Author Topic: Been using the search but.... [Al frames / tyre pressure] (Read 3097 times)

Vava · « **on:** 20 July, 2009, 07:51:54 pm »

noob here please forgive - two things-

I got 'richards bike book' today and have been perusing - says in there that aluminium frames last 3 to 5 years - didn't realise this - what would I look for on the frame to know if it is still safe as I recently bought a racer and I don't know how old it is?

It is an Orbea sport larreau.

second - I got a tyre pressure guage from halfords and blew up the tyre to 80psi - it should have been 100 psi and within 5 minutes the inner tube split grr. Husband got the last laugh as he said you don't need a guage you can do it by feel but that is not helpful to a noob as I dont know what the right pressure feels like - thats why I bought the guage to get the right pressure and then feel it so that I could recognise it in future! Thanks in advance for any help.

Biggsy · « **Reply #1 on:** 20 July, 2009, 08:25:09 pm »

Sounds like old advice. How old is the book? Most aluminium frames are built with fat and thick tubing that will last many years if not a lifetime. I don't know your particular bike, though.

You're right that a pressure gauge is good for newbies (and convenient for anyone if it's built into the pump). Sounds like the tyre or tube wasn't fitted properly or was faulty. Just try again with another tube. Inflate to the recommended pressure marked on the tyres if in doubt. You can deviate from this once you have more experience. It's a good idea to have the front tyre a bit softer than the rear as it takes less weight.

Ian H · « **Reply #2 on:** 20 July, 2009, 08:34:38 pm »

Quote from: Biggsy on 20 July, 2009, 08:25:09 pm

Sounds like old advice. How old is the book?

Originally published long before fat-tubed alu frames. Dunno how comprehensively it's updated (new editions appear every so often).

Vava · « **Reply #3 on:** 20 July, 2009, 08:41:36 pm »

border-rider · « **Reply #4 on:** 20 July, 2009, 08:42:09 pm »

Yeah, old advice. I've only had one Al frame, but I got it 13 years ago and used it a lot, and it's now being used by someone else on here on a regular basis. As long as you don't crash, it should be fine for many a year.

Biggsy · « **Reply #5 on:** 20 July, 2009, 08:47:25 pm »

Another thought re the tyre: Make sure the wheel has adequate rim tape fitted. The tape needs to prevent the tube going down the deep spoke holes if your wheel has those.

Vava · « **Reply #6 on:** 20 July, 2009, 08:51:06 pm »

there is no tape in the rim it is covered with what looks like a layer of silicone - was wondering if I needed tape as well. The silicone smoothes the edges of the spoke dips so there are no sharp edges but there are dips in all the spoke 'holes' that are big enough to fit a smartie sweet in.

Ian H · « **Reply #7 on:** 20 July, 2009, 08:53:13 pm »

Plastic rim tape is okay in my experience, though others have reported problems with it. Is it a road bike or a mountain bike?

Vava · « **Reply #8 on:** 20 July, 2009, 08:54:49 pm »

road bike

Biggsy · « **Reply #9 on:** 20 July, 2009, 09:01:27 pm »

Use a strong tape like Velox cloth or a plastic high-pressure rim tape if you think air pressure could force the inner tube down the holes with the current stuff.

gene hunt · « **Reply #10 on:** 20 July, 2009, 09:12:00 pm »

I have only ever used Velox cloth rim tapes, had nothing but problems with plastic rim tapes.

Vava · « **Reply #11 on:** 20 July, 2009, 09:28:27 pm »

ta guys spotted some on wiggle!

alecstilleyedye · « **Reply #12 on:** 21 July, 2009, 08:55:11 am »

+1 for velox, and the idea that modern alu frames have such a shelf-life is rubbish.

Ian H · « **Reply #13 on:** 21 July, 2009, 09:12:31 am »

Use talc on the tube and the bead of the tyre (helps it all slip into place). When it's back on, pump to about 60psi. Check all round the tyre and see if it's sitting properly on the rim - there will be a moulding line or similar that should be the same distance from the edge of the rim both sides all the way round. Increase the pressure by another 10psi and check again, and so on. If the tyre lifts at one point then reduce the pressure and try to manually reseat it, then start again. If this doesn't work then there's something more fundamental amiss.

Biggsy · « **Reply #14 on:** 21 July, 2009, 01:02:53 pm »

Quote from: Vava on 20 July, 2009, 08:51:06 pm

there is no tape in the rim it is covered with what looks like a layer of silicone - was wondering if I needed tape as well. The silicone smoothes the edges of the spoke dips so there are no sharp edges but there are dips in all the spoke 'holes' that are big enough to fit a smartie sweet in.

I would expect the silicone stuff in fact to be a tape or band that does come off, but tape could be applied over the top if you can't get it off. A better tape may not be absolutely necessary for Smartie-sized dips, but it's good to use top quality rim tape anyway.

mike · « **Reply #15 on:** 21 July, 2009, 01:04:02 pm »

have the smarties fallen out? that'll be the problem..

Biggsy · « **Reply #16 on:** 21 July, 2009, 01:05:31 pm »

Smarties would be the cheap equivalent of Veloplugs - except may get messy when the rim gets hot!

Vava · « **Reply #17 on:** 21 July, 2009, 05:24:11 pm »

- you guys are great thanks for all the tips - will get cracking shortly - oops wrong phrase methinks!

rogerzilla · « **Reply #18 on:** 21 July, 2009, 08:23:27 pm »

My favourite tape is this stuff:

Specialized Rim Strip Road 700c Pair

It's thin and, in many years of use, totally reliable. The stuff to avoid is the hard yellow plastic stuff Michelin used to sell, because it cracks.

Tubes only explode with a bang if they are outside the tyre. This means some of the tube was probably trapped under the tyre bead. The other possibilities are that the tyre was much too narrow for the rim, the rim wasn't a hook-bead type (really unusual if the bike is less than 40 years old) or the rim is in some way damaged so it won't hold a tyre. I once had a steel rim that had splayed from hitting a pothole, and it blew tyres off without warning until I got some new wheels.

Vava · « **Reply #19 on:** 21 July, 2009, 09:02:20 pm »

Quote from: rogerzilla on 21 July, 2009, 08:23:27 pm

I once had a steel rim that had splayed from hitting a pothole, and it blew tyres off without warning until I got some new wheels.

are 700 x 23 tyres the same as 700 x 23c?

alecstilleyedye · « **Reply #20 on:** 21 July, 2009, 09:15:38 pm »

it's 700c x 23 actually, but it doesn't matter if you drop the c completely; it means nothing these days (700 rims are not 700mm anyway).

Vava · « **Reply #21 on:** 22 July, 2009, 05:12:52 pm »

I am getting a bit fed up - I bought some new tyres from halfords. They were 11 quid each. I put them on the bike and wasnt happy with them because the measurement lines round the edge wern't even so I took them off and redid one of them really really carefully. Pumped it up to the correct pressure and then noticed a slit in the tyre about 2cm long near the rim. Presumably I must have cought it when I was taking it off or putting it on but I didnt expect to find a slit in a new tyre. Is this 'normal'?

I got some new tyres from wiggle - 2 x Continental Grand Prix 4000S Tyre 700x23 Black and I am hoping they will be ok - dejected.

Biggsy · « **Reply #22 on:** 22 July, 2009, 07:31:11 pm »

It's not very easy to slit a tyre in the process of fitting (tube yes, tyre no), so it may well have been faulty. You'll probably get a refund if you say you fitted it normally then immediately discovered the slit.

Uneven seating of a tyre is a common little problem, and if you're lucky will correct itself when the tyre is refitted and fully inflated, but sometimes it may never be quite right (not that you'd notice a small error when riding). Hopefully your Contis will be better anyway.

andrew_s · « **Reply #23 on:** 22 July, 2009, 09:27:24 pm »

Did the slit in the tyre actually go through the tyre?

There's a reinforcing strip just above the tyre bead that can give the impression of a crack or cut if it starts to separate. This is of no significance and can be ignored.

TimO · « **Reply #24 on:** 22 July, 2009, 10:49:28 pm »

You said that you may have caught it taking the tyre off or putting it on. I could be wrong, but I hope that doesn't mean you were using tyre levers to put the tyre on? You shouldn't need to use them to do this, and if you do, there is a good chance that you will catch the inner tube and end up with holes in it. If this is what happened, then oops.

If the tyre is very tight, there are tools to help get it on, but they are different to tyre levers, and won't catch the inner tube.

Author Topic: Been using the search but.... [Al frames / tyre pressure] (Read 3097 times)

Vava

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border-rider

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