Black Betty

[CaminoRacer]

Got a feeler gauge for the valve check. I'm gonna gamble and hope that it's still in tolerance, so I won't pre-order shims. It's still under 10k miles (barely ) and I know lots of guys don't actually have to adjust anything for 20-30k miles. We'll see. Should we take bets? It's got 8 valves, guess how many need adjustment and the winner gets a prize

[Eye of the Tiger]

What is this?
My first bike was a 1977 GS750. I later had a GS550. Love these things. Getting harder to find, though.

[68_427]

Yeah I feel like CA that wouldn't fly.

Then again most things aren't legal in CA.

Register in South Dakota then.  You can register anything by mail.  That's how people have plated 2 strokes in Cali

[CaminoRacer]

Finally got my plate! To celebrate, I rode to get tacos with the plate in my pocket in case I got pulled over.

In case anyone is wondering, it's been more than a month and I never got hassled. Sometime this week I'll mess around with mounting the new one. I think I'm gonna have to take the rear axle off to slide the mount on the left side. I could put it on the right side pretty easily (just pop the castle nut off), but I figure it'll look better as a quasi-chain guard.

Also thinking about finally swapping to clip-ons. I want to get new levers at the same time. Current ones work fine but have a lot of vertical play.

[Eye of the Tiger]

Vertical play helps you remember how old it is, and that the brakes are not super great.

[CaminoRacer]

I'm also gonna upgrade the front brakes to a two-pot caliper and modern rotor

[Eye of the Tiger]

I'm also gonna upgrade the front brakes to a two-pot caliper and modern rotor

Very good plan.
Also, don't forget to carry around an extra condenser, a toothpick, paperclip and rubber band ... in case your points get fouled up.

[CaminoRacer]

If I swap forks to a later 550 with two rotors, or a 650G with two rotors, I can do the upgrade and have two slightly smaller 295mm (instead of one 310 mm) rotors. But my current forks are in good shape, just need progressive springs and new oil. The two rotors have better stopping power obviously, but would be more work. Worth it?

[CaminoRacer]

I went ahead and ordered a CBR1100xx Blackbird rotor from ebay. Having a part from a world speed record holder means my bike is also a world speed record holder, right?

[Cookie Monster]

Nice. I have an R6 rear master cylinder on the way as well. Because race bike.

[CaminoRacer]

[Cookie Monster]

Wait, is your rotor the same size as the Blackbird's? Or did you get the entire caliper and MC setup too?

[MX793]

Wait, is your rotor the same size as the Blackbird's? Or did you get the entire caliper and MC setup too?

Same size.

[Cookie Monster]

Interesting... I would have expected the Blackbird's to have been bigger (even though it does have two front discs).

[CaminoRacer]

It's 310mm vs. 295mm stock. I'm going to get a two-piston Kawasaki caliper and a bracket that swings the bottom bolt out so it'll fit on the larger rotor.

Same bolt spacing, but I have to drill the holes out a bit. It'll also need a small spacer to center the rotor in the caliper. Overall it's a lot lighter than the OEM disc (all steel) and provides a lot better stopping power. With SS lines and good pads, it should actually be able to lock up the wheel. I don't think I can do that now.

I'm not sure if I'll have to change my MC. If I swapped to two rotors I would need a larger diameter, but with the single rotor I might be fine. I'll wait and experiment once it's installed.

[MX793]

Interesting... I would have expected the Blackbird's to have been bigger (even though it does have two front discs).

Twin 310s is pretty big.  The liter-bike class runs 310-320 mm fronts.  Hayabusas run 320s.

[CaminoRacer]

With the 310mm rotor, apparently the pads hang off the rotor a bit. A 320mm would be the best fit, but the GS brake swap master is still experimenting with those. If I was less impatient I might have waited to see his results.

[Cookie Monster]

Twin 310s is pretty big.  The liter-bike class runs 310-320 mm fronts.  Hayabusas run 320s.

I should have reworded that - I expected the GS's to be smaller (which it is - 295 mm, which is even smaller than my X's rotor).

[CaminoRacer]

Really? Interesting. CB300f has a 296mm single rotor

[Eye of the Tiger]

Buells have damn 9000 mm rotors.

[Cookie Monster]

Really? Interesting. CB300f has a 296mm single rotor

My 250X has a 298 mm front rotor. 250R's have a 250 mm rotor.

[CaminoRacer]

A whole 2-3 mm larger!

[Cookie Monster]

A whole 2-3 mm larger!

Except my bike weighs like 150 lb less than yours.

[CaminoRacer]

I gotta weigh it sometime. Maybe I'll see if I can use the pallet scale at work. It probably weighs less than you think it does. The 550 seems like the perfect cafe racer size - still has the cool 4 cylinder but is lighter than the 750s.

[Cookie Monster]

I gotta weigh it sometime. Maybe I'll see if I can use the pallet scale at work. It probably weighs less than you think it does. The 550 seems like the perfect cafe racer size - still has the cool 4 cylinder but is lighter than the 750s.

http://www.motorcyclespecs.co.za/model/suzu/suzuki_gs550%2077.htm

476 lb wet.

Another point of reference:

http://www.suzukicycles.org/GS-series/GS550E.shtml

Shows 431 lb dry.

Not really surprising considering it's a 4 cylinder with a dual exhaust, old school steel frame, 4 carbs, twin shocks in the back, etc. Modern literbikes are still in the 440-450 lb range so it's not surprising that yours would weigh more.

[CaminoRacer]

I'm willing to bet it's under 400 lbs dry now that I've ditched the dual exhaust, airbox, chopped the frame, etc. The exhaust alone dropped over 20 lbs.

With the Blackbird rotor, a chopped front fender, and a lithium battery it'll be even better. I don't want to mess with the engine yet so any performance gains will be from weight reduction.

[Eye of the Tiger]

Don't forget to take a good poop before you ride. Every ounce matters.

[CaminoRacer]

I added weight today but I finally have a license plate. The axle wasn't long enough so I put it on the shock bolt.

[CaminoRacer]

I weighed it today. Didn't totally fit on the scale, so I had to weigh the front wheel and then the back wheel. Came out at 140/300, so 440 lbs wet (full tank of gas), so using the same 45 lb difference between wet/dry as those numbers posted above, I'm at 395 dry.

[12,000 RPM]

What kind of scale did you use

I want to weigh my bike now