Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Bullet with the UCE engine => Topic started by: Sectorsteve on March 16, 2015, 05:20:55 am
-
My back brake has still never come right.
its been dodgy for about 18 months now.
Ive just been working around it as I've gotten so used to it, and i cannot be arsed taking the back wheel off for the 50th time.
when you get on and move forward, i can set the brake to not grab by depressing the brake pedal. the pedal needs to go down a fair way. It reacts with a little violent snap and then the brakes good.
Hill starts require you to do this again. Downhill all well, uphill, it might be required to snap the pedal to set it right again.
Im baffled as to why this is happening. How is it, that there can be that much of a gap at times(long way depressing the brake pedal.) then when its normal its just a few inches. THeres only so much room in the brake drum, so why is this happening?
Does the spring that pulls the lever back need to be quite strong?. THe replacement i got from hitchcocks was different to the original. Doesnt seem to be as strong.
Im just about due for some new pads, but i don't think ill bother buying new cams, pivot bolt, springs etc as these will be the same as what I've got. its a $%&*ing nightmare this brake.
-
Far out. Either it is that brake pedal spring, or the two springs for the brake shoes within the assembly. I'm assuming that the brake rod adjuster nut is at the right setting, as the brake works normally for you sometimes. The brake pedal spring does need to be of a particular tension so that you can adjust accordingly with the brake rod adjuster nut. But it is hard to conclude what the real culprit is without actually comparing it with another Enfield/brake assembly.
-
This is a long shot (but by now aren't they all), on some drum brakes, my BMW for instance, there are two different rate springs in the hub. Does RE use two different internal springs? and would it make any difference??
-
The "snapping" mentioned is what would bother me. I advise checking the anchor bolt - mine worked loose, and, the whole brake assembly was rotating a few millimeters every time the brakes were applied. the resultant hammering eventually led to a rear brake lockup.
-
You need to have the entire mechanism checked in detail. I would second the motion that one of the bolts might be loose
-
Id say that pivot bolts come loose. Ill check now.
-
Since you tighten everything down after the removal process, I'm really not sure why your anchor/pivot bolts loosen up. They shouldn't be, and you've got new parts too :(
-
About to do a bit of tinkering. But can somone remind if this is the procedure when tightening the back wheel etc.
1)Get the brake all lined up.2) Do up the wheel nuts.
3)Depress the brake pedal, or tighten the brake nut.4) tighten up brake pivot bolt.5) loosen off the rake rod nut.
-
That's not the way I do it.
With the axle nut, the big hex nut behind the axle nut and the anchor nut just forward of the axle backed off I then tighten the brake rod nut to move the brake arm forward. This expands the brake shoes which should centralize both shoes with the brake drum. The brake shoes should move their pivots and the cover plate assembly they are attached to to the correct position.
I then tighten the anchor stud nut, the large hex nut and the axle nut.
With these tightened, I back off the brake rod nut, just until the rear wheel will turn easily by hand without the sound of the brake shoes dragging.
Once this is done, I take the motorcycle for a short trip, checking to make sure the rear brake is working.
If everything is OK the last thing I check is to see that the brake light lights up when the rear brake pedal is depressed.
-
+1 what Arizoni said!
-
Hi there, thanks for your reply.
the pivot bolt was a bit loose, and my swing arm plate has a 5-6mm gap allowing the plate to move.
If i was to do it this way(loosen wheels nuts, tighten brake arm nut) then the whole brake plate will rotate anticlockwise slightly due to the fact that my swing arm slot is wider than the bolt. it was like this when i bought it and its now wider. Ive no idea why they make these swing arm slots wider than the bolt (by about 3/4mm) This to me seems like a flaw. SO. If i did it the way you said Arizoni, then the pivot bolt would be on the high side of the swing arm slot meaning that when you apply the brake, it will want to move clockwise - or forward. (I'm going to weld a steel flat bar closing this gap in the swing arm. THis is the problem i think and i know its happened to many RE riders.)
So what i did was:
loosened everything off.
set my snail cams tighter, as they needed another notch.
pushed the pivot bolt down leaving a 5-6mm gap between this bolt and the high side of the swing arm slot.
tightened the big hex nut a little - finger tight really.
tightened the pivot bolt in brake plate a little bit with socket - just a little to stop it moving.
now all thats in place, i tightened the wheel nuts tight.
then i tightened the brake arm rod nut, like you said above
then tightened the pivot bolt nut pretty tight
then loosened off the brake arm rod nut.
took for a ride and all sweet.
its all about that gap in the swing arm slot.
This will explain why when theres more weight on the bike its more prone to happening and also when going up hills.
i betcha if i weld a flat bar closing up that gap, this will never ever happen again.
If I'm right, i think RE should look at making that swing arm slot gap/pivot bolt snug as a bug in a rug. For something that has so much force on it, having a gap, moving parts etc. i don't think it makes sense. I think i may go NUTS and get a locking nut and a spring washer, as well as welding a bar to close that gap.
-
...........i betcha if i weld a flat bar closing up that gap, this will never ever happen again.
If I'm right, i think RE should look at making that swing arm slot gap/pivot bolt snug as a bug in a rug. For something that has so much force on it, having a gap, moving parts etc. i don't think it makes sense. I think i may go NUTS and get a locking nut and a spring washer, as well as welding a bar to close that gap.
another option is finding some stainless tubing to create a sleeve for the bolt ....
-
Ha! Great idea gremlin!