Brompton rear rim , should I replace?

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Philip Benstead
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Brompton rear rim , should I replace?

Post by Philip Benstead »

As per title, should I replace.

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20230606_170231(0).jpg
Philip Benstead | Life Member Former CTC Councillor/Trustee
Organizing events and representing cyclists' in southeast since 1988
Bikeability Instructor/Mechanic
PT1029
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Re: Brompton rear rim , should I replace?

Post by PT1029 »

Can you manage a more in focus photo?
If concave, it is on its way put, how quickly will no doubt be debatable.
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simonineaston
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Re: Brompton rear rim , should I replace?

Post by simonineaston »

+1 for a photo that focuses on the rim itself - tip: if using a phone, try tap-to-focus or if using a camera, try the macro setting (often a small flower).
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
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Chris Jeggo
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Re: Brompton rear rim , should I replace?

Post by Chris Jeggo »

Use an Iwansson gauge (e.g. https://ynrinstruments.co.uk/products/y ... -crown-too) to measure rim thickness. Replace rim if thinner than 1mm.
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geomannie
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Re: Brompton rear rim , should I replace?

Post by geomannie »

Chris Jeggo wrote: 7 Jun 2023, 8:09am Use an Iwansson gauge (e.g. https://ynrinstruments.co.uk/products/y ... -crown-too) to measure rim thickness. Replace rim if thinner than 1mm.
+1
geomannie
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531colin
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Re: Brompton rear rim , should I replace?

Post by 531colin »

Image003 by 531colin, on Flickr

Just take a round file to an old vernier gauge.
Measure at lots of points around the circumference and also up and down the brake track. Its usually thinnest in the middle of the brake track.
Modern "machined" rims often vary in thickness around the circumference, even when new. (another triumph of appearance over utility)
2_i
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Re: Brompton rear rim , should I replace?

Post by 2_i »

Chris Jeggo wrote: 7 Jun 2023, 8:09am Replace rim if thinner than 1mm.
Maybe 1mm is too conservative. If it is thinned down to 0.5mm anywhere, then for sure the replacement is a must, I usually acted by 0.7mm.
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Philip Benstead
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Re: Brompton rear rim , should I replace?

Post by Philip Benstead »

I filed my Verner and then removed wheel from the bike, removed tyre but on close inspection I found the crack.

I had spare rime and rebuilt the wheel whilst at it change the chain.

I am leading a ride on Sunday in London it's a good job I checked.

20230607_153333.jpg
Philip Benstead | Life Member Former CTC Councillor/Trustee
Organizing events and representing cyclists' in southeast since 1988
Bikeability Instructor/Mechanic
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simonineaston
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Re: Brompton rear rim , should I replace?

Post by simonineaston »

Good shout! Hope the ride's a good 'un :-)
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
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geomannie
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Re: Brompton rear rim , should I replace?

Post by geomannie »

Philip Benstead wrote: 7 Jun 2023, 3:44pm I filed my Verner and then removed wheel from the bike, removed tyre but on close inspection I found the crack.

I had spare rime and rebuilt the wheel whilst at it change the chain.

I am leading a ride on Sunday in London it's a good job I checked.


20230607_153333.jpg
Ouch! I have only once had rim failure while riding, going fast down a long steep hill since you ask, and it's not a situation I want to repeat. Great that you have trapped it.
geomannie
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