Topic: '75 CB550K - "Le Mans Special" - muffler fell off at 80mph

[Ringo]

And I believe member joeyputt's street-legal 550 is coming in at around 320lbs, but don't quote me on that.

Edit: spoke too soon.  He's coming in at under 300, and expects to stay there.

[Ringo]

Alright TG, you put enough doubt in my mind that I had to go back out to the shop and bring the camera this time.  I'll let the photos do the talking:

Let me say, it was no easy task holding the bike upright for an accurate measurement while taking the photo!




nice and level


And to judge the scale's accuracy.  I regularly weigh in on the medical scale at work around 175lbs, fully clothed.  So here's a discrepancy of 2.5 lbs.   


As I said, the tank is down roughly a gallon of fuel (5gal tank), so that's (+/-)4 gallons x 6 lbs/gal = 24 lbs.  3.4 quarts of oil at 1.875 lbs/qt = 6.375 lbs... so all in all, 30 lbs of "wet".

182 (front) + 175 (rear) = 357 lbs, wet.  Add that 2.5lb discrepancy to the front and back, and we have 362 lbs.    Minus 30 for fluids...332 lbs dry.

I can't tell you exactly where every little bit of weight was lost, TG.  Extreme weight-loss wasn't one of my main goals for this build, it just happened in order to fit the bike to my vision.  And as such, I've never weighed the composite pieces, so I can't say how they compare to stock (obviously they must have come out lighter). 

I'm no magician, but I'll chalk it up to the magic of fiberglass...and losing as much of the original bike as I could.   

Perhaps you should send me your tank and seat so I can replicate them in fiberglass (or carbon fiber!  ) this winter, TG.

[Syscrush]

This makes me want to get going on my custom tank and tail, AND get serious about my diet!

At least I'm not jealous of your shoes.

[Ringo]

Hahahahaha, yeah they're the comfy wear-around-the-house loafers.  What can I say, you caught me.   

[turboguzzi]

as you can see it's a race only thing, where i did try to get to lowest weight possible, so to that list you can add quite  a few other items like hollow rear axle, ally wheel spacers all around, lightweight brembo calipers, lightweight clutch activator, ally triple clamps, internal starter clutch removed, primary chain sprocket turned down, rear sub frame is cut to minimum, possible, seat is ultra light race unit,  lightest marving racing exhaust system, no silencer...
the only item where i found that a few pounds difference was not worth the fire risk in a crash was in the gas tank: its stock and compared to the fiberglass racing ones its just about 3 pounds more.

If i was alone with this figure, i would understand, but check also Howel's and Bwaller's road racers, they are all about 320-315, same about my friend's bikes here in the italian classic championship. my bike is the white number 666, the other are my friend's, they are all out racers and none goes under 320...take out 5 lbs for fairings and you are still at around 315 stripped.

So as much as I do want to believe what i see, something doesnt add up... think about all the other stuff that you do carry, and you tell me if its only an extra 10 pds.

BTW, honda's own exotic  CB500R, full of Ti, magnesium and what have you was 305, so that's why i am a bit sceptic about 320 street bike stories

never mind though, if you did manage to bring your street bike down to 330 then you are a talented tuner, compliments indeed, no tongue in cheek

TG

[Ringo]

My 330+ vs your 315...maybe.  But you also have that extra front rotor/caliper, which I could see weighing 5lbs easily.  So we're left with somewhere around a 20lb weight difference...?  With that list you gave me, that sounds entirely possible.  We're starting to split hairs, though.  I can't imagine many things on that list saving much more than a couple pounds...more likely ounces.  But every last bit is important for a race machine.   

I love the race bike, by the way.




Edit:  I have to say, your skepticism doesn't sit well with me.  That is to say, your concern has me concerned.  While I'd like to believe these numbers are true, I'm going off a simple bathroom scale here.  And I'm starting to need closure!    I'll be on the lookout for someone willing to let me park the bike on their commercial scale.  Whether my numbers are right or wrong, I want to find out.  I know I've stripped a whole hell of a lot off this bike, but as you say, if it doesn't add up, it doesn't add up.  So fear not, turbo, I'll get you an accurate weight soon!

[Roach Carver]

If you can find any guys with race cars they will likey have some scales that are quite accurate. one under the front, one under the rear and done.

[fastbroshi]

Any company that does commercial shipping should have a scale that should do.  They have to weigh their semis w/ trailers all the time.

[turboguzzi]

Dont worry ringo, enjoy your ride whatever the numbers and don't forget that 5% better riding skills are worth 50 pounds or more.... When you go road racing and a 220 lbs dude with exploding leathers passes you on the outside, you soon realize that. I'm 180lbs / 6'4" myself and there's only so much i can do against a 5'8" / 140 lbs typical Italian racer!

the only point was that knowing some real numbers i wanted to give you a perspective. My 500/4 racer is in pension anyway, not planning to do any development/weight reduction work in the near future, so not too worried either. 

BTW, the suzuki discs i am using are very light, 4.5mm thick i recon, ditto for the small brembo calipers with ally pistons. All in all not lighter than a stock, thick single disc and heavy caliper but pretty close.

Cheers

TG

[alternativeauto]

Just got back from the around-the-block shakedown, grinning like an idiot the whole way.  The bike runs great!  Couple small details to hash out, but by and large it's finished!  The "silencer" sounds killer, really pissed-off sound to it.  I took a vid, but managed to cover the mic with my finger when I switched hands to rev it.  I'll go out and grab a better one soon.

And if someone can tell me how to imbed this, that would be great.  I've done it before, but for some reason I couldn't get it to work.
http://youtu.be/a8hd_dWNElw

Wow! I love the Lemans Gulf paint scheme so much. Have you seen the Walz Hardcore build done in the same scheme? Bravo to a stunning build!!!

[Syscrush]

This was probably already covered, but what rearsets are those, and do they clear the kicker OK?

Also, my heart still skips a beat everytime I see that subframe/tail treatment.  This bike is what made me realize that I had to do my own tank & tail instead of sticking with my plan to get stuff from BCR.  I enlisted the help of a friend who is a sculptor and showed him your bike (not as something to copy, but as an example of something f'n awesome) and he loved it, too.

Sorry about the mushiness, but a bike like that brings out the romantic in me.

[bwaller]

If you find a place to weigh more accurately Ringo you may be surprised what you find. Mine came in at 322 dry with fairing & bellypan, but I actually stopped worrying about losing grams just to get it finished. I'll re-focus in the winter after all the little in season changes needed.

My bathroom scale wasn't close but actually weighed heavy compared to the commercial scale I ultimately used. One significant weight savings is also with race tires. The Avons save pounds and apparently Dunlops are even lighter!

[Ringo]

Thanks for that info, bwaller.  It's been so rainy here I haven't had a chance to hunt down a commercial scale.  Soon, I hope!

Syscrush, the rear sets were machined by a guy on the Do The Ton boards.  He doesn't have a company or anything yet, but does great work.  Same guy who made my top triple clamp.  They clear the kick start with about 3/4" to spare.  It really depends on how you mount them though.  My mounts are part of the frame, and tucked in as much as possible.

Alternative, thanks man.  I haven't seen that Walz build, least not that I can recall.  I'll have to google it.

[Ringo]

I had to do a little photoshoot for a magazine the other day, so because there hasn't been any photos in this thread in a while, here ya go:

[alternativeauto]

Alternative, thanks man.  I haven't seen that Walz build, least not that I can recall.  I'll have to google it.

Now I have 2 favorite builders...

[Syscrush]

Looks even better with the seat foam on there!

[Syscrush]

How is anyone to know that you're HARDCORE unless you have it sprayed down the side of your tank?

[rickyracer]

Sweet bike!!!  Nice work

[ScottCB550]

what kind of tripple clamps are those? I am doing my 550 now

[Ringo]

Hey Scott, it's the stock lower clamp, and a billet upper clamp, made by this guy:

http://oldschoolspeed.blogspot.com/

He has the dimensions for a cb550 clamp after doing mine, so it should just be a matter of pestering him to make you one.

[Bluegreen]

I love your bike man. In particular your frame mods and the paint scheme. How does your frame handle vs. a stock frame? I have a Gulf Duke as my desktop right now. I also like where you put your license plate. How's that going with "the man" ?

[Ringo]

The frame is really no different than stock, handling-wise.  Besides the subframe mods, I just welded up the stamped-steel seams.  No crazy bracing.

As far as the plate...well I live in Montana, which should say everything.  Cops here can really only be bothered if you're speeding.  I know the plate position is illegal, and it's not lit, but having a sheriff follow me for a few miles (and not care) was a good test!  And at the time, I hadn't gotten the bike registered, so I was running a plate from another bike! 

[sangyo soichiro]

GREAT pictures, mate! 

[bill440cars]

       Wow! Nice Build Ringo! Earlier today, I saw the one Joe was doing and now Yours. Outstanding job!

       I haven't been on here much in awhile and I am trying to catch up. Great Video too. 

[Ringo]

Thanks Bill!  It was a fun build, and it's a fun little bike to scoot around on.