OzVMX Forum
Clubroom => Vintage Track => Topic started by: steve234 on May 05, 2009, 10:11:35 am
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Just a query for the dirttracker's, do you run rim locks or are they not necessary?
Cheers,
Steve
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Run 1 cause your going to be in the 8-10psi range and you dont want it spining, get 2-3 tubes and cross them over the rim to soft lock it. leave the valve nut half way up the valve, if you see it going in or acroos then you can deflate and pull the trye backward to realign it before it pulls the valve off the inner tube.
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Hey freaky, what do you mean by get two to three tubes and cross them over?
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i think he means rim tapes.run 2 rim locks if you can.some old speedway bikes used to put self tappers in the rims. locking onto the bead of the tyre.this will eventuly stuff your nice alloy rims
cheers
jim
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I mean cut up a inner tube into an inch wide strip and lay it over the rim At 90 degrees to the bead use one rim lock and 3 strips, sort of like something in each quarter ( just space them out. Easy if you fit tyre first then pull back bead and drag strips though, seat tyre and pump up, then cut the flaps off close to the rim but so you have it against rhe side wall.
Ill try take a picture for you this week.
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No rim locks ......same method as Freaky
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ditto to oldfart and freaky ;)
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i am used to bikes that put out hp.if i used this method my tube would rip out in the fist race.500cc 4t 11:1 comp big cam and runing on methenol, no match for 4 bits of rubber.
cheers
jim
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Try it it with 1 rim lock and 3 strips, i bet you cant if you did it right ;)
Ask Jason crump, but he also uses hair spray on the bead
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:D It works Jim trust me ;) I was told this trick many years ago by the then Australian sidecar champion Bill and/or Keith Sewell. Z1000/900 kawapowa running smoothbores Ivan tighe cams and all the hi zoot mods imaginable drinking methanol and putting out somwhere back then well over the 100hp mark. Kinda makes a single cylinder500cc 4t pale into insignificance. All this driving the biggest muther tyre you've seen in your born natural all held in place by 4x 50mm rubber strips cut from an old inner tube. (maybe he was QLD champ can't remember :-\) the method definately works extremely well right down to 7lbs and 42hp with a new 5.50x18 knobby as that's what I run and never has the tyre crept let alone tried to spin out the valve. I use it for dirt track and mx and everything inbetween and I won't ever go back to rim locks as there is simply no need ;)
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Thanks guys just one question Freakshow,
Do you feed the strip between the tube and rim or over the tube?
i.e. is the intent to lock the tyre at the bead or the tube to the rim.
Cheers,
Steve
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I think i go under the lot, probally dont matter so long as you have as much rubber as you can under the bead and then out over the tyre wall. the rubber strip locks by not being able to roll up under the bead and also holds onto the sidewalls so they cant move by being between them and the rim.
Let me take a photo and you see it prity simple when you see it, doc right i wont go back to stuffing about with 2 rim locks its the hardest part of changin a tyre, and quite frankly the only time i have spun a tyre out was using just 2 rim lock, personally i think you have more chance spinning out a tyre jim by using rim locks than using this method.
I think the tribe has spoken. Go the strips :O)
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guys
you all have different ways.all i can tell you is the hagon tt500 was built by my older brother and raced since 1990 it has 2 rimlocks on the rear wheel and it has never spun a tyre.and it is fast it will out gate most modern bikes speedway or chooky.i have pics to prove that fact.my brother (the fossil)is a very good dirttracker at one stage the english team (early 70s)asked if he would be a reserve rider when a few riders crashed.
using 19in speedway tyres i would use rim locks these tyres are soft.
they are a stock item in the antig speedway/grasstrak parts list in the uk
cheers
jim
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ummm I run Mitas speedway tyres on borrani rims, trust me it works regardless of bike or rider,
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this rubber strip method is new to me but it sounds like you've proved it! it would certainly be good to get rid of those pesky rim locks. i might try it 1 day. cheers wally.
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I run a Dunlop K180 and/or Michy trials for dirttrack..pretty soft tyres ;)
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WALLY
how about you and me look in the pits on sunday and see just how many bike do or dont use rimlocks.there should be about 120 bikes so we shall get a good indication as there will be modern and classic right down to that mss velo
see you sunday
ps stop the rain now pls
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most A graders use 6 self tappers
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not saying it's the method everyone uses Jim just stating an alternative method that works and has some merit. I use it and won't go back to the pesky rimlocks but as always everyone has their own ideals ;)
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Yep i understand freaky-no need for a photo, i will try it
OLDYZMAN
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doc
what ever works is good rimlocks ,self tappers, rubbers,poking the valve stem through the side wall of the tyre,and a new thing called moose tubes dont get flats so i am told
cheers
but will check in pist just to see other peoples methods
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Run 1 cause your going to be in the 8-10psi range and you dont want it spining, get 2-3 tubes and cross them over the rim to soft lock it. leave the valve nut half way up the valve, if you see it going in or acroos then you can deflate and pull the trye backward to realign it before it pulls the valve off the inner tube.
I was running at same pressures ay 8 - 10 and found was getting tyre slip with 2 x rimlocks, then speaking to another whos been Dt for long time and he said he run arounfd 18 psi because the michelins flex to much in the walls, so gave that a try never getting tyre slip now and seems to grip better and more controlable. I thought we should only run at around 10psi in slippery muddy conditions, what pressures are others running and do you get tyre slip running higher pressures ???
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JIM, i think you mean bib-mousse, they arent new michelin had them out for years , we have used them mainly on enduro bikes, only thing is the pressure is fixed so you buy one pressure and thats it, it like a foam donut that replaces the tube, i have one on my YZF front as we speak, im not sure how they would go on flat track , they are for more an upright profile.
Rosco most guys on our dolomite run between 8 -15, depending on if they want grip or slip, i find if im not getting angles or coming in dead, a few more psi and the back end seems to want to flow rather then bog. i think it depends on your style and you bikes turn in and drive out, what ever works is you PSi on the day :D