Topic: Front drum 77 cb750k

[SugaFreeReese]

And on another note, I'm not here to argue. It's not my intention to strike anyone's nerve...

I hate unsafe riders and unsafe motorcycles all the same.

I'm just saying I posted on here because I'm interested on what people know of, and thing about a front drum on a 70's 750. Not to be told that the bike I ride every day safely through downtown is unsafe and that I should have no part in working on it.


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[SugaFreeReese]

a dab of silicone behind the pads will stop the squealing.

I'm going to try that and upgrading to SS brake lines.


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[70CB750]

Hey man, RR is OK, he can come over as smarta$$ but he knows lot and tells it his way.  Nobody is doubting your skill, did you build your bike fom scratch? Including the engine or you had a good engine to use?

I am mixing K3 with 78F to have a long distance hauler, LOL all the dreams of caged man .

[Retro Rocket]

You can take my comment anyway you like , i based my comment on the comments you made and no malice was intended at all, if thats the way you take advice then cool but don't blame me for pointing out the mistakes you posted for all to see. I'm not talking down on you, i'm telling it as it is, playing the victim doesn't help you. There are a lot of very knowledgeable people here and plenty that, if they could be bothered, would agree 100% with everything i've said and point out the failings in your posts, its easy to retract things you've said after i've picked up on them but if that really is the case then why not say so earlier, you can't bash me for commenting on something if you haven't told us all the facts correctly ?, it seems that everything i picked up on has now changed...? If you want advice on brakes and handling i could talk all day on it, I'm anal about motorcycle handling and know how to set up a bike to race standard if thats the case, your bike is lowered and you want to put an antiquated front brake on a 500+pound motorcycle, both detract from the handling and braking of the bike. If your one of the guys that only comes here for the back patters then thats cool, but don't b1tch when someone points out mistakes , we all have 2 wheels and a lot of people that would rather have you stay shiny side up, its up to you what you do with the advice...

Thanks 70CB750  Typing comments isn't a virtue but saying it as I see it is...

[SugaFreeReese]

Short answer - yes.

A CL77 or a 69 CB450 front drum will work.  Both can use the CB750 axle, but you will need spacers to make up the difference.  Be accurate with that.
The forks are narrower on those bikes.   You would also need a lever and the cable.   Now, I will also add that the stock disc does work much better than
either of these options.  MUCH BETTER.   I'd advise that if you are dead-set on it, look for a 4LS brake of some sort and spend the money to set it up correctly.   This can/will become very pricey.   

However, I ran a brake from a CB450 on my bike or a year or more before switching it out for the 4LS that is now on it.  Night and day.
Still - no match for a modern disc brake, but very comparable to the stock disc.  With the CL77 / CB450 brake I found that in a panic stop, I would tend to lock the back brake up before the bike really slowed.   

Another thing to consider - if you re-lace the wheel (I know you don't want to) you'll have to get a rim that is drilled for a drum.  The spoke holes are angled differently than disc hubs - the spokes have more angle to them.

I too am enamored by the look of a mechanical drum on the front of a CB750.  Doesn't make the most sense but it does look good.

Is that your bike in the photo ?    Was it at the hand-built show in Austin recently ?

This was very helpful! Thank you for the info!

I'm also really into the look, but if it's going to remove most of my stopping power I'll save it for a smaller bike.

I will look into it though because at some point I won't be able to refuse my want for it any longer. I just wanna do it "right".


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Get a 4LS brake off an old Suzuki GT750, Guzzi Eldo, or if you have $$$, a Fontana. Those brakes can be made to work as good as your single disk. That 450 brake or any other Honda one is only a 2LS. So double that for a 4LS and you got some serious stopping power. But setup and shoe material is key.

I love the look as well. The 2LS brakes on my old Triumph are very good but they've been adjusted properly.

In a panic stop situation you will have no issues. But...if you track it or do mountains you could get some brake fade. Drums don't like a LOT of heavy repeated usage.

Is that the same axel size and width?


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[SugaFreeReese]

You can take my comment anyway you like , i based my comment on the comments you made and no malice was intended at all, if thats the way you take advice then cool but don't blame me for pointing out the mistakes you posted for all to see. I'm not talking down on you, i'm telling it as it is, playing the victim doesn't help you. There are a lot of very knowledgeable people here and plenty that, if they could be bothered, would agree 100% with everything i've said and point out the failings in your posts, its easy to retract things you've said after i've picked up on them but if that really is the case then why not say so earlier, you can't bash me for commenting on something if you haven't told us all the facts correctly ?, it seems that everything i picked up on has now changed...? If you want advice on brakes and handling i could talk all day on it, I'm anal about motorcycle handling and know how to set up a bike to race standard if thats the case, your bike is lowered and you want to put an antiquated front brake on a 500+pound motorcycle, both detract from the handling and braking of the bike. If your one of the guys that only comes here for the back patters then thats cool, but don't b1tch when someone points out mistakes , we all have 2 wheels and a lot of people that would rather have you stay shiny side up, its up to you what you do with the advice...

Thanks 70CB750  Typing comments isn't a virtue but saying it as I see it is...

I'm sorry I got offended. I do see your point and I apologize for bouncing back and forth on the comments. Stressful day is leaking it's way to the thread. I do respect your advice and I will take it to heart.

I'm a bit of a hot head right this second...

Like I said though I'm going to keep the rotor and caliper and tune them up. Any advice on a possible upgraded set up (single) that fits stock forks?


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[SugaFreeReese]

Also if anyone reads the "rear works as well as the front" comment I wasn't thinking and typing the same. I meant they both work how they are supposed to. Tuned to the specs in the book. Not in comparison to each other just that they're both working close to 100% what they're supposed to. Sorry again.


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[greenjeans]

An axle from a 72 Suzuki GT750 will not work right out of the box.  You will have to turn it down on one end to fit the CB750 forks.   I'm not 100% on this - been a year or so since I did the swap.  It's possible that I used a CB axle, but I'm pretty sure I used the Suzuki axle.  Another thing about the GT750 hub, you will also have to machine a few millimeters off the brake plates in order to fit into the Honda forks.   I can't remember exactly how much, but I have a thread somewhere on here in this forum that has those numbers - I'll have to look.   But - you can use the GT750 speedometer cable with the brake and CB gauges.

[SugaFreeReese]

An axle from a 72 Suzuki GT750 will not work right out of the box.  You will have to turn it down on one end to fit the CB750 forks.   I'm not 100% on this - been a year or so since I did the swap.  It's possible that I used a CB axle, but I'm pretty sure I used the Suzuki axle.  Another thing about the GT750 hub, you will also have to machine a few millimeters off the brake plates in order to fit into the Honda forks.   I can't remember exactly how much, but I have a thread somewhere on here in this forum that has those numbers - I'll have to look.   But - you can use the GT750 speedometer cable with the brake and CB gauges.

That's awesome. Send the link if you find it.


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[Stev-o]

I meant they both work how they are supposed to. Tuned to the specs in the book.

How do you tune brakes?

[SugaFreeReese]

I meant they both work how they are supposed to. Tuned to the specs in the book.

How do you tune brakes?

Haha stopppp! I adjusted them. All new guts. Shoes, springs. Fluid, pads. The whole she-bang! Hahaha


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[greenjeans]

here's a link:  http://www.caferacer.net/forum/technical/14376-anybody-slapped-suzuki-4ls-cb750-6.html

the thread is pretty long winded, but towards the end it has the measurements and some detailed photos.   At the end of it all - it was really pretty simple.

[Lostboy Steve]

All my rear brake does it lock the wheel up if Im heavy on it without using the front. I guess that can me mistaken as working better since the disc doesn't lock as easily or at all without the rear. Either way it took a few tries before I got my disc 100% quiet.

[750K]

You could try deglazing the rotor with a diamond stone or possibly cross drilling the rotor, I know deglazing mine periodically keeps the squeal away.

[Henning]

a dab of silicone behind the pads will stop the squealing.

I'm going to try that and upgrading to SS brake lines.

SS brake lines won't make it brake harder, they will change the way the brake lever feels. There was a long thread about that recently and several posters reported that SS lines give the lever a wooden feeling, and felt that a new set of OEM rubber lines was a better choice for these bikes with the brakes they have.

[SugaFreeReese]

a dab of silicone behind the pads will stop the squealing.

I'm going to try that and upgrading to SS brake lines.

SS brake lines won't make it brake harder, they will change the way the brake lever feels. There was a long thread about that recently and several posters reported that SS lines give the lever a wooden feeling, and felt that a new set of OEM rubber lines was a better choice for these bikes with the brakes they have.

This is perfect timing as to I was about to buy some.


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[SugaFreeReese]

Well, I completely tore apart my front end. I got a new rotor, cleaned everything out, drained all the old fluid (found some nasty grit in everything) and put the brake in front of the fork on top. Also added the red brake squeal stop you can get at napa or any other spot. Hopefully my squeal will stop forever but if not I guess I'll just get really good at changing everything out every month. Haha. Thanks for the advice all!


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[70CB750]

I guess the rubber vs SS is a matter of personal opinion.  I went with SS and could not be happier. T

The not-wooden-feeling comes from the rubber hose expanding instead of delivering the pressure where it counts.  It reminds me bit of the smart guy who dipped his pads in oil to make sure they don't grab too hard. 

[Retro Rocket]

  It reminds me bit of the smart guy who dipped his pads in oil to make sure they don't grab too hard. 

Hahahaha, that reminds me of this guy i went to school with, Andrew Rhodes, the first ever burnout he attempted in his car he used brake fluid to get the wheels spinning instead of oil  about a week later, most of the paint on his rear panels was falling off...
I couldn't bring myself to tell him , I didn't want to spoil his fun....

[Lostboy Steve]

  It reminds me bit of the smart guy who dipped his pads in oil to make sure they don't grab too hard. 

Hahahaha, that reminds me of this guy i went to school with, Andrew Rhodes, the first ever burnout he attempted in his car he used brake fluid to get the wheels spinning instead of oil  about a week later, most of the paint on his rear panels was falling off...
I couldn't bring myself to tell him , I didn't want to spoil his fun....

We used to use a little bleach diluted w/ water.

[Henning]

I guess the rubber vs SS is a matter of personal opinion.  I went with SS and could not be happier. T

The not-wooden-feeling comes from the rubber hose expanding instead of delivering the pressure where it counts.  It reminds me bit of the smart guy who dipped his pads in oil to make sure they don't grab too hard. 

No need to restart that discussion in this thread. The thread I referred to is here if anybody wants to plow through it: http://forums.sohc4.net/index.php?topic=136811.0

[Retro Rocket]

  It reminds me bit of the smart guy who dipped his pads in oil to make sure they don't grab too hard. 

Hahahaha, that reminds me of this guy i went to school with, Andrew Rhodes, the first ever burnout he attempted in his car he used brake fluid to get the wheels spinning instead of oil  about a week later, most of the paint on his rear panels was falling off...
I couldn't bring myself to tell him , I didn't want to spoil his fun....

We used to use a little bleach diluted w/ water.

I had V8's, i just dropped the clutch....

[Jayelwin]

This is what you want:

http://mz3.net/stopping-brake-squeaks.html

Works great. Brakes squeal has nothing to do with the pad contacting the rotor. Brakes squeal is the pad vibrating and hitting the back of the caliper.

This stuff simply cushions the back of the brake pad and eliminates the squeal. It works every time I've tried it. Fabulous stuff.

[Lostboy Steve]

  It reminds me bit of the smart guy who dipped his pads in oil to make sure they don't grab too hard. 

Hahahaha, that reminds me of this guy i went to school with, Andrew Rhodes, the first ever burnout he attempted in his car he used brake fluid to get the wheels spinning instead of oil  about a week later, most of the paint on his rear panels was falling off...
I couldn't bring myself to tell him , I didn't want to spoil his fun....

We used to use a little bleach diluted w/ water.

I had V8's, i just dropped the clutch....

haha yeah I know, you cant beat that bleach smoke though...

[lucky]

In front of the leg from the factory, from what I know from old timers, it was common to swap the lowers to have the brake behind the fork.

Do you know, off hand, if it changes the effectiveness?

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I can't imagine it would make big difference, the working surface - aka brake pads on disc  - stays the same. People go to dual discs to get better breaks.

BRAKES.