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I love that herpes is the default metaphor for CR.net these days.


RJB, cool your jets.....you are getting your help so scoop the sand out of your vag and listen up.


Asking questions that have multiple answers and expecting one answer is not going to help you. So let's run back to the project planning stage for a second.

At this point I will remind you that your brakes are only as good as the traction your tire has. The single disc has the ability to lock up on a stock bike, but it takes effort and there isn't a lot of feel up at that top range. The stock drum has a lot of fade and generally any disc conversion is considered an upgrade. What you want ideally is the ability to easily use the entire range of your brakes from light touch to locked up with the maximum amount of feel.

but before we get to the good stuff I will answer your question about the cb550/450/750 dual disc conversion. You are correct those bikes did not come from the factory with dual discs. However honda at one time planned a dual disc conversion accessory kit for all three bikes and did at one time sell one for the 750 for a breif period. The forks have lugs for both discs and basically you convert a stock one sided caliper bracket to bolt to the other side by shaving one of the mounting points and making a spacer for the other. You also reverse the caliper by pulling a crush pin in the caliper so the line exits the opposite side. Search cb750 dual disc conversion and you will find tons of articles on it, the 450 uses the same caliper and fork legs but are shorter, the 500/550 uses similar pieces and the method is the same but only the wheel interchanges. The 450/500/550 forks are preferred over the 750 since the forks are shorter. We will talk about how to mount them up later.

There are two major approaches to improving your bikes braking which is what I assume what you really want to do. A lot of it depends on how the overall bike is setup. If it is closer to stock I would almost say take the weight penalty of dual discs and bigger forks just because it a) looks more impressive, b) is going to add more rideability, and C) you are understressing components which are normally used to working on heavier bikes.

But let's talk about the first approach for a second. The lightness approach or the understressing method. If your bike overall is 50-100 lbs lighter than stock or more (if that is possible) then it may behoove you to work the lightness to your advantage. The simplest way is to get a cb360 disc front end (same as the 350G) and slide it right into your trees. Since the 33mm forks are pretty spindly I would add a fork brace, a tweak bar bolted under the bottom clamp (a fork brace bolts to the sliders, a tweak bar bolts to the fork tubes in case you don't know the difference), an aluminum rim (18"), braided hoses, and a modern master cylinder with a piston size 14mm or one size larger than that. Make sure your fork springs and rear shocks are paired nicely and setup for your weight.

What you gain is braking improvement by making your overall package work less hard. The only unsprung weight you add is the fork brace, and you remove the heavy drum. You get rid of brake pressure loss due to hose flex by using braided lines, and the new master works like a new master so you probably get back some efficiency there. Plus you keep your stock speedo gauge and because the 360 one has the same ratio as the old one and you just run a cable.

What you lose is the increased rigidity of a thicker tube front end and the ability to get better parts like cartirdge emulators and cheap mass produced fork springs.


If your bike is closer to stock weight (and by now I hope you have figured out you need to be weighing your bike), then while the above approach will work it won't improve the handling, won't improve the feel too much, and you will still be stressing your components as they were stock, which means the brake will feel shitty.

Enter the neck bearing chart:

http://scandalon.com/2009/06/motorcycle-steering-stem-bearing-size-chart/

cb350 uses: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB450/K1-K7: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB550K/K1: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB750K (1969-1978): 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

See a pattern here? Unfortunatly what you don't see is that the stem heights are different for all three bikes, with the 450/500/550 being the closest to the cb350 stem height. You will still have to make a spacer that fits under the top clamp to allow the nut to tighten down properly, and you will have to measure that yourself, but basically you bolt the entire front end Triple trees to tires right into your 350 neck. You will also need to make new steering stops - you can buy dirt track bolt on ones, or you can drill and tap the stock stops in the clamp and put a bolt in there. either way, it is pretty easy. Now you can stop here and already you would be miles ahead of the game, however, if you got a 450 front end you can search out a hondamatic 750/ GL1000 front rim and upgrade to alloy. You can also run braided lines. Again, better springs, maybe cartridge emulators, and a fork brace. no tweak bar unless you really want it. But even stock the components on the bike will be underworked and will be an improvement over your stock 350 stuff. It is at this point if you really want to go overkill you can do the dual disc converion that many 450/500/550/750 owners have done for 40 years.

As with anything nobody is gonna write you instructions. It isn't fair to us or to you who needs to learn not just how to do custom work but how to be brave enough to plunge into custom work with little more than a well reasoned idea of how it goes together.
 

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quote:Originally posted by Geeto67

I love that herpes is the default metaphor for CR.net these days.


RJB, cool your jets.....you are getting your help so scoop the sand out of your vag and listen up.


Asking questions that have multiple answers and expecting one answer is not going to help you. So let's run back to the project planning stage for a second.

At this point I will remind you that your brakes are only as good as the traction your tire has. The single disc has the ability to lock up on a stock bike, but it takes effort and there isn't a lot of feel up at that top range. The stock drum has a lot of fade and generally any disc conversion is considered an upgrade. What you want ideally is the ability to easily use the entire range of your brakes from light touch to locked up with the maximum amount of feel.

but before we get to the good stuff I will answer your question about the cb550/450/750 dual disc conversion. You are correct those bikes did not come from the factory with dual discs. However honda at one time planned a dual disc conversion accessory kit for all three bikes and did at one time sell one for the 750 for a breif period. The forks have lugs for both discs and basically you convert a stock one sided caliper bracket to bolt to the other side by shaving one of the mounting points and making a spacer for the other. You also reverse the caliper by pulling a crush pin in the caliper so the line exits the opposite side. Search cb750 dual disc conversion and you will find tons of articles on it, the 450 uses the same caliper and fork legs but are shorter, the 500/550 uses similar pieces and the method is the same but only the wheel interchanges. The 450/500/550 forks are preferred over the 750 since the forks are shorter. We will talk about how to mount them up later.

There are two major approaches to improving your bikes braking which is what I assume what you really want to do. A lot of it depends on how the overall bike is setup. If it is closer to stock I would almost say take the weight penalty of dual discs and bigger forks just because it a) looks more impressive, b) is going to add more rideability, and C) you are understressing components which are normally used to working on heavier bikes.

But let's talk about the first approach for a second. The lightness approach or the understressing method. If your bike overall is 50-100 lbs lighter than stock or more (if that is possible) then it may behoove you to work the lightness to your advantage. The simplest way is to get a cb360 disc front end (same as the 350G) and slide it right into your trees. Since the 33mm forks are pretty spindly I would add a fork brace, a tweak bar bolted under the bottom clamp (a fork brace bolts to the sliders, a tweak bar bolts to the fork tubes in case you don't know the difference), an aluminum rim (18"), braided hoses, and a modern master cylinder with a piston size 14mm or one size larger than that. Make sure your fork springs and rear shocks are paired nicely and setup for your weight.

What you gain is braking improvement by making your overall package work less hard. The only unsprung weight you add is the fork brace, and you remove the heavy drum. You get rid of brake pressure loss due to hose flex by using braided lines, and the new master works like a new master so you probably get back some efficiency there. Plus you keep your stock speedo gauge and because the 360 one has the same ratio as the old one and you just run a cable.

What you lose is the increased rigidity of a thicker tube front end and the ability to get better parts like cartirdge emulators and cheap mass produced fork springs.


If your bike is closer to stock weight (and by now I hope you have figured out you need to be weighing your bike), then while the above approach will work it won't improve the handling, won't improve the feel too much, and you will still be stressing your components as they were stock, which means the brake will feel shitty.

Enter the neck bearing chart:

http://scandalon.com/2009/06/motorcycle-steering-stem-bearing-size-chart/

cb350 uses: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB450/K1-K7: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB550K/K1: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB750K (1969-1978): 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

See a pattern here? Unfortunatly what you don't see is that the stem heights are different for all three bikes, with the 450/500/550 being the closest to the cb350 stem height. You will still have to make a spacer that fits under the top clamp to allow the nut to tighten down properly, and you will have to measure that yourself, but basically you bolt the entire front end Triple trees to tires right into your 350 neck. You will also need to make new steering stops - you can buy dirt track bolt on ones, or you can drill and tap the stock stops in the clamp and put a bolt in there. either way, it is pretty easy. Now you can stop here and already you would be miles ahead of the game, however, if you got a 450 front end you can search out a hondamatic 750/ GL1000 front rim and upgrade to alloy. You can also run braided lines. Again, better springs, maybe cartridge emulators, and a fork brace. no tweak bar unless you really want it. But even stock the components on the bike will be underworked and will be an improvement over your stock 350 stuff. It is at this point if you really want to go overkill you can do the dual disc converion that many 450/500/550/750 owners have done for 40 years.

As with anything nobody is gonna write you instructions. It isn't fair to us or to you who needs to learn not just how to do custom work but how to be brave enough to plunge into custom work with little more than a well reasoned idea of how it goes together.
no way is the OP going to read that.....
also he already said that we are a last resort....i assume that because he thought someone was being mean....
 

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quote:Originally posted by Geeto67

I love that herpes is the default metaphor for CR.net these days.


RJB, cool your jets.....you are getting your help so scoop the sand out of your vag and listen up.


Asking questions that have multiple answers and expecting one answer is not going to help you. So let's run back to the project planning stage for a second.

At this point I will remind you that your brakes are only as good as the traction your tire has. The single disc has the ability to lock up on a stock bike, but it takes effort and there isn't a lot of feel up at that top range. The stock drum has a lot of fade and generally any disc conversion is considered an upgrade. What you want ideally is the ability to easily use the entire range of your brakes from light touch to locked up with the maximum amount of feel.

but before we get to the good stuff I will answer your question about the cb550/450/750 dual disc conversion. You are correct those bikes did not come from the factory with dual discs. However honda at one time planned a dual disc conversion accessory kit for all three bikes and did at one time sell one for the 750 for a breif period. The forks have lugs for both discs and basically you convert a stock one sided caliper bracket to bolt to the other side by shaving one of the mounting points and making a spacer for the other. You also reverse the caliper by pulling a crush pin in the caliper so the line exits the opposite side. Search cb750 dual disc conversion and you will find tons of articles on it, the 450 uses the same caliper and fork legs but are shorter, the 500/550 uses similar pieces and the method is the same but only the wheel interchanges. The 450/500/550 forks are preferred over the 750 since the forks are shorter. We will talk about how to mount them up later.

There are two major approaches to improving your bikes braking which is what I assume what you really want to do. A lot of it depends on how the overall bike is setup. If it is closer to stock I would almost say take the weight penalty of dual discs and bigger forks just because it a) looks more impressive, b) is going to add more rideability, and C) you are understressing components which are normally used to working on heavier bikes.

But let's talk about the first approach for a second. The lightness approach or the understressing method. If your bike overall is 50-100 lbs lighter than stock or more (if that is possible) then it may behoove you to work the lightness to your advantage. The simplest way is to get a cb360 disc front end (same as the 350G) and slide it right into your trees. Since the 33mm forks are pretty spindly I would add a fork brace, a tweak bar bolted under the bottom clamp (a fork brace bolts to the sliders, a tweak bar bolts to the fork tubes in case you don't know the difference), an aluminum rim (18"), braided hoses, and a modern master cylinder with a piston size 14mm or one size larger than that. Make sure your fork springs and rear shocks are paired nicely and setup for your weight.

What you gain is braking improvement by making your overall package work less hard. The only unsprung weight you add is the fork brace, and you remove the heavy drum. You get rid of brake pressure loss due to hose flex by using braided lines, and the new master works like a new master so you probably get back some efficiency there. Plus you keep your stock speedo gauge and because the 360 one has the same ratio as the old one and you just run a cable.

What you lose is the increased rigidity of a thicker tube front end and the ability to get better parts like cartirdge emulators and cheap mass produced fork springs.


If your bike is closer to stock weight (and by now I hope you have figured out you need to be weighing your bike), then while the above approach will work it won't improve the handling, won't improve the feel too much, and you will still be stressing your components as they were stock, which means the brake will feel shitty.

Enter the neck bearing chart:

http://scandalon.com/2009/06/motorcycle-steering-stem-bearing-size-chart/

cb350 uses: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB450/K1-K7: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB550K/K1: Upper: 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

Honda CB750K (1969-1978): 26 x 48.5 x 15.2 Lower: 30 x 50 x 14.4

See a pattern here? Unfortunatly what you don't see is that the stem heights are different for all three bikes, with the 450/500/550 being the closest to the cb350 stem height. You will still have to make a spacer that fits under the top clamp to allow the nut to tighten down properly, and you will have to measure that yourself, but basically you bolt the entire front end Triple trees to tires right into your 350 neck. You will also need to make new steering stops - you can buy dirt track bolt on ones, or you can drill and tap the stock stops in the clamp and put a bolt in there. either way, it is pretty easy. Now you can stop here and already you would be miles ahead of the game, however, if you got a 450 front end you can search out a hondamatic 750/ GL1000 front rim and upgrade to alloy. You can also run braided lines. Again, better springs, maybe cartridge emulators, and a fork brace. no tweak bar unless you really want it. But even stock the components on the bike will be underworked and will be an improvement over your stock 350 stuff. It is at this point if you really want to go overkill you can do the dual disc converion that many 450/500/550/750 owners have done for 40 years.

As with anything nobody is gonna write you instructions. It isn't fair to us or to you who needs to learn not just how to do custom work but how to be brave enough to plunge into custom work with little more than a well reasoned idea of how it goes together.
no way is the OP going to read that.....
also he already said that we are a last resort....i assume that because he thought someone was being mean....
 

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Discussion Starter · #24 ·
Ken- I may have snapped a little, but I asked the question because I have ZERO experience with these old bikes and what works with what. You provided me with no advice other than to read a book or use the internet. Why reply to my post at all if that's all you had to say?

Geeto- I REALLY appreciate that post. That is exactly the kind of information I was looking for. I have religiously checked this forum every day since I joined on the off chance that I might come across some info that applies to something I'm working on. So yes, I know that there are many guys here who know what they are talking about from many years of experience and trial and error. The only reason I said this was a last resort is because I have seen alot of guys get blasted for asking stupid questions and I suspected I would get the same treatment.

I understand that no one is going to write it out step by step, hell I wouldn't do it either. I was just looking for someone to point me in the right direction. Sure the stock brake is fine, but it isn't the best and I would like to make it better. I didn't want a dual disc because it looked cool, I just noticed that there are a ton of people doing it, so I figured it must be for a reason.
 

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Discussion Starter · #25 ·
Ken- I may have snapped a little, but I asked the question because I have ZERO experience with these old bikes and what works with what. You provided me with no advice other than to read a book or use the internet. Why reply to my post at all if that's all you had to say?

Geeto- I REALLY appreciate that post. That is exactly the kind of information I was looking for. I have religiously checked this forum every day since I joined on the off chance that I might come across some info that applies to something I'm working on. So yes, I know that there are many guys here who know what they are talking about from many years of experience and trial and error. The only reason I said this was a last resort is because I have seen alot of guys get blasted for asking stupid questions and I suspected I would get the same treatment.

I understand that no one is going to write it out step by step, hell I wouldn't do it either. I was just looking for someone to point me in the right direction. Sure the stock brake is fine, but it isn't the best and I would like to make it better. I didn't want a dual disc because it looked cool, I just noticed that there are a ton of people doing it, so I figured it must be for a reason.
 

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There are a couple of ways of doing it
1. fit a second left fork leg to right side. Looks a bit odd as one caliper is in front and one behind fork leg
2. fit different forks with dual disc capabilities.(Any of larger model CB's, 450, 500,550)
3. fit a completely different front end (Suzuki Katana is eay with minimal welding)
Options 2&3 are best as the stock 33mm forks are a bit flimsy.
Honda 35mm forks work OK but are a bit heavy
Katana forks are 41mm and about same or lighter than stock forks
There are other forks that can be fitted but so far the stock or Katana are all I've done
I've posted pic previously of CB350 drum in Katana 600 forks on CB360
but here it is again

The blue forks are 2002 GSXR750, same length as stock Honda forks
 

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There are a couple of ways of doing it
1. fit a second left fork leg to right side. Looks a bit odd as one caliper is in front and one behind fork leg
2. fit different forks with dual disc capabilities.(Any of larger model CB's, 450, 500,550)
3. fit a completely different front end (Suzuki Katana is eay with minimal welding)
Options 2&3 are best as the stock 33mm forks are a bit flimsy.
Honda 35mm forks work OK but are a bit heavy
Katana forks are 41mm and about same or lighter than stock forks
There are other forks that can be fitted but so far the stock or Katana are all I've done
I've posted pic previously of CB350 drum in Katana 600 forks on CB360
but here it is again

The blue forks are 2002 GSXR750, same length as stock Honda forks
 

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Bottom line, don't bother. Dual disc set-ups have absolutely no advantage and several disadvantages, such as unsprung weight,etc compared to several other brake choices.

Ken
 

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Bottom line, don't bother. Dual disc set-ups have absolutely no advantage and several disadvantages, such as unsprung weight,etc compared to several other brake choices.

Ken
 

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I believe you can't have too much brake.
You can learn to use it if it's got plenty of 'stop' but you just go slower if there isn't enough (which is why I'm fitting drum to modified 360 :D)
 

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I believe you can't have too much brake.
You can learn to use it if it's got plenty of 'stop' but you just go slower if there isn't enough (which is why I'm fitting drum to modified 360 :D)
 

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PJ,
Essentially true under racing conditions, but when the extra weight and stopping force overwhelms the forks and suspension it becomes counterproductive. If you can lock up the front wheel with good street rubber, you have enough brake.

Ken

quote:Originally posted by crazypj

I believe you can't have too much brake.
You can learn to use it if it's got plenty of 'stop' but you just go slower if there isn't enough (which is why I'm fitting drum to modified 360 :D)
 
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PJ,
Essentially true under racing conditions, but when the extra weight and stopping force overwhelms the forks and suspension it becomes counterproductive. If you can lock up the front wheel with good street rubber, you have enough brake.

Ken

quote:Originally posted by crazypj

I believe you can't have too much brake.
You can learn to use it if it's got plenty of 'stop' but you just go slower if there isn't enough (which is why I'm fitting drum to modified 360 :D)
 

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Geeto,
I still contend that a properly set up drum is not as crappy as you think. Have you ever actually ridden a 350/360 with a properly set up ( adjusted, bedded, lubed) front drum? I agree that most drums and single piston disc brakes are crappy.

Ken
 

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Geeto,
I still contend that a properly set up drum is not as crappy as you think. Have you ever actually ridden a 350/360 with a properly set up ( adjusted, bedded, lubed) front drum? I agree that most drums and single piston disc brakes are crappy.

Ken
 

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quote:Originally posted by Geeto67

Asking questions that have multiple answers and expecting one answer is not going to help you. So let's run back to the project planning stage for a second.

(snip)

As with anything nobody is gonna write you instructions. It isn't fair to us or to you who needs to learn not just how to do custom work but how to be brave enough to plunge into custom work with little more than a well reasoned idea of how it goes together.
That was a great explanation. Kudos.

My CB360 stock, single-puck caliper is more than enough for hard stops. My long-ago GT350 had a drum brake and I seem to recall it worked pretty well.
 
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