Weight loss program

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johannes factotum
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Joined: Tue May 02, 2017 9:03 am

Weight loss program

#1 Post by johannes factotum » Tue May 02, 2017 10:06 am

Hi all. What are all the most effective weight loss areas for the Canadian 500? Pipes for sure. What's the lightest RZ500 known?

RC45
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Re: Weight loss program

#2 Post by RC45 » Tue May 02, 2017 11:11 am

My track bike is right at 345lb with a liter of premix. I am anticipating a further 10lb savings with the RZV alloy frame.

While the Jolly Moto mild steel pipes help, the bikes is completely stripped. Magnesium wheels, TZ500 fiberglass fairing, TZR250 tank, cut down wiring harness, oil pump delete, tiny battery, no subframe, aluminum and Ti fasteners etc.

There are some bits on my bike that add weight compared to stock - such as the beefy ZXR750 forks and CBR400 swing arm, but they don't bring the bike back to stock weight.


Other than after market pipes and lighter wheels, I don't imagine there is much more that can be done to cut weight from the stock bike though.

It would be interesting to compile a list of lightly modded RZ500 weights.
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

silverstrom
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Re: Weight loss program

#3 Post by silverstrom » Tue May 02, 2017 4:10 pm

To save even more weight build it naked and lose the weight of the front fairings, birdcage, and belly pan.

johannes factotum
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Joined: Tue May 02, 2017 9:03 am

Re: Weight loss program

#4 Post by johannes factotum » Tue May 02, 2017 6:44 pm

Need bodywork. Will be operating in triple digit speed. I was thinking of removing as many stock pieces as possible like airbox, battery, oil system etc. Are any of the USD forks like the Ohlins GP grade stuff any lighter than the stock forks? Also the shock. How much lighter if any are high end wheels from stock? I'm building a set of super thin gauge pipes to the T.S.I. specs. Anyone know how much lighter Ti would be from thin 304 stainless? I want something like a 100hp YZ125 with a fairing...

RC45
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Re: Weight loss program

#5 Post by RC45 » Tue May 02, 2017 7:40 pm

In all reality I don't believe you will get below 300lb. The engine is just too heavy. You would need light weight TZ250 forks, any light wheels will do - modern OEM alloy street bike wheels or period magnesium wheels.

But don't go too wide or your bigger tires start adding back weight.

You will need to completely gut and strip the bike - to the point of not being street legal at all.

This is what 345lbs with a steel frame looks like:

Image
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

johannes factotum
Posts: 6
Joined: Tue May 02, 2017 9:03 am

Re: Weight loss program

#6 Post by johannes factotum » Tue May 02, 2017 8:39 pm

Pretty bike. What kind of frame are you running? What about the front end? I live in Austin. Would love to get together and have a closer look.

RC45
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Re: Weight loss program

#7 Post by RC45 » Tue May 02, 2017 9:15 pm

Front end is 91 ZXR750R, rear is CBR400RR NC29, frame is RD500 with external bracing (to be removed) tank is TZR250 1KT, everything not essential deleted. What ever was left was moved to the nose behind the dash. All fasteners where possible are aluminum or Ti, big ZXR750R radiator etc.

TZ500 fairing and seat. Jolly Moto pipes, Mikuni Flat slides, Madman Engineering undercut transmission, stock top end.

The build thread (cataloging the buying and ever changing direction of the build - with photos that Image shack is no longer resizing so it is a pain to read early pages) is here:

http://www.rzrd500.com/500phpBB3/viewto ... =7&t=10316" onclick="window.open(this.href);return false;

The last time it was actually on track in March 2012.

https://www.youtube.com/watch?v=6PduKL85aYA" onclick="window.open(this.href);return false;

As for a more active Houston RZ500 rider/track junkie - pstamper is your man :) - me, I am more of a tinkerer and track day duffer.

http://www.rzrd500.com/500phpBB3/viewto ... =7&t=14600" onclick="window.open(this.href);return false;
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

Ade SYM
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Joined: Wed Sep 15, 2010 4:48 pm
Location: Lecicestershire

Re: Weight loss program

#8 Post by Ade SYM » Wed May 03, 2017 9:11 am

johannes factotum wrote:Hi all. What are all the most effective weight loss areas for the Canadian 500? Pipes for sure. What's the lightest RZ500 known?
In my humble opinion when it comes to weight lose on the bike i always look a little closer to home as it is a lot cheaper for me to loose a few Kilos than to turn to the bike with £££ costs for lighter exhausts and Carbon wheels etc...

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Kalim
Posts: 263
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Location: France - Nantes

Re: Weight loss program

#9 Post by Kalim » Wed May 03, 2017 9:30 am

When I purchased the front end from an YZF 750, I weighted each element for comparison.

A fork leg (arm?) from the RD weights 4,1kg, and same from YZF (with oil).
The stems have the same weight.
R1 caliper is 960g each vs 1200g on the RD.
Complete wheel has exactly the same weight too, which surprised me.
12,6kg including tire and bearings, for both bikes.

The complete front end from the RD500 is 25,8kg, versus 25,2kg for the YZF.

So not a lot to gain with this front end. However the YZF is more than 20 years old.
Probably more to improve with a real modern front end.

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two-stroke-brit
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Location: Houston tx

Re: Weight loss program

#10 Post by two-stroke-brit » Wed May 03, 2017 1:12 pm

what about hollow Ti axles,spacers and nuts etc
She might not be pretty but always a fun ride !!

RC45
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Re: Weight loss program

#11 Post by RC45 » Wed May 03, 2017 2:54 pm

I checked again last night - steel fuel tank is about 9.5lbs, alloy TZ250 tank about 4.5lbs.

So that's 5lbs in a tank swap (which will require chopping and welding on the TZ tank) and 10lbs on a frame swap to RZV frame.

Whatever weight savings an exhaust swap nets - I have never weighed stock pipes and only every had after market pipes on hand.

As for wheels, when I swapped the aluminum GSXR750 3 spoke for a magnesium wheel, net weight savings was 4lbs - the front magnesium setup probably only accomplishes a net 2lb saving but in exchange you get 320mm floating Brembos.

The bottom line is that after the easy and cheaper low hanging fruit like frame, wheels and pipes - the effort and cost adds up.

But it is a fun excercise :). Good luck!
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

steveho
Posts: 229
Joined: Thu Aug 20, 2015 4:01 pm
Location: Southampton, England

Re: Weight loss program

#12 Post by steveho » Wed May 03, 2017 3:24 pm

[quote="RC45]

But it is a fun excercise :). Good luck![/quote]


I too find it fun/fanatical in chasing minimum weight. My 3MA YZR rep currently weighs 295 lbs dry, without fairing/seat. However this has taken carbon wheels, Ti spindles and fasteners etc, magnesium yokes etc. Not bragging, just saying that this is a keeper and needs real attention to detail to minimise the mass. It is just that heavy old RD engine that is letting the side down! Only joking, she is a trusty old powerplant, and will one day benefit from Ti crankcase bolts, and maybe lightweight flywheel/proper race ignition.
Ade SYM wrote:
In my humble opinion when it comes to weight lose on the bike i always look a little closer to home as it is a lot cheaper for me to loose a few Kilos than to turn to the bike with £££ costs for lighter exhausts and Carbon wheels etc...
In fact Ade SYM has a point....!
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wolfgangh
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Re: Weight loss program

#13 Post by wolfgangh » Wed May 03, 2017 4:56 pm

My ANTENA 3 replica with Micoproducts frame, R6 swingarm, mag wheels and full carbon bodywork (self supporting seat without rear subframe) but fully streetlegal with lights, mirrors, sidestand, kickstarter etc weighs 157kg with all liquids and 2l petrol.

My MARLBORO bike with stock, braced steelframe and the 118RWHP engine with dryclutch, titanium engine case bolts etc. weighs close to 160kg, but there is still potential for losing 5kg - 7kg with lighter wheels and lighter bodywork (it has pretty heavy DUCATI alloy wheels and fiberglass bodywork incl. Stock steel tank). So I believe my personal limit is 150 kg, everything below gets crazy expensive.

RC45
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Re: Weight loss program

#14 Post by RC45 » Wed May 03, 2017 5:11 pm

Now if only we could get aftermarket magnesium RZ500 engine cases LOL :)
CBR1000RR SP2 HRC WSBK
TZ500V/OW53 Track bike
YZR500 OW81 Clone
OW69 Daytona 200 Replica - 784cc Monster
NS400 Track Bike
RS250R NF5
TZ250T 2KM
TZ250B 3YL
TZR250 3MA Track Bike
427ci C5 Z07

steveho
Posts: 229
Joined: Thu Aug 20, 2015 4:01 pm
Location: Southampton, England

Re: Weight loss program

#15 Post by steveho » Wed May 03, 2017 5:21 pm

Hi Wolfgangh,

Your achievements are without doubt impressive in my view.
Your 'wet' weights of 150-160 kg (330-353 lbs) are pretty realistic of what is typically achievable in the real world for a 'legal' road bike with an RD500 engine. I am hoping for 140 kg for a 'marginally legal' road based race replica when measured 'dry'. My side stand weighs over 1 kg, so am now making a carbon version. This will probably break, and ruin an expensive paint job..... I think I am clinically insane and now need professional help!!!!! LOL.

Still, we all need a passion.... :shock:

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