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Discussion Starter #1 (Edited)
I am thinking after I salvage the parts I need from this "parts" bike, I may start a track bike. I have the necessary stuff to do so. Any thoughts on a CB550 track bike for NESBA vintage class track days? My current bike should be on the road this month or next for sure. I will post some pictures.

J
 

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Not sure about the vintage rules these days; but I raced a '75 CB550 'back in the day'. A bit heavier than it's competition then (eg. RD350's); but handling and powerband were advantages. If you can put good brakes and suspension bits on it, the motor is bulletproof. Should be fun!
 

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Discussion Starter #3
thank ron, I am unloading if off the trailer today, so this weekend will be parts assesment time. I have an extra engine and was thinking of going to the bigbore 605cc kit. Any suggestions? The entire motor is tore apart, so now would be the time for me to dig into it.

As for brakes and suspension, I was going to use the same Hawk GT NT650 front end I have on my other bike. Upgrading to VFR caliper up front and maybe a modified rear swing arm in back... not really sure on this part. If I use the stock swing, I put progressive shocks in the rear, and would prob do the same here. How was yours set up?
 

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All you really need to do with the motor is balance the rotating parts (crank/rods/pistons), so a little cylinder head work to improve the flow, and put some bigger/better carbs on it. The bottom end of the thing is great, and will take whatever you can throw at it; but the 'flow' side of things limits the stock motor pretty severely. If you have access to a flow bench, do it that way and match the flow on all four.

If the rules allow major changes to the suspenders, do whatever you're comfortable with. The Hawk front end should improve things quite a bit. All I could do (30 years ago) was use progressive fork springs and good shocks on the rear. It was good enough to win in the class I was running. A bit of bracing on the stock swingarm should be sufficient. Any more than that and you'll start showing the weaknesses in the frame.

Keep us posted lad!
 

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Discussion Starter #5
so you are saying do or do not put big bore kit in? As for sync'ng the carbs, I have a guy in NJ that does it on a water based manometer flow jet. Any recommends on the type carbs? Klien? Minuki? UPgrade from another bike? And what do you suggest I do to shore up the supports on the rear swing arm? by the way, loving the ideas
 

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as far as big bore kit, well... there's no replacement for displacement, as 'they' say. I'm just not a fan of making bigger holes in the crankcase. If you're okay with it, then do that!

Wasn't referring to 'synching the carbs'. I was talking about using a flow bench to optimize (and match) the airflow in the cylinder head; but it sounds like your 'guy in NJ' may have that covered.

I'll see if I can dig up some olde drawings of the swingarm....
 

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Discussion Starter #7
thanks, looking forward to it. not sure if I want to deal with the bore out right now, I have an extra engine - maybe that one.

As for the carbs, you recommeded bigger ones - any suggestions? I have rebuilt top to bottom my Kleins off my street 550. I would not mind a bigger better carb. Do I salvage off a bigger bike? If so, what? Or do I buy off the shelf? If so, What?

Looking forward to your responses!

Sweet looking rides - really like the vintage stuff!
 

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Your carb choices will really depend upon how much airflow you get on the bench. You can start with the stock Keihins (if I recall correctly, they're either 26mm or 28mm throttle bores) and tune them for the flow. What I found 'way back when' was that the engine needed more volume than the stockers, and I ended up with 32mm Keihins. I think they came off of a CB750.

Don't worry too much until you get the engine together and start tuning. Either a dyno or a good plug chop will tell you whether you need to change carbs.
 

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Discussion Starter #10 (Edited)
here are the updated pics off my custom street WIP, I am posting here for feedback on the rear race cowl. I am thinking this is what I want to do with the track bike. Red tank and red/white rear cowl.

FEEDBACK WANTED!

All photos have been updated on the picasa google pics: http://picasaweb.google.com/dwysywd/...ey=RJ3C8-XJV6E
 

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Jeff,

A stiffer swing arm is better; but....

If all the bearings are stout the stocker may be enough. It really depends upon how hard you will be pushing the bike. My experience was that the bike 'wiggled' pretty seriously without some additional support; but I was working that bike pretty hard in a class with some superior hardware. Running in a vintage class is likely to be a bit different.
 

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Discussion Starter #13
That sounds great. I didn't know if there was something obvious or not that I needed to do. I am already on the hunt for a smokin deal on the front end. But I am not really going to be working on this until I get my other WIP finished. If you have any other useful tips, let me konw. I will keep both threads updated as far as progress is going.

J
 

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I saw this guy on a ride last weekend (photo also in another post of mine). Nice looking home-boy racer, barely street legal.



Up here there is a huge collection of guys (somewhere around 30 or so) who road race old Honda 160's a the local track. It is apparently quite popular because the bikes are as bullet proof as can be, parts are plentiful, they're easy to work on, and...if everyone is riding the same thing...the racing is very close.

http://www.viciouscycle.com/
 

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I saw this guy on a ride last weekend (photo also in another post of mine). Nice looking home-boy racer, barely street legal.



Up here there is a huge collection of guys (somewhere around 30 or so) who road race old Honda 160's a the local track. It is apparently quite popular because the bikes are as bullet proof as can be, parts are plentiful, they're easy to work on, and...if everyone is riding the same thing...the racing is very close.

http://www.viciouscycle.com/
That. Is. Beautiful.

I've wanted to build a club-style racer for years, but never had the money. Still don't, oddly enough.

No sidestand. Clubman bars. Look at the rear sprocket, "Geared for the moon, Mr. Sun!!!"

Freakin' sweet.
 
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