CB350G 360 400F brake upgrade options?

[overdraft]

Hi all!
I built a CB350 up ( http://www.dotheton.com/forum/index.php?topic=21812.0 ) and I swapped a 360 front end on to get the disc brake look I was after...
So, it turns out, as has been discussed, that the early disc brakes SUCK!
Originally I was going to twin the stock ones, but by the time you add up the rare as rockinghorse shit stock caliper, a fork leg, a rotor and a fender mount solution it's getting to be a bunch of money and it's gonna be heaaaaavy!!! So I'm looking for alternatives.
At the moment I'm thinking of using a larger/better/lighter rotor and a more modern caliper somehow adapted to the stock hub and fork but before I get too far into i thought I'd check and see if anyone else has already worked out an upgrade for this weaksauce brake system!
Any advice appreciated!

 

[overdraft]

ok, looks like this isn't something that's been done before by anyone on this site so i'm going to press on myself...

plan is to get a modern-ish caliper and make an adaptor that will attach to some or all of the mouting points for the stock brake swingarm and position the caliper for a replacement modern rotor
modern rotors are significantly lighter so should help with unsprung and rotational weight, although that's not the ultimate goal.
because the caliper mounting points are on the inside of the fork and i'm adding the thickness of the adaptor to that there are going to be clearance issues between the caliper and the spokes so i've kind of eliminated 4 & 6 pot options as they extend inward quite a bit. still thinking a newer 2 pot caliper will generate more grab than the stocker and if i can get a larger rotor in there that'll help too.

also, i'm not sure how many people would be interested in this, i think some people will think it would damage the vintage look, but if there are some people out there who are i'll take the time to document the process.

wish me luck!

 

[mydlyfkryzis]

I added the Slingshot Cycles Stainless braided brake line to me CB360. The brakes are not like a 2012 Ducati, but they are much improved over the original rubber lines in feel and modulation. I can get the wheel close to lock up on dry, smooth pavement without a problem (I feel I could lock them up, but I've done that on a motorcycle, and it was a little painful). With the rubber lines, I could squeeze the lever to the bar and not get that much braking power.

I haven't put new pads on yet, but there are better pads too.

For a lot less effort than retrofitting another caliper and hardware, you can get a reasonable performance from the stock brake.

they brakes on my bike at this point work better then they ever did. I bought the bike in 1978, it was just over a year old, and the brakes were sucky even "new".

 

[overdraft]

way ahead of you...
rebuilt with new pads, piston and seal

new master

stainless line

and they STILL suck!

 

[Bert Jan]

I did this:

more here:
http://www.dotheton.com/forum/index.php?topic=32298.70

And did this:

more here:
http://www.dotheton.com/forum/index.php?topic=26406.0

 

[overdraft]

thats EXACTLY what i'm shooting for! thanks! checking out what you've done there will help tons!

 

[mydlyfkryzis]

It doesn't help that you have the brakes on the wrong leg and backwards. You are missing parts too.

The brakes go on the left fork. You are missing the positioned spring and bolt too.

They will never be as good as modern brakes, but doing it wrong doesn't help.

If you can't get the stock brakes right, I wonder if you would get something different right.




Sent from planet Earth using mysterious electronic devices and Tapatalk

 

[overdraft]

If you can't get the stock brakes right, I wonder if you would get something different right.

really? straight to treating me like i'm an idiot because i don't subscribe to your paradigm of simply replicating the past without pausing to think about or understand it?

flipping the fork makes not a whit of difference to the braking function. the connection is under compression rather than tension but that fact is irrelevant to how firmly the caliper grips the rotor which is the issue here. don't believe me? that's how PJ did it just for fun on his 360.and i got the idea originally from a vintage racer who did it on his 450 and if it didn't work on the track those guys wouldn't have it. the alignment screw? um, maybe a factor if everything you have is shot to hell and your warped rotor is pushing the caliper piston out too far for the stroke on your master cylinder... if everything is trued up i don't believe it does anything.

anyway, i scanned your build thread and the bike looks nice (although a bit too 'stock' for my taste ). you'll love the pamco ignition when you get it... works like a hot damn. i had to file mine a bit to get it to fit, but operationally it's been flawless.

 

[mydlyfkryzis]

Not so much an idiot, but it is difficult to tell if you are doing it 'wrong' on purpose. Or just blindly bolting things together. That happens a lot on these sites

I am pretty blunt. I wouldn't of said "I wonder" if I was going to call you an idiot. I would of said it outright.
O
While the brake function works either way, and Crazypj does do some 'crazy' things, if the brakes are set up wrong they won't work as well.

Either left or right leg, you are missing the positioning screw for the brake arm. That means the caliper piston will retract more, causing increased lever travel.

Personally, I like the historical aspect of old bikes. The old bikes are not really well suited to 'modern' performance as the rest of the bike is not up to much more either. The forks are twisty, the chassis too flexible, the electric system marginal. My 64 Chevy Impala was similar. A 25 amp alternator, flexible chassis , crappy brakes. But if you replaced the engine, brakes, added a modern suspension, it really isn't a 64 Chevy anymore.

Not saying you shouldn't customize the bike, but for me, the value is in the contrast of the old bike versus new.

I have a 1991 750 Nighthawk. 15 years made a BIG difference in bikes. The NH handles better, stops better, has competent electrics. Was also much cheaper then the restoration of my cb360. When I want to ride a smooth, well handling bike, I have the NH. The NH is not as nice as the 2012 BMW 800 GT I recently rode. But I'll not spend too much time trying to make the 750 a Beemer either.

I will add fork braces, better shocks, etc. but not reinvent the wheel.

I am wearing out the soapbox. Lol

Fwiw, the popular improvement in the day was to have the dual disk in the front. I believe the 400 had the left fork leg with the same brake in mirror image. It would give some improvement. While maintaining a period look.

When I bought my cb360, the brakes were as good as any other at the time. The ss lines really improved them over stock.




Sent from planet Earth using mysterious electronic devices and Tapatalk

 

[overdraft]

ya, i appreciate you pointing out that it was mounted backwards and agree that that might have been valuable information if i had done it in error. maybe just say that and not add the speculation about whether i could 'get something else right'.
we're in agreement about the adjuster screw function and no, that's not part of this particular issue. and my braking expectations are admittedly coloured by my other bikes, an 05 and an 08 both with radial mounted calipers. we'll have to agree to disagree on the acceptable level of modernization for these old girls... i notice you're willing to give up the stock rectifier and points for a performance upgrade i was actually intending to twin the 'stock' brake (it's actually a 360 front end that i swapped onto the350), but i started adding up the bits... calipers are pricey, then a new fork leg, rotor, fender mount, brake line, everything needs rebuilding and refinishing... and my build is peppered with modern components anyway so thought i'd see if there was a different solution.
also, binary line is priceless!

 

[lingo]

I am in the middle of doing twin disc conversion on my 450. I picked up an entire spare frontend for $75. I am cleaning and painting this weekend and should have it all back together by next. It can be done on the cheap. I can't fault anyone for wanting a modern front end though. Mine is going to be a side car rig, that is why I am doing to brake swap. When I have the time and money I will probably build a leading link for it.

 

[mydlyfkryzis]

In for a dime, in for a dollar. If you are going to upgrade the brakes, the forks should be too. Better the whole system. Modern brakes on the old twisty fork is a bit of a kludge.

As far as the electric upgrade goes, I am for it without crying foul. I spent a lot of time with my bike totally stock. that meant constant dead batteries, poor running as points wore out. A concession to my keep it stock attitude, I also want to keep it runnable. Electronic ignition and a better rectifier.rehulator keep it roadable.

I upgraded my 64 Chevy to a modern (for the time) Alternator. A 25 amp alternator barely kept the lights going on it. 60 amps was a whole lot beeter, and the point style regulator was always breaking. I had a high performance point type regulator, and it sucked too. I never did upgrade it to electronic ignition, but I would of if I had kept it longer.

I put foam pods on in 1979, it was a period update, so no foul there. Using foam pods is not violating that rule either. I have tapered roller bearing on the fork, also from around 1980. Also a period correct improvement.

I also upgraded my headlight on my CB360 in 1979 to the H4, but the 55/60w bulb killed the battery even faster. I removed it but saved it. the light in the CB360 now is from 1979, but has a 35/35w bulb from DCC.

I am not going to bore it out for performance, put Mikuni's on, or extend the swingarm. the brakes are as good as those brakes can get, and since they stop the bike, and I won't be racing, they are good enough.

I'll do reliability improvements, because I want it reliable to ride, but I don't need the nth performance update.

I am going back to stock airboxes, with UNI Foam filters replacing the inserts, and if I can find stock headers and mufflers, I'd go back to them. The bike ran better stock then with the pods, and I'd rather have the quieter intake, and quieter exhaust nowadays.
Better Shocks, yes, Bronze swing arm bushings, yes. I don't mind making it a little more reliable, and eke out some internal improvements


So I am not making a pure bike, but when you see it running down the road, you will know it's a well taken care of machine and that it is pretty much stock.

Not many people here own the machine they are working on for 35 years, so their feelings about how to make it look will differ too. Me and Sophie have history. I bought here the same year I was married. My wife and I went a lot of places on her. It is probably the reason I kept her, even though she was hidden in the basement for 20 some odd years.

So if you go out and buy a bike to modify, your emotional attachment is going to be different then if you owned it for as long as I have.

 

[pamcopete]

Well, I did a brake upgrade on my '74 CB750. Very similar to the CB450. I replaced the forks, brake caliper, disc, fender and spoked wheel with parts from a Yamaha XS650, mainly because I had a spare set of forks from a XS650, but all the other parts were available from www.mikiesxs.com .

This to get rid of the obsolete brakes and what I considered a harsh ride with the stock CB750 forks. Just for good measure I also replaced the master cylinder and installed a Stainless Steel brake line. Now, when I squeeze the brake lever, the bike comes to a nice controlled stop.

 

[Clifton]

I hated the stock brakes too. If any one has ridden a modern sport bike they would know how much these old CB's brakes are a joke. This is kind of right up that I did.

http://forums.sohc4.net/index.php?topic=101234.25

 

[overdraft]

Psycho,
I think I have that same caliper on the way (although it's a right side one). For the bracket my intent was to come up with a bolt up solution as I'm not a welder... it remains to be seen if that's possible... and like you I have resigned myself to redrilling a 4 hole pattern in the rotor since modern rotors are all 6 hole. Thanks for the link. Everyone's ideas all help!

 

[Clifton]

Getting it welded would be a PITA as you would have to bring atleast the front end to them. If you do go that route I used compressed air on an old banjo fitting to align the caliper with the rotor. I only tacked my bracket in place ( mig with spool gun) and had a friend finish welding it with his tig. I didn't even drain the fork.

 

[overdraft]

ya, my forks are just rebuild/repainted so if i can create a bolt on solution that's my preference. plus if it's possible then i can share the pattern if there are any other less-than-purists who would like a bolt on solution to improve their braking at low cost/low hassle.