chewy Posted January 2, 2011 Report Share Posted January 2, 2011 Following the topic on IRC tyres going down; I would like to keep folks posted with my recent experiences, /I have to qualify my observations with a bit of bulls*it I have been a qualified Mechanical engineer with a list of letters I could put after my name for 45 years about the same amount of time I have been riding trials bikes so I do have some idea of the difference between sh*t and pudding. Ok rant on; I bought a new Sherco in October and before using it fitted an IRC rear for the going around here. I have entered and ridden in 3 events since then and pottered in the garden a bit. I would say no more than six hours running time with some of that waiting in queues I am of an age where I don't thrash at anything. I have had to retire from all three events due to rear tyre deflating (but only when in useit will stay up for weeks on the stand in the garage!), I checked all spoke tensions after first outing blew tyre up and put it away. Anyway long story short.end today I got through 12 whole sections after having "unfrozen" the carb before tyre deflated and came off the rim. I have just cleaned and had it all apart refitted and checked and air is p****ng out of several spokes so I had a close look at the rim tape. It was clearly not fitted properly in the first place and of course it has now taken a set so it will need to be replaced. However my main gripe is who calculated/designed the fit of the rim tape and who fitted it; the "seat " for said tape is 26mm wide X 4mm undercut (if you have done this job you will understandthat the tape is supposed to fit into an undercut in the rim. the tape fitted from new (by Sherco) is 32 mm wide by 2.1 ( Iwould venture to say it started out at 1.25 X1/8 inch)so there was no way it could fit properly in the first place. Is it standard practice to allow the customer to fault find? Quote Link to comment Share on other sites More sharing options...
nzralphy Posted January 2, 2011 Report Share Posted January 2, 2011 Yes it is mate. Sadly. Ask for a new wheel. The wheel comes from the wheel supplier and they should cover it. It is also common to have to fettle/finish many of the bikes delivered new to us all. Low production volume bikes is the problem. Quote Link to comment Share on other sites More sharing options...
greg Posted January 2, 2011 Report Share Posted January 2, 2011 I think to blame irc tyres particularly is a bit harsh, leaking through the rim tape is not down to the tyre!!! I have found that a can of the white foam puncture stuff, Fini-lec i think it used to be called cures it .When i bought my new 06 gasser the shop supplied a can ready. You just have to watch it doesnt block the valve. Quote Link to comment Share on other sites More sharing options...
geodet Posted January 2, 2011 Report Share Posted January 2, 2011 I have the same problem. I also bought mine in October and have ridden 3 Trials all ending in a very soft Michelin. Before I venture into treating the spokes with silicon I now suspect that I will have to replace the tape on mine as well. Can anyone tell me where to get a rim tape of the correct size so that I dont waste time that I dont have? Thanks Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted January 2, 2011 Report Share Posted January 2, 2011 I have the same problem. I also bought mine in October and have ridden 3 Trials all ending in a very soft Michelin. Before I venture into treating the spokes with silicon I now suspect that I will have to replace the tape on mine as well. Can anyone tell me where to get a rim tape of the correct size so that I dont waste time that I dont have? Thanks Before you slag off the wheel was it staying up before you ditched the mitch? If so as a qualified engineer you will know that as soon as you mess with something there is a chance that you have initiated the problem, and that to get a tyre on and off the tape can be disturbed. The tapes are supposed to be oversize so they squeeze into the gap. Quote Link to comment Share on other sites More sharing options...
scoobydo Posted January 2, 2011 Report Share Posted January 2, 2011 (edited) The new beta rim solves this problem at a stroke - no tape ! Why can't all the other manufacturer's follow suit and use these latest type rims ? Appreciate this doesn't solve your problem though - previous reply made a good point though - did it leak before ? Good luck hunting the problem down - gotta be one of the most frustrating thing's to happen ! Edited January 2, 2011 by Scoobydo Quote Link to comment Share on other sites More sharing options...
pete_scorpa3 Posted January 2, 2011 Report Share Posted January 2, 2011 ..... as soon as you mess with something there is a chance that you have initiated the problem, and that to get a tyre on and off the tape can be disturbed. The long running problem I have with my Scorpa rim tape was caused by me when I changed a tyre. I just nicked the rim tape with the end of a tyre lever, damned thing has leaked ever since. I really wish that I'd been more careful. I've tried the Sikoflex trick whch slowed the leak down to an acceptable rate, it stays up for about a week, so I live with it. Quote Link to comment Share on other sites More sharing options...
chewy Posted January 2, 2011 Author Report Share Posted January 2, 2011 Just for clarity I am putting this tyre onto my missus's bike and hers on mine to check it, air bubbles coming out of several spokes speak for themselves, implicit in my question was who specifies what should be fitted in order for it to work? and who ensures that the correct part is fitted properly? It certainly shouldn't be me but as I am a doctor and I've had a good look at the problem I could make a better solution with a stanly knife a sheet of rubber and a tube of superglue, when you pay good money you expect at least a reasonable product. Quote Link to comment Share on other sites More sharing options...
copemech Posted January 3, 2011 Report Share Posted January 3, 2011 Chewy, I don't want to seen over critical, but as Dabster stated, thic could be self induced with the tire change. Fact is if you even toutch the rimband when doing a tire, it can be dislodged. Thus the leaky spokes. Changing tires will not help this. Flip side of this is probably the fact that wheels and tires are probably mass assembled to spec and supplied to the bike manufacturer. I am always carring a pocket air pump in the camelback, in the event of picking up a puncture during a trial, and have loaned it many times to "leaky" riders. Seems to me, the newer rim bands with the integrated stem are the way to go on a conventional rim now. I have not fitted one as yet, but my tire holds air for months! Even with that, rimband fitment is closer to art than science. A true skill, as I have had my ass kicked by these many times. Require proper lube as well, and plenty of it! Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted January 3, 2011 Report Share Posted January 3, 2011 The new beta rim solves this problem at a stroke - no tape ! Why can't all the other manufacturer's follow suit and use these latest type rims ? Appreciate this doesn't solve your problem though - previous reply made a good point though - did it leak before ? Good luck hunting the problem down - gotta be one of the most frustrating thing's to happen ! ....because they are not perfect! Unless maintained much more than normal rims then they can have problems. Quote Link to comment Share on other sites More sharing options...
baldilocks Posted January 3, 2011 Report Share Posted January 3, 2011 The new style rims dont have a band but in time I think the spokes will cause greater problems, on my montesas I was forever changing the small spokes, just couldnt stop them snapping. A further problem is the tyre comes off a DiD rim easier for some reason, dont know if this applies to the new Morad rim. My last three bikes have come with the rim band Copey describes and I havent touched any of them and they have been fine. The bikes were an 07 Sherco an 09 Gas Gas and an 2010 Gas Gas, the first two bikes did the SSDT 3 times between them without a problem. The design works if the band is fitted properly in the first place. Quote Link to comment Share on other sites More sharing options...
chewy Posted January 4, 2011 Author Report Share Posted January 4, 2011 The design works if the band is fitted properly in the first place. I think that is the key phrase, since my rant and as the shops are all closed I tried putting a wind or two of PTFE tape under EVERY spoke nipple and took the opportunity to check out the trueness of the rim ; it was 6mmm out of concentricity and 4mmm out axially with as others have noted a big flat at the weld. I have a ring roller and have considered getting a decent rim profile extruded making hubs etc etc. Literally to RE invent the wheel...... progress eh. Quote Link to comment Share on other sites More sharing options...
nzralphy Posted January 4, 2011 Report Share Posted January 4, 2011 It's a new bike. I think a few people a missing a trick here.... Chewy has been changing tyres and bikes (probably hundreds of each) in his time in and around trials. Yet he still gets a new bike with a wheel that doesn't hold air from new! And even if he did remove a tyre to 'take a look' the the wheel/band should be able to handle a bump or two. The design is below par. WARRANTEE time.......... go ask for a new wheel mate, and accept nothing less! Ralphy Quote Link to comment Share on other sites More sharing options...
copemech Posted January 5, 2011 Report Share Posted January 5, 2011 It's a new bike. I think a few people a missing a trick here.... Chewy has been changing tyres and bikes (probably hundreds of each) in his time in and around trials. Yet he still gets a new bike with a wheel that doesn't hold air from new! And even if he did remove a tyre to 'take a look' the the wheel/band should be able to handle a bump or two. The design is below par. WARRANTEE time.......... go ask for a new wheel mate, and accept nothing less! Ralphy Oh yes, that will work!---NOT!!!!!!!! You are not getting a new wheel because of a rimband! I don't care if you threaten to jump up and down and pee your pants! You will only leave with wet shoes! Quote Link to comment Share on other sites More sharing options...
copemech Posted January 5, 2011 Report Share Posted January 5, 2011 The design works if the band is fitted properly in the first place. progress eh. In reality, I think Chewy has come to love to hate these things as much as I do!!! In many respects, they are a total pain in the ass! Even off new! The design is soo jikky in the first place that it requires almost ultimate precise fitment to work, only test is holding air(which his did untill put into application), and even then may have problems. Even though this design seems industry standard for years now, and in a sense the price we pay for light weight and tubeless radial tires with good grip, I admit the fact the tolerances seem shoddy to me in this world of fine euro craftsmanship. Possibly we need to outsource this as well. Duh! For the same reasons, getting a new bike is a blessing and a curse. Takes me a week or more in the shed at night to go over everything, including rebuilding of wheels by packing each and every spoke nipple with silecon grease for corrosion prevention and truing wheels to whatever acceptable level I can attain. Most would never do it, yet a bit of prep here can save a lot of agony down the like if you plan upon keeping a bike. The corrosion issues in rims are a bigger issue as time goes on, and it only gets worse. Not having run the DID style rims, It does seem to be becoming more popular with the brands in a different manufacturer now. Time will tell. You gotta run what you brung! And make it work! Quote Link to comment Share on other sites More sharing options...
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