Tyre liners - joints and bumps

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Tyre liners - joints and bumps

Postby familyguy » Sun Nov 16, 2008 2:16 pm

I've just been changing my tyres, and have reinstalled my tyre liners (blue Tuffy's, 120PSI, 23c).

On one set of wheels I've trimmed them, but they still bump on the overlap every time I ride over the joint on smooth roads. I didnt trim them to meet flush, cause that'd be darn near impossible, just a minor overlap and a tapering end.

On the other set wheels the liners are overlapped and skewed towards the sidewall to avoid the lump, but its still there, and now there's a heavy point in the wheel. If I spin the wheel and hold the axle, there is a definite wobble because of the overlap adding a point weight. Not that it would matter on the bike, cause my 90kg would stop that problem 8)

Some people trim them, some dont. I believe manufacturers say not to.

What do you do?
Can you feel the ends?

Jim
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by BNA » Sun Nov 16, 2008 2:26 pm

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Postby Matt_Matt » Sun Nov 16, 2008 2:26 pm

I ride with slime tyre liners. I don't trim or sand and I don't feel them.

What pressure are you riding at ?


Matt
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Postby Kalgrm » Sun Nov 16, 2008 3:44 pm

The manufacturers recommend NOT trimming.

I've got untrimmed Mr Tuffy liners in my one bike with tubes. No bumps. I don't really know how you can get bumps - the pressure in the tube should equal out the bump if the tyres are sound.

I would suggest deflating the tyre most of the way and moving the bead around on the rim. I suspect the tube is pinched or the tyre's bead is not seated correctly.

Oh, and to taper the liner effectively, put the liner end between two sheets of grease-proof paper and iron it flat with the clothes iron*. The taper should be paper thin at the ends, otherwise the liner may abrade the tube (according to others - I haven't seen it happen to my tubes yet.)

Cheers,
Graeme

(* If the wife is emotionally attached to the clothes iron, it might be wise to wait until she is not around. It doesn't do anything to the iron, but she won't believe some bloke from the internet who says "Trust Me!" :)...)
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Re: Tyre liners - joints and bumps

Postby wombatK » Sun Nov 16, 2008 5:53 pm

familyguy wrote:I've just been changing my tyres, and have reinstalled my tyre liners (blue Tuffy's, 120PSI, 23c).

I've used Slime Tyre liners at around 100 psi (on 23c road bike and on 26 in MTB slicks). Have trimmed them to fit, and not paid any attention to whether I tucked the cut end under the uncut end (as some people recommend).

Only trouble I've had with bumps was with an Innova 26 in slick tyre from T7 on the MTB. I tried dropping the pressure to 80 psi, but still got bumps. I concluded it was slack quality of the tyre bead - when I changed to a serfas barista slick had no more bumps trouble. Also found the Innova's punctured much more often.

But if I were you, I'd first make sure it wasn't your twins jumping around in the trailer :lol:
WombatK

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Postby Shard » Mon Nov 17, 2008 2:08 pm

No trimming here, just hit ~2500km on mine today. I use about a 1cm length of inner tube cut open in half to mask the overlap on the tubside. If you don't do this the inner tube itself gets eaten away over time.
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Postby njg02 » Sat Nov 22, 2008 11:10 am

I just slit an old inner tube lengthways. No problems.
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