Topic: 1977 Cb400f Cafe Build

[Powderman]

Keep in mind the CB400F was a drum brake and I am converting to disc with CBR wheel. I will have to add a brake stay and will weld it on the swing arm where necessary. I was going to ask whether there was another swing arm that would work. Do you know off hand who the members are that have done this conversion and the one with the box swing arm? You can still only go as wide as the chain will allow without have to space the front sprocket out as well. I have mill/lathe in my shop and access to anything else I need , so, like you, if you run into a problem there's nothing that a little imagination can't fix. Instead of measuring the swing arm width I need to know the width of a 140 tire mounted on a 3.5" rim first. I see width's listed but they are always different than real world numbers depending on the application and brand of tire.
I haven't had any luck finding any results for anything, no matter what words I use in the search function here.

[braveg]

Hey PM, good to see your progress and sorry to change the subject a little, but seeing as powdercoating is your thing, I remember a while back on CR.net there was a discussion about powdercoating exhaust headers but i cant find it cos the search doesnt work very well...my usual powdercoater here in SA has just started offering high heat powdercoating and was wondering if this would work on my cb400? I have just picked up a set of headers that aren't the original and as such I don't mind powdercoating/painting them. Any suggestions? Is high heat powdercoat up to the task or is ceramic coating the only way to go?

Thanks man
G

I have found the high temp powders (good to 1200*f) to be too finicky when it comes to prep. If you don't have it perfect it will fail and start to flake off. I no longer offer high temp in my business for this reason. You do a perfect job and the powder starts flaking and the coater gets blamed for doing a piss poor job. No standard powder will work on exhaust pipes as it is only good to spikes of 500*f and most pipes at the first bend out of the head exceed that by a bunch. I would stick with Ceramic, a bit more expensive but able to handle the higher temps (up to 2000*f). Unfortunately it doesn't have the durability of powder and I've seen people ride hard and stop at the car wash and power wash the ceramic right off because of the shock in temp difference. Also color selection is highly limited with Ceramic.

Thanks man out of interest, what kind of process would you consider a proper prep of the exhaust for high heat pc'ing? one last question and I will stop jacking your thread

[Retro Rocket]

Keep in mind the CB400F was a drum brake and I am converting to disc with CBR wheel. I will have to add a brake stay and will weld it on the swing arm where necessary. I was going to ask whether there was another swing arm that would work. Do you know off hand who the members are that have done this conversion and the one with the box swing arm? You can still only go as wide as the chain will allow without have to space the front sprocket out as well. I have mill/lathe in my shop and access to anything else I need , so, like you, if you run into a problem there's nothing that a little imagination can't fix. Instead of measuring the swing arm width I need to know the width of a 140 tire mounted on a 3.5" rim first. I see width's listed but they are always different than real world numbers depending on the application and brand of tire.
I haven't had any luck finding any results for anything, no matter what words I use in the search function here.

Sorry, bit of brain fade {having a few beers} last night, was thinking stock drum brake..

ttr400 is the member with all the great 400 parts, here's his site.

http://www.ttr400.com/index.html, there's a swingarm on parts page 3, he has lots of nice parts..

There are 2 search functions on the forum, one under your name , top left of the page and the one at the top right of the page..
Just had a thought, there was a really nice 400 in bike of the month a while back, i think it won so it should be in the BOTM gallery....

I have found that with most japanese mag wheels, the rear sprocket carrier sits a long way to the right so its usually possible to maching some off the carrier on the sprocket side, to get the chain to line up better, i am not sure what size front sprocket the 400 use but CycleX have 10mm offset front sprockets in 17 tooth and 18 tooth....530 chain i think....

!st post of the morning, hope this one makes sense...

[Powderman]

Keep in mind the CB400F was a drum brake and I am converting to disc with CBR wheel. I will have to add a brake stay and will weld it on the swing arm where necessary. I was going to ask whether there was another swing arm that would work. Do you know off hand who the members are that have done this conversion and the one with the box swing arm? You can still only go as wide as the chain will allow without have to space the front sprocket out as well. I have mill/lathe in my shop and access to anything else I need , so, like you, if you run into a problem there's nothing that a little imagination can't fix. Instead of measuring the swing arm width I need to know the width of a 140 tire mounted on a 3.5" rim first. I see width's listed but they are always different than real world numbers depending on the application and brand of tire.
I haven't had any luck finding any results for anything, no matter what words I use in the search function here.

Sorry, bit of brain fade {having a few beers} last night, was thinking stock drum brake..

ttr400 is the member with all the great 400 parts, here's his site.

http://www.ttr400.com/index.html, there's a swingarm on parts page 3, he has lots of nice parts..

There are 2 search functions on the forum, one under your name , top left of the page and the one at the top right of the page..
Just had a thought, there was a really nice 400 in bike of the month a while back, i think it won so it should be in the BOTM gallery....

I have found that with most japanese mag wheels, the rear sprocket carrier sits a long way to the right so its usually possible to maching some off the carrier on the sprocket side, to get the chain to line up better, i am not sure what size front sprocket the 400 use but CycleX have 10mm offset front sprockets in 17 tooth and 18 tooth....530 chain i think....

!st post of the morning, hope this one makes sense...

I had to machine off .300 off the spacers,  seal lip, the sprocket tabs and bury the bearing .300 further in on the Ninga250R wheel to make it line up on my XR so I'm quite familiar with that process. Fortunately there were other Honda's that share the same basic cush drive hub with the only difference being the sprocket spacing. So I think there is one that will replace the 600f1 and line the sprocket up correctly if not minor machining to get them in line. This is all very easy work in my book to accomplish modern parts that work on the older vintage stuff.
Sorry we got off on the wrong foot but got it cleared up. Thanks for your help. I think we are in the same boat.

[Retro Rocket]

No worries, check out that link i posted....

[Powderman]

Hey PM, good to see your progress and sorry to change the subject a little, but seeing as powdercoating is your thing, I remember a while back on CR.net there was a discussion about powdercoating exhaust headers but i cant find it cos the search doesnt work very well...my usual powdercoater here in SA has just started offering high heat powdercoating and was wondering if this would work on my cb400? I have just picked up a set of headers that aren't the original and as such I don't mind powdercoating/painting them. Any suggestions? Is high heat powdercoat up to the task or is ceramic coating the only way to go?

Thanks man
G

I have found the high temp powders (good to 1200*f) to be too finicky when it comes to prep. If you don't have it perfect it will fail and start to flake off. I no longer offer high temp in my business for this reason. You do a perfect job and the powder starts flaking and the coater gets blamed for doing a piss poor job. No standard powder will work on exhaust pipes as it is only good to spikes of 500*f and most pipes at the first bend out of the head exceed that by a bunch. I would stick with Ceramic, a bit more expensive but able to handle the higher temps (up to 2000*f). Unfortunately it doesn't have the durability of powder and I've seen people ride hard and stop at the car wash and power wash the ceramic right off because of the shock in temp difference. Also color selection is highly limited with Ceramic.

Thanks man out of interest, what kind of process would you consider a proper prep of the exhaust for high heat pc'ing? one last question and I will stop jacking your thread

Clean, degrease, blast with aluminum oxide or sand and make sure you don't handle the part with human hands before coating. The high temp powders usually have a silicone content that won't allow second coat adhesion, so get it right the first time or strip and start over. Coat it as soon as possible after prep.

[Powderman]

No worries, check out that link i posted....

Will do. I have been to his site. The swing arm is a bit pricey for my blood for a bike I am just going to flip. I talked to a local shop that I coat for and they are going to pull me a 130-80 and a 140 used tire for me to use for mock up to see if all my plans will work.
ttr400's website says he is going on a trip and won't be supplying parts until 2014

[Powderman]

Retro, I was able to find this same setup I am trying to accomplish at Denoon. I was able to enlarge this pic enough to see they are running a 120-80/17. Clearance looks tight at the chain. The 120 would be 4.72" wide as opposed to the 130 at 5.12" or a 140 at 5.51". Being as the CBR600f1 wheel is as wide as the stock CB400f tire (4.00-18). I don't think I want to put the largest tire I can fit in there and possibly upset the handling characteristics. Am I on the right track?

[Retro Rocket]

Hard to tell from that photo exactly what he has done but if you are happy with the 120 the it should be ok, it looks like it pushes the sidewalls out a bit maybe squaring off the tire a bit, it would be nice to know if he did anything with the sprocket carrier to align the chain. I would get the wheel centred in the swing arm first and see what the chain line is and take it from there, i would say some machining will be needed to get the chain straight. Does the 400 run a 530 chain..?  Can you see how much clearance that wheel has to the swing arm..?  I'll see if i can find the purple 400 on this site that has been Hot rodded and see what it has in the rear...

I'll be back...

[chris mcshifty]

What are the benefits of the cush drive. Looks like an awesome build

[Retro Rocket]

This is Kevins bike {TTR400}  It has a different swingarm, probably one he sells and looks like he has stock size rims.



Looks like you'll need to get the rim centered in the swingarm and see how much room you have and start working from there... Leave the tire choice till you know how much room you'll have....

[Powderman]

What are the benefits of the cush drive. Looks like an awesome build

The cush drive has rubber cushions between the drive hub and the wheel itself to lessen the shock of the power to parts in the motor. It is not important on this build but I had to use it as part of the whell package.

[Powderman]

Major rant just happened. I typed about 10 minutes worth of info and pics to answer the post here and when I went to open the thread back up to post a pic it closed instead erasing everything I typed. I hate when that happens.
 Retro, The 120-70-17 I just mounted is 1/4" wider than the 4.00-18 stocker even though the wheel is at least 1.5" wider. This tire has 1/2 clearance in the left and 3/8" on the right side of the swing arm in its most forward position. The relationship in size between the two tire and the size of the bike tells me this combo will do just fine. The cush drive needs extensive machining to move the left side hub seal, the hub bearing, and the sprocket mounting tabs to the right to line up the chain. I went through this same whole process on the Ninga wheel on the XR so I am quite familiar with that process. I need to get the hub and caliper bracket mounted before taking measurements.
Can someone in short laymans terms explain how a tire too wide negatively effects handling. I won't decide if I want to go with a 130 or not until the 120 is finish mounted on the bike. A 130 would look meaner but not at the cost of handling response. It also is dependent on chain clearnance if I have the extra 5mm.

Left side clearance, pic doesn't show it but there is a good 1/2" there. The stock spacer from the CB wheel centered the CBR wheel perfectly. I only need to get the caliper bracket on to figure the right side spacer. (that left side spacer will go when the cush goes there.:


Right side:


Left side:


Lots of room in front:

[Retro Rocket]

OK, i may have confused you a bit with tire sizes, everything i said earlier in the thread relates to the tire to rim size ratio, It can adversely effect handling by having the wrong size tire on any given rim, you don't want too big a tire or too small a tire on your rims. You are able to use a 130 on that rim as it is the correct size tire for the 3.5 inch rim, as stated earlier , i am running a 140 x18 on a 3.5 inch rim which is fine. The only problem i can see with the wheel sizes is a slight loss in rolling diameter which will slightly effect ground clearance. You should be able to easily set the bike to handle well with a 120 or 130 tire on the rim you are using. You are also using a matched set of rims, which is good. There are plenty of guys on the forum that run wider rims and tires, the main problem i see with a lot of the conversions is usually related to the front end conversion that a lot of guys do, using the triple clamps and forks from other bikes that don't share similar offset to the Honda clamps, like the GSXR clamps, most have a 35mm offset where the Honda 750K's i am referring to have a 60mm offset, the smaller offset of the Suzuki clamps adds trail which in turn slows down the steering response, adding stability in a straight line but taking away from turn in when cornering, making it harder to turn in..?  The wheels and tire sizes you are using are quite tame compared to some of the conversions on the forum so i wouldn't be worried at all, just use a matching set of tires as most tires are made to perform as a set....  Hope that helps some....

[Retro Rocket]

Another thing, with the GSXR sprocket carrier i had machined to fit, i only took material from the area where the sprocket mounts to the hub, where the sprocket actually bolts on, no where else....  When you tale the sprocket off you can see the surface with the 5 {what ever number} bolt holes are for securing the sprocket, thats the area i machined... Very simple and straight forward..

[Powderman]

I'm not sure with the cush drive hub and everything on the CBR wheel whether it will physically fit between the SA arms. The f1 hub is very thin to begin with so taking material off the sprocket tabs only may not give me enough to align the chain. Won't know till I have a hub in hand, I'm searching for a cheap one on ebay now. Unless someone here has one they want to let go cheap.
remember right now I have th CBR front wheel on the CB400 forks. I will be converting the complete CBR f1 front end.

[Retro Rocket]

I'm not sure what the triple clamp offset is on the 400, but i would measure both the 400 clamps and the CBR clamps to see how much difference there is....This is a pic of a GSXR top triple clamp,  the 35mm measurement on the right hand side is the offset, its the measurement from the center of the steering head to the center of the fork clamp.....

[Powderman]

I'll have to research the CBR offset but the 400f looks in the 60mm range.

[Powderman]

I'm glad to see this bike was well maintained,NOT. I pulled the sprocket cover off to put the chain back on to take some side measurements and found the cover filled with thick dirty greasy crap and some corn and orange and green things. The motor in there was just caked with years of road grime.

[Powderman]

Well I have the rear all sorted out now. I moved the cush drive hub bearing over 4mm to the right along with the seal and the hub lip for the seal and then moved the sprocket over 13mm to get it back in line. I ordered the proper f1 caliper bracket so all I need now is the cush rubbers. The wheel and tire both have no clearance issues at all and going to a 130 will still leave enough room.
There was a 6mm wide shoulder keeping the bearing from moving inboard. I took 4mm off it leaving 2 mm which I think is substantial enough.


Then 13mm off the sprocket tabs:


Leaving plenty of tire clearance:


Then I had some foam mixed up and poured to start playing with the shape of the seat.

[Powderman]

Decided to hand fab some side covers for it out of aluminum and polish them. I knocked one out just to see what they looked like. What do you think?

[Retro Rocket]

Good work on the rear wheel mate....   The 17's look good on the 400, they look a little small on the 750 though, i have a set of 17 inch GSXR wheels on a chassis at the moment but i'm going to replace them with the 1988 GSXR1100 rims, they are 4.5x18 and 2.75x18....  Are you going to repaint the rims..?

[Powderman]

Good work on the rear wheel mate....   The 17's look good on the 400, they look a little small on the 750 though, i have a set of 17 inch GSXR wheels on a chassis at the moment but i'm going to replace them with the 1988 GSXR1100 rims, they are 4.5x18 and 2.75x18....  Are you going to repaint the rims..?

I'm a professional powder coater, DUH. I think I will just leave them the way they are, NOT. Just kidding with ya, Rocket. I am planning on Transparent Metallic Teal for body work and Pearlescent White for the frame . I haven't yet decided on which color for the wheel. I may polish the lips of the wheels and then color the spoke section.

I am also contemplating whether to add this fairing or not. It's for an RD400 but fits pretty well on this build. What do you think?

[Retro Rocket]

Cool, i forgot about the powdercoating bit...   I used to powder coat and electrostatic spray here in Aus, back in the 80's...

[Powderman]

Got the rear caliper bracket on and figured out what I need to do to secure the brake stay rod. I'll add a mount when I do the swing arm brace later this week.



Finally got the cardboard mock up of the seat done and need to transfer it to foam for final contouring and radiusing of edges before sending it for a mold.