How light can an XS be?

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arcticXS

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Hi all!
I am trying to "improve" my 1977 D model, while maintaining the classic 70's look.
By this I mean keeping the stock tank, stock looking sidecovers, chrome 2-2 exhaust, chrome or alloy fenders, round classic headlight, and so on, while at the same time dropping weight where possible and improving brakes, suspension and engine.

I have already dropped the OEM twin disc front brake, and replaced it with a single 320 mm ISR full floating disc and a 4-piston Brembo caliper. That alone dropped 5 kgs (11 Lbs) off the front end. Then I got an alloy front fender from The Tank Shop in Scotland, and lost another kg (2 Lbs). I have also changed exhaust, carbs, filters, handlebar, etc.

So my question is how light can an XS be, stripped to the max, but still looking mostly stock, and also be somewhat street legal, i.e.having indicator lights, at least 1 stand, headlight, 1 mirror, etc?
 
I am working on a project right now that weight became one of my priorities. Thus far I have shed close to 60 lbs of excess baggage. I started with a 76 frame and lost 25-30 lbs in the form of losing the center stand and mounting brackets, rear footpegs and mounts. seat frame behind the shock mounts etc. Then I lost my rear fender and tailight in favour of a fibreglass fender and small tail light assy' I scrapped my signal lights for small bullet shaped after markets. I scrapped my stock instruments for a tiny speedo.
I then got serious and changed the front end and wheel for an 18" wheel and beefed up air assisted front end from a RD400. Same on the rear ..18" wheel and swing arm from the same 400. I changed the stock seat to a smaller cobra style.
I threw off the stock handlebars, air boxes, battery and battery box. Pod filters, a tiny battery and aluminum battery box, and retro looking bars are next. I still haven't dealt with the headlight, fuel tank, front fender, stock exhaust, front footpegs, etc. but can save a few pounds there too. Bike is still legal and still looks relatively like a stock old school bike. At this point it reminds me of a 60's Triumph or AJS..kinda
I am guessing it will be 100 lbs lighter when all is said and done. And when you take into account the fact of me weighing only 128 lbs....soaking wet....and always ride solo...I don't need to do anything to the engine in order to be a real road burner!!!
I'll post a few pics in the near future...
 
If you like to kick, you could remove the starter motor.............save 6 lbs. Change over from a Standard 15 litre tank to a Special 11 litre tank and save 10 lbs. ( gas weight that is)

Actually, while on this topic, I'd like to put a Standard tank on my Special so that I can hold 15 litres of gas. Anyone want to do a swap................my Special tank for your Standard tank?
 
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I'm far from an expert and I think mouser has addressed this, but I'd think a set of forks/tripple tree from some newer bike would lighten it? I bet the repro tank that mikes xs sell is lighter than my oem tank. I'd light to know how light you can get it though. Be sure to keep us updated.

RG just order one!:thumbsup:
 
The last time I weighed my bike it was 381 pounds. It is raked and lowered but is otherwise just a stock bike with some parts taken off of it.

If you want to lose weight fast, pull off the entire electrical system; harness, black boxes, battery box, starter motor. Then put on a PMA and rewire just the ignition, turn signals and headlight. Put your side covers back on to cover the gaping hole where all the dead weigh once was and it will still look stock.

Or as mouser suggested, just go on a diet. I knew this guy who had a hopped up dirt bike. He had thousands invested, dyno slips, the whole deal. He talked a lot of shit but in the end, he was well over 300 pounds which pretty much doubled the weight of the bike when he was on it. I wish he would have offered to race for pinks.
 
Next time to take the motor apart remove all the internal starter gears.You don't need them if you use the kick only.A list 4 pounds weight reduction.
 
a guy in victoria australia,,, has made his own alloy xs650 frame in his own welding jig then sent frame and jig off for heat treatment ,, i think the frame weight was 9kilo.... its on the yamaha xs650 club of australia ,,,,kevs turbo regards oldbiker
 
mouser said:
Now I am even more determined than ever to show you what i have been up to....anyone with a stock engine wanna race an old dude for pink slips?,,,, :D
Click to expand...

I'm game! My bike has a stock engine!!! Oh, wait you mean on another 650, not my FZ1, huh?

Someone here claims to have a 650, maybe not so stock, running mid ten's. I'll admit, I'd have problems running him down even on my FZ. I'm stuck at an 11.2 @ 126 so far. That said, my newer Yamaha weighs in at nearly 475 wet + my 220lbs in full gear.

I don't know the owner, but this one looks fast...
Yamaha-XS-650-Street-Tracker.jpg


-R
 
Spun wheels on a streetbike, would make me a little nervous. They are not dangerous, but I'd check the tire pressure every time I got on the thing.

On a race bike? Bring it on.
 
I'm hoping to come in at 360# with my wife's bobber...but I'll be happy if we're under 380#s So far:
-Removed everything I didn't need
-Bobber seat, 2.2 gal wassel replica tank
-Alum top clamp
-Shorie ultra light battery
-Newer lighter cut down seat rails
-No guage cluster

I got a guy I know that had his hard tail bobber come in at 360#
 
Rick Sieman (DIRT BIKE's Super Hunky) did a really funny article about weight loss. He was a bit on the heavy side so always bought Open class bikes and threw all kinds of power adders on them to haul his large self around rapidly, one day he read that each 10 lbs lost was like adding 1 HP. He did some quick math, decided that it was way cheaper for him to lose 80 pounds than it was to hop up his KTM 4 stroke, so he went on a diet.

After about two weeks of being on the diet, his wife walked in the house with a bag of Whoppers and fries, a jar of jalapeno peppers, a six pack of beer, a catalog of performance parts and said 'Here. That diet has made you a miserable SOB for too long'. :laugh:

On an XS, it's relatively cheap and easy to lose about 75-80 pounds real quick by doing the things mentioned: lose the center stand, turn signals, extra wiring, different exhaust, remove the airbox etc. That's all just unbolting stuff. Then it starts to get interesting and expensive: cutting off brackets, lightweight fenders, light fuel tanks, etc. The Mule bike's frames have been modified for a single downtube and the engine becomes a stressed member, that should be good for another 10 pounds or so. I'd say it's quite possible to get one down to around 375 or so and still be street legal with twin shocks etc.

Then comes the real money and time: go with a monoshock and carefully pick a front end, maybe another 5 pounds.
 
im thinking alum swingarm is your next move. but most are square tubing. if you wanted your bike to be a sleeper, this would be a dead giveaway somethin is up.
 
I just pulled my bike onto the scales at work and it's now 366 pounds. The only [weight] changes I've made since the previous 381 is starter removal and aftermarket carbs.

Still running stock wheels, stock tank, and heavier than stock forks, so there is plenty of room to trim some more if I was so inclined.
 

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