| Author | Message | ||
     Jdugger |
Several have asked, so I'm going to try and remember and run down all the things I've done to shed weight on my track bike. Pic #1: * Removed rear brake reservoir. Aluminum mounting hardware for the rear brake where suitable, and drilled fasteners otherwise. * FMF Apex Exhaust -- 10lbs! * Buell Race Shock  Pic #2: * I fabricated my own subframe for the 1125r. It's about 2-3 lbs lighter than stock, plus sheds the stock batter pan/ under tail which isn't light. (1lb or so?) * The subframe is AL6061 with 4043 filler, and it's a real bitch to custom build one because it's NOT a square piece. * The existing wiring harness and fuse boxes were re-routed, and all street lighting eliminated. * I kept a tiny brake light -- when I'm taking lessons from local racers it's useful for monitoring my trail braking. * I'm using a Carbon Speed 8-cell battery. 10+ lbs savings! * There's plastic tubing around a lot of the zip ties to increase friction (grab) and avoid the plastic ties rubbing things. * Most things are supported rigidly by plastic (nylon) or aluminum fasteners, backed up with zipties. * Total weight savings here is something more than 15lbs.  Pic #3: * Lightweight AL brake banjos with Ti fasteners. This is a longer than stock line easing front wheel swaps.  Pic #4: * Ti pinch hardware  Pic #5: * Removed all belt guards -- easy to do with the FMF pipe, and it saves a SHOCKING amount of weight. * One can see the aluminum fasteners used on the heel guards. Those are all over the bike and took about 3lbs of steel off the machine in total! * I'm using the Precision Engineering GP shift kit. It weighs a ton, and I can't say I recommend it in it's current form because of that. The SS linkage and toe piece alone are half the thing's weight! I've written them about it, too, but not seen a response. * Cycle Pirates Rear Sets -- up and back a bit. Perfect! I've been really happy with these.  Pic #6, 7, 9: * Top view of the custom subframe. Notice all the plastic fasteners holding the body work.  * Top view of the custom subframe. Notice all the plastic fasteners holding the body work.  * Top view of the custom subframe. Notice all the plastic fasteners holding the body work.  Pic #10, 11: * All the street lighting and electrical is gone. * Brembo Forged AL MC for brakes with plastic and AL reservoir. All Ti and Al hardware. * Buell Race Suspension * All bodywork held by nylon hardware. The one SS bolt holds a camera mount. * Starlane GPS laptimer   Not pictured: * Ti hardware for rear brake caliper * Lightweight race rotor * Forged Magnesium 16.5 wheels In total, I think I managed to get more than 25lbs off the bike, and possibly 30. And, with a different fairing bracket and a couple of more mods, could probably get another 5 or so. She's getting lighter... | ||
| Brumbear |
what about the kickstand? and a wave rotor? Just kidden that is some cool beans right there ? Is it really 10lbs different from the stock exhaust? | ||
| Blur |
How much did all that Ti hardware cost? Looks good and nice job on that subframe. I really like those rear set brackets too. | ||
| D_adams |
Brumbear -- The stock can weighs about 20.5 lbs, most small can exhaust systems weigh between 9-11 lbs. | ||
| Boogiman1981 |
that is a nice diet!! | ||
| Esa |
so what's the final weight ? I've done similar stuff except sub frame mod but with chain conversion and buell race rear sets, I'm at 400lbs. | ||
| Johnnys999 |
Where did you get forged magnesium wheels for the 1125, from EBR? I really don't like the single rotor/caliper concept. It restricts your choices for light weight wheels, rotors and calipers. We all know going to light weight wheels offers the best improvement in performance because of weight loss. | ||
| Ratsmc |
What is the weight of the stock wheel? How about the weight of wheel caliper and rotor? The perimeter brake concept is meant to reduce the need for a heavy wheel. Has that actually been accomplished? | ||
| Firebolt020283 |
So let me get this right Johnny. You want to add a lot more weight by adding another brake just to shave a few pounds by using a different wheel? I was under the impression that the front wheel setups on modern wheels were much lighter than most other options to begin with. Buell racing used to sell the magnesium wheels for the race bikes so I would not see why EBR would not as well. | ||
| Ratsmc |
Firebolt, I don't have the numbers to back this up but the claim is that the front wheel already is lighter than most of what you can get out there because the spokes don't have to be strong enough to handle the torsional forces of the brakes. | ||
| Jdugger |
I don't know the final weight right now -- I've not weighed it. It's a lot lighter, though. I had to adjust my preload settings to accommodate the changes. The Ti bits are roughly $10 per bolt. It ain't cheap, so I only used it where I could save unsprung weight. The Forged Magnesium wheel is a marchesini that I picked up on ebay. It had been adapted to Buell use. The amazing thing about it: the 70T stock pulley weighs more than the wheel! Being a 16.5, it's got limited usefulness in America: 1. there are no major race classes that support 16.5 wheels left that I know of, and 2, you can ONLY run full-on race slicks, nothing else is made in a 420. | ||
| Chessm |
im curious to see what the total $ per lbs ratio was on this bike's weight loss | ||
| Thefleshrocket |
I think the real question is, how did the weight loss affect your lap times? | ||
| Fresnobuell |
...then we want to see $ per second dropped per lap...then calculate the total number of laps per year and give us an overall annual cost per second breakdown. geez. I hope those inquiring are truly just curious. As has been stated (possibly by JD) in another thread, the first 20 pounds of weight shed are cheap. Tne next 10 are significantly more expensive and the next 10 are very expensive. thanks JD for all the info and pics. It's helpful for us that have made the easy cuts and may be progressing to an even lighter bike in the future. | ||
| Blackflash |
very well executed | ||
| Jdugger |
> I think the real question is, how did the weight loss affect your lap times? Well, I can tell you this: On Jan 1, I set a new personal best by just over 2 seconds at Cresson. That was a cold day! The next week I took another .6 seconds off my personal best at Eagle's Canyon, and my lap average has improved by over a second! On cold days, with unideal track conditions, etc. So, I'd say it made a difference! Even if it's just "all in my head", it made a difference. Oh, and the bike a tankload easier to push around the shop!  | ||
| Kaotikevo |
nice work, i'm liking the nylon fasteners, i'd be curious to know what the end weight turns out to be. | ||
| Kirb |
I assume the battery tray is welded in? The plastic ties holding the battery concern me...any way to put in a stainless zip tie? They are not very heaby and won't break like the plastic ones do. Anyway, looks like some hard work went into that. | ||
| Jdugger |
The battery tray itself is a welded piece, and then it's fastened with two nylon and two aluminum 1/4-20 fasteners through the square tube of the sub frame itself. The battery is snug in the tray, and the zip ties just hold it in place, so there's little load on the ties. A lot of hard work went into the subframe, and looking back on it, I should have just pushed the stock one though the band saw. My design solved some of the wiring harness and fuse box issues a bit more elegantly than the OEM subframe, IMHO, though, while creating other issues of it's own; the OEM subframe isn't "square", so it's enormously difficult to get right. | ||
| Avalaugh |
Jdugger lovin the bike, great job. How has the bike faired up to race use ? Any problems with engine/gearbox failure or is the rotax as good as all the hype ! | ||
| Barker |
I got ride of that plastic body panel thingy behind the dipstick and the passenger seat. | ||
| Bads1 |
How tall are you and what do you weigh ?? | ||
| Jdugger |
> How tall are you and what do you weigh ?? 5-10, 165. If I lost 10lbs, I'd be under my high school weight. It's realistic to think I can loose 5 and maintain that... | ||
| Jdugger |
> Any problems with engine/gearbox I've had one notable thing happen: A bit of the shiny facing came off one of the intake cams, so we replaced the intake cam and finger followers. Motor ran fine, but we discovered it during a valve adjustment and elected to make the repairs. | ||
| Fresnobuell |
JD-Do you have a catch can for the fuel venting? If so, can you take a pic and describe what you did, please. Great job. | ||
| Jdugger |
> Do you have a catch can for the fuel venting? No. In pic #1, look just to the left of the curved, clear tube that makes the rear brake res. If you look closely, you will see a relatively straight, thin black tube running downwards and a bit forward. If you look very carefully below the rear brake lever, just before where the toe piece adjustment area begins, you can see the end of that thin black line, resting against the motor casing. That's the fuel vent line. The picture doesn't give you perspective, but it drips clear of the exhaust. |
