Possible design flaw.

[Cuber]

Hi all

Need help in whether my bike has a design flaw.

Basically the gap between BB shell and triple crankset is smaller than the chain, Gap 4-5mm chain 6mm and because it has a massive oversized BB shell when the chain came off due to incorrect derailer adjustment and damaged the carbon frame more than what you would normally expect .

This only happens on the model with a triple crankset and I have never seen another bike where gap is smaller.

This basically means you will get maybe 2-3 (maybe 1) chain offs and the frame will be shot.

Personally think this is a design flaw,what do you think?

will try to post photo.

thanks

[Cuber]

Dont think I explained this well enough and will try to put it another way.

Is it acceptable that if your chain comes off between massive oversized frame and crank that you have to remove the crank to retrieve the chain and the carbon frame is chewed to bits.

Wish I could upload a pic

My bikes a cube agree race with ultegra triple chainset and I think the bike should not be offered as triple without some type of chain catcher as damage caused by simple chain off is a lot greater than expected.

thanks

[Bill]

Do you have a warranty on it? Also do they have a 1800 number you could call?

[RBurrelli]

I have not been riding for that long, but for the past two years I have never had my chain come off for any reason. If the bike has been setup properly I would wonder why that would happen.

"simple chain off" sounds like this is something that happens on a regular basis. It should not.

[JohnV]

You are not talking about a cheap bike here. If you just bought that bike new from a LBS, I would take it back and have them warranty the frame. The chain should not come off under normal riding if the bike was assembled correctly at the LBS. The fact that it's a triple has nothing to do with it. I ride a triple and have almost 2,000 miles on the bike since November and I have never had my chain come off.

[Cuber]

(07-21-2011, 05:18 PM)Bill Wrote:  Do you have a warranty on it? Also do they have a 1800 number you could call?

The shops not interested and i live in uk and the bike is german so only have internet address which am getting no answerto e-mails.

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(07-21-2011, 08:50 PM)JohnV Wrote:  You are not talking about a cheap bike here. If you just bought that bike new from a LBS, I would take it back and have them warranty the frame. The chain should not come off under normal riding if the bike was assembled correctly at the LBS. The fact that it's a triple has nothing to do with it. I ride a triple and have almost 2,000 miles on the bike since November and I have never had my chain come off.

Yes just bought over internet from distant seller.

The reason i mention triple is because my friend has same bike on a double and the gap between bottom ring and frame is larger allowing the chain to come off and do minimal damage unlike mine where the chain could compress the carbon BB shell because of the gap size(Im not talking chainstay clearance im talking about clearance between small ring and both oversized frame tubes that meet the BB shell)
Personally ive never rode a bike where this has been the case and wondered was it common?

I,ve also did thousands of miles without chain offs on previous bikes.

Thanks

[JohnV]

It shouldn't matter if the bike is made in Germany, any Cube dealer should be able to warrant the bike provided that you purchased it from a Cube dealer. Was the bike purchased at a Cube dealer or did you buy it from the Internet? The problem with buying bikes from Internet bike shops is that pretty much all of them send the bikes still in the box unassembled. If you do the assembly yourself and don't take it to one of their authorized dealers, they will drop the warranty on the bike. On Bike Forums you hear this happening all the time and there isn't much you can do but absorb the cost of any repair. You may not be getting a response from Cube because they may have no record of you purchasing the bike from an authorized dealer. If you have more than one bike shop in your area, take it to a different shop and see if they are willing to work with you.

[Cuber]

Forgot to say bike was incorrectly set up(bike shop) causing the chain to come off but I dont want to go down this route as chains can come off for differnt reasons operator error ,potholes while shifting aswell as incorrect adjustment.

Im more concerned by the amount of damage that it causes on this bike and wondered if it was acceptable/common that for whatever reason if a chain comes off a Carbon framed bike that the frame might end up damaged beyond repair.

Sorry if im not explaining this well.

Thanks all

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(07-22-2011, 12:59 PM)JohnV Wrote:  It shouldn't matter if the bike is made in Germany, any Cube dealer should be able to warrant the bike provided that you purchased it from a Cube dealer. Was the bike purchased at a Cube dealer or did you buy it from the Internet? The problem with buying bikes from Internet bike shops is that pretty much all of them send the bikes still in the box unassembled. If you do the assembly yourself and don't take it to one of their authorized dealers, they will drop the warranty on the bike. On Bike Forums you hear this happening all the time and there isn't much you can do but absorb the cost of any repair. You may not be getting a response from Cube because they may have no record of you purchasing the bike from an authorized dealer. If you have more than one bike shop in your area, take it to a different shop and see if they are willing to work with you.

Yes bought from cube dealer over internet,They set the bike up apart from bars and pedals and they are not interested in helping me in any way as they consider it not part of warranty.

I think there is 2 issues here.

1 Chain coming off which can happen for reasons I said before.

2 What am really interested in is the amount of damage which can occur on this bike when a chain comes off and whether this is normal/expectable.

thanks

[GeorgeET]

Cant remember ever having a chain come off. Sounds like your inner stop needs adjusting. AS far as damage , nothing you can do about it now. Make sure the chain stays on, do you use the inner cog a lot? Photos would help asses damage.

Its easy to post photos here just go to preview post and a photo insert section is on bottom.

[DaveM]

I've seen a lot of bikes where the gap between the chainrings and the chainstay is very tight (I think that is what you are asking about.) And I've seen frames get badly damaged when the chain gets wedged in there. Many companies would see the risk of this and put a chain blocker on the bottom to prevent this happening, especially on a "delicate" frame like carbon. But not everyone. No idea if you will be able to get them to warranty it, but worth it to hassle the maker a bit and see if you can get something out of them. On any bike you have to assume the chain will eventually drop even if everything is adjusted right. If you get the right combination of bumps and shifting, it's going to happen.

[Cuber]

(07-25-2011, 07:54 AM)DaveM Wrote:  I've seen a lot of bikes where the gap between the chainrings and the chainstay is very tight (I think that is what you are asking about.) And I've seen frames get badly damaged when the chain gets wedged in there. Many companies would see the risk of this and put a chain blocker on the bottom to prevent this happening, especially on a "delicate" frame like carbon. But not everyone. No idea if you will be able to get them to warranty it, but worth it to hassle the maker a bit and see if you can get something out of them. On any bike you have to assume the chain will eventually drop even if everything is adjusted right. If you get the right combination of bumps and shifting, it's going to happen.

Hi dave

Not just chainstay im talking about but full bb shell and both of the frames tubes that meets the shell.

Had a look at a giant carbon frame with similar oversized BB and there was plenty of space for chain to drop and not wedge.

Will try to upload a pic again>

Trying to contact maker but because of the language barrier might be hard

Thanks

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Not letting me upload pic!