What the.. !!

[Tangoup51]

Interesting story with no conclusion (Yet)

So, my bike is a Team boardman 2014 CX - I've had it for two years and It's only recently after swapping my front disc rotor I noticed something "Quirky" about this bike.


The front fork, FYI, is a Rigid XC Disc design made from full carbon (except the odd alloy insert)

I upgraded my front Rotor from The stock Avid G2 cleansweep to a two piece Shimano Ice tech rotor; after doing so I had noticed the rotor Would Not Turn when on the bike, this was because the 6 Rotor bolts that mount to the hub were catching on the bottom leg of the fork (The leg that goes directly to the lower caliper mount bolt)

This annoyed me, but I got clearance thanks to a metal file and some minor tinkering.

Some time later, This problem bugged me as it persisted at the back of my mind, having about <1mm of clearance down there. I had purchased protective stickers and even resorted to marking the rotor heads with a paint so I could see if it ever was catching. This worked fine.

But I did not want to write-off my fork before the warranty ran out this upcoming December, so, i refunded the rotor and went back to Stock Avid!

.. This did not cure the issue, infact! it made it worse.

After mounting the *ORIGINAL* front disc with the *ORIGINAL* 6 mounting bolts.. It was catching! Imagine that?

Now, I have yet again gained clearance by swapping rotor bolts to a smaller type with "Filed" heads.

You can see from the pictures how close the gap is. - Also, if you will note that my protective sticker was "ripped" up a little from when the original bolts went through them, you can see a minor indentation in the fork leg, that's just where the paint was chewed away, beyond that ridge is carbon fiber.

This is about 0.5 < MM of clearance that you see on the photos.

I've tried installing washers on the axle but it simply pushes the caliper too far outboard and the rotor catches on it the caliper, even with Hilariously skinny washers.



I am all out of ideas now, I tried contacting boardman but they only advised me to take it into a LBS.

I don't think an LBS would be able to solve this issue however. What are your thoughts/ideas?

(Yes, this was a halfords bike, but I did all the building and assembling myself)


Final Note: The Rotor Bolts Do Not Catch, there is still a 0.5MM < Clearance, but is this safe?

 

[winjim]

Have you taken the hub apart at all? You may have a spacer in the wrong position.

 

[Tangoup51]

I took apart the hub in the quest to find this issue. I had two spacers equal size on either side, I ensured the axle width was equal throughout; despite swapping spacers of various kinds and in various ways The best I could do was Either getting the problem fixed with the Rotor bottoming out laterally and hitting the Caliper; or the original clearance issue.

 

[cosmicbike]

Never noticed it on my 2014 CX Team. If I get a minute I'll pop out and grab a pic.

 

[Tangoup51]

That'd be smashing mate.

 

[cosmicbike]

Sorry for the delay, was at work last night and didn't get a chance to get out. Mine is stock, out the box with the exception of the brake calipers which were changed to BB7's. It is very tight indeed....

 

[winjim]

I took apart the hub in the quest to find this issue. I had two spacers equal size on either side, I ensured the axle width was equal throughout; despite swapping spacers of various kinds and in various ways The best I could do was Either getting the problem fixed with the Rotor bottoming out laterally and hitting the Caliper; or the original clearance issue.

Had you dissassembled the hub prior to installation of the rotor? Are you certain that the spacers are exactly the same thickness? I have spacers in my hub which are about a fag paper different but which cause a similar issue if they are installed the wrong way. Also, how are you adjusting the brakes after changing the rotor, do you slacken off the caliper mounting bolts and basically refit, or leave the caliper in place and hope it slots back in?

Incidentally, what makes you think an LBS would not be able to solve the problem?

 

[Tangoup51]

Sorry for the delay, was at work last night and didn't get a chance to get out. Mine is stock, out the box with the exception of the brake calipers which were changed to BB7's. It is very tight indeed....

Thanks for this pic, it gives me some peace of mind, I ask you not to be concerned either as there is nothing you can do to get that 0.5MM< Gap closed, whether it's play in bearings or hard cornering I have not been able to set off the rub. - If you're using a single piece rotor you will also find if it does ever "catch" it pushes the entire rotor outward, so the action has somewhere to go.

Also you may want to find some protective stickers you could put down there, anything thats skinny but indeed strong. Debris gets shoved inbetween the rotor bolt heads and the fork and can chew it up over time.

Thanks my man.

 

[Tangoup51]

Had you dissassembled the hub prior to installation of the rotor? Are you certain that the spacers are exactly the same thickness? I have spacers in my hub which are about a fag paper different but which cause a similar issue if they are installed the wrong way. Also, how are you adjusting the brakes after changing the rotor, do you slacken off the caliper mounting bolts and basically refit, or leave the caliper in place and hope it slots back in?

Incidentally, what makes you think an LBS would not be able to solve the problem?

Thanks for your questions.

I have disassembled the hub and rotor many times in order to find a perfect balance and fit. I ensured each installation was as equal and accurate as the last, whether it was axle centering or correct torque on the rotor heads.

Yes, I am sure. The spacers are cheap generic Chinese ones and they are absolutely identical, they may be cheap however but they aren't biased to any particular direction or side.

Another good question there,

After I finished checking the hub and rotor - I put it all back together and tightened the QR skewer to a "moderate" firm, but nothing super ridiculous,

from there I have the brakes completely disengaged (even caliper mount bolts are loose) and I find success in tightening the inboard pad all the way in and then tightening up the caliper mount bolts gradually.

Afterward it comes out with a snug and correctly aligned fit. - The Caliper alignment on that picture looks off but I can assure you it is indeed correct.

The problem occurred after editing spacers in any way to bias the left (disc) side.
In which case, even after bottoming out the inboard pad so it is pushing the caliper furthest possible away from itself, after tightening the caliper bolts down the rotor would continue to rub against the inboard pad until the inboard pad was disengaged completely. - At which point the rotor would start engaging with the caliper.

I had tinkered with this many times, but with any kind of small spacer I had there was no way I could get the rotor from side-kissing the caliper.

My only ounce of success came when I decided to create a "Plastic" or "epoxy" washer, made from light-plastic (which was some times coated with epoxy) to put as a spacer on the OUTSIDE of the hub, without interfering with the Tiny male/female splines that hold the wheel on in the QR mechanism.

This had worked, but, it didn't make me feel entirely safe.



As of now, I have gained clearance and I Don't think the forks are designed to be at all far apart. I would advise some protective stickers down there as debris does get stuck inbetween bolt heads and the fork from time.


Thank you for your advice however it is much appreciated. !

 

[Ajax Bay]

An interesting challenge: thank you for sharing.

As an aside, please note, @Tangoup51 , that @winjim does not normally post in Times New Roman, and infer subliminally what you wish.

 

[winjim]

An interesting challenge: thank you for sharing.

As an aside, please note, @Tangoup51 , that @winjim does not normally post in Times New Roman, and infer subliminally what you wish.

I don't know what you mean. But yes, interesting.
That does look like a very tight fit, even on @cosmicbike 's photo. What make and model are the hubs?

 

[cosmicbike]

I don't know what you mean. But yes, interesting.
That does look like a very tight fit, even on @cosmicbike 's photo. What make and model are the hubs?

The hubs are not marked in any way, and Halfords simply list them as 32 hole 9mm quick release. Rims are Mavic Xm319 but of course have no bearing on the subject.

 

[Tangoup51]

I don't know what you mean. But yes, interesting.
That does look like a very tight fit, even on @cosmicbike 's photo. What make and model are the hubs?

Mmm. Interesting banter here. - That question popped into my mind recently too, and I found some answers.


You see my rear wheel is a 10 speed cassette, and the freehub body on mine isn't a dull boy, considering all the play in it.

Considering the mileage of <1K miles I investigated the matter further; discovering to my surprise that the 10mm Allen you need to take off the freehub body whilst in the axle was actually a 11MM Torx key of some kind, After investigating this was due to it being a cheap-knock-off hub of some earlier less common designs for this type of freehub.

Or atleast, that's what I found online. I Also scored out Boardmans own website to check out their own range.

They do not list their Halfords sponsored bikes on their websites, but despite that I still found the same generic cheap hub on the front/rear wheels of sub <£600 models.

So I don't think the cheap hub had any relation to Halfords, it's just a small cost-cutting edge that boardman took to put it in a lower price bracket. - Just like they did on this bike with the front mech, which has its own place in hell reserved already.

But the hub provided on this bike isn't the cheapest thing in the world, it feels more of a pre-modern shimano rip off.

 

[cosmicbike]

I do find it entertaining that most people hate the SRAM Microshift FD on these bikes. I've covered just shy of 6000 miles on mine in all weathers and find it shifts perfectly.

 

[Tangoup51]

I do find it entertaining that most people hate the SRAM Microshift FD on these bikes. I've covered just shy of 6000 miles on mine in all weathers and find it shifts perfectly.

I don't believe it's backed by Sram. There's an own company called Microshift and they make that specific derailleur. Unless i'm mistaken which I'm sure i'm not.

Also, yes, it shifts fine but it is INCREDIBLY heavy. I just bought a Sram Apex FD for £20 and My god it's so much easier to shift, i'm talking about on the paddle, it no longer feels like a gearbox in a Soviet WW2 tank, besides it's nice to have the Apex shifter going to an Apex derailleur, both in feel and in mindset.