U can call me stupid/crazy whatever, but I'm doing it!

[speedgsx98]

I've always been a weight savings fool. Before I go on, know that I'm on my 22nd motorcycle, have been riding over 20 years, and am a former motorcycle mechanic and have worked in nearly every aspect of the industry from tech, sales, store mgr, aftermarket supplier doing sales/tech support, etc.

Now, here's the scoop. I have a 2003 ZX-6R, full titanium akrapovic exhaust and a 4 cell LiIon battery. It's my guess that the bike's dry weight is currently in the neighborhood of 335lbs with the above mods...which happens to be identical to the dry weight of a '08+ ninja 250R.

The 636's brake rotors are similar in size to the 250R and the vehicle is basically identical in weight to mine now. I'm done with the canyons, and my bike is used for cruising only to lunch or the beach and for extended wheelies ;-) A single front disc should be adequate to haul me down from sane speeds at least once, but will obviously be inadequate for repeated successive stops from higher speeds.

I will be removing one brake rotor and caliper saving me 5.5lbs or so. I will also be replacing the 9.8lb 120/70 Dunlop Q2 with a 120/60 7.85lb Michelin Power pure. The rear tire I will be mounting a 160/60/17 10.68lb Michelin Pilot Power in place of the 13.6lb Q2 180/55/17. An overall savings of 5lbs just on the tires. I'll also be placing a +2 renthal aluminum sprocket on the back which should liven things up a bit. I'm anticipating easy 3rd gear clutch-ups with the lightening and gearing, whereas now, only 2nd gear is possible from a seated position(no bouncing up).

- 5lbs tires
- 5.5lbs brake weight reduction

So, now I will have a bike in the neighborhood of 325-330lbs dry, I weigh 150 and ride conservatively...and will be putting some nice EBC HH pads on the remaining front brake rotor. I'll let you know how it all goes. Ordering the parts soon and will have everything on within the next couple months or less.

Before you feel bad for me, I have money and can afford to try this experiment that most people only do for looks. I barely ride the thing, and I work literally 100 ft from my driveway. I understand the profile of the rear tire will be compromised not allowing the full lean angle. Attempting to corner aggressively could very well put me past the available tread on the sidewall and lowside me...again, I remind you that other than the wheelies, I ride pretty straight in the corners these days. Got all the knee draggin out of my system years ago =) My goals are more flickability and lofting the front in 3rd gear which I anticipate both will be achieved!

[speedgsx98]

Banged it out yesterday in my driveway. Changed tires by hand even. Front brake rotor and caliper was actually closer to 5.5lbs with all the hardware. +2 Renthal sprocket didn't fit. Not enough chain...so still running stock sprocket which is actually a good thing. Anyway, it now comes up in 3rd with clutch no problem with stock gearing!!! Fook yeah!

2nd gear comes up under power using NO clutch...just holding it open lifts the front wheel up in the high RPM's...no cracking it open, no body english!

Been putting off yanking the emissions. That's next, and I usually remove my radiator fan in the wintertime since it's not needed, just been busy with the kids this year. In my younger years I would remove the horn, but nice to have here in CA with the traffic! Although that usually saves about 4-6 oz.

Any questions, feel free to hit me up. Bike stops ok, but haven't put my EBC HH pads on yet since they didn't come in yet. That happens on wednesday. I'll update after they go on. I've run EBC HH's in the past and there is definitely a decrease in lever effort and an increase in braking power. Good thing is I probably won't be doing any more stoppies. Bad news is I'll be doing more wheelies ;-)

Oh, and btw, of course the bike is much more flickable as you'd expect losing 5 lbs worth of tires and all that weight off the brakes. It accelerates quicker...noticeably. It basically feels similar to a +3 change in the rear with regards to accel and wheelie capability and yet so much lighter feeling. THe 160 tire profile in the rear doesn't give me a lot of lean angle. Basically, just need to pretend you're on a 250 ninja with stock tires. Basically, try not to go nutz on the lean angle...which is fine with me. I think I like this little experiment but like I said, I'll know for sure when I get the new pads on and take it out for more than a 2 mile round trip test drive.

[tgold]

I've been a weight reduction nut myself. Last Saturday I just traded my 325lb SV650 superbike for an '05 ZX-6R in supersport trim and I'm already putting it on a diet.

Unless you've already done some serious weight reduction besides the mods that you've mentioned, I doubt your bike is that light.

The manufacturer's "dry" weight is usually extremely optimistic and it could better be referred to as design weight. The design weight is calculated by taking the ideal weight of each individual part as designed and adding them all up. The problem is that almost every part on the bike is heavier than the design weight just because of the way that they are manufactured. Also, the manufacturers leave out any fluids and even the battery weight, so the claimed weight is always way lower.

I believe my '05 ZX-6R is heavier than your bike in stock form, but I'll be extremely happy to get it to 350lbs or below and I expect it to take a lot of work. IMHO the best bang for the buck is the lightweight battery (which you already have), but saving weight in the wheels is king. I like the Marvic Penta or Piuma models as a very good option for a light weight wheel.

In any case, Best of success to you!

Timm

[speedgsx98]

^^^Awesome. Congrats on the new bike. Yeah, dry weight between the two is strictly for comparison since in '03, manufacturers listed the dry weight only.

I know it's not 319, that's just the dry # relative to stock dry #. Either way, do have 36lbs off it =) It really is night and day how the bike is now.

Diff bikes are diff of course. My 2008 ZX-10R I sold last year came with a OEM steel header while the prev version came with a OEM Ti header. Best weight loss per dollar is to get a LiIon battery (I like Shorai btw) and use www.denniskirk.com to shop for the lightest tires that fit the bill for you. Q2's are among the heavier ones...especially their fronts. Bt-016's have heavy rears, but decently light fronts.

Another thing I thought of recently with regards to upsizing the rear sprocket is the fact that when you do, the sprocket diameter is larger. I always knew that but when thinking about moving the rotating mass of the chain further from the axis of rotation, you're getting more gyro effect and a higher moment of inertia as a result. Yet another reason to stick with stock gearing. Fortunately, with my bike clutching up with ease in 3rd with stock gearing...it saves me from wanting a speedo healer(even though it's off stock by 8% or so.

For a good read, check out this article: Sportbike Wheel Comparison - Sport Rider Magazine

With the weight savings from the tires @ 5lbs over the Q2's, and the single rotor, I'd estimate that my setup would feel just as light if not lighter than someone running Q2's with the BST carbon fiber wheels. Being that the tires are further from the axis of rotation that the rims, Picking a lightweight tire can have a profound effect. Suddenly, getting the same effect for the cost of a set of tires seems like a pretty good deal relative to forking over $3,400.

I suppose if I wanted to continue on the lightweight path, I could go nuts and cut the subframe, ditch the OEM headlights for a projector beam unit and go with fiberglass bodywork. But I'll stop where I'm at. But my bike is ridiculously clean...prob the cleanest '03 out there. Bought it 6 mo. ago from my good friend who only put 4k miles and was always covered in his garage.

Pic below is with the 2 rotors still and the Q2's btw.

[IMG][/IMG]