weight reduction ?

[73novaguy]

No. A standard Harley hub will have 5 bolt pattern on both sides. One side is smaller thread pitch because they have larger bolts on the drive side. Just type in Harley Rear Hub and see what you come up with. I gave 50 bucks for an entire wheel with junk outer rim. As far as offset. The nice thing about Harley is everyone one and their brother wants to customize. So I'm going to use a flat sprocket with a spacer to get exact. I'm also running the 1/4 offset front though to.

When looking for one, they all have the same bearing od but around 2000 Mosel year they switched to different rear axle size. Some are 3/4 and some are 1 inch. Mine was a 1 incher so I bought some single row 3/4 bearings and turned the length of a stock Harley axle down so it would fit myRadian swingarm. The Radian swingarm was also machined out to 3/4 fir the axle. If you plan on using stock XS swingarm you should be able to get the conversion bearing easy enough

 

[73novaguy]

Damn, Pollock us fast!!! While I was chicken pecking on my Ipod he blew past me! Lol

 

[Travis]

Looks like they were aluminum after 1997. I'll figure something out. Thanks for the info guys.

 

[mule]

No. A standard Harley hub will have 5 bolt pattern on both sides. One side is smaller thread pitch because they have larger bolts on the drive side. Just type in Harley Rear Hub and see what you come up with. I gave 50 bucks for an entire wheel with junk outer rim. As far as offset. The nice thing about Harley is everyone one and their brother wants to customize. So I'm going to use a flat sprocket with a spacer to get exact. I'm also running the 1/4 offset front though to.

When looking for one, they all have the same bearing od but around 2000 Mosel year they switched to different rear axle size. Some are 3/4 and some are 1 inch. Mine was a 1 incher so I bought some single row 3/4 bearings and turned the length of a stock Harley axle down so it would fit myRadian swingarm. The Radian swingarm was also machined out to 3/4 fir the axle. If you plan on using stock XS swingarm you should be able to get the conversion bearing easy enough

As to axle and bearing fit ups, I had 5 Radian swingarms I gathered up machined to accept .750" axles. Then I can use good sized bearings and make stepped spacers. Also, I remove the stock Harley double row bearings, make a thin aluminum spacer ring and install a single row bearing. This is a significant weight savings(original theme of this thread?), but yes, you do need to buy new bearings. When lacing up the wheel, have Buchanan's use 7-8 spokes. The hub spoke holes are for 7 gauge spokes which are the biggest(heaviest) made. Have them stepped to 8 gauge to save some more oz.'s.

On the Radian swingarm thing, I have a few totally set-up which I'm not going to use. I'm finally having my own design of complete frames and swingarms made up from scratch. A very light package. Looks good and will accept wide tires, so the Radian swing arms aren't needed. There are pictures on my website.

 

[jmcgowan]

Awesome, gotta start somewhere! I wish I would have done this over the last couple of years! The list would be huge and it would save a lot of time for people when selling parts on the internet and weighing them for shipping estimates.

Travis,
I weighed the bars that came off mine, and with grips they way 3lbs. I'm not sure if they're stock though, because they didn't have steel slugs welded in ?

 

[mule]

Ok, here's a little specific data. I think if there is any aspect to bike building that fascinates me the most, it's trying to cut weight. I've done it the easy way, the hard way, the cheap way and the expensive way. So I have a little experience at it. One of my favorite all time articles is the one from the early 70's (Cycle Guide). They took a DT1(RT1?) and bought/changed/drilled/swapped everything they could to get the bike as light as possible. You couldn't do that now with an R-1 or Ducati or whatever without spending $40K. But being that we're all in love with this freakin' antique XS650 motorcycle, there's lots we can do to lighten them up without spending a lot of money. There's a limit on HP to be had, (except for that new guy's 130HP 650!), but we have a huge oppurtunity in the weight reduction department!

Handlebars: McGowan said the stock bars weighed 3.0 lbs. I suggest getting a digital scale that can weigh in grams. A lot of the smaller parts and even larger parts can be measured accurately with a scale like this. The weights I'll provide will be in lbs/oz.s and grams. You will see very quickly that the grams make more sense and you should look at percentages.

Stock bars -3 lb 0 oz. or 1360g
New Vortex aluminum flattrack bars low bend w/crossbar- 1 lb 13.4 oz. or 833g
Steel K&N low bend steel no crossbar - 2 lb 7.25 oz. or 1113g
Stainless Woods Racing no crossbar - 1 lb 11.0 oz. or 791g

I think if you removed the Vortex "crossbar" they would be even lighter than Woods bars and if you trimmed the width of ANY of the bars they would be lighter still!

 

[grizld1]

These bikes can be lightened quite a bit without major surgery. I've cut around 50 lbs. from my D-model and retained a near-stock look. The first thing to focus on is unsprung weight. Installing a plastic front fender from an old GS-series Suzuki (can't recall which) with a Daytona alloy tweak bar for bracing cut 2 lbs. off my front end. A Brembo full float rotor with titanium fasteners and titanium fasteners for the caliper and fender cut another 3-3/4 lbs. 520 chain and sprockets cut 2 lbs., with about 1-1/2 lbs of that unsprung. Lightened chain adjustor blocks with titanium fasteners and adjustor screws and locknuts cut around 1/4 lb. out at the end of the swingarm where it counts. Custom Works Performance alloy-body shocks eliminated around 1 lb., half of it unsprung weight. I use a Veypor data logger with magnetic speedo pickup on the back wheel (magnet sunk in a 1/4" hole in a sprocket bolt head), so I gutted the gears out of a spare speedo drive, using only the shell; with elimination of the speedo cable, this cut around 5 oz.

On general chassis lightening, replacement of OEM double-wall pipes and mufflers with 1-5/8" single-wall pipes and Emgo 17" megaphones cut around 10 lbs. Replacement of the battery box with a homemade aluminum unit with elimination of the safety relay and mechanical regulator cut around 5 lbs. Replacing pegs and controls with Raask rearsets eliminated around 2-1/2 lbs. VM36 carbs and pods eliminated about 2 lbs. Turn signals aren't required in the State of Ill, so they came off and 3 lbs. went with them. I found an aftermarket seat with a plastic pan for the TX650A-XS650 F in NOS condition gathering dust in a local shop; it weighs out 3 lbs. lighter than OEM--and is more comfy on long rides (unfortunately there's no manufacturer's identification anywhere on the thing, so I have no idea who made it). Losing the center stand eliminated 8 lbs. Due to a gimpy right leg (old riding injury), 700 cc. displacement, and static CR north of 10:1 I'm unable to kickstart this motor, so the clutch cover is plugged and the kicker, shaft, and gears have been removed, cutting 4.5 lbs. (if you can do without the electric boot, you can lose around 14 lbs. by removing the starter motor, solenoid, reduction gears and bendix gear train). Eliminating OEM clocks and mounting plate for a single electronic unit (Veypor VR1) clamped to the bars on rubber and mounting an Emgo ignition switch in a hole in the headlight shell cut around 1-1/2 lbs, and another 1/2 lb. or so was eliminated with a Sparx alternator, with a rotor that sits much closer to the centerline.

These machines really respond to being lightened up--go for it!

 

[Travis]

Excellent information Grizld1!!! Welcome to the site!

 

[yamaman]

Grizld, sounds like you've created a bike to well suit your needs, well done!

I've read a few of your posts on other sites, but never seen a pic, some pics detailing your mods would be awesome!

Some say that an XS is not a performance/sports bike, but that's the only way I see it. A bike from a bygone era where most all bikes were sporting machines. Only dependent on it's owners whims! So much different to today, where if you want sporting performance, you buy an R1 etc etc, todays world is so catorgorised. The XS comes from a time when a bike was simply a bike! Cheers

 

[mule]

I like that! "A bike from a bygone era where most all bikes were sporting machines!" That says it all.

 

[grizld1]

Almost forgot another couple of items--installed aluminum bearing spacers front and rear and a hollow dirt bike rear axle last Spring. Re. pics, I'll oblige when I figure out how to get 'em to go where they're supposed to; in the meantime there's a shot of the bike (or sometimes a piece of it) in the Yamaha 650 Society News from time to time, when I have an excuse to slip one into a tech article.

Right, Yamaman, my XS650 will never perform like the bone-stock ('cept for Ohlins shock and Race-Tech springs and emulators) SV650 Zook it shares the barn with, but somehow I wind up spending more saddle time on the old bike. As you say, back in the day we had specialized touring bikes, some specialized dirt bikes, and sport standards, but nothing resembling the niche specializations we're offered now. The SV and a few other machines out there represent a return to the basic motorcycle, but they're considerably less versatile, necessarily, than the old platforms. Super motard type street bikes also seem to revive an old concept: lively, versatile, small displacement machines that are competent on the street and off; the difference being that the modern super motard bikes actually are competent, and the old street scramblers, with very few exceptions, were anything but!

 

[gus33]

I put XS1100 special (slotted) rotors (front disc) on the front of my 79 650 Special, and XS750/850 slotted front discs on the back. It is a bolt on job and the discs are half the weight and twice as good looking.

 

[BigJimmyW13]

- Ivan Hoey at work

- race engine...56.8 kg no oil, carbs, left side case off​

- std motor...68.7 kg...edit..no oil, carbs, left side cover off​

- 11.9 kg saved​

- check out the kick start shaft roller bearing

- in case...HK2016​

- in sidecover...KH2516​

Well I had seen this weight reduction before and was going to try and find it again for you, but it looks like someone beat me to it! No worries. What is the weight reduction for? Racing or regular day to day riding? Reason I wonder is b/c someone suggested the battery removal. That is true (I run a batteryless system) for day to day riding, but if it's for racing. Think about taking out the alternator all together.... and just run the battery.

If for racing, take the lighting off. If for day to day or combo Smaller plastic and LED lighting.

Either way, chunk the starter. Chunk the switches. One brake system? Hey these may seem crazy, but you wanted ways to reduce the weight.

 

[jay760]

Years ago at a hillclimb I overheard a comment, what's the point in losing all that weight off the bike, when the rider is the size of him

 

[mule]

Have you actually weighed the 2 types of discs?

 

[Scrambled]

I am going to try and figure out how much weight I have shaved off my '78 standard. I am off to a good start and every part I have replaced weighs less than stock.

 

[peanut]

its a real shame this topic seems to have died .

I'm currently rebuilding my 79 2F and whilst replacing the rear brake shoes today I was shocked at the weight of the rear wheel which weighed 38 lbs .


I should think that reducing the weight of the sprocket ,rotor/s and hub and using a lightweight tyre would have a significant effect on unsprung weight and improve steering , handling and acceleration .

I'm sure the racing fraternity have been doing this for over 30 years but it might be interesting to see what is available to us as a result of all that investment and R&D

I was pleased to see that the 'Laboratory was accessable this week and rather hoped that it might be used for projects such as weight reduction and handling improvements etc but I wouldn't want to see anyone deprived of titsnbums

Maybe there could be a laboratory sub forum 'think tank' for collaboration on special projects

 

[gus33]

Have you actually weighed the 2 types of discs?

I haven't weighed them but they are thinner by a 30% and because they are slotted they have less metal per disc.

 

[TwoManyXS1Bs]

Yeah, I could use a 'weight reduction program'. No, no, the bike's fine, just me...

 

[Nickyd]

Any one know where i can find a lighter front fender? like a specific place i can buy one or what bike i could get one off that would fit with no modification?
Thanks guys!