Topic: 75F' 750 cafe w/ CBR F2 mods

[Shtonecb500]

I have left over parts, multiple options for front end combinations, going to use the cheapest most bolt on route possible. The motor is getting torn down and re built, I'm still sourcing a titled frame and I'm using this untitled frame for mock up as of right now. I thought I had a stock front end up but the forks were off a chopper so the tubes are extended and the lowers are earlier but have had parts shaved off, I cant use them.

I have a front end and swing arm from a vfr700 interceptor, all balls conversion bearings have been out of stock all year. I was only able to get the lower and not the upper....or vise versa.

I have an earlier gsxr 750 front end and rear wheel but for the 750 but need a conversion stem, so it will be saved for a 550 project  since its more of  a bolt on application for a 550 frame.

I'm using a david dixon yoshi exhaust I got for free from Dolomite here on the forum (what we think is a real dixon yoshi pipe), filled the tank with metal rescue and it cleaned up wonderfully, that thing was roasted on the inside.

The tank, front and rear end are coming from the donor bike pictured below.

[seanbarney41]

mock up looks tasty...would love to see the VFR stuff get used as it seems like a good option for truly improved handling...forks are long enough to not mess up cb750 geometry, unlike all the gsxr stuff (except the very earliest gsxr's that are only marginally better than the vfr stuff anyway)
I know cbr600f4i wheels swap into the vfr stuff easily so you can run some big sticky 17's

[Terry in Australia]

That is a beautiful tank mate, if you decide not to use it, I’ll buy it, my F2 was originally black, and I’d love an original survivor tank to put back on it.

[Shtonecb500]

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[Shtonecb500]

mock up looks tasty...would love to see the VFR stuff get used as it seems like a good option for truly improved handling...forks are long enough to not mess up cb750 geometry, unlike all the gsxr stuff (except the very earliest gsxr's that are only marginally better than the vfr stuff anyway)
I know cbr600f4i wheels swap into the vfr stuff easily so you can run some big sticky 17's

the vfr set up I have has a big rear at 18" and a smaller front at 16". The rear axle is the same so stock axle works with vfr rear wheel. I have a harley hub fitted to the gsxr fork right now, just havent made it up to a harley shop and asked for spokes and a rim that would work. The idea of having cbr wheel options sounds good to me. I could get a swing arm made for 300 I think....to accept any wheel option, versus figuring out how to mate the vfr swing arm to the 750 frame.

[BigJimG]

Any idea what bearing numbers you actually need for the conversion?  There's plenty of bearing houses in the Detroit area, I'm sure All Balls aren't having them custom made.

[Shtonecb500]

Any idea what bearing numbers you actually need for the conversion?  There's plenty of bearing houses in the Detroit area, I'm sure All Balls aren't having them custom made.

No, I’ll figure it out though. Good idea.

[Shtonecb500]

Damn, that air filter makes me want to leave it open under the seat. The frame rails needed 1.5" of material added to the ends of rails so the lights would be flush with the cowl. I have about 1-1.5 inches of the front of the seat tucked snuggly under the tank, it works very well. I was either going to cut away that length from the front of the seat or just add material in the end, like i ended up doing. I didn't want to cut the seat or change it, but now it doesn't give me the elusion of the seat being ALOT shorter than the tank, but from the front of the bike the rear end looked a little too stubby and doesnt anymore...so thats fixed.

[SOHC4 Cafe Racer Fan]

Nice breadbox air filter. You don't see too many of those anymore.

Yeah, keep it open.

[754]

 A lot of bearings for tapered are custom ground off the shelf bearing,  so if it has same number , it does not guarantee it fits..
 Like for sure that is the case on 750 k and F frames

[Shtonecb500]

Nice breadbox air filter. You don't see too many of those anymore.

Yeah, keep it open.

idk what to do for an oil tank if i do.

[Shtonecb500]

That is a beautiful tank mate, if you decide not to use it, I’ll buy it, my F2 was originally black, and I’d love an original survivor tank to put back on it.

If I decided to sell I'll let you know first. I didn't want to repaint it either....I have another one that has been lined in the inside so I can paint that one.

were there any differences between the SS tank from 75-78? any size differences?

[754]

Make an oil tank, it will be fun..

[Shtonecb500]

Make an oil tank, it will be fun..

DYI oil tanks are like 60-70 bucks. I might go that route if I cant lock a used one down for cheaper than that.

[Shtonecb500]

mock up looks tasty...would love to see the VFR stuff get used as it seems like a good option for truly improved handling...forks are long enough to not mess up cb750 geometry, unlike all the gsxr stuff (except the very earliest gsxr's that are only marginally better than the vfr stuff anyway)
I know cbr600f4i wheels swap into the vfr stuff easily so you can run some big sticky 17's

what would a 16 front and 18 rear do to a 750 ? lol

[Shtonecb500]

Nice breadbox air filter. You don't see too many of those anymore.

Yeah, keep it open.

Ive been looking for a reason to use this thing, I have one for a 550 as well. I want them to be the focal points of the bike though....so getting rid of side covers is needed.

[seanbarney41]

mock up looks tasty...would love to see the VFR stuff get used as it seems like a good option for truly improved handling...forks are long enough to not mess up cb750 geometry, unlike all the gsxr stuff (except the very earliest gsxr's that are only marginally better than the vfr stuff anyway)
I know cbr600f4i wheels swap into the vfr stuff easily so you can run some big sticky 17's

what would a 16 front and 18 rear do to a 750 ? lol

I think it bottoms out on a lot of pipes...I dunno that 18 front, 16 rear thing was a brief 80's phenomena.  I think it would make a cb750 dangerously twitchy.  It makes for scarce tire selection.  And guys who have those bikes work hard to swap to 17's.  I had a VF500f with that wheel combo and the geometry to make that 16" front work is buit in and they handle amazing.

My opinion on the open triangle is way too many guys make bad design choices to achieve it.  What is so special about shunning the most obviously useful place to locate stuff just so you can have a hole in your bike?  It seems like a few guys have done it well, it gets on the internet, and then everybody thinks its required.

[Shtonecb500]

sooooo the rear calipers are hard to find and expensive as #$%*. I didnt know that.

[SOHC4 Cafe Racer Fan]

sooooo the rear calipers are hard to find and expensive as #$%*. I didnt know that.

Rear CB750F calipers are getting more difficult to find.  Check with Bill Benton (on the forum).  I believe he has a 77-78 caliper.  You will also need the stabiizer bar that keeps the caliper in position on the disc.  It mounts to both the caliper and swingarm.

[Shtonecb500]

I may have found almost everything for a  full brake system, I missing some small things here and there. I managed to get the races installed and the tripled bolted up correctly. The 78 swing arm was taken apart, cleaned, greased and installed as well so now I have matching wheels. The costars are growing on me.

I need those parts in the red circle, does anyone have them?

[Shtonecb500]

Races were installed, the 78' swing arm was installed, I sourced rear brake disc caliper back plate and a caliper off a goldwing, the back plate is missing the pins A and B. I just found one on Ebay for 15 bucks but the pins looked really rusted. Hopefully I get lucky because all the other ones are 50 plus dollars. I've decided to eliminated the rear sets, keep the stock oil tank and use the side covers, use the chin scoop but it will be easily removable, I'll paint my spare F tank that is lined and keep this tank on the shelf. The stock mud guard fits in there perfectly with the rear cowl, makes everything nice and neat. Stock foot controls, stock hand controls, new tires, LED turn signals front and back, and I'll make up some "L" brackets about an inch and a half out to mount the chin scoop away from the exhaust pipes.

I plan on replicating the chin scoop, matching rear cowl and seat pan with fiberglass so I have copies for future builds. The seat pan I'll make with metal and fiberglass, there is another rear cowl I need to replicated as well. There is a fully hand polished motor sitting in the corner with a bent crank, it's a 78' and my buddy has a ss titled frame I could buy off him I think. Otherwise I have the original motor I posted at the beginning of the thread and I can just rebuild that like I planned. There seems to be lots of body work to showcase a nice paint job or pin striping....im thinking about it instead of just blacking this thing out.

[Terry in Australia]

That is a beautiful tank mate, if you decide not to use it, I’ll buy it, my F2 was originally black, and I’d love an original survivor tank to put back on it.

If I decided to sell I'll let you know first. I didn't want to repaint it either....I have another one that has been lined in the inside so I can paint that one.

were there any differences between the SS tank from 75-78? any size differences?

Sorry for not replying earlier mate, yep if you do decide to sell that black tank I'd appreciate you letting me know first, money waiting. The tanks were the same size but the petcock threaded tube sizes were different, I can't remember which one was bigger though, it's too long since I played with them.

[Shtonecb500]

I just purchased Matt Bochnaks How to: cb750 engine rebuild top and bottom for $50 bucks.

lll have two 750 motors to rebuild at the end of march, I'll be watching these videos until then while I source a second motor.

[Shtonecb500]

sooooo the rear calipers are hard to find and expensive as #$%*. I didnt know that.

Rear CB750F calipers are getting more difficult to find.  Check with Bill Benton (on the forum).  I believe he has a 77-78 caliper.  You will also need the stabiizer bar that keeps the caliper in position on the disc.  It mounts to both the caliper and swingarm.

I was able to score some cheap parts off of eBay, they were scattered in amongst the ridiculously priced parts. I actually bought a second complete set up because I was able to part it together for so cheap. 2 FULL sets of brake plate and calipers for around 140 bucks.

[Shtonecb500]

Any idea what bearing numbers you actually need for the conversion?  There's plenty of bearing houses in the Detroit area, I'm sure All Balls aren't having them custom made.

You make a good point, Ill dig into the numbers and see if I can make something work. I had a blown front wheel bearing on my R80 while I was in South Dakota....there was a bearing factory about 10 minutes from where I was staying and they had exactly what I needed...I was amazed.