Mountain Bike Reviews Forum banner

King ISO front disc sets caliper too close...

5K views 44 replies 20 participants last post by  Bikinfoolferlife 
#1 ·
Although the LBS faced the Fox disc tabs to ensure they are parallel, when I installed the Marta SL caliper (without shims) and King ISO front wheel, the outboard pad is touching the rotor and needs to moved right (when looking head-on at the fork/caliper) several millimeters.

I know this has been dealt with in the past concerning the various King/fork/brake combos that sets the caliper too close to the rotor (without any shims). Some have pointed the fingers at King, and at this point, I have to agree.

This is my first King front hub (all my previous disc hubs were Hope Bulbs). I've never had an issue with any of the discs (Hope C2 Pros, Hope Minis, Hope Mono Minis, Formula B4s, Formula B4 SLs, Formula B4 SL+, Shimano XTR/XT and Magura Marta SL) that I've used on numerous forks, including a Fox/Marta SL. This leads me to believe that the King is the source of the problem.

So, I can either:
1 - use the Magura tool to continue facing the Fox tabs; or
2 - use a 1mm washer between the Fox dropout (disc-side) and the King serrated washer which will push the leg outward.

Since I don't have immediate access to the Magura tool, I tried #2 and it worked. However, I'm somewhat concerned that the flat washer against the smooth Fox dropout could potentially cause the wheel to dislodge in the dropout. I guess with enough skewer tension, and the serrated washer on the non-disc side would minimize this likelihood. Also, in thinking about it, my Hope Bulbs all have flat, non-serrated surfaces and I've never had any issues.

So, what have you done to fix your problem?
 
See less See more
#2 ·
I really think it's a King issue as well. You really need to remove quite a bit of material (at least 1 mm) with the Fox/King/Marta combo and not just face them. I think it will improve as the hub breaks-in but not that much.

It was really bad when I switched forks to a Manitou_Minute. The 180mm rotor was actually rubbing the post mount on the fork. I've since dropped down to 160mm which fits between the post mounts and works better. I've tried some other hubs and they have much more clearance than the King.
 
#3 ·
Been there done that

I posted about this a few months back. It's a bad combination for sure. Many have had a problem with that combo. I had to mill quite a bit off to get things to line up, and still needed microadjustments etc.

I think most of the problem lies with Fox actually. I've heard of folks having problems with Hopes/king iso/fox forx also. I believe that all companies have things within ISO specs, but there is some leeway there. My guess. Fox has it's tabs as inboard as possible, and King likely has that shell sitting as "wide" as possible within spec. Put the two together with a caliper that doesn't allow outward adjustment, and you have a problem. I even sent a wheel to King to re-measure and they said it was within spec.

Ultimately other frustrations led me to ditch my marta calipers, but I did have things centered and working for a bit. I did need to do the microadjust trick quite a bit.

I don't like the idea of that flat washer though on the outside of the hub, I think you are right in that it may cause some slippage.

Good luck with things. I got uncomfortable shaving the tabs at about 1.5mm.
 
#4 ·
Yep, I distinctly remember your post about the problems. And, I also recall why you ditched your Martas. So far, my Marta SLs are working amazingly well on my SS and I don't suspect any issues with them on my Racer-X. But, time will tell....as it always does.

Ya, I'm not fussy on the washer either, but, I really don't think it's going to be an issue. Afterall, both Hope Bulb axle faces are completely smooth and after 5-yrs of racing and riding, I've never had an issue (knock on wood).

With that said, I'm going to try and get access to the Magura tool to remove more material from the Fox fork.
 
#5 ·
Hey Mike, can you

Take a picture of your quick fix.... I to have the King, Marta, Fox combo with some of the same issues (the rubbing went away once the brakes were broken in...). My shop has the Magura Gnanomatic (sp?) and they took off about 1 mm.

I bought an extra wheelset (XT discs), and found they rub horribly, so I shimmed the rotor on the XT front wheel to push the rotor out more. The front works ok now (switching from King to XT front wheels) however the exact opposite problem occurred with the back wheel (the XT rear axle seems longer than the King... Dooooppp :mad: ), Anyway for now I am just going to stick with 1 wheelset and maybe readdress it during the winter.

Jag
 
#6 ·
Jag said:
Take a picture of your quick fix....
Sure, I'll do it tonight...but, there really isn't much to see. I simply added a thin washer on the disc-side of the King ISO front hub. The washer effectively moves the Fox leg outward, moving the caliper with it. This gave me enough clearance to run the caliper drag-free.

Shimming the rotor would effectively make the problem worse since it is moving the rotor further into the caliper.
 
#7 ·
Yah but...

1speed_Mike said:
Shimming the rotor would effectively make the problem worse since it is moving the rotor further into the caliper.
In my case the brakes were set up initially with the King wheels in mind (longer axle)... therefore the XT front wheel (rotor) needed to moved out to match the King axle spacing...Basically I am saying that I agree with you in that the King front hub seem to be the culprit...

The reason I would like a picture is for the sizing of the washer...

Thanks,

Jag
 
#8 ·
wow, i have the exact same problem with King ISO disc front hub, Fox Vanilla forx, and Grimeca system 8 disc brakes. the outboard pad rubs against the rotor. so far all i have done to correct for this is file down the caliper mounting point but i dont want to go too far as it wont be perfectly prallel if i dont use some kind of vice/guide.
 
#9 · (Edited)
Here are some pics to illustrate the problem between the Marta SL caliper, Fox fork and King ISO hub. The caliper does not have any shims and is tight against the Fox fork's disc tabs (which have been faced already).



By using a standard washer (OD = 19mm; ID = 9.7mm; and, t = 0.8mm), this helps offset the Fox's disc leg slightly, which provides the necessary clearance. Not ideal, but until I have access to the Magura Gnann-o-mat, this is all I can do.

 
#10 ·
Same deal Fox / DT Hügi, not just King

Had the same problem with my Fox TALAS, Magura Louise/FR, and DT Swiss FR hubs. I got the fork faced, and it was still too tight by about 0.7mm.

After measuring the hub, caliper, and fork, it seemed to me the fork was furthest away from the target dimensions.

I had difficulty finding any documents that specified what the tolerances were, I concluded IS2000 is kind of an informal thing.

Another issue is the serrated washer, which digs into the fork legs by some unspecified amount.

I ended up setting up the caliper in a mill and taking off 1.2mm off the mounting surfaces. Works great but don't do it unless you are ready to give up your warranty, and can make sure the surfaces come out flat and parallel to the original ones.

I put a tad of Hylomar on the mating surface of the fork to help prevent corrosion to the mag casting when assemblng.
 
#11 ·
Chalk me up as another on the list of CK Hub + Fox Fork + Marta brake that has rub on the outside pad. It's not super bad, seems to be < 0.5mm off. And if I take spin the front wheel it will spin for >30 seconds before stopping. I plan on taking my bike in to the shop this weekend to have them machine a little bit more off the fork mounts (after I go for a ride on Saturday).
 
#12 ·
Have the same problem with '03 XT and CK

I purchased a set of wheels based on the King ISO hubs and have the same problem of too far outboard rotors with the Shimano 755 brakes on a Fox 100 RLC. The front is particularly bad.

My other XT-based wheels are fine. I'm wondering, use the 1mm washer or have the King hubs faced...

:confused:
 
#13 ·
Oh, this is just great. I've been wetting my pants because my Fox F100X, Hayes Mag Plus, and CK wheelset will be here next week and I can't wait to throw everything on my Truth. Now I hear this. Well, I'm glad I heard about it now before I started building up my frame and not after I set it on fire from the frustration.
 
#14 ·
yup...

looks like king iso disc hubs space the rotor too close to the fork. atleast if it's spaced closer towards the center of the hub, you can use spacers to ove the caliper that way.

i tried calling a few shops that carry high end stuff, and i had to repeat "do you guys do disc tab facing" with each shop rep. about 3-4 times, they didn't have the slightest clue to what that is. finally found one shop that has it, $30 and a week wait for my bike to be done....fogettaboutit.

i've got a king iso laced to a alex td17 29er rim. i tried to use a 03 xtr caliper with my rigid kelly disc fork, no dice. then, switched the caliper to a mono mini, and the clearance is ok, after i scraped some of the excess paint off the inside of the tab (don't try this unless you've got some major balls). everything seems well now, but tomorrow will be the true test, i'm taking my bike out for a long ride tomorrow. should be ok though. seems like alot of people have this problem, especially with the fox fork/king iso/marta set up.

i'm starting to like that cheap ass real disc hub i got free from a buddy (and they are $15 on ebay). it's built like a king, however the company is dead. i've got about 400 miles on it and not a single problem and the bearings are even smoother than the day i bought that thing home.

cheers!

1speed_Mike said:
Although the LBS faced the Fox disc tabs to ensure they are parallel, when I installed the Marta SL caliper (without shims) and King ISO front wheel, the outboard pad is touching the rotor and needs to moved right (when looking head-on at the fork/caliper) several millimeters.

I know this has been dealt with in the past concerning the various King/fork/brake combos that sets the caliper too close to the rotor (without any shims). Some have pointed the fingers at King, and at this point, I have to agree.

This is my first King front hub (all my previous disc hubs were Hope Bulbs). I've never had an issue with any of the discs (Hope C2 Pros, Hope Minis, Hope Mono Minis, Formula B4s, Formula B4 SLs, Formula B4 SL+, Shimano XTR/XT and Magura Marta SL) that I've used on numerous forks, including a Fox/Marta SL. This leads me to believe that the King is the source of the problem.

So, I can either:
1 - use the Magura tool to continue facing the Fox tabs; or
2 - use a 1mm washer between the Fox dropout (disc-side) and the King serrated washer which will push the leg outward.

Since I don't have immediate access to the Magura tool, I tried #2 and it worked. However, I'm somewhat concerned that the flat washer against the smooth Fox dropout could potentially cause the wheel to dislodge in the dropout. I guess with enough skewer tension, and the serrated washer on the non-disc side would minimize this likelihood. Also, in thinking about it, my Hope Bulbs all have flat, non-serrated surfaces and I've never had any issues.

So, what have you done to fix your problem?
 
#15 ·
LBS Helped Me Out

My LBS, Louisville Cyclery here in scenic Louisville Colorado, took a look at my problem. It took about two minutes of diagnosis, the guy handed me a couple of shims for the rear brake, gave me a little insight into my brake system and I went home of dialed it in.

FWIW, the front brake is maxed out on adjustment, but I was able to get it to work by taking out all shims and washers on the front brake.

Nothing like an experienced mechanic. Also, they didn't charge me a cent. Guess where I'm getting my next road gruppo...
 
#17 ·
hmm...

yea, i thought the avid mech discs were my last hope, before i took a chance with the mono mini. i ran the mono mini brake yesterday for a 25 miler, no probs with rubbing!!! thank god, i really love the feel and modulation of a good set of hydros.

then, i remembered that the avid juicy also use the cps system, and it got me thinking, maybe use a juicy up from??? i may get a wb bw.8 fork for my 29er, and the juicy will probably be the best way to go when i want to swap forks.

hey drevil, love your utilitiman!!!

cheers!

Drevil said:
Same old story with me. King ISO, Fox F80 RLT, and Hope Mini brakes. It was also ugly on the Kelly rigid fork. I had the Fox faced, and it still sucked. I got Juicy, and with the amount of side adjustment allowed, it's all good.

rickyd
 
#18 ·
Treybiker said:
Oh, this is just great. I've been wetting my pants because my Fox F100X, Hayes Mag Plus, and CK wheelset will be here next week and I can't wait to throw everything on my Truth. Now I hear this. Well, I'm glad I heard about it now before I started building up my frame and not after I set it on fire from the frustration.
The Hayes brakes have the post mounts, which allow easier alignment without using shims. I'm getting King hubs which I'll be using Hayes hydro. brakes with. Is there enough adjustment with the Hayes brakes to avoid the rub being discussed?
 
#19 ·
Well, according to my buddy, the rest of my parts (Hayes, F100X, CK wheels, etc.....) should be in from QBP tomorrow. I'm going to ride my single speed with him and his shop guys tomorrow after they close and then (start to) build it up and drink some beer when we get back. I'll let you know what I run into if I get that far.
 
#20 ·
just in case you didn't read the go-round from a few months ago, I contacted King in March and this was their reply ( they have a point in that the machining process is more accurate than the casting of the fork legs):

Sent: Monday, March 08, 2004 10:55 AM
Subject: Re: clearance issues with Iso front hubs and Fox forks


Hi Bill,

I have heard of this issue with about every imaginable combination of fork and brake. All I can offer to do for you is to have you send in your hub and we will measure it in our machine shop to make sure it it within the ISO tolerance specifications of .401" +- .010". Since we have been manufacturing the ISO hub I have never had one come back that was out of spec. You are still welcome to send it back though. Please let me know if you would like to send it back and I will assign you an RA#.

A good thing to keep in mind is that machining is a more accurate manufacturing process than casting of forging.



Thanks for your patience. We have recently relocated to Portland and are still getting settled in.

JEN
Tech/Warranty
King Cycle Group
2801 NW Nela Street
Portland, OR 97210
503.972.4050
 
#21 ·
Iso?

OLAK said:
just in case you didn't read the go-round from a few months ago, I contacted King in March and this was their reply ( they have a point in that the machining process is more accurate than the casting of the fork legs):

Sent: Monday, March 08, 2004 10:55 AM
Subject: Re: clearance issues with Iso front hubs and Fox forks

Hi Bill,

I have heard of this issue with about every imaginable combination of fork and brake. All I can offer to do for you is to have you send in your hub and we will measure it in our machine shop to make sure it it within the ISO tolerance specifications of .401" +- .010". Since we have been manufacturing the ISO hub I have never had one come back that was out of spec. You are still welcome to send it back though. Please let me know if you would like to send it back and I will assign you an RA#.

A good thing to keep in mind is that machining is a more accurate manufacturing process than casting of forging.

Thanks for your patience. We have recently relocated to Portland and are still getting settled in.

JEN
Tech/Warranty
King Cycle Group
2801 NW Nela Street
Portland, OR 97210
503.972.4050
What does a Chris King "ISO" hub have to do with ISO (as in www.iso.org)? Are they using "ISO" as a brand name or what? :confused:
 
#22 ·
dave_f said:
What does a Chris King "ISO" hub have to do with ISO (as in www.iso.org)? Are they using "ISO" as a brand name or what? :confused:
There is an International Standard spec for disc brakes which includes measurements and tolerances on calipers, rotors, hubs, fork mounts, etc so they can all work together. Several years ago everyone had their own mounting, 4 bolt Formula/Coda, 5 bolt Hopes, 6 bolt Hayes etc. Now almost everyone follows the 51mm mounts and 6 bolt rotors. The most noteable exceptions would be Manitou's insistance on 74mm Post Mount and Shimano's centerlock rotors.

Anyway, King used to sell a universal disc hub that used adapters for the many different mounts. Since almost everyone adopted the IS 6 bolt rotor mount, King decided to make an IS specific hub and called it the ISO Disc.
 
#23 ·
follow you so far

Homebrew said:
...King decided to make an IS specific hub and called it the ISO Disc.
I know it sounds like splitting hairs, but calling an "IS specific hub" the "ISO Disc" may be misleading. Maybe the following could help:

Statement:

"we will measure it in our machine shop to make sure it it within the ISO tolerance specifications of .401" +- .010"

Possible translation 1:
"we will check it to make sure it's within the manufacturing tolerances of the design specifications we made up for that part. Whether anyone ever has or will make a fork or brake that will work correctly with it is unknown."

Possible translation 2:
"we will check it to make sure it's within the manufacturing tolerances as specified in IS(O?) standard number xxxx, revision y.y which ensures that forks and brakes manufactured in compliance with that standard will work together."

Which translation should I be reading?
 
#24 ·
dave_f said:
What does a Chris King "ISO" hub have to do with ISO (as in www.iso.org)? Are they using "ISO" as a brand name or what? :confused:
ISO publishes standards: thats exactly what they do. Information on what they are and how they are funded is available on their website. maybe you should be the chairman of the bicycle comittee :D Big advantage to manufacturers is that their stuff will bolt on to other peoples stuff. With Shimano, they feel that they are big enough that people can just damn well buy their BB for their cranks
 
#26 · (Edited)
dave_f said:
I know it sounds like splitting hairs, but calling an "IS specific hub" the "ISO Disc" may be misleading. Maybe the following could help:

Statement:

"we will measure it in our machine shop to make sure it it within the ISO tolerance specifications of .401" +- .010"

Possible translation 1:
"we will check it to make sure it's within the manufacturing tolerances of the design specifications we made up for that part. Whether anyone ever has or will make a fork or brake that will work correctly with it is unknown."

Possible translation 2:
"we will check it to make sure it's within the manufacturing tolerances as specified in IS(O?) standard number xxxx, revision y.y which ensures that forks and brakes manufactured in compliance with that standard will work together."

Which translation should I be reading?
ISO is pretty specific and much more meaningful. it is not necessarily the same as IS. I can assume that there is an ISO published standard for bicycle disk brake hubs, which includes the dimension mentioned above. Maybe you can do some research on this and get back to us.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top