Ghetto and wheels – WTF?

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  • Ghetto and wheels – WTF?
  • Am I missing soomething?

    Premier Icon sockpuppet
    Subscriber

    this link is useful

    my first set took a while

    did racing ralphs onto 5.1 rims yesterday in about 25 minutes from taking the teeny tiny tubes out of the boxes (well 20″ looks tiny…)

    went up right away with a track pump. for once 😉

    nickegg
    Member

    Followed Allen Kellys instructions to the letter and had no probs at all.

    Could not have been simpler. Makes £50 ‘proper’ tubeless kits completely redundant and an absolute rip-off. I can’t see any advantage to using them over two BMX tubes and some sealant.

    …..and can be done with just insulation tape, packing tape and old valves too!

    cynic-al
    Member

    How well does it work when swapping tyres?

    nickegg
    Member

    No idea as i was using a new trye anyway. Apprantly there’s no need to re-new when swapping tyres.

    I will find out one day.

    franki
    Member

    Jeez, what a ball ache.
    Never had any probs with tyres & tubes myself. 😉

    nickegg
    Member

    A ball ache how???

    Unless you like getting thorn punctures that is 😉

    No more patches and tubes too.

    franki
    Member

    Hardly ever have punctures on my mtb. Probably one every 6 months or fewer.
    Nearly always from thorns mindyou…
    If it became an issue I’d think about trying something else though…

    Easily the best upgrade i’ve ever made to a bike. £20 to turn a fast XC bike into a faster XC bike which punctures less and rails corners and descents like a dream?

    Yes please…

    Why would a tubeless tyre rail corners and descend (sp) better than a tubed tyre??

    richc
    Member

    you can run lower pressures and you won’t get pinch flats.

    If you haven’t tried tubeless + sealant you really are missing out

    Lower pressures on corners means they will be wallowing doesnt it? I prefer a balance of ‘give’ in the tyre and it being hard enough to maintain its shape rather than riding a jelly.

    I wont get pinch flats but will end up with dinged rims. Hmmm, that sound encouraging.

    Surely they drag like a bitch as well?

    cynic-al
    Member

    you won’t get pinch flats.

    Sorry, that is incorrect.

    Premier Icon phiiiiil
    Subscriber

    I’ve changed tyres in a wet field just before a bike race before; I was all ready for it to not work and put tubes back in but they went on fine using the same rim strip and just a track pump.

    Last week I accidentally rode over a barbed wire fence that had been trodden into the ground; there are three puncture marks in the rear tyre and one in the front but other than a little top-up before the next ride I’ve not had to do anything at all. I like that… 🙂

    sharkbait
    Member

    Lower pressures on corners means they will be wallowing doesnt it? I prefer a balance of ‘give’ in the tyre and it being hard enough to maintain its shape rather than riding a jelly.

    I wont get pinch flats but will end up with dinged rims. Hmmm, that sound encouraging.

    Surely they drag like a bitch as well?

    No, No and No.

    If you don’t know anything about a subject it might be best not to comment.
    😕

    richc
    Member

    cynic-al – Member

    you won’t get pinch flats.

    Sorry, that is incorrect.

    How so? how can you pinch flat something that isn’t there?

    I think Sheldon Brown showed how most drag, or rolling resistance, is caused by the energy ‘absorbed’* by the tyre deforming when it rolls beneath the wheel.

    You can reduce how much energy is absorbed by either pumping the tyre up harder, so it deforms less, or by reducing the amount of rubber being deformed, say, by removing the inner tube.

    I can’t prove or disprove this, but it works for me. I’m running under 30psi instead of over 35psi, yet the tyres roll just as fast (and feel faster over rough ground).

    The tyres don’t wallow in corners, in fact, the bike seems to spring out of the corners faster than it went in.

    And I’ve bashed my rims a few times now with no obvious dings, certainly no more than when i was running tubes.

    *Or something, you know what i mean

    Sharkbait, thats why i am asking, so that i can know something about the subject. No No & No doesnt really answer anything does it.

    Please explain oh wise one

    higgo
    Member

    I gave up on the great tubeless experiment about three years ago. I was using Eclipse kits and putting a new tyre on. It was a direct replacement for the tyre I’d taken off which had worked fine but was worn out. I just could not get it to inflate and I lost it – the whole f***ing lot ended up in the field behind my house.

    But for all the hassle one thing is sure – tubeless makes a significant improvement to the ride.

    Time is, so they say, a great healer and I’ve had two BMX tubes and a bottle of wheel milk sat in the cupboard for a few weeks now. One day soon I’m going to give it another go. Because it’s worth it.

    You can reduce how much energy is absorbed by either pumping the tyre up harder, so it deforms less, or by reducing the amount of rubber being deformed, say, by removing the inner tube.

    Is he not reffering to the contact area being deformed rather than whats inside the contact area?

    At least i can try to understand your answer rather than being mocked

    And I’ve bashed my rims a few times now with no obvious dings, certainly no more than when i was running tubes.

    I have dings in my rims when running tubed. Surely i will get more if i run lower pressures on tubeless?

    Premier Icon theotherjonv
    Subscriber

    in fact, within reason if tyres deform as they pass over obstacles they have reduced rolling resistance. A very hard (high pressure) tyre has to climb over every lump and bump, and in doing so so raises the whole of the bike and rider by the same extent which takes energy (ignore suspension action which we’ll assume is pretty well the same for hard vs soft tyres)

    So yes, higher pressure usually reduces rolling resistance on a flat surface (like road) but off road is a hindrance.

    And to the earlier posts, we’re talking about running 30psi here, not a wallowy 10psi.

    The tyres don’t wallow in corners, in fact, the bike seems to spring out of the corners faster than it went in.

    I thought the benefit (One of) is that you get lots of tracktion because the lower pressure allows the tyre to deform to the trail more. Surely this deformation causes an amount of ‘wallowing’ in the corners over and above a higher pressured tubed tyre? Maybe their stronger sidewalls make up for this? Surely a tyre that is putting more surface area onto the trail due to its lower pressure is inherently going to drag more than a tubed tyre at higher pressure?

    I see what you are saying theotherjonv but surely we are talking minute amounts of benefit on obstacles balanced out with much higher amounts of flat on any given trail?

    Premier Icon theotherjonv
    Subscriber

    no, we’re talking obstacles that seem minor compared to our size but compared to the size of wheels, etc. are significant. Unless your rides contain lots of genuinely flat (ie tarmac) even the flat fireroads are covered with stones, pebbles, roots, etc. where the deformation of the tyre is beneficial.

    cynic-al
    Member

    cynic-al – Member

    you won’t get pinch flats.

    Sorry, that is incorrect.

    How so? how can you pinch flat something that isn’t there?

    Indeed – you cannot pinch the tube, you just rip the tyre instead.

    Pressures:

    Weirdly, lower pressures are faster, to an extent. There was a great thread about this on here while back. To summarise: With a hard tyre, you climb and fall with each nobble and pertuberance – the climbing uses a surprising amount of momentum/energy. With a softer tyre, it deforms instead of rising, so you use less energy. Applies less with slicker tyres and smoother trails where the footprint/friction is a bigger factor.

    You can go too far with low pressures, leading to wallowing, feeling the rim and even rolling off the rim – it depends on the bead fit and sidewall strength, but you can get lower than using tubes. I happily run at 30psi.

    Fair enough the otherjonv 🙂

    What about the bigger surface contact area. Does that not negate the benefit?

    Wiredchops
    Member

    jonv is right in a sense. Lifting a small amount of rubber over an obstacle is much more energy efficient than lifting a whole bike over it. Hence, tyres, suspension, bent arms, soft seats etc. etc.

    However, when comparing a tubeless tyre at the same pressure as a tubed tyre, those that quote sheldy are right. Dynamically, a tubed system has a lot more mass to shift about over a bump. If you take into account how quickly the tyre is asked to deform, this can result in quite large forces according to old Newty boy. Hence, a tubeless tyre seems smoother simply because there’s less of a tyre to squish. (in technical terms)

    tonto
    Member

    It seems on a subject like this there will be a multitude of differing views, some based on experience, some on cod science reasoning.
    My understanding, after reading many similar threads, is that the lower pressure and thinner effective tyre makes for a grippy yet free rolling wheel.
    Flats seem to be less frequent, but not unheard of and a spare tube is still adviseable as a torn tyre can be more likely to end your ride.
    These benefits are not easy to quantify and balance against the faff of initial instalation, although the majority of ghetto users seem to be happy to continue once they have fitted their first set.
    I have not switched to ghetto yet as the idea of getting messy when swapping tyres does not appeal. When the trails dry out I will give them go.

    Re: deformation. Where the deformation occurs doesn’t really matter, what matters is how much energy (your rolling energy) is used to cause the deformation. If there is less rubber to deform, it requires less energy. This effect holds true no matter how flat or bumpy the trail is, as your tyre still deforms on a flat trail (it bulges out at the side under your weight).

    Re: Traction vs Wallowing. The extra traction allows me to push against the tyre more as i trust it to grip better. Although it maybe does compress more, like a suspension fork it gives me that energy back when it rebounds. Infact, another advantage of removing the tubes is that the tyre can compress and rebound quicker, giving you that extra pop.

    Re: Extra contact area. i think the effect of the extra contact area is far less than that of the tyre deforming (see above).

    Re: me typing like some sort of engineery type w@nker. I’m at work, in an engineering office. it rubs off unfortunately 😳

    Edit: and it took me so long to type that about three people have already said the same thing, ah well.

    Premier Icon theotherjonv
    Subscriber

    In a word no.

    In several other words, friction is minor and even if contact patch is 30% higher, 30% more of not a lot is not a lot.

    Whereas raising potentially bike plus rider at say 80/85kg, even if it’s just by a few mm over each obstacle hundreds of times each ride soon adds up.

    Why do you think slicks vs knobbly are so much faster? Or knobblies with a ‘continuous’ centre tread – even the action of rising up and over each knob makes a difference

    Wiredchops
    Member

    To be pedantic, statically, a tubed and tubeless system would have pretty much the same contact area. It’s only when you start moving the system that things get different.

    Premier Icon theotherjonv
    Subscriber

    I’m making the point that within reason lower pressure is faster rolling, not slower, over rough’ trails, even if the roughness appears minor. I’m not even considering the effect of more rubber, others are far more able at arguing that point.

    My effect is noticeable whether you have tubes or not. I’m prepared to accept the effect is enhanced by having less rubber to squish. The risk of low pressure with tubes is pinch flats, ergo the benefit of tubeless for me is:

    1. I can run lower pressures for lower rolling resistance, better grip, and not risk pinch flats as a result of having lower pressure

    2. Reduced risk of ‘normal’ punctures (thorns / flint shards usually for me)

    richc
    Member

    Indeed – you cannot pinch the tube, you just rip the tyre instead.

    In my (limited) experience if you have got to the point of ripping a tyre, if would be just as knackered with a tube in it, as you end up with the black bubble of doom then an almighty bang.

    Actually in that case you are better off again with tubeless, as you just get sprayed with white shit, whereas the tube can further tear the sidewall making a bodge impossible and leaving you with no other option but to walk.

    ive got some tyres with many close knobs and they are very fast which supports the theory

    hora
    Member

    Anyone paying 70quid for the latest batch of Stans is wasting their money, I mean if you cant try a tenner method, then fools money etc.

    nickegg
    Member

    I’m loving the armchair science…. 😉

    To be fair, my motivation was simply to overcome puncture problems with the Nevegals that came with my bike. The rest is fringe benefits.

    cxi
    Member

    Does it matter what size 20″ tube you use?

    Either of these any good?

    http://www.bonthronebikes.co.uk/109-473887
    or
    http://www.bonthronebikes.co.uk/109-473888

    richc
    Member

    just get one with a removable core, and a screw thread with lock nut and it will be fine

    Much more informative guys. Thanks

Viewing 45 posts - 1 through 45 (of 76 total)

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