Tubular strange cuts

[1415chris]

Hi All,

After my tubs inspection, I found quite strange tread's cuts.
Strange as this is the first time after 4-5 years running similar to FMB tubes and open clinchers, I can see something like this.
The more strange it is that I noticed one of the cuts on the rear one day, after two rides, today checking how this cut is performing, I found another two...???
They appear on the front and rear in the same shape, rear ones, as you can see on pics, are bigger.
Is there any chance that this can be a tread's failure, not necessary cuts?

Rear:



Front:

[ricey155]

I'd say tyre issue rather than cuts, email them see what they say would be good to hear how it happens

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[MJB]

FWIW......

I picked up a similar scalloped shaped slash/cut in a 25mm FMB Paris-Roubaix rear tyre, however, I'm 99% certain I rode over a damaged sharpened, raggedy edge of an embedded road reflector.

My tyre was damaged to the point where the slashed area flapped up away from the cotton carcass. I used some tubular glue at 40psi to re-adhere the flapping piece and have ridden the tyre for 18 months since with no issue or new scallaped cuts.............

I also ride on 24mm FMB CX comps and have a silk wall set of 25mm FMB PR's and have not seen any damage.......... yet..........

[1415chris]

Rather three of them, in my case

[1415chris]

Ohh it seems that the post I was responding to above disappeared.

I got Francois' respond:
"...For circles in treads, it is a problem with the compound, it is not our company which makes treads. It is not a problem with hand-made tire..."

It doesn't sound encouraging. A bit shame, they roll really nicely . I glued it, I'll keep an eye on them.

[HammerTime2]

I don't understand (from an American perspective of customer service) Francois' response.

If the customer (you) supplied the tread for FMB to put on a tire, then it's not FMB"s responsibility. If FMB subcontracts, i.e., purchases, the tread from another company, then it is FMB's responsibility to the end customer (you). FMB can in turn demand compensation from its supplier, but FMB still has a responsibility to you.

[1415chris]

Fully agree.
I was a bit struggling to understand his expresion, his English let's say is not the strongest.
I will try to elaborate with him to have more understanding, French would be perfect, but unfortunately my one is not existing.....

[HammerTime2]

with regard to the FMB tires, you can send them any tire you want and they will put that tires' tread on thier casing. I know of people who send them michelin mud clincher cyclocross tires and have the tread applied to the tubular FMB's. a great idea if you don't mind paying $200 per tire

This is what I was thinking of when I wrote

If the customer (you) supplied the tread for FMB to put on a tire, then it's not FMB"s responsibility.

[Geoff]

@1415chris, how long did you age those tires before mounting them?

[1415chris]

I usually give hand-glued tubulars/tyres 4-6 months sometimes more before mounting them.
If I have to make a change and my tyres stoage is empty, they go preatty straight away without much ageing.
In this case I think it was about 2-3 months.

[1415chris]

I did not want to open the new thread, as this relates to the same tubulars.

I have never had experience with this kind of damage/fault, neither tubulars nor clinchers.





The rubber is not damaged in this place, I have not noticed any significant impact which could cut the cotton threads. The bulge appeared on the very slow climb.
I exchanged words with Francois, he is suggesting that: 1) the combination of too much pressure and the impact for example a pothole, 2) or an object crossing the thread and cutting it.

Up to 120psi, I don't think it is too much pressure.
And as I mentioned I have not noticed anything extraordinary which could draw my attention. Mileage 2000km.

What are your thoughts?

[tommasini]

Your casing has some tearing of individual plies - I've occasionally experienced this over many years but have never seen one that bad - it's unsafe and definitely a goner.

[ghisallo2003]

Yes, I have seen this. You need to throw away I am afraid: a zone of weakness is allowing the bulge, which can catastrophically fail in a blow out. I would not waste time chasing the manufacturer, who is likely and legitimately able to say this is a normal consequence of damage caused by riding. You may though want to consider longevity in future buying.

[TwiggyTN]

That was a bad day in Francois' garage it seems. I have had one FMB over the years with a noticeable lump when ridden, barely noticeable on the stand. The tire soon developed a slow leak and was done after about 500mi. Send these pictures to FMB directly and see what they say. They might make good on it for you....

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[1415chris]

Just to add, I had to change it during the ride, as it was too big to go through the brake caliper.
And of course it is a goner for me.