totty79 Posted March 5, 2016 Report Share Posted March 5, 2016 The mixed experience with tubes is due to rim locks and pressures. Low pressure without a rim lock is highly likely to result in the valve stem being torn of and a flat. Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted March 5, 2016 Report Share Posted March 5, 2016 My observation was in the general, not particularly the current Sherco/Dunlop issue, context of tubeless rims and tyres where the pressure is the same as without a tube thus the tyre gets the same grip (designed to be airtight unlike a conventional tubed setup) on the rim as it would normally so security bolts are not a consideration? Quote Link to comment Share on other sites More sharing options...
totty79 Posted March 5, 2016 Report Share Posted March 5, 2016 I'm not sure I follow your last post. If you run a tube at 4psi without a rim lock on pretty much any tyre or rim make I would expect the valve to be torn off the tube. I can't guarantee this will always happen but I've experienced it and I've spoken to others with the same experience. Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted March 5, 2016 Report Share Posted March 5, 2016 This is in danger of becoming dragged out but, to explain my post. The facts seem to be that some folk successfully use a tube with a tubeless rim and tyre and others don't. We all know that, regardless of security bolts, a tubed tyre on a tube type rim does eventually creep and take the tube with it so we keep an eye on the valve and straighten things up every so many events. As a tubeless tyre gets a really good grip on the rim, once properly blown on, it should not creep, certainly not any faster than a conventional tubed setup with its relatively poor grip on the rim. The puzzle is, leaving aside faulty manufacture which normally is not the problem, why should some tyres happy at 4psi without a tube move so rapidly at 4psi with a tube that the rider does not get a chance to notice it and the valve tears out, but others stay put? Quote Link to comment Share on other sites More sharing options...
cleanorbust Posted March 5, 2016 Report Share Posted March 5, 2016 I can only report on my own experience but this is that I've run tubeless tyres with tubes with no problem whatsoever on a Sherco then a Scorpa for about ten years. This has the advantage that the tyre stays at the pressure I set (no annoying marginal leaks where the tyre seals against the rim). I've straightened up the valve on the rear perhaps twice in ten years of regular use, but it certainly wasn't near to "ripping out". I too had my doubts about the reliability of running tubes in tubeless tyres until my local trials dealer, whose cheap tyre fitting service I took advantage of in a moment of laziness (I'd normally fit my own), advised me to do myself a favour by running tubes. His opinion was that unless my name was Michael Brown (it isn't) I wouldn't notice any difference in tyre performance (I haven't). I normally run 3.5/3.75 psi in the rear. Quote Link to comment Share on other sites More sharing options...
the dabster Posted March 8, 2016 Report Share Posted March 8, 2016 The thing I struggle with is why have tubeless technology (which we know works effectively) and compromise the principle by returning to tubes.. Surely the tyre/wheel manufacturers are compelled to ensure compatibility with current brands. To me its unacceptable when riders are out at events on brand new bikes and they suffer component failure in an area that has established technology that proved good enough to supersede the tubed set up. It is a different argument with older machinery and rims from earlier periods. Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted March 8, 2016 Report Share Posted March 8, 2016 You are right, it is not acceptable, but if a replacement tyre is not forthcoming, for whatever reason, then the tube offered is better than not using the tyre. Most trials riders don't want to get in to extended wrangling over consumer issues. The more common reason was to cure the leaking spoke nipples on earlier rim designs. Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted March 8, 2016 Report Share Posted March 8, 2016 My observation was in the general, not particularly the current Sherco/Dunlop issue, context of tubeless rims and tyres where the pressure is the same as without a tube thus the tyre gets the same grip (designed to be airtight unlike a conventional tubed setup) on the rim as it would normally so security bolts are not a consideration? A tubless tyre with a tube will not get the same grip as one without as you have introduced an extra spring. Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted March 8, 2016 Report Share Posted March 8, 2016 You are no doubt correct but, outwith the Michelin laboratory or unless ridden by a famous Yorkshire rider at the extremities of grip, how much is the extra flexure of 1.5mm of soft rubber really going to affect things for most riders (many of whom seldom seem to check tyre pressure anyway) in comparison with steady deflation due to leaky spokes? Quote Link to comment Share on other sites More sharing options...
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