of pedalling in an event got to do with wheel size anyway?

    Nothing, and no one made any such connection. The statement I made was of my view of DH as not
    truly cycling because, among other things, it involves minimal pedalling. Isn't this the core point
    of cycling?

    > > > I don't disagree with the fact that they can be used, but I don't think they are _as good_ as
    > > > the smaller/wider wheels.
    > >
    > > Why not? Don't knock it till you've tried it. Gary Fisher put a persuasive case to the UCI
    > > and won.
    >
    > Have you tried it?

    Yes. It's a different experience, but neither superior nor inferior, in my view.

    > It would be unfair of me to try and ride a bike with my road-going 700C wheels and compare it to
    > my mtb with 26" wheels.

    True.

    > Are any companies making 700C wheels that take wide mtb tyres?

    Why are you fixated on wide MTB tyres? How much riding will the OP (and most recreational riders,
    for that matter) do which will require wider than 40mm tyres? Tyre pressure is more relevant than
    width for most XC courses.

    > No? Well there's another reason not to use 700C wheels on an mtb.

    Since you don't know what wider 700c tyres are like offroad, you're making a leap of faith in
    dismissing it. The 700c wheel's disadvantages in terms of tyre choice is a different issue.
     
  6. Hippy

    Hippy Guest

    "Jose Rizal" <[email protected]_._> wrote in message news:p[email protected]...
    > > I would think that moving to a larger wheel would have the following disadvantages (all other
    > > things being equal):
    >
    > > 1. Weaker
    >
    > How?

    "Even though a 700c wheel is actually slightly heavier than a 26" wheel, the difference in
    "bash-strength" (the ability to survive impacts) is enough to render a 700c wheel damned near
    useless for rutted jeep trails and urban curb-hopping."
    http://www.precisiontandems.com/artbillwheelsize.htm

    > > 3. Slightly more weight
    >
    > It depends on the rims and hubs used.

    Well, it's bigger so if you could assume that the lightest 26" components will be lighter than the
    lightest 700C components. I guess if you were using skinny rimmed 700C (is there any other kind?)
    you would have to compare the weight saving due to skinnier rim with the weight saving with shorter
    spokes. Also the 700C rim is bigger, therefore heavier.

    > > 4. Slightly less torque
    >
    > What torque are you referring to?

    Maybe he means they are harder to spin up to a particular speed? Weight is further out than
    26" wheels.

    hippy
     
  7. Jose Rizal

    Jose Rizal Guest

    hippy:

    > "Jose Rizal" <[email protected]_._> wrote in message news:p[email protected]...
    > > > I would think that moving to a larger wheel would have the following disadvantages (all other
    > > > things being equal):
    > >
    > > > 1. Weaker
    > >
    > > How?
    >
    > "Even though a 700c wheel is actually slightly heavier than a 26" wheel, the difference in
    > "bash-strength" (the ability to survive impacts) is enough to render a 700c wheel damned near
    > useless for rutted jeep trails and urban curb-hopping."
    > http://www.precisiontandems.com/artbillwheelsize.htm

    Read it in context; the guy's writing about a tandem bike (double the load of conventionals) going
    through "rutted jeep trails" and "urban curb-hopping". Furthermore he doesn't explain what the
    failure mechanism is for the 700c rims, and doesn't provide any test results. It's his
    unsubstantiated opinion.

    700c wheels may be slightly weaker in lateral loading, but "tacoing" is only an issue with large
    drops such as in FR and DH courses. Radial strength is determined by the spokes' tension, not the
    rim diameter.

    > > > 4. Slightly less torque
    > >
    > > What torque are you referring to?
    >
    > Maybe he means they are harder to spin up to a particular speed? Weight is further out than
    > 26" wheels.

    This is an age-old exaggeration. It only matters when going from rest to speed, and even then the
    difference is hardly noticeable. While you're moving (which is the majority of the time in cycling),
    changing speed is the only time this will come into play, and the difference in effort between
    accelerating a 700c and a 26" wheel from x rpm to y rpm (where x > 0) is SFA.

    Do the static test: put your road bike on a repair stand and spin the crank by hand from rest to a
    certain speed (re-mount and use your trip computer if you like). Do the same thing with your MTB and
    compare the effort.

    Next: spin the MTB crank by hand to a speed you like, and once you reach a constant speed value,
    accelerate to a higher speed and note the effort. Do the same to your road bike and compare.

    Pretty qualitative testing, but a good indicator of relative differences in effort.
     
  8. gescom

    gescom New Member

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    Alot of touring bikes now use 26" wheels for the extra strength when carrying heavy loads. Its also known to be the world 'standard' size tyre, as in you can easily find replacements or tyres in poorer countries of the world.

    I guess looking at how many unsurfaced roads we have in oz 26" wheels are not such a bad idea.


    I think the main difference in comparing cyclocross to mtb's is a cultural one. Cyclocross is mostly european whereas mtb'ing is mostly american.


    If you look at the euro bike market their models are more multi-purpose. Towns are closer to each other and there is less of a car-oriented society/culture. Add decent reliable transport and you can get by without a car. A good example of what we are missing out on can be seen here http://www.koga.com/uk/index.asp . Looking at their catalogue they only make 4 mtb's.


    Most aussie and american kids would start off with a bmx, a flat-bar small chunky wheel bike so the progression to a mtb is more natural for them.

    By comparison to Koga-Miyata Trek Australia (www.trekbikes.com.au) offers around 28 different mtb's. That's not so good IMO.
     
  9. Jose Rizal wrote:

    > Cyclocross events show that 700c wheels can be used just as well offroad as 26".

    CX riders do not "bounce around" on off-road terrain. They usually unmount and carry the bike over
    the obstacles running. Besides, are you sure they use exaclty the same lightweight 28" rims that
    roadies do?

    --
    Best regards, Rado bladteth Rzeznicki http://www.widzew.net/~bladteth/rower.html
    mailto:[email protected] MCM #252
     
  10. Jose Rizal

    Jose Rizal Guest

    Rado bladteth Rzeznicki:

    > Jose Rizal wrote:
    >
    > > Cyclocross events show that 700c wheels can be used just as well offroad as 26".
    >
    > CX riders do not "bounce around" on off-road terrain. They usually unmount and carry the bike over
    > the obstacles running. Besides, are you sure they use exaclty the same lightweight 28" rims that
    > roadies do?

    Mountain bikers on 26" wheels also carry their bikes over large obstacles, despite any bravado
    stories you may hear, especially in races. If you've ever seen cyclocross events, you'll observe the
    same terrain and riding forms in mountain XC. Any XC terrain that 26" mtbs tackle are also tackled
    in the same way by CXs.

    I didn't state that CXs use lightweight road rims, but the same diameter rims with wider
    cross-sections and corresponding wider tyres. The issue is rim diameter; with the appropriate tyres
    700c-wheeled bikes can be used just as effectively in most offroad conditions as 26". Other things
    not related to functionality affect the practicality of 700c wheels, such as availability of tyres
    when used for general touring in relatively remote areas, the range of tyre tread designs, heavy
    riders and low pressures for comfort, and so forth. The issue of lateral strength is raised when it
    comes to the rear wheel and jumps and dropoffs (if you consider FR and DH, which I haven't
    considered in my statements above). A rear 700c rim's spoke tension spread will be a lot more
    affected by the dish than a 26" rim. That is, both sides of a 700c rim will have a considerably
    larger average difference in spoke tension than those of a 26". This can be addressed by using
    offset rims, however.
     
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