Band brake help needed

[FOMOGO]

Ok, who is the band brake expert??? And to make matters worse the band brake is on my Super Bronc. So it really is an odd configuration.

I took it all apart today and tried to sort it out. It will not stay square to the drum. It was twisted at the top as the 2 eyes were not parallel. I put it on a flat surface and it just appears that the ends were twisted slightly. I put it in a wood working vice and lined the 2 eyes up parallel to one another. I reassembled it and it still wants to lean off to the side of the drum. It acts like it needs an ear to hold the band over in line with the drum. There is a good 20 degree difference in the band and the drum. I took it back apart and turned the band around and put it all back together. It still wants to lean the same direction.....

I took that pic yesterday and it doesn't show it as well as it could. But you can see the bottom is off to the right of the drum. It doesn't look as bad in the pic as it really is. If you blow it up you can see the furtherest away eye is crooked. I will have to take a better pic of it in the morning.

Thoughts???? Ideas?????? What now?????


Doug

 

[creia]

Doug,
While lining up the 2 eyes parallel to each other would seem to be the "logical" (and expected) correction, that sometimes does not work. (e.g., it is possible that the drum was not parallel/level with the mounting box from the factory) It has been my experience that brake bands will hang the way they want to hang, regardless if the eyes are lined up or not. You will have have to compensate by bending the eyes SLIGHTLY whichever way is needed to get the band to square up with the drum which of course is critical for proper operation. It will not take much of a bend as even a tiny 1/16" bend of the eye will swing the end of the band which is 4" away probably 3 times that. Also, (very important), make sure you are checking for proper alignment with both of the eye roller pins installed, as that makes a BIG difference on how the band will hang and align with the drum! My son had to do this last year on his VT-8 when he installed a brand new brake band he purchased from Ron Kimball. When you get that band dialed in you will find that it will have unbelievable stopping power, and it is VERY easy (almost too easy, really) to lock up the rear wheel if you are not careful.
Michael

 

[jeep2003]

weld a U on it for tabs to keep in in check

 

[FOMOGO]

weld a U on it for tabs to keep in in check

Jeep, I had that thought... Spot weld a U on at the 6 O'clock position.

But I didn't because I feel like it can be fixed without that. I am going to do what Michael said to do above and see if that will correct it. I think it will.

 

[FOMOGO]

Doug,
While lining up the 2 eyes parallel to each other would seem to be the "logical" (and expected) correction, that sometimes does not work. (e.g., it is possible that the drum was not parallel/level with the mounting box from the factory) It has been my experience that brake bands will hang the way they want to hang, regardless if the eyes are lined up or not. You will have have to compensate by bending the eyes SLIGHTLY whichever way is needed to get the band to square up with the drum which of course is critical for proper operation. It will not take much of a bend as even a tiny 1/16" bend of the eye will swing the end of the band which is 4" away probably 3 times that. Also, (very important), make sure you are checking for proper alignment with both of the eye roller pins installed, as that makes a BIG difference on how the band will hang and align with the drum! My son had to do this last year on his VT-8 when he installed a brand new brake band he purchased from Ron Kimball. When you get that band dialed in you will find that it will have unbelievable stopping power, and it is VERY easy (almost too easy, really) to lock up the rear wheel if you are not careful.
Michael

Thank you for taking the time to explain this for me. And adding the important information. I had the pins in it and then it didn't line up so I took it apart and turned the band around thinking it would lean the other way BUT I didn't put the pins back in AND it still leaned the same way..... Overlooking the obvious.... I have the hole assembly on the bench trying to make it function correctly, instead of fighting it on the bike... I will pursue this further tomorrow with this information in hand and I think I can make it work now.

Thanks again,

Doug

 

[Sprocket86]

From my experience with band style brakes is that it doesn't really matter where the band rides or floats in the non applied position, but when the band is applied this is where the stand off or stationary mount's position in relation to the center line of the brake drum becomes crucial for proper self energization of the brake band when in the applied position.

When the dimensions are correct, man these band style brakes work awesome!

 

[Havasu Dave]

I'd have gone with more room in that "slot" and then welded on a U-piece as Jeep suggested. Probably would have left the U-end open, as the weld will make it more than strong enough. You're making a very solid mount there, I just think you haven't given yourself enough room for alignment.

I'm no expert, but I've done a few, and will be doing one again shortly without benefit of engine plate to weld to, so this is also on my mind. I'll use a pin running laterally from the side where the JS adjuster/mount is at and hopefully not tweak it the first time I hit the brakes.

Michael is right about them being tweaked sometimes and having to align them. Just remember, after you hit the brake a few times and heat it up, it ends up being whatever it is sitting like. That's why I advocate more room in the slot. When they rub during riding, it's annoying as heck.

 

[FOMOGO]

I'd have gone with more room in that "slot" and then welded on a U-piece as Jeep suggested. Probably would have left the U-end open, as the weld will make it more than strong enough. You're making a very solid mount there, I just think you haven't given yourself enough room for alignment.

I'm no expert, but I've done a few, and will be doing one again shortly without benefit of engine plate to weld to, so this is also on my mind. I'll use a pin running laterally from the side where the JS adjuster/mount is at and hopefully not tweak it the first time I hit the brakes.

Michael is right about them being tweaked sometimes and having to align them. Just remember, after you hit the brake a few times and heat it up, it ends up being whatever it is sitting like. That's why I advocate more room in the slot. When they rub during riding, it's annoying as heck.

Dave that is actually the factory Comet torque converter/brake arrangement that came on the bike. Every piece has Comet stamped in it. I may make up a little 14 gauge sheet metal insert to slid in the bracket with a snug fit and let it just touch the band to hold it where it lines up with the drum.

I am going with Michaels suggestions first and then see if I will still need a support. Either way I will get it lined up with the drum and make it happy in the end.

Thanks,

Doug