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Author Topic: rear brake self centering?  (Read 916 times)

draggin

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rear brake self centering?
« on: September 25, 2013, 12:49:17 PM »
This is a real bad idea, don't do it!!!!
http://www.youtube.com/watch?v=gHRm_t_8DYE
« Last Edit: March 12, 2014, 05:48:14 PM by draggin »
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JVS

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Re: rear brake self centering?
« Reply #1 on: September 25, 2013, 01:14:09 PM »
It was posted here somewhere before. Read the comments on that video. I'll try to find that topic. Apparently it might not be a safe idea It is not a safe idea/practice..

edit -

here's the thread - http://www.enfieldmotorcycles.com/forum/index.php/topic,12728.msg141848.html
« Last Edit: September 25, 2013, 01:23:30 PM by JVS »
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Ducati Scotty

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Re: rear brake self centering?
« Reply #2 on: September 25, 2013, 01:44:09 PM »
If you just tighten up the rear brake adjustment nut all the way to engage the brakes before you tighten all the axle hardware, the brakes should be centered.  Then tighten up the axle and other bolts, and loosen the adjustment nut to get to proper adjustment.  If you don't do this you'll probably notice weak braking since they're generally not centered.  Thanks to Bare (I think) for the tip of tightening up the adjuster rather than holding the brake pedal down, that way you don't need three hands.

Scott

JVS

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Re: rear brake self centering?
« Reply #3 on: September 25, 2013, 01:48:43 PM »
If you just tighten up the rear brake adjustment nut all the way to engage the brakes before you tighten all the axle hardware, the brakes should be centered.  Then tighten up the axle and other bolts, and loosen the adjustment nut to get to proper adjustment.  If you don't do this you'll probably notice weak braking since they're generally not centered.  Thanks to Bare (I think) for the tip of tightening up the adjuster rather than holding the brake pedal down, that way you don't need three hands.

Scott

LOL, so true.
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Arizoni

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Re: rear brake self centering?
« Reply #4 on: September 25, 2013, 11:01:47 PM »
has anyone seen this? your thoughts?
http://www.youtube.com/watch?v=gHRm_t_8DYE
Yes and the guy in the video is wrong.

Be sure to follow the link in JVS's post to find the way to set up a RE's rear brake.

Reading thru the manual which is posted on sheet two of that link tells me that yes, the rear brake plate holes are slotted, and no, the bolts in those slots were never intended to be loose like the guy in the video seems to think.

They are slotted so the brake cam can shift to a position where it is applying pressure on both shoes at the same time.  The bolts that hold the brake cam guide in  place are supposed to be fully tightened with the guide in that position.

This adjustment should never need to be done if the cam guide bolts are never loosened.  It is not needed for instance if your just adjusting the drive chain.

Even after doing this, it is still necessary to fully expand the brake shoes to center the backing plate with the drum before the large nut that holds it in position on the swing arm is tightened.
This has to be done any time the drive chain is adjusted.
« Last Edit: September 25, 2013, 11:04:10 PM by Arizoni »
Jim
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Re: rear brake self centering?
« Reply #5 on: September 25, 2013, 11:08:19 PM »
i watched this a few days ago, and could not figure out what his procedure was supposed to accomplish. has he put anything up after the road test, perhaps a view through the back window of an ambulance?
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Ducati Scotty

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Re: rear brake self centering?
« Reply #6 on: September 25, 2013, 11:13:14 PM »
I'm guessing it was really poorly adjusted to start with, so any change my have seemed like an improvement.

Scott

ace.cafe

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Re: rear brake self centering?
« Reply #7 on: September 25, 2013, 11:41:17 PM »
I would exercise caution with any internet commentary or technical videos on YouTube regarding the Bullet.
There are some good ones by people who know, but there are a lot more by people who don't.

« Last Edit: September 25, 2013, 11:44:01 PM by ace.cafe »
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JVS

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Re: rear brake self centering?
« Reply #8 on: September 26, 2013, 11:21:21 PM »
Well, I tried to inform the viewers of that video about the discussion we've had on this forum regarding the issue and how it might be unsafe to proceed with that 'mod'..and I had pasted the topic link in the comments using spaces etc. Anyways, the uploader deleted my comment and responded with this -

Quote
This mod tells you how to centre the brake plate. If you know what you are talking about then you will clearly see that no problem can possibly occur.. After many thousands of miles my brake still works well...I say again, if you are not a competant mechanic, then dont do this mod yourself because how can you be sure you have reassembled the brake correctly.

If that's true, then okay, but leaving those nuts/bolts kind of lose like we discussed is not a good idea..But he's done 'many thousand of miles' and it 'still works well'  :-\
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Arizoni

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Re: rear brake self centering?
« Reply #9 on: September 27, 2013, 04:38:51 AM »
I think most RE owners are smart enough to know that leaving nuts/bolts loose is asking for problems.  Especially on a machine that traditionally loosens even tight nuts and bolts all by itself.  ;D
Jim
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Roeland

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Re: rear brake self centering?
« Reply #10 on: September 27, 2013, 06:14:28 AM »
Hi,

This was one of the first modifications I did and it worked for me. When taking the hole brake assembly apart I noted the threaded holes in the bush to take the 2 bolts which you can then lock into a slightly loos position by the 2 nuts. If this was not the design intend than the thread to the holes in the bush would be unnecessary and misleading?

Kevin Mahoney

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Re: rear brake self centering?
« Reply #11 on: September 27, 2013, 10:22:18 AM »
Let me make this simple - DO NOT DO THIS!
I understand his point but Arizoni is correct. I might agree with loosening the bolts a smidge, centering the shoes and then tightening them but not loose or semi loose bolts. If for no other reason because the bolts themselves are not designed to be taking that side to side load.

Roeland

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Re: rear brake self centering?
« Reply #12 on: September 27, 2013, 11:56:59 AM »
Yes I agree,  but when I initially tried to centre my brakes and I loosened or even remove the 2 bolts I could absolutely not get any adjustment even if I would have jumped on the rear brake pedal because the whole thing was so securely bolted from the inside into the bush (which is threaded)? It was impossible for me to centre the brake shoes properly before slightly loosening the bolts from the inside of the drum brake - the outside bolts seem to be only there for additional security and locking the entire thing into place? Am I missing something?

Arizoni

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Re: rear brake self centering?
« Reply #13 on: September 27, 2013, 11:01:18 PM »
Roeland
The fact that your brake currently works with the bolts slightly loose says that it is possible for the shoes and cam to find a location that is correct.  The trick is to find that position and then to tighten the retaining bolts down so that it remains correct.

About half way down page two of this link is a copy of the Royal Enfield instructions on how to do this.  It is highlighted with a red bracket.

http://www.enfieldmotorcycles.com/forum/index.php/topic,12728.15.html

To paraphrase what it says, with the bolts slightly loose so that the cam and its  guide can move if forced to, assemble the backing plate & shoes with the drum installed on the bike.
Tighten the brake actuation lever as hard as possible to force the shoes and cam to a centered position.  Then, remove the force and carefully remove the backing plate & shoes from the drum.
Without moving anything, carefully tighten the two bolts.  The cam and shoes are now properly aligned.

When reassembling everything it is necessary to once again tighten the brake shoe actuator rod to centralize the assembly with the drum and wheel.  Tighten the large nut on the backing plate stud which protrudes thru the swing arm flange and the large nut that is in line with the axle.  (The chain adjustment requires checking before tightening these two fasteners).

Once both large nuts are tightened the brake actuator lever rod that connects to the foot pedal needs to be adjusted so the brakes do not drag when the pedal is not depressed.
Jim
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Kevin Mahoney

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Re: rear brake self centering?
« Reply #14 on: September 28, 2013, 12:20:10 AM »
Again I think Arizoni is right. I have sent the video to the tech folks at the factory for an opinion. Regardless of waht the cure turns out to be I think you have pointed us at a valuable adjustment that many of us should consider. Lets get it sorted out properly and then see now it works for others.