Time to replace rim?

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gxaustin
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Re: Time to replace rim?

Postby gxaustin » 3 Jan 2021, 3:43pm

I had a failure of an Open Pro rim. On later examination the thickness of the brake track was a shade under 1mm, as measured with an Iwanson gauge.

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Mick F
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Re: Time to replace rim?

Postby Mick F » 3 Jan 2021, 4:05pm

Done some measuring.

Tyre inflated to 100psi. Digi callipers measured on a few areas of the rim with the jaws pointing upwards from the hub, as the tyre is wider than the rim of course.
Inflated to 100psi and it comes out as 22.45mm as a sort of average.

Deflated the tyre and repeated.
Comes out as 22.32mm

ie, not much difference at all, though it is detectable.
0.1mm ish.



Are we considering a "normal" 700c diameter rim, or any diameter rim?
I'm measuring and considering a 406 (20") rim. Does that make a difference to this?
Mick F. Cornwall

Jay Gee
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Re: Time to replace rim?

Postby Jay Gee » 4 Jan 2021, 10:18am

iandusud wrote:Try pumping your tyre up to 100 psi and stand back :D


What fun! The rim failed around 120 psi and my ears were ringing from the pop!

rim pic.jpg

Brucey
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Re: Time to replace rim?

Postby Brucey » 4 Jan 2021, 10:22am

the thought of that happening whilst you are riding is enough to give you the willies....

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

iandusud
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Re: Time to replace rim?

Postby iandusud » 4 Jan 2021, 1:05pm

Brucey wrote:the thought of that happening whilst you are riding is enough to give you the willies....

cheers

I've witnessed it! Not my bike I hasted to add.

iandusud
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Re: Time to replace rim?

Postby iandusud » 4 Jan 2021, 1:06pm

Jay Gee wrote:
iandusud wrote:Try pumping your tyre up to 100 psi and stand back :D


What fun! The rim failed around 120 psi and my ears were ringing from the pop!

rim pic.jpg

I hope you're paying attention at the back Mick F :D

Mike Sales
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Re: Time to replace rim?

Postby Mike Sales » 4 Jan 2021, 1:10pm

Brucey wrote:the thought of that happening whilst you are riding is enough to give you the willies....

cheers


I was accelerating down the hill from the traffic lights when there came a loud bang and I found myself lying in the road with my bike. As I lay there assessing the pains I noticed a sliver of aluminium next to my bike on the tarmac. Only bruises suffered. That is how I learned that rim wear could be a problem.

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Mick F
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Re: Time to replace rim?

Postby Mick F » 4 Jan 2021, 2:00pm

iandusud wrote:
Jay Gee wrote:
iandusud wrote:Try pumping your tyre up to 100 psi and stand back :D


What fun! The rim failed around 120 psi and my ears were ringing from the pop!

rim pic.jpg

I hope you're paying attention at the back Mick F :D
Oh yes indeedy! :shock:

I'm keeping an eye on both front and rear on Moulton as I always use both brakes. The rear wears more due to the grit and muck off the roads .............. rear wheels are always dirtier than front wheels.

I bought a new pair of rims early last year, so if my riding gets more than it's been these last few months, the existing rims will need to be ditched. Believe me, I'm monitoring the situation.
Mick F. Cornwall

Jay Gee
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Re: Time to replace rim?

Postby Jay Gee » 4 Jan 2021, 5:04pm

Mick F wrote:If I feel so inclined tomorrow, I'll take out the rear wheel, remove the tyre and tube, and measure again.


I found that I could push deflated tyre and inner tube to one side of the rim to measure the brake track thickness with an Iwanson gauge - no need to remove wheel or tyre.

That makes it a very quick job and something that I will definitely be doing on a regular basis from now on. Fun as my controlled explosion was in the garage, I would not want it to have happened on the road.

Very grateful to this forum for pointing me towards Iwanson gauges, at £3.25 with free postage from ebay there's no reason not to have one available.

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Mick F
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Re: Time to replace rim?

Postby Mick F » 5 Jan 2021, 4:49pm

Jay Gee wrote:I found that I could push deflated tyre and inner tube to one side of the rim to measure the brake track thickness with an Iwanson gauge - no need to remove wheel or tyre.

That makes it a very quick job and something that I will definitely be doing on a regular basis from now on. Fun as my controlled explosion was in the garage, I would not want it to have happened on the road.

Very grateful to this forum for pointing me towards Iwanson gauges, at £3.25 with free postage from ebay there's no reason not to have one available.
Thanks.
Good info.

Bought my gauge from Toolzone in Plymouth. Similar price if my memory serves me correctly.
Rolson is the make. Cheap as chips. :D
Mick F. Cornwall

Mike Sales
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Re: Time to replace rim?

Postby Mike Sales » 5 Jan 2021, 5:05pm

Mike Sales wrote: That is how I learned that rim wear could be a problem.


I still have Chris Juden's article from Cycletouring (and Campaigning) which describes how to bend a spoke so that with its aid and a vernier caliper you can measure wear accurately. The bent spoke is somewhere in my tool collection even now.

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531colin
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Re: Time to replace rim?

Postby 531colin » 5 Jan 2021, 6:13pm

Image003 by 531colin, on Flickr

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Sweep
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Re: Time to replace rim?

Postby Sweep » 6 Jan 2021, 9:59am

Mick F wrote:Bought my gauge from Toolzone in Plymouth. Similar price if my memory serves me correctly.
Rolson is the make. Cheap as chips. :D

Do you have a link?
Sweep

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Mick F
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Re: Time to replace rim?

Postby Mick F » 7 Jan 2021, 9:12am

Sweep wrote:
Mick F wrote:Bought my gauge from Toolzone in Plymouth. Similar price if my memory serves me correctly.
Rolson is the make. Cheap as chips. :D

Do you have a link?
This is mine.
https://www.rolsontools.com/product/diamond-gauge/
There's no way on God's Earth that I paid that! :lol:

£3ish from Toolzone in Plymouth. They don't list it now though.
Mick F. Cornwall

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Sweep
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Re: Time to replace rim?

Postby Sweep » 7 Jan 2021, 12:51pm

Mick F wrote:
Sweep wrote:
Mick F wrote:Bought my gauge from Toolzone in Plymouth. Similar price if my memory serves me correctly.
Rolson is the make. Cheap as chips. :D

Do you have a link?
This is mine.
https://www.rolsontools.com/product/diamond-gauge/
There's no way on God's Earth that I paid that! :lol:

£3ish from Toolzone in Plymouth. They don't list it now though.

thanks for looking Mick - explains why I couldn't find it.
Sweep