[Homanpv]

posted once before and since then I've gotten my bike running now time to turn her into a racer.
was thinking i wanted to do a more modern sport bike front end swap, but iv read on a few other forums that its real only benefit is cosmetic?
the real question about it is what kind of front end is the best choice.
i have a 73 cb500f i have seen guys go with dirt bike front ends over a sport bike and wondered if there was a reason for that as well.
also would like to get rid of the stock rear shocks and I'm assuming the flebay cheapies probably wouldn't be the best option for the best results.
lastly i was thinking about some after market carbs and wondered if anybody had any suggestions on which way to go with that?
oh and this bike is being built for fun on the roads not a track bike but just want to maximize what i can get out of it if that makes any difference to the answers you all may have.
appreciate the help gentlemen.

 

[Homanpv]

are these just totally stupid questions?
or nobody just willing to help me out here

 

[Geeto67]

These aren't totally stupid questions, they just get answered once a week here so it burns people out.

So while a modern front end may give you better brakes (provided you don't want to do something stupid like want to use a drum brake and the spoke wheel) handling all depends on geometry. You need to do the homework. Personally I would just work through the dual disc conversion on the stock forks, put a cartridge emulator in the forks, and lace an 18" front rim to the hub. And then see if you really need more.

Rear shocks: Call Dave Quinn and order a set of hagon shocks setup to your bike and rider weight. this is the least expensive way to great good rear shocks. They won't be fancy eye candy like the ebay chinese cheapies but they will work a hell of a lot better. The reason I suggest dave is he will really work with you to get you the right shock, buying an off the shelf pair of anything won't get you that. Also do your swingarm pivot bushing at the same time, rear shocks are useless if your swingarm is moving around.
Hagon


Aftermarket carbs: Kehin CR. It's the only set worth spending the money on and you'll probably spend more than you paid for the whole bike. I don't know what "other" aftermarket carbs you are looking at but if they aren't Kehin CRs, old mukuni smoothbores, or flatslides it isn't worth it (inless you found some rare weber setup for a 550). I don't know if you'll get performance enhancement out of the bike without a cam and head work though - but they will look impressive:
DYNOMAN PERFORMANCE - Austin, Texas

 

[Homanpv]

Thanks Geeto.
I don't mean to be a bother and re ask stuff I'll go a bit harder when searching before throwing up a thread. I'll start looking into the dual disk on the front and give Mr Quinn a call.
I'll start lookin more into the cam and head work as well. Though some fancy carbs would look real nice don't wanna spend the money just to look cool (not yet anyway)

 

[jaguar]

Has it passed a state inspection and been used on the street for more then a few miles?

 

[kenessex]

are these just totally stupid questions?
or nobody just willing to help me out here

These are not really stupid questions, but more from a position of ignorance. I have been doing the motorcycle thing since the CB500K was a current model, as have many others here. That means that we have lived the progression from crappy suspension and wooden feeling disc brakes to modern suspension and big discs with 4 piston calipers that transfer forces into well triangulated frames and fat sticky tires. A cb500K will never be what a CBR600RR is with respect to power, handling, brakes, ergonomics or suspension, even if you bolt a whole bunch of modern parts on it.

The question now becomes what does the bike want to be and what do you want it to be and are those desires compatible? So, what Geeto has suggested is a reasonable way to go with maximizing what you have. I would not bother with the CRT carbs or with a cam and porting. I would completely rebuild the stock front end or get a GL1000 front forks. Go with dual discs and 18 inch alloy rims front and rear with a wm3 front and wm4 rear. If you want to spend some more money the get heavy duty stainless spokes from Buchanan's.

That should get you to a good starting place to move on to the next stage which is ergonomcs and have you look at the footpeg, seat and handlebar relationship.

Ken

 

[Homanpv]

Jaguar, has not passed an inspection but iv been running it just around my neighborhood. unfortunately the owner before me decided to do a half assed attempt at making it a cafe so i have to get blinkers and a tail light before it will pass. figured while its cold might as well do what i can now mechanically before worrying about getting it legal, it was cheap the engine runs and had a title though so I'm not complaining.

kenessex, after Geeto's reply i do believe i am going to go with rebuilding the front end and getting the dual discs on for the breaks instead of a modern swap. thanks for the tip on the 18 inch rims as well ill see what i can find.
the bike already has rear sets and clip on bars, unfortunately i will have to look into the seat as the previous owner had an ugly fiberglass tail with just a quarter inch piece of foam for the seat.

 

[jaguar]

If it has not passed an inspection and isn't used much then whats the idea behind the swap?
You need seat time to know what the weak links are in the bike. Also need a good baseline to know if your mods are any good.

 

[Homanpv]

Jaguar, i get what your saying. I'm not going to do the swap as of now. just waiting to get home from the in-laws so i can do the front end rebuild. then going to lace an 18 in rim on and go from there.

 

[Big Bad Bob Dog]

Do not put the CR's on it unless you're porting the shit out of that head. Dynoman only sell the 29's for the 500/550. Air wants to travel in a straight line. Your manifolds are kinked then they take a 90 degree turn into the cylinder. You need to take a good chunk of alloy out of there and make new manifolds for it. The volumetric efficiency of the stock head is a dick. Ask me how I know. Thank me later for saving you the money.

Untill then, keep the stock carbs. Stock airbox. Do a good service, will yield best results. But I'll let you in on the biggest superist baddest sickest secret ever to get power out of a 500/550.

Two things after you're bike has decent rubber, brakes and suspension.

1) The 500/550 will not pull redline in top gear. Not even close. Drop a tooth on the front sprocket. You will still sit on the highway fine, but feel like you gained 10hp.

2) Fuck me sideways. Get a quick turn throttle. You need literally two handfulls to get those carbs open. Access what you have. Don't argue. Do these two things first. Thank me later.

Also. Here:

http://forums.sohc4.net/index.php?topic=20601.0

This is 1 million times better than playing dress up with the guys who think they know everything.

I fucking hate cafe racers.