Author Topic: SoCal Mut-N-Chop CB750 - ITS DONE!!!! (Read 81063 times)

brycegp · « **Reply #75 on:** January 23, 2011, 12:50:22 PM »

No takers on a fiberglass version of this tail section?? ok...on to the front brakes...

So I mounted the dual front brakes. Calipers have new seals. I haven't even rigged the brake hoses so there is no fluid in the system. And the pistons are fully depressed inside the caliper.

Its dual disc and the left side is aligned and allows the wheel to spin. But then I bolt up the right side caliper...then the wheel is on lock down. It will turn if I force it. But there is a lot of pressure.

I've played with the shims at the caliper arm mounting points. Several different variations of shims here and there to try to get the alignment right...but no luck.

Here it is with no shims at the mounting points. Any suggestions??

unitedguitar · « **Reply #76 on:** January 23, 2011, 05:28:37 PM »

I'm not sure if it set up the same way with a dual disc setup but on the single disc there is a screw that goes through the bracket that holds the caliper up. It has a spring around it and goes through the fork housing. That is how you set the caliper spacing for the disc.

brycegp · « **Reply #77 on:** January 23, 2011, 05:48:38 PM »

Unitedguitar - mine is the same...but the PO didn't put them on the bike so I haven't add them back yet. But these brakes worked before I tore it down...so its just a matter of figuring out the geometry of the mounting points, I think.

I'm not sure that missing the adjustment screws would cause my problem...though I will install them. They're on order...

Any other possible solutions?

unitedguitar · « **Reply #78 on:** January 24, 2011, 12:15:10 PM »

That is really the only thing I know to do. Hopefully putting those in will work but other than that I have no clue. Sorry.

cobrajunkie · « **Reply #79 on:** January 24, 2011, 02:09:31 PM »

This is the centering adjustment for the caliper that will square it up to the rotor. Should do the trick.

An this is what my caliper looked like before I disassembled it last night. Something missing? Yikes!

unitedguitar · « **Reply #80 on:** January 24, 2011, 03:45:22 PM »

Holy cow cobra! How long had you been riding with it like that? I'm not going to lie though, I've been riding my 750 without one of the engine mounts on it. Just one of the small ones though. I like to live on the edge.

cobrajunkie · « **Reply #81 on:** January 25, 2011, 03:08:55 AM »

I purchased the bike 3 months ago and only rode it home from the PO nearby. I'm also missing the D spacers in the upper triple tree clamps but no visible cracks there.

mrrch · « **Reply #82 on:** January 25, 2011, 11:51:43 AM »

I had to grind down one of the lugs on the fork when I added the second caliper, but I did then shim the brake disc out as well. Is the mount shimmed out (in towards the hub)?

brycegp · « **Reply #83 on:** January 25, 2011, 12:16:03 PM »

Quote from: mrrch on January 25, 2011, 11:51:43 AM

I had to grind down one of the lugs on the fork when I added the second caliper, but I did then shim the brake disc out as well. Is the mount shimmed out (in towards the hub)?

It is not shimmed in the pic above. but previously I did add shims to the mounting points in a variety of combinations but i couldn't get it right...so I just took them off entirely.

Mark M · « **Reply #84 on:** January 25, 2011, 02:27:45 PM »

That bolt with a spring won't help with allignment - it's purpose is to stop the brake piston being pushed too far
back into the caliper. Fork flex can push them in so far that it will then take more than one pump at the lever
to get the pad to touch the rotor. Lots of people ride without them as the risk is low, it would take a good tank slapper or simmilar to push the piston back that far.
You need to take another look at how the mounting arm is ligning up on its fork leg mounts.
An issue I had was caused by a non standard mudguard not allowing the mounting arm to move far enough outwards from the wheel. Make sure it can swing a little past the position it needs to be in before you fit the screw that has the spring on.

unitedguitar · « **Reply #85 on:** January 25, 2011, 02:56:21 PM »

I hate to discredit your idea about it not being an alignment bolt but it really is just that. The spring pushes it towards the wheel while the bolt only allows it to go so far inward. Yes part of that includes keeping the piston in the right place. No that doesn't mean you should leave it out and forget that it is supposed to be there. One thing you will notice is that the whole caliper will actually move a little bit when you depress the brake lever. The piston moves toward the disc which ever so slightly moves the whole assembly outwards making the stationary pad come into contact with the disc. That is why the brakes only have a piston on one side. This is part of the reason why it is on a pivot at the fork.

What I would do is take any shims that are in the mount out, put the alignment screws and springs back in, get it to where the bike moves freely and then adjust from there. Also, do you have a fender on it? It has to be adjusted more without a fender. I ran mine without a fender for a while and when I decided to put the fender back on I had to adjust it with the alignment screw of all things to account for the different spacing from the fender mount. I know that is why there are shims in there but it would probably be easier to do it without them. Just a thought.

Mark M · « **Reply #86 on:** January 26, 2011, 07:10:23 AM »

You can lead a horse.......

brycegp · « **Reply #87 on:** January 26, 2011, 08:20:53 AM »

Thanks guys...for all the input. I'm going to go ahead and use all your ideas.

The alignment bolts/springs are on order and I have some ideas on the shims that might make it right. The opposite side is working so i am going to duplicate those shims and see that fixes my problem.

When aligning these things you have to consider both axes of alignment. In the first trials, I was only adding shims to the top mounting points, which served to move the caliper closer to the rim but also tilted the caliper on the vertical axis...probably fixing one point of stress but causing another.

If I shim the top and bottom mounting points equally or close to equal...that may fix both points of stress and fix the issue.

I'll report back...

unitedguitar · « **Reply #88 on:** January 26, 2011, 02:04:08 PM »

I guess they are called alignment screws because Honda engineers back in the day were so stupid they couldn't call it a keep your piston from popping too far out screw. The piston can only move so far in either direction. The other side of the caliper will stop it from going too far out and it can't go any further in than flush with the caliper housing. Which it wouldn't even be able to go that far in with a brake pad on it. There isn't enough room for it to move that far in. Sorry, I'm right and you are not Mark M.

The bottom shouldn't need to be shimmed out any. The place where it mounts on the fork should stick out a little bit further than the points where the fender mounts up. That is unless some of the material for the bottom mount has been removed for some reason. I would go to a hardware store with a fender and find a washer that is the same thickness as the mount for the fender. They should have something that is close.

brycegp · « **Reply #89 on:** January 31, 2011, 11:36:07 AM »

I experimented with both Unitedguitar and Mark M's suggestions. Verdict is...! Mark M wins. NOT THAT I'M TAKING SIDES...

So my adjustment screws came in and I put them on and tried to align the caliper with that adjustment point. No luck. It is pretty evident that the adjustment screws are there to limit the caliper arm's range of movement so that, after wear to the brake pad, the caliper doesn't roam too far in either direction.

Proper caliper alignment in the vertical and horizontal axes is dependent on the caliper arm mounting points. So I loosened all the mounting point bolts and then tightened down the caliper on the caliper arm. I did this so that basically the caliper arm would tell me where it wanted to seat. Then I measured the gaps at the mounting points so that I could add the proper amount of spacing to align the caliper on both axes.

I added 1/4" spacers to both top mounting points. 4 small washers. AND I added 1/8" spacers to the bottom mounting point. 2 small washer.

The wheel now spins freely.

mrrch · « **Reply #90 on:** January 31, 2011, 12:32:13 PM »

Are your brake lines staying like that or are they being routed behind the forks?
Glad you found a fix.

brycegp · « **Reply #91 on:** January 31, 2011, 02:24:21 PM »

Quote from: mrrch on January 31, 2011, 12:32:13 PM

Are your brake lines staying like that or are they being routed behind the forks?
Glad you found a fix.

I'm just playing with ways to run the brake lines...don't know how the finished version will look just yet.

OH...and credit MRRCH with a helpful suggestion as well... Good call on the shims.

cobrajunkie · « **Reply #92 on:** January 31, 2011, 02:34:11 PM »

wow. Sorry for the misinformation there but glad you got it fixed. Learned something new.

brycegp · « **Reply #93 on:** February 04, 2011, 12:31:23 PM »

So its time for me to figure how to finish the oil tank.

VOTE NOW!! VOTE NOW!! VOTE NOW!! VOTE NOW!! VOTE NOW!! VOTE NOW!! VOTE NOW!! VOTE NOW!! VOTE NOW!!
1. Paint (include color)
2. Polish and Clear coat
3. Chrome

The tank unfinished...will be mounted under the seat in the triangle.

The bike for reference.

lordmember1969 · « **Reply #94 on:** February 04, 2011, 03:20:08 PM »

Chrome would be cool:) Nice bike

wannabridin · « **Reply #95 on:** February 04, 2011, 03:44:47 PM »

Wow, cool oil tank!! I vote polished! Any thread for how you built this?

brycegp · « **Reply #96 on:** February 04, 2011, 04:16:32 PM »

Quote from: wannabINDUSTRIdin on February 04, 2011, 03:44:47 PM

Wow, cool oil tank!! I vote polished! Any thread for how you built this?

See reply #38 & #47 on page 2 of this thread...

Greggo · « **Reply #97 on:** February 04, 2011, 05:30:53 PM »

Bomber tank looks awesome with the white walls!

brycegp · « **Reply #98 on:** February 12, 2011, 01:45:57 PM »

I'm mounting my oil tank today before I have it chromed. Still have to tweak the mounting points to get it level.

Made my own steel braided oil lines for under $40...

brycegp · « **Reply #99 on:** February 12, 2011, 05:42:58 PM »

Got the level right. And the oil lines are perfect.

Very happy with how it came out!

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Author Topic: SoCal Mut-N-Chop CB750 - ITS DONE!!!! (Read 81063 times)