UltimateSL7

I've been dealing with an issue where my front wheel is basically slanted to one side. Mechanic confirmed the wheel is dished perfectly but the dropout tolerance/alignment is not precise. We've tried few different wheels and no matter how you flip the wheel, it's tilted to the same side.
Basically the dropout on one side sits about ~1mm higher than the other side so for the wheel to sit vertically straight, the axle and the dropout needs to have a gap of 1mm to compensate on the shorter side. So what I would have to do is manually center the wheel which means on the one side, the axle is not touching the dropout and then I tighten the QR. My understanding is that the axle needs to sit in the dropouts as the QR nuts are not designed to hold wheel if it's not fully seated and my mechanic said if you put enough body weight, it will shift into the dropout and the wheel will tilt slightly again.

It's a Canyon Ultimate rim brake and Canyon has been great in replacing the fork but the new fork I got is the same issue except now it's tilted to the other side. I was told not to file anything off the fork such as the dropouts as that can compromise the integrity of the dropouts.

Canyon will be sending me another fork to try but I'm wondering if I'm chasing my own tail here? If it's an Aliexpress frame, then I'll be fine with it but spending thousands of dollars, I just want to get a fork that's symmetrical so the wheel at least sits straight.

Let me know your thoughts...My mechanic said get a new fork fork from Canyon but have them check the fork before sending out another one. Is my expectation too high? Is this something common on other brands like Trek/Specialized? I kind of feel bad for Canyon having to send out 2 replacement forks. If the next fork also has the tolerance issue I'll probably just live with it at this point.

grumpus

Sheldon thinks the QR skewer alone is sufficient to hold a rear wheel in place, but that means having to tweak the wheel every time you fit it. My inclination would be to tickle it with a milling cutter (9mm,10mm?), to avoid that you could epoxy a small metal spacer into the dropout. I'd be sure to tell anyone who would listen about how Canyon can't build straight frames (if this is definitely the problem - does the mechanic just want to slag off Canyon because you didn't buy it from him?).

HillRider

If the third fork still has the problem, I would glue in a spacer as suggested above. I would not mill away material from one dropout on a carbon fork.

FBinNY 

This is where decent hand skill and a well suited file are your best friends.

If you don't have one, buy a RAT-TAIL file of medium cut (too fine and you'll be there all day, too coarse, and it's easy to over file), and a diameter as close to, but smaller than 9mm. Now it's only a question of removing a bit from the tip of the slot in the longer blade, so that side of the axle goes deeper, moving the top away from that blade. Note that there's something like a 6 or 7 to one ratio for rim position vs. slot depth, so file only a bit at a time, and test often. Finish by nicely shaping the oval, keeping in mind that you want a U not a V shape so the axle is solidly on then bottom instead of cradled. If filing directly into carbon, be sure to seal the exposed edge with lacquer.

Of course, if you do go a bit too far, you can correct by filing from the other side. However don't make this a sketch comedy routine whereby you try to eliminate rocking of the dining table and end up with a coffee table.

BTW- if you have bad hand-eye coordination you can improvise a guide to keep the file square, using a 5/16" OD tube forced over the tapered end of the file,


FWIW- Online offerings often fail to provide details of diameter or cut (they give length which you care about least) so I suggest going to a store where you can see before buying.

Andrew R Stewart 

I have seen this carbon (and AL) fork blade length discrepancy a lot. The rim is off center often only a couple of MMs. With about a 3x factor (dropout width VS rim radius) that means about a half MM of dropout slot removal is often the amount to be filed out.

What can't be changed, but still could be in play, is blade splay to either one side of center or in a twisting manor (axle VS crown not parallel). With a steel fork both of these can be "prodded" but with Al or carbon forks I consider these to be uncorrectable. So, having a corrected centering wheel might look right but still be less then aligned. Andy

UltimateSL7

Thanks everyone for the great replies. Canyon has advised not to file anything on the fork, could be for a liability reason.

They acknowledged it’s a small production defect and asked if I wanted another fork and I said yes so I’ll probably be getting a 3rd fork.

I know there are manufacturing tolerance specs so I’m not sure if this is just reality with carbon bikes or should I expect better especially it’s a name brand.

It doesn’t look too bad if you don’t pay attention to it because the rim brake short of covers that area but every time I wash my bike and look at the wheel from behind, it’s just awfully tilted to one side.

HillRider

Maybe I've been lucky or you (and Andy) have been unlucky but I have owned two aluminum and 5 carbon forks over the years and none of them have had the misalignment you have. And, yes, I'm fussy enough to have noticed. I hope third time is the charm for you.

FBinNY 

Let's face facts here. The number one priority in fork design and manufacture is proper alignment of the front wheel so the bicycle tracks correctly. Forks, including many relatively low end models have done so for over a century.

While it's possible that a fork could do that even if it looks very wrong, the odds are against it.

Calling it a minor defect indicates, to me that the company isn't serious about quality, and places marketable features above function and performance.

In short. They simply don't care.

CliffordK

It is probably best not to do any major modifications on the fork while it is still under warranty.

With some fork alignment tools you can determine if the fork blades are aligned properly.

UltimateSL7

I really didn’t anticipate that I would have to deal with fork alignment issue with Canyon. I have 2 low end Trek and Giant bicycles and I’ve never had that issue. Hopefully the 3rd fork will do the job, if not I’ll just live with it and avoid the brand next time.

I don’t have enough posts to post picture at this point but just the way that the dropout areas are moulded on these canyon forks, they look really cheap quality. Something that you might find on eBay/Aliexpress forks.

CliffordK

Upload some photos to your album and we can snag them.

https://www.bikeforums.net/g/user/560043

https://www.bikelockwiki.com/where-are-bikes-made/

I'm not surprised that they're apparently using Taiwan as at least part of their manufacturing.

It may be that younger, smaller companies have growing pains, especially when importing from China or Taiwan.

Ideally they would have a jig that they would test 100% of the forks/frames for alignment. But that would mean an extra step, likely automated.

FBinNY 

Please don't just live with it. If the 3rd fork isn't right, send it back, and keep doing so until they either get it right or decide you're a PIA and send a refund instead.

Companies get away with poor quality because, either their customers aren't discerning enough, or are "willing to live with it".

The ONLY way makers will focus on quality is if their customers make the cost of dealing with poor quality more expensive than producing quality in the first place.

Consider ----- You paid them with quality money, not some counterfeit bills, so poor that they'd be easily spotted. They need to deliver on comparable quality.

Sidebar----
I was a manufacturer for most of my life. Early in my career, I visited an old line company, I was considering to produce a component for me. I spent time with their engineer tweaking my original design based on production considerations. In the end, I had a part better than I planned on, for less money. As I was leaving, he handed me a pencil out of a jar on the desk. I was about to toss it into my bag when I noticed that it had erasers on both ends. I looked up and he said "read it".

"if you don't have time to do a job right, where will you find the time to do it again"

I've kept this in mind, and it was reflected in things that I manufactured. It's now your job to make the folks at Canyon wish they'd seen one of those pencils.

oldbobcat

For the record, Taiwan is the premier producer of consumer-grade products of carbon fiber. There is more expertise in mass producing bicycle frames here than in any other place in the world. It wasn't always this way. I remember stories about Scott, not supervising the production of CR1s closely enough 20 years ago, but those days are long gone.

Some of the solutions recommended here are pretty radical for never having seen the problem in person. I would not pass a verdict on this for until I checked the alignment with a dropout alignment tool.





Obviously nobody should try to cold-set a carbon fork, but I'd want to see what it looks like before going further.

UltimateSL7

Thanks everyone. I’ve uploaded few pictures which show the poor quality/moulding deformity of these carbon forks. Since I can’t post images or links yet, if you click on my profile you might be able to see the photo album.

On both forks, one side is always perfect like one of the photos and the other side is basically deformed. The first fork that came with the bike, the deformity actually interfered with the quick release nut.

In terms of alignment, one of the photos show how I have to position the hub relative to dropout to Center the wheel vertically. On both replacement forks, I basically have to do that on different side.

let me know what you think about these images. Is that normal with carbon moulding or is it just lousy QC?

FBinNY 

The aren't terrible looking, but also not what I'd expect on a quality fork. Keep in mind that cosmetics don't directly affect function, however makers knowing they have fussy customers try to do better on that front.

It's now moot as regards that fork, but curiosity would have me checking that the dropouts are square and parallel, as mentioned above. You do not need an expensive tool for the job. A straight 6" threaded rod, a few washers and 2 nuts is all you need (LT $5.00 at the hardware store.

Thread on one nut and washer, and adjust so the rod can sit inside one dropout and end just shy of the other. Add the washers and 2nd nut and tighten firmly. (don't go crazy, you're not riding it.)
Now sight through the opposite slot, and the end of your rod should be right where it would be if it sat in the slot. Repeat for the other side.

BTW - I know i'm being tough on Canyon here, but IMO if companies have adopted the attitude that their customers are going to be the final QC inspectors, it's up to those customers to do their job well.

Andrew R Stewart 

This needs to be repeated. Carbon structures should not be attempted to be aligned by bending. Even with this added caution note someone here will not read the text and instead will see the images and think it's the right process for their fork.

All this focus on dropout alignment and using "H" tools to check and/or correct, is nearly meaningless here. Drop outs not being parallel is the least important aspect of alignment, there's no bike steering/tracking issue when the drop outs are only non parallel. But since we have the tools to see non parallel drop out condition we tend to place importance on it and under value the other alignment aspects (which have far fewer tools to check for). The only "safe" aligning is by removing drop out slot material, the filing that a couple of us have mentioned. And this blade length adjustment will only correct one aspect of misalignment. Andy

UltimateSL7

Cosmetic wasn’t something that I was too concerned about but I noted because it is not a “cheap” bike.

Alignment is my biggest concern because the mechanic/and I cannot make the wheel vertically straight without filing or adding material.

If this is something that one should expect..I know it’s not a $15k S-Works, then I will be ok to live with…

oldbobcat

Yeah, that looks like crap. I know that Scott, Trek, Specialized, or Giant wouldn't try to pass off work like that. Or if something like that snuck out, they'd warranty it it a minute.


And filing the dropout slot won't change anything because its the shape of the blade cutout hitting the skewer end and axle end nut that's causing the misalignment. The third image here shows a glimpse of the inside of the opposite blade, showing that they are essentially symmetrical at the dropout end.


Possible solutions: (1) Send the photos to Canyon and ask them what they think; (2) Return the bike; (3) try a wheel with a smaller skewer end and smaller endnuts; (4) buy an aftermarket fork from a reputable supplier. And if you send photos to Canyon, include an inside view of the how the axle fits on the inside of the fork blade.

Thinking about this, I'll surmise that Canyon designed this fork around a specific wheelset that just happened to have smaller endnuts and skewer ends. The face on that axle nut is huge.

oldbobcat

Andy, the purpose of my post was to recommend further checking before taking a file to the fork. And as you can see from the photos, filing the dropout would only make it worse.

UltimateSL7

On the original fork, the initial diagnosis was the QR nut was too big and the deformity is hitting it. First thing mechanic did when I took the bike there was to grab a smaller QR from his shelf and tried it. 10 minutes after he said the second problem is the dropouts aren’t aligned - nothing can be done other to do some filing which he is not willing to do. Smaller QR didn’t really solve the issue.

FBinNY 

You don't show the back side, nor do I think it's possible to photograph it usefully, but I suspect that the issue may be the locknut on the hub.

Measure it across the points of the hex and compare to the inside pocket on the blade. If you have a dentist friend, beg a few pieces of bite test film. This will give conclusive evidence that the locknut edges and fork touch.

If it is the hub locknut, and if that hub came with the bike OEM, than you have conclusive proof that Canyon is totally lacking in engineering and design staff. If as they claim, stuff is made in Far East, and brought to Germany for final QC, then I wonder what those QC people are doing with their time.

CliffordK

You can always try sitting it on the ground with the wheel/axle in the fork without a skewer which would give you a better view of what is happening.

I've always been a little suspicious of pure carbon fiber dropouts. If you clamp the skewer down hard enough to hold the wheel up off of the dropout, then you'll likely damage something.

Too bad, if a company knows they have a return, they don't take the time to verify the replacement part is properly aligned and functional.

oldbobcat

Yes, but he wasn't looking at how the nuts were fitting on the inside. Lacking alignment tools, try fitting a Shimano or Campagnolo front wheel made built around a "standard" hub, and report back.

oldbobcat

We're on the same page.

CliffordK

From the OP's album:
https://www.bikeforums.net/g/album/26616744



The inside has a similar profile to the outside.

So, it is quite possible that the issue could be on either side of the hub and locknut or the skewer.

As I mentioned, sitting the fork on the hub without the skewer will give a better view of how well the axle is seating in the notch.

If this was sold as a bare frame, then the buyer has to find hubs to match the frame.

On the other hand, if it was sold as a complete bike, then the manufacturer must ascertain that all the parts work well together.

Nonetheless, the bike should have at least a little tolerance for parts variation.

Could hubs with end caps work better? I'd rather a smooth surface interacting with the CF dropouts anyway.