# Light-Bicycle carbon rim-bead cutting tyre sidewalls.



## ozzybmx (Jun 23, 2013)

I've done a good bit of searching with no break on anyone else having this issue.

I have a set of Light bicycle carbon rims, they are the XC version 29er rim that i run on my CX bike. The picture on the page clearly shows the rim bead being very rounded but this is not the way i received my rims. 

My rim bead was a sharp square edge with burrs on it, i thought it was a bit shabby finish but i suppose you get what you pay for... i have a set of ENVE wheels too and with the price difference you get quality and CS.

I filed the carbon burrs off and fitted up my tyres and over the next 2-3 weeks the rims cut through the sidewall of 3 racing ralph tyres, the first one i thought was an accident, after this i took a file and smoothed off the edges on both rims. Its now a semi rounded edge but i was left on the side of the road a few days ago where the rear has now done the same again on a Vittoria Randonneur Cross Pro tyre, these are a hefty sidewall trekking tyre and its cut the bead exactly where it was cutting in on the others.

Has anyone else had this issue ? I emailed Light-Bicycle after i realized what the issue was and they didn't reply, that was 2 months ago and now its done the same again on this Randonneur tyre after 880km.

I run the wheels tubeless and apart from this small but ride ending issue the wheels are spot on ! The reliability of this bike is very important as i use it for long gravel grind rides, once the bead is cut its hard to even get a tube in as it tears the already sliced bead and bubbles the tube out the side.

I'm thinking it was a process missed out but i cant be the only one who's had this issue of an unfinished square bead.

cheers


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## upstateSC-rider (Aug 21, 2004)

You have a pic of the bead as you originally received it? I'd be curious to see it.
Check out the 29'er components section of mtbr...


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## ms6073 (Jul 7, 2005)

I have two sets and runs ours with Specialized Trigger and Challenge latex tubes and have not had any such issues. What pressures are you running? I am guessing you are relatively low (sub 30-psi?) pressures in which case the cause and effect may be inverse. Is it possible the tires are 'micro-burping' as I could see causing such cuts as the tire losses pressure increasing lateral flex especially through fast, off-camber corners.


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## ozzybmx (Jun 23, 2013)

No... I dont have a picture. I thought the issue was sorted but obviously not

My pressure is 50-60psi running cx tyres..


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## Lelandjt (Sep 11, 2008)

I've seen a lot of LB MTN rims and none had sharp edges on the bead hook. Take pictures and email LB again, maybe your first email didn't get through.


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## ozzybmx (Jun 23, 2013)

I sent an extensive email the last time, it sucks when they don't reply after putting in some effort to explain. Now that i am sitting with another destroyed flat tyre, i might take some pics of "my sanding job" on the bead and email them to LB. Hopefully later today if i get a chance as i need that bike.


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## ozzybmx (Jun 23, 2013)

Ok, here's the rear rim that's just split the Vittoria Rondonneur.

You can see where the "square edge" was, its pretty smooth now but i think the overhang is still too much.





LB says the inner width should be 21mm and the outer is 27.4mm, i reckon if my rims had have been machine finished on the bead that they should probably be thinner than this... possibly by up to 1mm each side going on the massive overhang i have.





Here is the typical tyre hole that i have already had on the previous 3 racing ralphs.



So i have now lost...

3 folding Racing ralphs (cut then tore when i installed a tube)
2 wire bead ralphs (Both nearly worn through, see pic below)
2 Vittoria randonneurs (1 cut and 1 worn through)

Many hours standing on the side of the road waiting on being picked up because of these catastrophic failures.

And just found this when i aired up the set of wire bead Ralphs that i had on BEFORE the Randonneurs, the Randonneur i took of was similar. The other Ralph i just fitted is starting to cut through as well.



Will send LB a link to this, wont hold out for a response though.


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## ozzybmx (Jun 23, 2013)

So i have sent 2 emails in the 3 days since posting this, sadly no reply. 

I believe they get back to you if you have crash damage and are buying a new rim. Obviously my issue with their QC and the fact they sold me unfinished rims now causing over $200 of tyre damage isn't something they reply to.

Will be cross posting this over on the MTBR thread too, not out of spite but if these guys are not dealing with issues they have caused then it needs to be shared.

Cheers Light-bicycle, with the junk rims and tyre damage its over $600 lost... thats without the time standing on the road and walking home.


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## spdntrxi (Jul 25, 2013)

I had that happen on my wife's bike.. with a GP4000s tire. not a carbon rim though.. Al. The damage was at least 3x longer then the one you are showing. Sent back to place of purchase and I'm hoping for a refund. Now I'm thinking I better pull the tire and check the rim


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## changingleaf (Aug 20, 2009)

The rim doesn't look that bad. It's very possible that the tire is separating because of the high pressure you are using tubeless. I've never seen those tires used above 45 psi tubeless. I'm suprised you haven't blown them off the rim. If they're tubeless-ready or tubeless tires they should be able to handle the pressure, but you did not say if they were. I had a pair of Zip 303 Firecrest clinchers and they had very sharp edge. They never caused the bead to separate, but did pinch flat more easily than other rims.


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## Jwiffle (Mar 18, 2005)

Sorry to hear about your tire trouble. Strange you haven't heard back from LB. I have the wider 29er rims on my mountain bike. One of them failed after just a few rides, but they got right back to me and sent me a new rim.

Have you been running all the tires tubeless? When I purchased rims last year, only the wider rim was designed to be run tubeless. The XC was not. The only reason I could the rim doing that to your tires is if the tire is actually moving forward and back along the rim, rubbing into the tire, which shouldn't happen. It may just be that you shouldn't run these rims tubeless if they aren't designed for it. Are you using a Stan's strip to run it tubeless? That may help.


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## ozzybmx (Jun 23, 2013)

Cheers for the replies. They are designed to run tubeless and I am using gorilla tape as the rim tape, all tyres "popped" onto the rim so there was a good seal, I was even able to run the wire beads as tubeless after sealing one side with a tube.

I had good comms from them while waiting on the rims, even after on "live chat" when I asked about pressures.... im wondering if they sent out a whole batch like this and are now doing the head in the sand trick.


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## wattiez (Dec 17, 2011)

Ozzybmx, if you went with the Narrow version, the max pressure is listed as 40psi.
The wide version accepts 70psi so maybe that's the best bet for you.

I run the wide on my mtb and have had no faults yet


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## ozzybmx (Jun 23, 2013)

wattiez said:


> Ozzybmx, if you went with the Narrow version, the max pressure is listed as 40psi.
> The wide version accepts 70psi so maybe that's the best bet for you.


I told them about the contradiction on their advert before i bought them, they still have not changed it. They confirmed that the wide and narrow are both rated at 70psi.

I am not questioning the durability or strenght of the rims, it seems mine missed out a process where the rim bead is shaped, i had a sharp square edge with razor sharp slags of carbon still attached from a mold of some sort.


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## ozzybmx (Jun 23, 2013)

Thread update, today i received a replacement set of rims from LightBicycle, i only had to pay $50 for the postage... which was a good result IMO.

They sent me the wider 29er rims which are only probably better for MTB as they are AM strength and 23mm inside diameter but i'll use these on my SS... on 20g heavier than the XC versions.

Kudos to LB for replacing them which is about as good a result from customer service as anyone could expect.


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