Unofficial Royal Enfield Community Forum

General Discussion => Tech Tips => Topic started by: fredgold52 on March 03, 2008, 06:44:14 pm

Title: Rear Brake Help Needed
Post by: fredgold52 on March 03, 2008, 06:44:14 pm
I'm talking about a 2006 65 with 400 miles on it.  I spent time adjusting the front brake so that the twin leading shoe thing would work as it's supposed to.  But the back brake is a mess.

If I literally stand on the rear brake lever I can skid the tire.  But in normal riding and stopping it is almost useless.  Does anyone have any advice or techniques I can use to make the rear brake more of a contributing member of this motorcycle?

Thanks,
Fred
Title: Re: Rear Brake Help Needed
Post by: Foggy_Auggie on March 03, 2008, 09:56:21 pm
Think it's the nature of the beast.  My rear brake sometimes chatters loud at slow speed stopping.  Assuming it's the brake shoe material.

May want to adjust the rear brake foot pedal height a little higher then how it came from the factory.  It helped on mine since my ankles aren't as flexible anymore.
Title: Re: Rear Brake Help Needed
Post by: fredgold52 on March 04, 2008, 12:49:37 am
Actually, I had it adjusted lower to get it out of the way of my foot.  I don't like the idea of my foot resting on the pedal in case the brake light is always on.  I set the pedal back up to the stock position hoping for more braking power.

The rear hub - where I assume the brake shoes are - seems puny.  Not much diameter to it.  If it was bigger the brakes might be better - but it's not so.

Are there any aftermarket shoes that will improve the braking?
Title: Re: Rear Brake Help Needed
Post by: scoTTy on March 04, 2008, 12:55:58 am
    uh , i adjusted my rear brake light where it doesn't come on when I hit the rear brake.. 
    only  the   front brake activates the light..   :P  hold over from the late 70's I guess..   ;D
    My right foot is artificial and i wear a size 12 so I've set the rear brake pressure to my heel
    which sometimes there might be a little more stomping on than one wants.
Title: Re: Rear Brake Help Needed
Post by: bobbytthemudman on March 04, 2008, 01:34:01 am
 old trick from my racing days, pop out the shoes and sand off the glaze, that helps at least till they glaze over again, which should be a while unless your a hard braker.
Title: Re: Rear Brake Help Needed
Post by: Foggy_Auggie on March 04, 2008, 04:03:53 am
  I don't like the idea of my foot resting on the pedal in case the brake light is always on.  I set the pedal back up to the stock position hoping for more braking power.


My right foot points to the right a few degrees (arthritis) so the raised foot pedal rests on the inside left toe of my shoe while riding.

My rear brake works about as usual for any motorcycle rear drum brake.  Just has low speed chattering noise at times.
Title: Re: Rear Brake Help Needed
Post by: baird4444 on March 04, 2008, 05:18:08 am
The rear shoes need centering as well. Loosen the anchor bolt, it is the nut behind the rod in the slot just forward and below the axle. Have someone stand on the brake pedal...  or I just  put my right foot on the pedal... to center the assembly and then lay over the seat and tighten the anchor bolt. Readjust the rod and you should be OK.
   I found I used to get the chattering when I'd wash it and then put it away...  probably some rust on the inside of the hub. Always go for a ride after washing and stay on the brake to dry it out...   careful; the first time you try to use them they will be very weak.
               - Mike
Title: Re: Rear Brake Help Needed
Post by: dogbone on March 04, 2008, 03:15:36 pm
Baird 4444 is correct, I originally thought it was dust buildup in the drum, but.....
by having my wife put her enormous weight on the petal, the drum centered .
 :D
Title: Re: Rear Brake Help Needed
Post by: baird4444 on March 04, 2008, 03:56:26 pm
Baird 4444 is correct,                 but.....by having my wife put her enormous weight on the petal, the drum centered .
 :D
                She helps with maintenance and doesn't read your mail??
                                    sounds like a good one!!
                                                          - Mike
Title: Re: Rear Brake Help Needed
Post by: dogbone on March 04, 2008, 05:56:03 pm
I would be in deep merde if'n she read my mail. ::)
Title: Re: Rear Brake Help Needed
Post by: fredgold52 on March 04, 2008, 06:21:00 pm
Baird, I'm on my way out to the garage to try this.  I'll let you know how it works for me.  It's got to help - no way these brakes could be worse.
Title: Re: Rear Brake Help Needed
Post by: LJRead on March 04, 2008, 06:32:26 pm


Yeah, my rear brake is very spongy too.  If I have it on the center stand and am just trying to check out the slack in it, it seems fine, but in use it is spongy as hell.  I'm wondering:  Once you've taken the slack out of the brake pedal and begun to feel resistance, how much more should it go down to stop?  How much (in other words) 'sponge' should there be?
Title: Re: Rear Brake Help Needed
Post by: fredgold52 on March 04, 2008, 11:58:52 pm
Well, I did what Baird suggested and it did help some.  Still not wonderful.

I'm gonna take the rear hub apart when it gets warmer and clean any glaze off the shoes, maybe file a couple diagonal grooves in them and put the whole thing back together all cleaned and adjusted.  Then if they don't work all that good at least I'll know I did what I could.
Title: Re: Rear Brake Help Needed
Post by: c1skout on March 09, 2008, 03:50:48 pm
My rear brake keeps getting better with use. At 350 miles I couldn't slide the rear on gravel, at 3000 miles I can lock it tight on dry pavement. I didn't do anything to it but ride.
Title: Re: Rear Brake Help Needed
Post by: LotusSevenMan on March 09, 2008, 09:27:29 pm
I am assuming these are right side brake pedals with a cross-over?
I find the original left foot rear brake, left side rod really pretty good with only about 950 miles on the clock and done nil to it!
I wonder if there is some torque flex etc in the cross over design?
Title: Re: Rear Brake Help Needed
Post by: Thumper on March 10, 2008, 12:02:55 am
Actually, I had it adjusted lower to get it out of the way of my foot.  I don't like the idea of my foot resting on the pedal in case the brake light is always on.  I set the pedal back up to the stock position hoping for more braking power.

The rear hub - where I assume the brake shoes are - seems puny.  Not much diameter to it.  If it was bigger the brakes might be better - but it's not so.

Are there any aftermarket shoes that will improve the braking?

As a test, recommend you adjust it back up to reduce freeplay. On the centerstand, adjust it until it engages (binds). Now back off until you have some freeplay (say about 3/4") at the rear pedal. Take it out for a spin and see if it performs as you'd expect. If so, then you'll have to sacrifice convenient foot positioning for working brakes.

Matt
Title: Re: Rear Brake Help Needed
Post by: fredgold52 on March 10, 2008, 01:40:58 pm
I am assuming these are right side brake pedals with a cross-over?
I find the original left foot rear brake, left side rod really pretty good with only about 950 miles on the clock and done nil to it!
I wonder if there is some torque flex etc in the cross over design?

I think you are right LSM.  I think my brakes could be centered better in the drum, but there is also a considerable amount of flex in the system.  Once the shoes engage, the lever will continue to flex another inch or more. 

When it's warmer I'll take it apart and re-assemble.  Some glaze removal and recentering will probably do it.
Title: Re: Rear Brake Help Needed
Post by: baird4444 on March 10, 2008, 08:08:51 pm
Fredgold-
there is considerable flexing or twisting in the crossover rod that goes from the pedal to the brakeside once contact is made giving that spongie feeling. I have read of a couple of fixes...  welding a length of 3/16 angle is one to keep it from flexing.
                  - Mike
Title: Re: Rear Brake Help Needed
Post by: cyrusb on March 21, 2008, 01:26:11 am
Your post made me check my back brake performance and it is weak also. It has gone unnoticed all this time because I'm a front braker with slight rear,(braking that is) so who knew? I can tell  you It's not the size thats the problem because a brake just about that size will stop a 500 lb 1977 XLH just fine. People who mentioned the twisting tube I think are spot on. Also the cranked operating rod cant help either,Why cranked? A straighter one would work on mine .
Title: Re: Rear Brake Help Needed
Post by: deepak on April 03, 2008, 10:46:03 am
I join the friends who believe that the Bullet rear brake needs a good improvement.
I am exploring some ways for this.
I think the rear brake could be upgraded from 6" single leading shoe type to 7" twin leading shoe type in which parts from the 7" front brake in current production could be used with some suitable modifications.
This would include following -
1) Modifying the existing rear drum and sprocket unit to have a larger drum with larger sprocket (42 or 44 teeth) on it.
Inner width of the new drum should be the same as the existing which may accomodate the wider(1.25")  7" shoes due to available space . The existing 6"shoe are 1" wide.If required due to space problem , the 1.25" width may be modified suitably .
2) Increasing the gearbox sprocket (18 teeth from 16)) suitably to maintaing the sprocket  teeth ratio, increasing chain length suitably.
3) Repalcing the existing 6" rear brake plate by the 7" Twin leading shoe brake plate with modifications such as removal of the pair of projections  (between which the projection on the front fork tube is accommodated) , Flattening the curved outer surface of the brake plate, ensuring the thickness for suitability for correct fitting etc .
4) The brake operating arms mounted on the brake plates would need to be shaped suitably
5) The link rod between the two arms as well as the main rod connecting with the barake pedal would need to be shaped suitably.
6) The width of the slotted portion on the rear fork plate which accommodated the brake plate connection would need to be increased to enable the two adjescent projections on the 7" brake plate.
I have not attempted the above yet, but a close look on both the assebly of the brakes inspired the idea to me .
Hope, the above idea may be useful.

Regards


Title: Re: Rear Brake Help Needed
Post by: cyrusb on April 03, 2008, 04:40:43 pm
Thats a lot of work . The stock size rear brake should not have any trouble at least skidding the rear tire if it worked correctly. Mine will not. I wonder if the bikes with left side brake pedal have the same trouble. The left side being more direct, without the twisting tube. I have not had the opportunity to open up the brake yet, but mine feels as though it has grease on it. Like I said earlier a brake just about that size works just fine on a 500lb XLH. So I doubt its the size thats the problem. It might be just the cam angles are wrong, limiting the leverage that they exert.
Title: Re: Rear Brake Help Needed
Post by: Bankerdanny on April 03, 2008, 04:47:36 pm
Rear drums of a similar size hae been used on more modern, heavier, and faster bike than the Bullet.

Besides, the front brake is much more important to stopping power, that's why manufacturers went to front disks land before adding them to the back and why so many cars still have drums in the back.

As long as it is properly adjusted the existing rear brake should provide ample stopping power.
Title: Re: Rear Brake Help Needed
Post by: cyrusb on April 03, 2008, 08:31:19 pm
Fredgold, couldn't you just lower the pedal at the splined connection and still have the brakes adjusted tight? I know this will probably not help the brake work any better but at least it would be adjusted right.
Title: Re: Rear Brake Help Needed
Post by: LotusSevenMan on April 03, 2008, 11:53:34 pm
Have to say my back brake works very well. Really pulls the bike up if required without the use of the front brake (done it just to see if it would). Has much better feel and action than the disc brake on my Honda FireStorm!!!!!!!!!!!!!

Have to say my Bullet has the direct linkage left side brake action  (as it was originally designed) and I'm sure that the additional  torque 'wind-up' of the right side transfer shaft is part of the reason for poor performance and that 'cranked' operating rod. Straight pull is best!! ; IMHO of course!
Title: Re: Rear Brake Help Needed
Post by: baird4444 on April 04, 2008, 05:10:26 am
Thats a lot of work . The stock size rear brake should not have any trouble at least skidding the rear tire if it worked correctly. Mine will not. I wonder if the bikes with left side brake pedal have the same trouble. The left side being more direct, without the twisting tube. I have not had the opportunity to open up the brake yet, but mine feels as though it has grease on it. Like I said earlier a brake just about that size works just fine on a 500lb XLH. So I doubt its the size thats the problem. It might be just the cam angles are wrong, limiting the leverage that they exert.

       cyrusb-  you are right...  the main issue in the leftfoot brake is that there is a ton of mechanical advantage LOST in this bodged up deal. Most of the braking should be done with the front but it would be nice to have more in the rear. The 2 easiest things that we we can do is to reset the arm at the axle to be at a 90 Degree angle to gain the most mechanical advantage. The other is to eat 2 double cheeseburgers a day to give you more mass to stomp on the pedal....     OK, make sure the brake plate is centered.
   I wuz looking at mine yesterday and there is some mech loss caused by the rod having that little bend in it to get it over the rear footrest.  If ya got a solo...  remove the footpegs and straighten the rod. If you are bound to take SWMBO  on a regular ride... I think the plate that the rod fastens to on it's front end could be extended with just a little welding so a straight rod could be used...  taking another flex out of the equation. There is more that could be done but these are the easiest.
              - Mike
Title: Re: Rear Brake Help Needed
Post by: scoTTy on April 05, 2008, 03:36:11 am
er so right now it's kinda like ABS brakeing and it doesn't work and you are looking for the hand brake___i've always been a front brakeR too...  rear brakes are for going down an inclined street in the rain...  and having to stop ...  :o




    and actually my electra's rear brake behaves in the manner it was built for... no problems here... ...  I catch it with my heel anyway since my lower right leg is carbon fiber
 
Title: Re: Rear Brake Help Needed
Post by: deepak on April 06, 2008, 09:06:49 am
As regads the stopping capacity , and the size of the rear brake, Royal Enfield (UK) did produce a 7" single leading shoe rear brake for some of their models which could be regarded  as a betterment and which is not seen on the bullet model ,probably because by the time the improved version of the rear brake was introduced, the bullet model was either discontinued or about to be discontinued.
Title: Re: Rear Brake Help Needed
Post by: LJRead on April 09, 2008, 05:56:50 am
While taking the rear end of my bike apart the past few days, I had a closer look at the rear brake setup.  What is quite obvious is that much of the mushy feel is because of the long lever arm of the brake lever itself.  Putting pressure on it should put great pressure on the brake pads because the mechanical advantage is so great.  I'm wondering if there might also be a small amount of flexing of the lever itself.  I suppose the lever of a left brake lever model must be the same, but wonder if such a long lever arm is really necessary.  What it all means is that there should be more than adequate pressure on the brake shoes when compared with the front brake.  Perhaps a shorter lever could be used, but I'm not sure how difficult it would be to relocate the pivot point forward. so that the brake lever could be made shorter (by taking a section out of it. Anyway, now I well understand why the thing feels so cushy.  Move the lever down one inch and you are only moving the brake adjustment rod forward by a mere fraction of that amount.  I don't think it needs to be that long - the lever I mean.
Title: Re: Rear Brake Help Needed
Post by: cyrusb on April 10, 2008, 01:49:24 am
I bet converting to right hand shift is the ticket. Belongs there anyway....imho
Title: Re: Rear Brake Help Needed
Post by: jest2dogs on April 10, 2008, 03:45:19 am
I have an inquiry in this section (re: 5spd right hand conversion) because of this very same concern. The energy and distance lost to the "play" in the right side rear brake pedal is astounding. Have someone else apply pressure to the pedal while you watch from the side. It's like using a wet rope to push a car.

As for the shifting, even tho' designed with a tunnel for the crossover shaft, the outer transmission case of the 5 spd has a "boss" on it for the casting of the shift lever pivot (forward of the right foot peg...it does not mount concentric with the kickstarter as on the 4 spd.).

Also, since I have a "bum" big toe on the left foot, the nail gets damaged easily. Switching to right side shift would alleviate the pressure point.

I can't help but think that crossover linkages and bandy-legged brake pedals aren't lowering the proper "feel" and responsiveness of the controls.

-Jesse, longing for that good time feeling.
Title: Re: Rear Brake Help Needed
Post by: fredgold52 on April 11, 2008, 08:49:29 pm
Rear drums of a similar size hae been used on more modern, heavier, and faster bike than the Bullet.

Besides, the front brake is much more important to stopping power, that's why manufacturers went to front disks land before adding them to the back and why so many cars still have drums in the back.

As long as it is properly adjusted the existing rear brake should provide ample stopping power.

I just love being told things like that.  It is a pleasant and long winded way of telling me I am wrong and that my rear brake is really fine - I just don't know it.

I have taken the rear wheel off and used the opportunity to center the brakes better.  I have adjusted the various adjustment points so it's back like factory.  The fact is, there is a tremendous amount of flexing in the connection from pedal to brake arm.  The whole thing is whippy and feeble.  The actual braking  force delivered by the brake which many have said is large enough to stop an old Duo-Glide, is weak.  Amazingly so.

I understand the relationship between the front and read brakes.  True, the front brake does the majority of the stopping.  However, on gravel, sand, wet leaves and many of the other road surfaces one finds here in the Midwest, a good back brake is helpful in keeping the bike upright.

As I ride the bake more, either the back brake is getting slightly better, or I'm getting used to it.  Not sure which.  One thing that I am sure of though is that I now have to plan ahead for intersections rather than just zooming up to them and knowing I have enough brake to stop in plenty of time.  But truly, the Bullet is so much fun that I don't mind the marshmellow rear brake quite so much.
Title: Re: Rear Brake Help Needed
Post by: cyrusb on April 11, 2008, 10:29:01 pm
Well,as said earlier , it's not the brake, its the actuation. I hate to say it ,but it might have been better if they used a cable. Its pretty obvious the problem stemmed from having to put the brake on the right for the US market. Theres a lot of details on these bikes I feel  happened that way, like the throttle cable crammed under the gas tank.
Title: Re: Rear Brake Help Needed
Post by: fredgold52 on April 12, 2008, 10:23:01 pm
I understand about that, Cyrus.  As one of my engineering friends once said, "There's nothing as permanent as a temporary fix."

I expect when this latest cold snap gets out of here, I'll be looking at ways to firm up the rear brake linkage.  Yeah, a cable might have been better.  Certainly no worse.
Title: Re: Rear Brake Help Needed
Post by: longstrokeclassic on April 14, 2008, 10:54:49 am
I seemed to have solved the problem , but now I have to take extra care not to lock up the rear wheel.  :o

Fitted one of these  http://www.royal-enfield.com/handlebar.htm    item R1032  Rear brake upgrade kit, which got rid of the flex.

Then later replace the kinked arm with a straight one and placed it in the lower fixing hole.  Important - note the position of the split pin.

The cheapest option would be to drill a new hole for the brake rod an inch below the existing one and fit a straight brake rod.

The Before and After photos are here  (entry dated 1st April)
 http://tinytim.forumcircle.com/viewtopic.php?t=576

Best of luck. and take care first time you apply the rear brake after modification, it really caught me out, Only after a moment of panic when the back started to slide around did I realise the rear wheel had locked and I hadn't removed my foot off the brake pedal.

Ric


Title: Re: Rear Brake Help Needed
Post by: LJRead on April 25, 2008, 06:47:42 am
Going through some old photos today, getting rid of a few, and lo and behold, I found an interesting thing.  Have a look at the UCE engined bike and notice that the brake linkage is all on the right hand side.  Note also that the lever arm is longer, giving a longer pulling arm at the back (the brake lever itself is already plenty long, as I pointed out before). 

It would be fairly straight forward to move the left had rear linkage to the right hand side, I should think.  The rear wheel could just be reversed and other components re-engineered to reverse everything.  Perhaps Royal Enfield should offer a kit to do this.  Seems like it would cure a lot of the woes we've been discussing in this thread.

[old attachment deleted by admin]
Title: Re: Rear Brake Help Needed
Post by: geoffbaker on April 26, 2008, 02:02:46 am
I'm in the process of a LH to RH gear shift. It hadn't occured to me that it would improve brake handling, too...

Good to hear!

(Of course, one must remember to brake with the correct foot each time. That may take a little getting used to :) )