Are my wheels knackered or just wrong items?

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Hudson1984
Posts: 213
Joined: 21 May 2012, 2:02pm

Re: Are my wheels knackered or just wrong items?

Post by Hudson1984 »

Brucey wrote:how wide are your tyres? How much load is there on the tyres? What diameter are your rollers? Would you describe yourself as a powerful rider or not? Are you a spinner or a masher?

All these things can make a difference. 85-90psi might be just fine or constitute underinflation. IIRC Lugano tyres don't have very high upper pressure limit and (in skinny widths) are therefore problematic for heavier/stronger riders on the road. On the rollers they are likely to be worse than that.

cheers


Tyres are 25c
Continental Race 28 (700c) x 25/32C tubes.

I'm heavy
not powerful
I probably mash because I don't have the smoothness to spin.

Happy to change tyres and or tubes. I picked these tyres to suit my Calima wheels which suggested 25 witdth.
thatsnotmyname
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Re: Are my wheels knackered or just wrong items?

Post by thatsnotmyname »

If you're using 25-32 tubes in a 25c tyre, then it's possible the tube is folding internally before being inflated, which might explain the shape in the pic. For 25c tyres, you don't need tubes larger than 18-23 max..
Hudson1984
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Re: Are my wheels knackered or just wrong items?

Post by Hudson1984 »

Schwalbe do an 18-28, should I swap to those and see how I get on?
thatsnotmyname
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Re: Are my wheels knackered or just wrong items?

Post by thatsnotmyname »

Hudson1984 wrote:Schwalbe do an 18-28, should I swap to those and see how I get on?


You could try that, or a narrower one (23 or 25 max) if you can find one.
Brucey
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Re: Are my wheels knackered or just wrong items?

Post by Brucey »

an 18-28 tube will be stretched when fitted inside a 28mm tyre. I'd expect it to be 'just right' (I.e. very slightly stretched) inside a 25mm tyre.

Apologies if this is obvious but the procedure is as follows:

a) Get one bead of the tyre on the rim
b) round the tube out slightly and fit it inside the cover, starting at the valve (you will have to push the valve down well and then pull the cover over the back of the valve stem).
c) starting opposite the valve, fit the second bead to the rim as far as you can with the tube still rounded out.
d) deflate the tube
e) fit the (short) remaining portion of the second bead, being absolutely certain that the valve stem is pushed upwards as the last bit of the bead goes into place.
f) inflate the tube to make sure that the tube hasn't been damaged
g) deflate the tube completely and inspect the bead seating (to be sure that the tube isn't pinched) by pinching the cover and being certain that the rim tape is visible.
h) half inflate the tyre, and check it is seated correctly (runs true)
i) fully inflate the tyre.

During e) you may need to pinch the cover (whilst the beads are under tension) to be sure that the beads are down in the rim well. Starting with the tube rounded out (b, c) will ensure that the tube isn't pinched, but it is only possible to do this if the tube is the correct size.

hth

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Hudson1984
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Re: Are my wheels knackered or just wrong items?

Post by Hudson1984 »

obvious is good. I'm still very green to this in all honesty - my last bike I had for 2 years and never had a flat so never had to bother with any of this.

My hack still has it's original tubes too.

I've ordered some 18-28s so hopefully they help

but:

a) Get one bead of the tyre on the rim
b) round the tube out slightly and fit it inside the cover, starting at the valve (you will have to push the valve down well and then pull the cover over the back of the valve stem).
>> By this do you mean put a slight amount of air in - guessing that's the term for "rounding out"
>> what do you mean by "cover" - sorry i'm sure that's very dumb query but don't want to assume. I'm guessing the tyre but want to be sure.

c) starting opposite the valve, fit the second bead to the rim as far as you can with the tube still rounded out.
d) deflate the tube
e) fit the (short) remaining portion of the second bead, being absolutely certain that the valve stem is pushed upwards as the last bit of the bead goes into place.
f) inflate the tube to make sure that the tube hasn't been damaged
g) deflate the tube completely and inspect the bead seating (to be sure that the tube isn't pinched) by pinching the cover and being certain that the rim tape is visible.
h) half inflate the tyre, and check it is seated correctly (runs true)
i) fully inflate the tyre.
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531colin
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Re: Are my wheels knackered or just wrong items?

Post by 531colin »

I don't often disagree with Brucey, but the best and easiest way to get a tyre on is in my video..https://www.youtube.com/watch?v=-XUFVrl0UT4
Using toestraps (or whatever) to hold the tyre down in the rim well only applies to stiff tyres like marathon plus.
edit....you need just enough air in the tube....if you put too much air in, the tube may not fit in the tyre without pleats, which will chafe and puncture.
Last edited by 531colin on 24 Feb 2020, 4:09pm, edited 1 time in total.
thatsnotmyname
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Re: Are my wheels knackered or just wrong items?

Post by thatsnotmyname »

531colin wrote:I don't often disagree with Brucey, but the best and easiest way to get a tyre on is in my video..https://www.youtube.com/watch?v=-XUFVrl0UT4
Using toestraps (or whatever) to hold the tyre down in the rim well only applies to stiff tyres like marathon plus.


Congrats on getting a Marathon on without levers - very impressive ;)

To be fair, that's probably about as good as instructional videos get. I reckon you could do it without the toe straps though..
Hudson1984
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Re: Are my wheels knackered or just wrong items?

Post by Hudson1984 »

you're my hero!

a change at the moment takes me about 30 minutes, 3 plaster, swearing and a pinched tube...

i'll have another try using the above advice (combination of) and see how I get on. Very hopeful it's just a pinched tube mixed with wrong size tube.

hopefully actually get to ride this ruddy bike before long
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531colin
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Re: Are my wheels knackered or just wrong items?

Post by 531colin »

thatsnotmyname wrote:
531colin wrote:I don't often disagree with Brucey, but the best and easiest way to get a tyre on is in my video..https://www.youtube.com/watch?v=-XUFVrl0UT4
Using toestraps (or whatever) to hold the tyre down in the rim well only applies to stiff tyres like marathon plus.


Congrats on getting a Marathon on without levers - very impressive ;)

To be fair, that's probably about as good as instructional videos get. I reckon you could do it without the toe straps though..


yeah, I can...or I could before arthritis....that vid.is 10 years old! We did it using the straps because its (probably) easier for beginners with straps....once you have done a few dozen, you get the hang of using a bit of tension on the tyre to keep the bead in the rim well.
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531colin
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Location: North Yorkshire

Re: Are my wheels knackered or just wrong items?

Post by 531colin »

Hudson1984 wrote:you're my hero!

a change at the moment takes me about 30 minutes, 3 plaster, swearing and a pinched tube...

i'll have another try using the above advice (combination of) and see how I get on. Very hopeful it's just a pinched tube mixed with wrong size tube.

hopefully actually get to ride this ruddy bike before long


You will be OK.
Note the bit of the vid. where I find the tube pinched under the bead and all I do is move the slack round a bit and poke the tube up with my fingers.
Brucey
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Re: Are my wheels knackered or just wrong items?

Post by Brucey »

531colin wrote:I don't often disagree with Brucey, but the best and easiest way to get a tyre on is in my video..https://www.youtube.com/watch?v=-XUFVrl0UT4
Using toestraps (or whatever) to hold the tyre down in the rim well only applies to stiff tyres like marathon plus.
edit....you need just enough air in the tube....if you put too much air in, the tube may not fit in the tyre without pleats, which will chafe and puncture.


I don't think we are in disagreement. But for most tyres (pretty much everything except heavier puncture proof tyres with stiff beads) the toestraps either won't work very well (because the tyre is floppy) or they are not strictly necessary; once the second bead is mostly fitted and has tension in it, pinching the tyre causes the beads to settle in the rim well and they will only pop out again if the tyre is stiff (and wants badly to be another shape) and/or the beads lose their tension.

Only this morning I fitted a 'bad combination', a GP5000 to a carbon rim (which was fitted with a thick-ish rim tape in a shallow well) and it was tight enough, right enough, but it merely caused 'pink thumbs' rather than red thumbs or red face, red thumbs, blue language etc. I don't think toe straps would have been any great help with this or many other folding tyres; once a folding tyre is squashed against the rim by the toestrap, I don't see how you can be 100% certain that the bead is in the right place; to do that means moving the tyre and that usually means moving the toestrap.

FWIW I believe that the single thing that would best improve the chances of fitting many tyres would be a thing that keeps the second bead under tension, so that it doesn't pop out of the rim well. That way you could pinch the tyre to get the second bead in the well, and be reasonably sure it is going to stay there.

cheers
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The utility cyclist
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Re: Are my wheels knackered or just wrong items?

Post by The utility cyclist »

thatsnotmyname wrote:If you're using 25-32 tubes in a 25c tyre, then it's possible the tube is folding internally before being inflated, which might explain the shape in the pic. For 25c tyres, you don't need tubes larger than 18-23 max..

It's possible for that to occur I guess but how likely is it to?
Surely when putting the tube in you would obviously notice that the tube is far too big for the rim and/or tyre, and for the deformation of the tube to be that significant it would have to be for an absolute age to have that kink would it not?
For it to be noticeable straight from the off after having got the wheels back from the bike shop more than likely says there's a flaw in the tube, even a rubbish bike shop wouldn't try to stuff a too large tube in, a 25-32mm tube is fine for a 25mm tyre and indeed the rims internal width is 17mm so a 25mm tyre will be closer to 27mm* when inflated in any case.
*As shown by the testing done by the guy at bicycle rolling resistance on same width rim.
thatsnotmyname
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Re: Are my wheels knackered or just wrong items?

Post by thatsnotmyname »

The utility cyclist wrote:
thatsnotmyname wrote:If you're using 25-32 tubes in a 25c tyre, then it's possible the tube is folding internally before being inflated, which might explain the shape in the pic. For 25c tyres, you don't need tubes larger than 18-23 max..

It's possible for that to occur I guess but how likely is it to?
Surely when putting the tube in you would obviously notice that the tube is far too big for the rim and/or tyre, and for the deformation of the tube to be that significant it would have to be for an absolute age to have that kink would it not?
For it to be noticeable straight from the off after having got the wheels back from the bike shop more than likely says there's a flaw in the tube, even a rubbish bike shop wouldn't try to stuff a too large tube in, a 25-32mm tube is fine for a 25mm tyre and indeed the rims internal width is 17mm so a 25mm tyre will be closer to 27mm* when inflated in any case.
*As shown by the testing done by the guy at bicycle rolling resistance on same width rim.


To paraphrase John Lydon - you could be right, you could be wrong...
PT1029
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Re: Are my wheels knackered or just wrong items?

Post by PT1029 »

Image https://imgur.com/iDQI3YZ (close up of the tube) to me looks like a case of a crease in the tube when fitted (as though the tube is too long so you have to stuff it in the tyre). When you inflate the tyre, the crease ends up as a sort of crevice in the tube. The edges of his crevice get abraided and eventually puncture. What you would see is a sort of slightly marked ring (from contact with the tyre carcass) around a completely unmarked/new looking circle (which was the crevice). I see it at work, but I would be suprised if it is this to see it fail so quickly - though if your rollers give the tyres a hard time as suggested up thread, it might happen quickly(?).
So, when you fit the next tube, before refitting the tyre bead, look round the tube for squidged in creases, if there are any craeses, distrubute the tube a bit more evenly around the tyre, if this is hard to do, let a bit of air out (assuming you put a pump or 3's worth of air prior to fitting the tyre).

Edit,
The bump is probably the valve going over the rollers, once the tyre has gone soft/flat.
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