Topic: Poxy frigging brakes!!

[mcpuffett]

i agree with Den, i have had issues with the inner piston sticking after the bike has been sitting for winter , and if your bearing retainer is'nt going in all the way it could be that your bearing is'nt all the way in to?

did you not have to have something made regarding your bearing ?   mick.

[Jim Shea]

My bikes looks the same as Spitfire, the spacer with the collar is on the brake side and the flat spacer is on the chain side, so hopefully that is correct. I had to have the bearings replaced and when the new ones were put in they were loose so a bead weld had to be put in. I still think the bearing retainer should be flush and that is the problem, quetion is why didn't the mechanic do it up all the way in? I will ask him today.
Jim.

[mcpuffett]

i'm guessing that the bead weld was put in the recess were your bearing goes then ground down till your bearing was a tight fit?  could be that your bearing is hanging up on that?   mick.

[Jim Shea]

God knows!! I just spoke to the mechanic and he said they were pressed in properly and were OK!! He also said that the 'top hat' shaped spacer does not sit against the bearing cover so it's not that!!
I am going to get some DSS pads as I have heard that EBC sintered pads can be larger than the 'original' ones?? Anyone heard this or had a problem with EBC pads being larger? The mechanic had a Kwakker Z1 and he fitted EBC pads and they were too big and he had to put standard ones in!

[Jim Shea]

I spoke to DSS they say that the pads would be the same thickness, back to square one; why is the disc not central and how do I sort it!!

[bryanj]

Sounds to me like the bearing isnt all the way in. The spacer should be tight against the bearing inner, to confirm just unscrew the retainer ring and put the wheel back in without it temorarily to see if the problem still exists

[Jim Shea]

Bryan,
Thanks. I was told that the spacer did not sit flush against the bearing retainer. If you look at spitfires pics, mine looks like that?
Jim.

[spitfire]

Hi Jim,
        From my own knowledge of my bike which I have owned since new and the Honda CB750F/F1 parts book (see previous post) does go on the disc side, also just checked my Honda Worshop manual's supplement for CB750F which again clearly shows this. I'd have a word with your mechanic if I were you !
The bearing retainer should be flush as on my bike, as I said before mine is as it was when it left the Honda dealer in 1976.

Cheers

Den

[Jim Shea]

Den,
I spoke to the mechanic and he said that the thread had been damaged previously on the bearing cover, that's why it is not all the way in. He also said that the spacer does not touch the bearing cover, it sits inside, or the wheel would not spin, which makes sense?

Jim.

[spitfire]

Jim,
     If I am looking at this correctly on the diagrams and my back wheel, the spacer goes through the bearing retainer and butts against the inner race on the wheel bearing, if the bearing is not fully home the spacer will stick out too far, the bearing retainer sticking out would indicate that the bearing is not fully home. If however as your mechanic stated that the bearing retainer has damaged threads and is not fully home against the bearing then the spacer should be giving you the correct gap on your caliper. However I would worry if that was the case, if the bearing retainer is not fully home it is not retaining the bearing fully and should be replaced. I will measure the gap on either side of my caliper for you so that you can check whether your disc/caliper is lining up correctly.

Cheers

Den

[Jim Shea]

Den,
Thanks. I had not considered that the bearing cover(steel disc with 4-5 holes in it?) actually did anything more than act as a cover for teh bearings to keep them clean! Are you saying that the cover actually retains the bearing? If so I wonder where I can get another one from? DSS maybe?
Cheers,
Jim.

[Bodi]

1: Whoever replaced your bearings screwed up. The problem you are having is due to the right side wheel hub bearing not being where Mr. Honda wants it. (unless you mis-mounted the caliper somehow and all bets are off)
You can fix it by making the brake side spacer #13 shorter by whatever distance the bearing is out from its normal depth and adding a spacer washer on the sprocket side to compensate but you MUST make sure the bearing retainer is actually screwed in tight against the bearing and that the bearing is fully seated against the weld bead. If this weld bead isn't making the seat shallower then all you need to do is seat the bearing properly and tighten down the retainer and all should be well.
2: There's some confusion about bearing covers and retainers. The cover at the sprocket is just a cover. The threaded plate at the disc side is the bearing retainer (#7 on the parts diagram)
This retainer is the only thing that locates the rear wheel axially, without it regardless of spacers etc the wheel would slide from side to side a bit.
Tightening the axle nut compresses a sandwich of the right spacer (#12), right hub bearing (#37), inner hub spacer (#17), left hub bearing (another #37), sprocket spacer (#15) and left outer spacer (#13). The outer sprocket bearing helps take the drive chain load and if I recall correctly floats on spacer #15 and is not part of the sandwich. The wheel is located by the retained bearing by the disc, the left hub bearing should locate itself against spacer #17.

You have the outer spacers correct. The brake caliper is fitting funny because the whole wheel is mislocated to the left of where it belongs.
The "weld bead" is scary. Where and why was a bead of weld required?
The right side bearing with that retainer is meant to be fully seated in the original bearing seat, with the retainer threaded in fully flush. The bearings do not need to be "pressed in", they should be a snug sliding fit on both sides. The right bearing should be seated just by threading in the retainer.
If the retainer ring threads have been damaged, you need a replacement retainer - not someone with a welder to make the bearing seat shallower.
The other possibility with the welding is a bead layed on the inner face of the retainer, this would not cause any problem with the spacing though. Your mechanic is right about that, the retainer isn't touched by the axle or any spacer. Find out what was welded and why. If the hub was welded to make the bearing seat shallower your mechanic has destroyed the hub and owes you a replacement in my opinion.

[Jim Shea]

Bodi,
Thanks, but now my head hurts!! The weld was put in because the hub was worn and the new bearigs were too loose when put in. I was assured that this was a normal engineering process, that has been used for years as a fix?
The only thing that I can see that does not look right is the circular disc(bearing cover?) with holes in it, is not seated flush. I am told by some that this does not matter and by others that it does matter??
Jim.

[Bodi]

The disc is the bearing retainer. It pushes against the outer race of the right side hub bearing, pressing it in against the bottom of the hole the bearing seats into.
That bearing (alone) sets the wheel position between the swingarm forks. Since the retainer/cover isn't screwed in all the way, it looks like the bearing is not as far in as it should be.
That would entirely explain your problem with the brake.
Occam's Razor, although a bit dull, suggests that this obvious answer is the right answer.

So first step is to make sure the bearing is fully seated to the depth intended by Honda. If it's just a super tight fit and not fully seated, you could compensate by adjusting spacers but some day it might just slide in all the way and you will have a new problem.

You can shorten the brake side spacer to centre the disc in the caliper and add some washers on the sprocket side, and the brake will work OK.

Personally, I would be concerned that something is very wrong with my back wheel and I only have 2 wheels; if it fails at some future moment I could be in a very hospitally situation.

Some of the other folks here with mucho experience should chime in. I really think the mechanic has farked the hub regardless of his good intentions and "standard practice".

[Jim Shea]

I must admit you have me worried. I will speak to the mechanic again tomorrow, he said that he didnt do it up tight because the thread was damaged. Now I am wondering if he didnt do it up because he couldnt?
Jim.

[bryanj]

Jim, the spacer i meant was the one between the bearings!
The bearing  should go into its hole up to a shoulder that the inside of the outer race seats on then the screwed ring goes in to hold the outside of the outer race tight, the spacer in the middle of the hub then  goes between the inner races of the two bearings and the spacers you can see go up against the outer side of the two inner races--with me so far? Hope so i ain't got a woolich account!

Now what this means is that with all the spacers in, the inside races of the wheel bearings are located in position by the wheel spindle when it is all tightened up

What locates the wheel in the correct position laterally is the shoulder inside the hub, that is machined there, and the screwed spacer, which needs to go tight to "clamp" the bearing!

Now welding the inside of the hub is OK AS LONG AS the bearing can still be pushed down to the shoulder machined in the hub and this is where i suspect you have a problem in that the bearing isn't going far enough in.

If that still dint make sense ring my mobile(07795162623) on Sunday night when i am at work (after 7pm) and i will try and explain it better---or just sell you the F2 lesters i have in my garage!

[Jim Shea]

Bruan,
Thanks. I must admit I didn't understand as I have never seen inside the hub where the bearings go! I think I need to get the wheel off and have alook than I can hopefully tell if the bearings are seated properly!
Where's SteveD when I need him? 
Cheers,
Jim.

[spitfire]

Jim,
     Just measured up my disc and caliper, the gap in the caliper that the disc passes through is 9.3 mm, my disc measures 7 mm, this only gives roughly 1mm clearance on either side if the disc is central. If your bearings are not fully home this will throw your caliper outward reducing the clearance on the inner side of the caliper/disc, bringing the inner brake pad closer to the disc.

Cheers

Den

[Jim Shea]

Thanks Den,
My measurements are the same. Trouble is the gap on the left of the disc is 3+mm and on the left 5+mm, hence the problem. I will take the wheel off tomorrow and have a look to see if there is anything obviously wrong with the way the bearings are fitted. Are there any measurements that I can take to check if the bearings are correct?
Jim.

[bryanj]

Cant think of any Jim, what i would do is this in order:-

Remove wheel complete and take out spindle with exterior spacers

Look at the screwed in retainer and see if it looks like the ring is tight against the bearing--if so the bearing isnt deep enough

Remove retainer (LH thread?) and see how far bearing is down the hole---from your descriptions i strongly suspect this is the problem.

[750goes]

When you get the wheel off, see if the bearing retainer is cross threaded ??

Or

hope this is not the case - they have put the wrong sized bearings in (too wide ??)

or

they have welded the hub in the wrong spot -or got a spot of weld splattered in the hub

then

tell them to buy you another rim - and do the job the right way

[Jim Shea]

Bryan,
I got the wheel off but I can not get the bearing cover off, I mean the circular plate with 4 holes in it?
Sitting inside the space between the cover and the bearing is a washer/spacer, I assume that is correct?
The cover seems to be threaded!! any ideas?
Cheers,
Jim.

[mcpuffett]

i believe its a left hand thread , not sure about the washer/ spacer though? any chance of a picture? ,   mick.

[Jim Shea]

Unfortunately I have put it back together now. If you can imagine the gap behind the bearing cover there is a washer that is the same  width as the 'top hat' spacer, therefoe allowing clearance of the top hat spacer against the bearing cover.
Jim.

[Bodi]

Washer???
Take a look at the exploded drawing back on page 1 of this thread.
The retainer/cover, #7, is not a disc - it is a cup shape. An oil seal #31 fits into it on the inside against the bearing. You can skip this oil seal if you use sealed bearings but should probably keep it regardless. The "top hat" spacer fits into this oil seal and seals out water and dirt. The inner rim of the metal cup retainer presses against the outer race of the wheel bearing #37.
There should be nothing else in there at all. ONLY[/b] the bearing, the oil seal, the retainer cover, and the top-hat spacer. Period.
There is no washer in the diagram. There should be no washer in there. If there's a washer, then the disc will be off centre in the caliper by exactly the thickness of the washer.