Any advice and/or recommendations are appreciated!!!
Needless to say, I am extremely upset!!! I have a 2007 Cervelo P3C with a Zipp VumaQuad Crankset and just noticed today that the small chainring has damaged the chainstay on the drive side as a result of the rings flexing and digging into the carbon!!!
I guess I should have listened to the various posts on this forum and others as well as the shop mechanics advice that the chainrings are a “cheap-ass” piece of aluminum that move and flex…you probably won’t like them.
So, is there anything I can do? Are there any Zipp representatives out there? I now regret buying a premium product only to find out that it provides inferior performance for the price along with damaging my frame.
There have been warnings about the Zipp VumaQuad’s being “flexy” and I guess I proved it the hard way!!!
Thanks for your help in advance…
Tom D. and/or any other shop owners or product reps., have you guys seen similar issues? If so, any advice? Will Zipp stand behind their product?
P.S. If anyone is interested in a set of Zipp VumaQuad’s I will be donating them for a tax write-off!
you didn’t put the “spacer” on one side as per instructions… Spacer 2 & 3. You could loosen the crank arm and pull it out to see the “gap”. I have installed a few and NOt used the spacer and been fine and I believe it was a Soloist SLC-Sl that the chainring rubbed and I re assembled it with the wavy washer and it was perfect. Just a hair differce makes all the differce. Go back to your shop and ask.
I did not install them…a very reputable local tri shop did. Can you describe the spacer from product sheet? Would I be able to see whether or not it is installed?
don’t be so quick to bash a product or its engineering…who has more experience? the guys who designed the product, the shop mechanic or you? I’m not bashing you, but it it seems to be a time honored slowtwitch tradition to instantly bash a product if something is not working properly and more often than not its user/mechanics error.
For what its worth, I use Vuma’s on My P3c and they are fine. Never a problem, no flexing into the stays, etc…they were installed properly and work as well if not better than I expected. And they look good to boot.
If they were installed incorrectly, find a new mechanic and shop…no excuse for a “reputable shop” to f-up installation on a $1000+ crankset.
P.S. If anyone is interested in a set of Zipp VumaQuad’s I will be donating them for a tax write-off!
I’ll take 'em! Please email me at acoggan at earthlink dot net if you’re really serious.
The damage occured from where the small chainring is connceted via one of the crank arm bolts. The inside face of the small chainring at this point which is square in shape…both edges of the “square” which are pointed have dug into the bottom bracket/chainstay area on the drive side.
I guess a question to be asked in this situation is who do you trust or listen to? The shop or the manufacturer?
I would like to think that the mechanics know more than most when it comes to bikes & setup, since they see a lot and work on a lot of different setups. I guess in my experiences I would trust a shop mechanic more than just a salesperson on the floor.
I will find out more when I have had a chance to take the bike in over the weekend to see what feedback I get. I’m just assuming in this situation that between the shop and manufacturer both are going to point the finger at each other while I’m left with frameset that is damaged as a result of being between the two. I’ll keep my fingers crossed and post an update later…
Sorry to be so late showing up to the party here…usctriguy also posted this to our LiveChat board, but I have been in Taipei all week for the bikeshow.
We have seen this before, and there are a couple of issues converging on the P3 that lead to this problem almost exclusively on this frame.
One, cervelo have chosen to flare the chainstays out behind the BB area, other manufactures are also doing this, but they push it a tiny bit further than most, and that significantly reduces clearances, many manufacturers such as Cannondale have also chosen to do this on the non-drive side and leave the drive side much flatter which is also a good solution.
Two, this is a hand finished area of the frame as there is a bond line under the paint in that area, that means that the size control of the frame in that area is done mostly by hand, so there can be a bit more variance here than in other areas in the frame.
Three, the vumaquad is unique in that the chainline is controlled by the non-driveside cup and not the driveside cup. For the other posters talking about putting in the bearing shims, this is the wrong solution, the shims only increase bearing preload and DO NOT affect chainline. the only way to change the chainline is to move the non-drive side cup in or out. This is why we require the frame to be chased and faced during installation, and in almost every case I’ve ever seen, the BB’s on carbon bikes are too wide due to the tolerance stack of bonding the cups into the frames. This leads in most cases to the chainline being too large when chainline is defined by drive side cup locations, but in our case, it leads to the chainline being too small due to the non-drive cup being spaced too far out board, leaving the crank too close to the frame. Of the 3 employees internally with P3’s and plus Kristen Armstrong’s olypmic winning P3, all required the non-drive face of the BB shell to be faced inward about 0.25-0.5mm to acheive proper chainline with the VumaQuad. Lastly we had one of our hardcore track guys score his P3 Track chainstay using a Campy Record track crank, he had about 0.25mm clearance, but it wasn’t enough. Fortunately the damage was only to the paint and was no risk to the frame, I would hope that your situation is similar. Realistically to do damage to the carbon, you would likely have felt the bolt scrapping against the frame, but a qualified shop should be able to inspect it for you and tell for sure.
Essentially, the shop needs to just face the non-drive side bb shell a bit and the problem will be eliminated. As for the discussion of flex, this has nothing to do with crankset flex, and we have tested in on our CEN crank testing fixture that even at the required load of 405lbs, the movement of the crank in the chainstay area is roughly 0.004" as the chainstay is almost collinear with the axis of deflection of both the crank and spindle. This is less than 1/5th of the frame deflection relative to the BB in this area under the same load, so depending on the use and load, you likely need somewhere between 0.5 and 0.75mm clearance in the unloaded condition to gurantee clearance.
Thanks for the help. I appreciate your help and everyone else who helped with this issue. Please do not take any offense to this, but merely an observation…
if Zipp is selling a $1,000+ product to the consumer and with the popularity of Cervelo especially within the triathlon market (I believe they are the #1 bike at Kona?) don’t you think the information posted above is important enough to inform both the consumer and retailer, so they can be better educated and hopefully avoid these types of situations, especially when it is known (i.e. “We have seen this before” and “I would hope that your situation is similar”)?
Good thing that it is only a cosmetic issue and not worse…