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Discussion Starter #1
On my 85 when I use the rear brakes, they don't seem to want to work very good. I can almost stand on the pedal, and they won't lock up.
I end up using my front brakes 90% of the time. I know the cable needs adjusted because I have to push the brake pedal quite a ways before I feel it begin to grab.
I'm thinking about sanding the drum to get rid of any glazing, and getting a new set of shoes. I really wish they would have made rear disk brakes on these.
On another note, can the shocks and forks be used w/o any air in them?
My front forks are a little soft, and I want to add some air to them. I'm the only rider with no luggage or bags.
What woud be a general PSI to have in them? I thought about running 5 to 7 pounds in the forks, and 3 to 5 in the shocks. Any help will be greatly appreciated. :beerchug:
 

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Adjusting the pedal to the proper position will help a great deal. That is, it will take less force to engage the brake. Make sure the shoes aren't too worn.
 

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On my 85 when I use the rear brakes, they don't seem to want to work very good. I can almost stand on the pedal, and they won't lock up.
I end up using my front brakes 90% of the time. I know the cable needs adjusted because I have to push the brake pedal quite a ways before I feel it begin to grab. I'm thinking about sanding the drum to get rid of any glazing, and getting a new set of shoes. I really wish they would have made rear disk brakes on these.
On another note, can the shocks and forks be used w/o any air in them?My front forks are a little soft, and I want to add some air to them. I'm the only rider with no luggage or bags.
What woud be a general PSI to have in them? I thought about running 5 to 7 pounds in the forks, and 3 to 5 in the shocks. Any help will be greatly appreciated. :beerchug:
First step on brakes is check wear indicator arrow and gauge on rear hub.
Second -adjust nut so lever and brake rod are at an angle no greater than 90* to each other.
Third- is the actuating cam clean, lubed and moving freely.
Fourth- are the shoes and drum glazed or oil/grease contaminated.

IMHO when the rear drum brake is working properly it provides plenty of stopping power for this bike with less danger of over braking and locking up the rear wheel. Releasing the brake on a rear tire sliding to the side will often cause a highside flip as the bike violently tries to straighten out, throwing the rider off the bike. Much more likely to happen on a bike with too powerful rear brakes that are hard to feel feedback on.

Early model (85-88?) vn750`s with air valve in fork tubes can run fro 0-7.1 psi.
Later models have no air valve in forks.

Rear shock setting depend on your weight. (usable air pressure is 0-43psi)
Clymer manual says damper preset on #2 and atmospheric pressure (0 psi) for a 150 lb rider.
At #300 lb ready to ride, and usually carrying a heavy bag or a preteen grandkid, I had the damping preset at #4 and max usable shock pressure of 43psi cold.
It was comfortable for me. YMMV
 

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Discussion Starter #6
I appreciate the replies all. I have owned several bikes over the years that have had rear drum brakes, and they worked great w/o any front braking needed.
I haven't taken off the rear wheel yet to inspect the brakes, but I am going to this weekend.
They just feel too soft to me.
I can understand about high siding it if the rear wheel locks up, and I have had too many close calls because of that, but fortunately I have been lucky enough to get out of a bad situation unscathed.
Do they make a semi-metallic pad for these bikes? Or am I stuck with organic, or OEM types of shoes?
 

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Sounds like your rear brake just needs some adjusting and cleaning.

You did not mention how many miles you have on the bike....there seems to be a "golden spot" for the rear brake...meaning on low mileage bikes the rear brake is not as good as one that has 10,000 or more miles on it. The design of the brake and use by the average owner seems to make them need a pretty long "bedding in" time.

Yours is a old bike..which means regardless of miles the drum might just be full of dust.

Follow Olhoss's suggestions, and then when doing the final adjustment , put the bike on the centerstand, spin the wheel (in the proper direction) and turn the rear adjustment nut in one half turn at a time until you feel/hear the shoes touch the drum. Then back it out 1/2 turn and you should be good to go.


KM
 

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Here are the front brake pads I found with an ebay search, Kevlar/organic, ceramic, and sintered bronze all represented
http://shop.ebay.com/i.html?_kw=750&_kw=vulcan&_kw=vn&_kw=front&_kw=brake&_kw=pads&_dmpt=Motorcycles_Parts_Accessories

Fewer choices for rear brake shoes it seems:
http://motors.shop.ebay.com/i.html?_nkw=vulcan+750+vn+rear+brake+shoes&_sacat=10063&_dmpt=Motorcycles_Parts_Accessories&_odkw=vulcan+750+vn+rear+brake+pads&_osacat=10063&bkBtn=&_trksid=p4506.m270.l1313

Found another possible cure for the soft feeling rear brake in the rear wheel installation directions in the Clymer manual, bottom of page 390. After inserting the rear axle and before tightening the nut do the following,

To prevent a soft or "spongy feel" to the rear brake, rotate the rear wheel and apply the rear brake several times. This will center the brake panel within the brake drum, resulting in a solid feel to the rear brake.
Then tighten the rear axle to torque specs.
 

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I have owned several bikes over the years that have had rear drum brakes, and they
worked great w/o any front braking needed.
I understand your feelings about not using the front brake, as I somersaulted myself off a borrowed dirt bike about 35 years ago by a too quick and over application of the front brake.

When I bought my first motorcycle, the vn750, at age 55, I was still leery of using it. I thought using only the rear brake would function similar to engine braking my rear wheel drive car or truck. For example, engine braking my truck tends to keep the truck tracking straight. Not so with heavy application of the rear brake on a motorcycle. It will slide out to the side. Use of the front brake too, will stop me about 3 or 4 times faster in an emergency than use of only the rear brake.

I have only learned from much reading over the past 2 1/2 years how important it is to learn to use the front brake correctly.

Please read the following essay on braking, and reconsider your aversion to using the front brake.
We would like to keep you around for a long time.:smiley_th
http://www.msgroup.org/Tip.aspx?Num=029&Set=

After reading the rest of the safety tips on braking, please obtain copys of David L. Hough`s books on Proficient Motorcycling and read them through too.
Especially note what he teaches on maximum or threshold braking.
It could save your life.
http://www.amazon.com/David-L.-Hough/e/B001JOWE2I/ref=ntt_dp_epwbk_0
 

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Discussion Starter #10
OlHoss I don't have an aversion to using the front brake. I use it all the time on mine but I like to have some good rear braking as well.
I took mine apart today to replace the rear tire and the pads are pretty worn with a lot of dust in the drum. I noticed the drum is glazed, but there was no indication of grease in there from the bearings. Besides if there was grease on the shoes it would lock up instead of being spongy. And I need to replace the bearings, they are a little stiff and are binding up a little bit when I turn them.
And to boot the final drive seals are leaking and there was 80W grease on the driveshaft coupler in the swingarm. :( So I guess I will be taking the drive apart to fix it while it's apart.
 

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Sorry RakerBill, there was no disrespect intented in my last post, only concern for the statement you made about previous bikes have a rear drum brakes "that worked great without any front braking needed."

I went back and reviewed the whole thread just now, and see that you say in the opening post that you do use your front brake for 90% of your braking. :smiley_th

I must thank you for teaching me something today with this statement.
Besides if there was grease on the shoes it would lock up instead of being spongy.
After 40+ years of servicing my own cars, I still have some misconceptions it seems. :doh:
This knowledge could save me some pain someday.

IIRC, dismantling the final drive and servicing it requires some special Kaw tools.
I don`t know what they are or if improvisations can be made to do the job. Good luck.:smiley_th
 

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Discussion Starter #12
I apologize to you as well OlHoss. On a motorcycle, if the pads are oil or grease covered I'm not sure if they would lock up or not. I have had a few cars and pickups that have had the rear brakes oil saturated after losing an axle seal, and especially my 3/4 ton ford pickup, if I breathed on the brakes they would instantly lock up.
I'm not undermining your experience as a mechanic, I have a few years, but not as many as you do. Mine is mostly small engines ie: mowers, tillers and such.
If I have offended you in any way I apologize. :(
Keep up the good work and safe riding.
 

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Discussion Starter #13
By the way, what is IIRC? I know what most of the others are, just not this particular one. :)
 

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No problem RakerBill. I try to have a thick skin and not take offence where none was intended. At the same time I try to be considerate of others feelings, and watch what I say online because it is hard to convey humor or tone without body language and voice inflections.

Regarding acronyms like "IIRC", I finally learned to Google them to get the meaning.
For example I just typed IIRC in the google search box and got a drop down menu with "IIRC meaning" included.

Clicked on it and got these links:
http://www.google.ca/search?sourceid=ie7&q=iirc+meaning&rls=com.microsoft:en-ca:IE-SearchBox&ie=UTF-8&oe=UTF-8&rlz=1I7ACGW_enCA379CA379&redir_esc=&ei=J7-YTZKOKYaRgQe_t4DRCA

That`s my non vn750 related help tip for the day. :)
 

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Discussion Starter #16
I will add that to my list of acronyms. Thanks all.
I never thought about doing the google search. :)
 

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Discussion Starter #18
That's a good idea Flaco, and I'm glad to hear you are good after your wreck.
I understand completely about the use of front and rear brakes. I use my front one all the time when I am riding, but my rear is too soft on this bike. I adjusted the rear one 2 weeks ago, and it's still spongy and it still will not lock up or even try to. I can all but stand on the brake pedal, and it's not working near as well as it should do.
I am going to replace brakes, both front and rear. Both sets are getting near their wear limits.
This bike is the ONLY one I have ever owned that the brakes are this bad on it. I will most likely replace the rear drum assy. as well to see if it will help along with the brakes.
My neighbors 49CC Yamaha scooter will lock up the rear brakes and they are controlled by a brake lever on the handlebars!
I'm hoping I can find someone who can turn the rear drum on this old beast, otherwise I will have to settle with sanding it to roughen it up.
 
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