Unofficial Royal Enfield Community Forum

Royal Enfield Motorcycles => Bullet with the UCE engine => Topic started by: Joel-in-dallas on April 25, 2014, 03:25:53 pm

Title: rear drum brake being a bit odd
Post by: Joel-in-dallas on April 25, 2014, 03:25:53 pm
Guys --
My rear drum brake now seems to take more force to engage. Also it doesn't seem to be stopping as well as it did. The bike only has 4300 miles, so I wouldn't think I need to replace pads yet. Is there some adjustment that may be off?

Any ideas? The bike is a 2011 G5 Classic in Green with gold pin stripes.
Title: Re: rear drum brake being a bit odd
Post by: lemming on April 25, 2014, 03:37:25 pm
Mine seems to be more of a foot-actuated rear light switch than a brake, really. It does slow the bike, a little, at least I THINK it does. I haven't really done any empirical testing, standardizing the coefficient of drag and equalizing testing conditions, etc. But my hunch is that there likely isn't a statistically significant difference in braking distance between the application of the rear "brake" pedal and a placebo. YMMV.  ;D
Title: Re: rear drum brake being a bit odd
Post by: azcatfan on April 25, 2014, 04:18:23 pm
Do the UCE still have single leading drum brakes?  If so it is very important to get the brake set and adjusted correctly along with the wheel alignment.  The back brake can pretty good for a drum, but it has to be set up and adjusted correctly.

Arcing the shoes and proper alignment and adjustment will make the rear brake quite useful.
Title: Re: rear drum brake being a bit odd
Post by: lemming on April 25, 2014, 04:21:53 pm
I just did a search, and it does sound like set up is a common concern. I will have to tear into it...or, rather, bribe my mechanic friend with single malt to tear into it while I watch and hope to gleen some useful knowledge such that I can begin to do more of this stuff myself.
Title: Re: rear drum brake being a bit odd
Post by: Joel-in-dallas on April 25, 2014, 04:57:34 pm
Ill have the shop look at it. I think I got it out of alignment (the brake, not the wheel) with a really hard stop about a week ago. The Back wheel locked up and skidded slightly. Letting out the brakes got me back and I didn't lose control of the motorcycle. But I think that might be it.

The guys are really good about helping me out. Their prices are fair, plus the guys check little stuff for me for free, cause I buy em beers when they are off duty at the bar.

Its fun that my RE dealership is also a bar and grill. If you haven't been to Strokers Dallas you really should give it a visit if you are in the area.
Title: Re: rear drum brake being a bit odd
Post by: singhg5 on April 25, 2014, 05:03:59 pm
Guys --
My rear drum brake now seems to take more force to engage. Also it doesn't seem to be stopping as well as it did. The bike only has 4300 miles, so I wouldn't think I need to replace pads yet. Is there some adjustment that may be off?

Any ideas? The bike is a 2011 G5 Classic in Green with gold pin stripes.

Clean the drum and brake shoes, and lube cam by taking off the rear wheel.

Don't know about Classic Green with Gold Stripes, but on Black G5 the brake shoes last very long time ;) say 5 years and lot of miles. The link below may be of some help.

http://www.youtube.com/watch?v=ASD9nFLSbmE

NB - You don't need to take off front wheel as shown in video, just pull rear wheel out by lifting the rear of motorcycle or tilting a little bit or placing a 2" thick wooden plank under the stand.

Title: Re: rear drum brake being a bit odd
Post by: Joel-in-dallas on April 25, 2014, 05:48:49 pm
Yeah, I think its an alignment thing. The G5 I have is the same as other G5s its just not the chrome edition. Ill get the shop to look at it. Because I know for a fact I don't have the tools, or the skill to take off the rear wheel.
Title: Re: rear drum brake being a bit odd
Post by: Ducati Scotty on April 25, 2014, 05:52:38 pm
Its fun that my RE dealership is also a bar and grill. If you haven't been to Strokers Dallas you really should give it a visit if you are in the area.

I have to talk to my local shop about expanding.
Title: Re: rear drum brake being a bit odd
Post by: foggy95 on April 25, 2014, 07:00:15 pm
Ill have the shop look at it. I think I got it out of alignment (the brake, not the wheel) with a really hard stop about a week ago. The Back wheel locked up and skidded slightly. Letting out the brakes got me back and I didn't lose control of the motorcycle. But I think that might be it.

The guys are really good about helping me out. Their prices are fair, plus the guys check little stuff for me for free, cause I buy em beers when they are off duty at the bar.

Its fun that my RE dealership is also a bar and grill. If you haven't been to Strokers Dallas you really should give it a visit if you are in the area.
Whatever happened to that TV show that was filmed there at Strokers? Rick Fairless (I think) was the owner/operator - more into choppers but I do see on Cycle Trader that they do sell Enfields....
Title: Re: rear drum brake being a bit odd
Post by: Joel-in-dallas on April 25, 2014, 08:27:25 pm
There have been a couple of reality shows filmed there. One was called "Texas Hardtails" and focused on the Custom Bikes and Service business. The other was "Ma's Roadhouse" which focused on the bar. I think both didn't last long because really there isn't enough conflict in either business to be gripping.

Strokers Dallas is a one of a kind place. I love it but its odd and not at all corporate or cookie cutter. Thats probably my favorite thing about the place.
Title: Re: rear drum brake being a bit odd
Post by: suitcasejefferson on April 25, 2014, 09:41:18 pm
My 2013 B5 had the same problem. Actually a lot of problems. You had to push the pedal way down to get anything, it would slow the bike a little bit, but also made a loud scrubbing noise. I took it all apart, and found that only one shoe was contacting the drum. That shoe and the drum were glazed. I removed the shoes, cleaned them with brake parts cleaner, and sanded them. I did the same thing with the drum. Like most rear drum brakes, the Bullet has a single leading shoe design with a single cam. The pivot point of the cam can be adjusted (I've never seen this before on any other bike) and it was off. I centered the brakes with the unit off the bike, by using the actuating arm by hand, and putting pieces of paper between the shoes and drum to get both sides even. It now works fairly well. More than well enough for a rear brake. And the scrubbing sound, which was most likely caused by glazing, is gone. I also adjusted by tightening the nut on the rod till I could feel drag on the rear wheel, then backed off until the drag just stopped, and the wheel spun freely.
Title: Re: rear drum brake being a bit odd
Post by: Sectorsteve on April 27, 2014, 12:54:49 am
I still have problems with my rear brake now. Have Had no back brake for months. Hope to get it sorted when parts arrive. Every time I think I get it right, it locks up again , usually damaging something in the process. I'm at a point where if I don't have it sorted , the bikes sold. IVe tried everything and am at a loss. What to do, what's bent, replace the whole rear end? I really don't know and I'm about tired of trouble shooting , spending money, buying stuff I don't need like swing arm bushes, wait time to ship this crap etc.
Title: Re: rear drum brake being a bit odd
Post by: lemming on April 27, 2014, 01:22:29 am
Wait, so is it the case that if one adjusts the brake such that it works properly, one is then more likely to, by virtue of having an effective brake, lock up the brake and bend the rear swingarm? If so, mayhaps I should live with a maladjusted, marginally functional brake in the interest of preserving the remainder of the rear end? She stops plenty quick on the front brake, I mostly use the rear in certain low traction circumstances and when engine braking approaching stops to signal that I am slowing. But I am a total n00b, so chances are better than not that I'm doing it wrong.
Title: Re: rear drum brake being a bit odd
Post by: azcatfan on April 27, 2014, 01:55:00 am
Wait, so is it the case that if one adjusts the brake such that it works properly, one is then more likely to, by virtue of having an effective brake, lock up the brake and bend the rear swingarm?

An effective rear brake on ANY bike can lock up when used heavily.  Weight transfer to the front of the bike during any braking condition is the reason.  No reason to fear about having a well adjusted rear brake.  8)

Sectorsteve, I believe, is experiencing an anomaly.  His experience hasn't happened to nearly anyone else, hence why no one can help him cure the exact problem, an issue I'm sure that is driving him nuts about now    :o
Title: Re: rear drum brake being a bit odd
Post by: Mr.Mazza on April 27, 2014, 02:21:29 am
My rear drum (Basically just broken in new drum and pads) is actually quite effective, just a little less than my front drum and my front drum is good enough to stop me in a short space! Combined with the engine braking I can stop pretty quickly, nearly on par with a small jap bike.

So yes, something have be out of adjustment ;)
Title: Re: rear drum brake being a bit odd
Post by: Arizoni on April 27, 2014, 02:39:52 am
lemming:
Sectorsteves motorcycle is the only one I've ever heard of bending the swing arm.  I'm still trying to figure out how that could possibly happen by just using the rear brake.  There isn't that much torque on the rear brake even if the rear wheel is locked up.

If the rear brake shoes are adjusted correctly, the coil spring on the rear brake lever will automatically disengage the rear brake as soon as the riders foot releases the pressure on the brake pedal.
Don't worry about it but remember, the front brake on your motorcycle does over 80 percent of the braking.
Several racers I know only use the rear brake to keep the rear of the bike from coming around under heavy braking.  (I'm talking about 120 mph down to 20 mph for a sharp turn).
Title: Re: rear drum brake being a bit odd
Post by: suitcasejefferson on April 27, 2014, 02:40:06 am
First of all, a bike can be ridden fairly safely without a rear brake. I put over 20,000 miles on a Honda Rebel 250 with no rear brake. It was not intentional. I had fabricated parts to move the footpegs and shifter 6" forward, to give me more room, as the bike was considerably too small for me. I had started to fabricate a new rear brake pedal and linkage, but never finished it, because I had no trouble riding without the rear brake. The Rebel is not a sport bike. In a faster than normal stop, almost all of the braking is done by the front brake, and because of the forward weight transfer, there is almost no weight on the rear wheel. Just touching the brake can lock it up.

However, if the rear brake releases as soon as you release the pedal, it should not be unsafe. If the brake locks up, and won't release, you're in trouble. Same thing if the brake does not operate in a linear fashion, if it goes from barely braking at all to sudden lockup with no or very little extra pressure on the pedal. The front brake on my Kawasaki Vulcan 750 had this problem. It was virtually impossible to control under hard braking, it locked up every time, without warning. It was a dual disc setup, and I solved the problem by removing the entire brake from the right side, leaving it with one disc. It then performed perfectly. It could be locked up, but actually took some effort to do it. Normal braking was uneffected. I have put almost 60,000 miles on the bike after that modification with no issues.

I am not a motorcycle mechanic, but I worked 36 years as an auto mechanic. The brakes are very similar. I believe Steve's problem is caused by the brake assembly itself. I don't see how the swingarm or suspension could have anything to do with it. It almost has to be something to do with the way the shoes are contacting the drum. The harder the shoes contact the drum, the more friction is created, up until the shoes and drum are locked together. Any rear brake can be locked up, but you should have to push pretty hard on the pedal to do it. I sure wish I could get a look at the actual parts. I realize the bike was in an accident, but any accident damage to the brake should be obvious. Not being that familiar with RE (yet) I wonder if all the parts are the right ones, and if there is any binding anywhere, including the pedal and linkage. It should take only a slight motion of the cam to force the shoes against the drum.

As I posted earlier, mine was not working right, I had it completely disassembled, centered it, and properly adjusted it, now it works fine. It's a very simple setup. Hard to imagine something wrong not being obvious.
Title: Re: rear drum brake being a bit odd
Post by: Sectorsteve on April 28, 2014, 06:37:29 am
It happened also to brian (whoguy)
Exactly the same thing same damage. Swing arm plate and all nuts washers and brake plate ruined. I've pulled the swing arm off. Its straight now. My new parts arrived but I've lost all confidence because everytime I think its sorted, it locks up. The faster I'm going the more damage and the more dangerous.
Remember I've done my brake shoes changed sprockets, chains etc on the re and never had this problem before..

lemming:
Sectorsteves motorcycle is the only one I've ever heard of bending the swing arm.  I'm still trying to figure out how that could possibly happen by just using the rear brake.  There isn't that much torque on the rear brake even if the rear wheel is locked up.

If the rear brake shoes are adjusted correctly, the coil spring on the rear brake lever will automatically disengage the rear brake as soon as the riders foot releases the pressure on the brake pedal.
Don't worry about it but remember, the front brake on your motorcycle does over 80 percent of the braking.
Several racers I know only use the rear brake to keep the rear of the bike from coming around under heavy braking.  (I'm talking about 120 mph down to 20 mph for a sharp turn).
Title: Re: rear drum brake being a bit odd
Post by: whoguy on April 28, 2014, 10:48:14 am
Yes it did... I believe the original washer and pin(bolt) is a relatively soft metal and can deform from overtightening (the wider than needed slot doesn't help either)... and can allow the drum assembly to rotate slightly and cause the drum brake to lock on.

The pin, washer and nut should be high tensile metal... or aircraft grade I reckon.
Title: Re: rear drum brake being a bit odd
Post by: lemming on April 28, 2014, 03:10:18 pm
Fortunately for me, a simple adjustment was sufficient to substantially improve the braking power. It is now capable of actually locking the rear wheel, though I backed it off a little so that takes a bit more oomph to accomplish. When adjusted as described above- tighten until the wheel stops, then back off until it moves free- it seemed a little over-quick to lock. So I backed off a couple turns, and it has good feel now. Strong, but not insta-lock. Thanks, all for putting up with my n00b-itude! You are most helpful!