I’m looking for some advice on an ongoing issue with a Zipp front hub on a mountain bike. The wheel is a Zipp Moto 3Zero.
I’ve repeatedly had problems with the front hub end caps deforming. After some use they seem to “mushroom,” making the thru-axle extremely difficult to remove. When I unthread the axle, the drive-side end cap remains stuck on it, so the axle won’t pull through the fork. The only way to remove it is to fully unthread the axle, let the fork legs spread as the end cap bears on the inside of the dropout, then drive the axle out from the non-drive side with a punch and hammer. Reinstallation requires hammering the axle back in.
I’m now on my third set of end caps in ~18 months, and the same issue has occurred again. SRAM warrantied the first two sets, attributing it to “impact damage.” This has happened across multiple forks (so I don’t think it’s a dropout issue), and all axles have been torqued to spec.
My question is: what obligation does Zipp/SRAM realistically have to resolve this? My concern is that sending the wheel back will just result in another set of end caps and the problem repeating. At this point, is it more sensible to cut my losses and rebuild the wheel with a different hub?
Any insights or similar experiences would be appreciated.
Where did you purchase the wheel? This may be one of those situations where the outcome is dependent on who is helping you. Are you speaking to SRAM directly, or through place of purchase? An established SRAM dealer may have a better relationship with the warranty people to get them to agree to something, which the customer service bods at a large retailer might not be able to do.
Do you have any pictures of the mushroomed end caps? Just out of interest
Doing the same thing over and over and expecting a different result is insanity. Contact SRAM directly and ask what their solution is. What fork are you using? Any mods? If they don’t offer different end caps that are stronger or an upgraded more robust hub, I suggest you rebuild with a more robust design. How long until the hub is damaged? Do they even have a stronger design? Obviously there is some flex in the system and the design is failing. Sucks but you’ll just continue to do this over and over again, it won’t magically get better on its own.
Unfortunately I can’t go through the original retailer. But a close friend of mine runs a little shop so to some degree can speak with SRAM directly through him.
‘Mushroom’ was perhaps a poor choice of words, you can’t see any deformation, I just assume it’s there because the end cap no longer slides over the axel freely, for instance if I hold just the end cap, the axel will not slide through unless I literally hammer it on.
One solution I did consider was to offer to send the Wheel with alternative hub and see if they will just build it up to that hub as a comprise. The issue I have is it’s a weird wheel and it’s very difficult and expensive to get the correct spokes and nipples in Australia.
Forks have been Fox 38 and RS Lyric. Agreed it’s unlikely to resolve with new end caps. Unfortunately Zipp doesn’t have an alternative hub. I’m thinking I might try see if they will agree to build it up to a DT 350 supplied by me as a compromise, I have one sitting around.
I agree that if they rebuilt with a different hub, that would be a good compromise. The sram website says ‘lifetime warranty’ so they could send a couple dozen endcaps instead.
Does the rim require special nipples because of the single wall design?
If memory serves, special washers but not special nipples (I’m pretty sure Zipp use Sapim in most of their wheel builds anyway), point being aside from the washers, you might find it easier to order the correct size and type spoke from a Sapim stockist than ordering a pack of spokes from SRAM as a Zipp spare.
In most Zipp wheels you’ll find nipple washers. It’s a pretty common practice in many carbon wheel sets. Rebuilding with another hub is a pretty easy endeavor with a competent wheel builder. Make sure they de-tension the wheel before removing the spokes. I’d also avoid cutting the spokes, just remove each one by one. SAVE THE WASHERS if they are present, they likely have a proprietary shape matching the profile of the rim and are probably tough to get replacements. Replacing the spokes and nipples is best practice in a situation like this as well. I doubt that a DT 350 hub and the Zipp hub have similar enough dimensions to ensure the spoke lengths are the same, so I would guess a factory rebuild wouldn’t be an option. They may credit a shop for labor in the form of SRAM chains.
++1 on this. Rebuild it to a DT350 with the special nipple washers and enjoy the little faff it will give you. If I was in your boat, I would even do the 350 rebuild even if I had to pay out of pocket, just due to the numerous design/QC related reliability issues seen on most Zipp hubs.
Sorry you have to deal with this lack of accountability/ownership of this issue by Zipp. It’s pretty appealing (and embarrassing) coming from this big of a company.
Chains as a form of warranty labor credit is a uniquely awful bike industry thing lmao