My new project... XT500 supermoto

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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

And the fitted pic:

Image
80 XT500 Supermoto!
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82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

Simple little upgrade for this bike today, the fitment of an LED stop / tails to ensure people see my lights, these are bright as hell. :)

Image

The only thing im not 100% sure about is that these give a red glow and maybe I should have opted for a white set, hmm... The problem is that I now have a red glow over my plate, not white as intended. I wonder if that’s something that would get me pulled over, hmm.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
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86 RZ350 F2 Hybrid

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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

I think this little array of light will tell even the most myopic of drivers (Sydney has them in spades) that, well.... IM STOPPING!!!!

Image

(I should add that the rear light is very red in real life, for some reason the camera doesnt capture any of this huge red glow correctly, but you should get the idea I hope)
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

Its been a while since Ive worked on this bike and I really need to have one big push to get the last jobs done and then register the thing... So this means one last look at the brakes as the front is binding on the spokes when you lean on the brake and turn as the spokes deflect a little. I always knew it was tight and it seems i was right, not that i wanted to be, hmm... I also want to improve the actuation of the rear master one last time and will replace the leaking small reservoirs with larger units, ie the OEM brembo front that came with the master.

Ive also decided I dont like the silencer. Its too loud. It looks great and small and cute, but its going to get me into trouble with so many cops where i live and getting pulled and then getting the bike cleared again would be hassle i dont need once Ive registered it. This means a larger muffler, but needs must... shame, but....

So, here is where Im at right now, looks good... just need those last detail jobs and it should be finished...

Image

Image

Image

Image

Image

Image
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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South_Oz
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Re: My new project... XT500 supermoto

Post by South_Oz »

Hey Jon, ya cant fit some thing inside the pipe to quieten it down?


Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)


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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

I probably could have Dave... hmm, I should have also said... Im not much of a fan of the supertrapp sound really, I always wanted one but its noisy and a bit rattly in use and I prefer the more chuf-chuf noise of a more normal silencer, heathen perhaps LOL. I will keep the s'trapp until ive completed new unit and have the option to refit it if i want, but if this new plan works out then i'll sell it as they are $600+ with the link pipe :(

FWIW I've been working on the new link pipe sections today and have it part mocked up (need to complete that and get it welded, the shorten the silencer itself), I will post a proper post on the whole job when I get some time and its done. I should really have done a sound clip of the old vs the new pipes really, ooops, bit late now as ive dismantled everything around the pipe.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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South_Oz
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Re: My new project... XT500 supermoto

Post by South_Oz »

Yep Jon I never really liked the ST sound either. My preference is for a alloy Hot Dog style resonator. I think alloy gives a more mellow sound.

Perhaps one of these might be worth a try Jon?

http://www.ebay.com.au/itm/BLOW-OFF-VAL ... SwMmBVi3UA" onclick="window.open(this.href);return false;

Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)


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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

yeah, alloy and stainless my pref too... watch this space, er... probably late next week as it will take a bit of time to run back n forth with the sections to the welder and also I want to fix the poor bend that Kedo did on the front pipe, shocking shower to deal with, but at least i can fix it :)

LOL, wtf is that all about... my turbo car doesnt even have a whistling bov... I did have one on a Golf I built in the early 2000s, but it was tiresome after a few roundabouts with all that '''tish'ing :/
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

What i should have said Dave is that the pic may well be misleading, these are small bikes and the silencer looks a reasonable size but bear in mind that the header is almost 2inches dia and the big end of the muffler is 3inches... not a lot of room to soak up noise in the cone (which wants to do the opposite) even tho there is mesh and wadding in there. The main noise reduction is the plates of course, thats the s/trapp way... hmm...

What id really like to do is this, pic from the net, but its for another time as Ive already sourced a side solution and will make that up first...

Image
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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South_Oz
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Re: My new project... XT500 supermoto

Post by South_Oz »

Thats a nice looking pipe.

Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)


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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

yeah, I fear my version if i make one may not be quite so sexy, but in the meantime I'll do the side pipe, good experience anyway :)
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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Re: My new project... XT500 supermoto

Post by JonW »

A silencer, my kingdom for a silencer... Or something like that...

As i’ve mentioned before, the problem with exhausts and the XT500 is that it’s a small bike, very small in fact. Yamaha got round this problem by using the vertical area behind the riders calf to place some of the silencing and then starting the part that you usually associate with the muffler as far forward as possible. It also fills the entire back end of the motorcycle on the right hand side, it does a good job of muting the XTs rage, but is large, heavy and works only with the skinny header pipes.

Image

If you google ‘XT500 supermoto’ and look at the images you can see a varied selection of exhausts people have used. Many have solved the problem with an underslung pipe derived from the SR. I decided that was not an approach I wanted to take as it this tends to make the XT500 look taller than it is. So sticking with the more ‘offroad bike oriented’ route across the top of the engine and out along the right side of the bike I found that most everyone else tended to use a system that fully filled the space at the back of the bike, some extending out past the number plate. These solutions endow the bike with a look of a heavy and large derrière, however there are in fact just normal sports bike muffler sizes and often have already been substantially cut down. I felt that I didn’t want to go this route, instead I wanted the continue the lightweight and elegant lines of the XT as being derived from a lightweight (for the day) off road machine with nothing more offered than was needed to get the job done. This was a problem I needed to solve and has consumed me from the start of this project.

I felt that I certainly solved the look with Kedo’s small supertrapp silencer, it was the right size and shape to give me the look I wanted, but it came at a price; the noise. Sure you can quieten a ‘trapp with the plates but physics will only allow a 3inch (76mm) OD (at the biggest end, 1.75 inch (44mm) inlet) with some packing and perforated inner wall to do so much work before its overpowered by the soundwaves that are determined to get out. If I’m brutally honest I also don’t really like the noise a Supertrapp makes and I was disappointed every time I started the bike as I really wanted a deeper, muffled note. One other consideration was that the supertrapp disks mean that the sound waves exited right under the clever LED turn/stop signal on that side, and I really didn’t want to damage one of those, its not that theyre expensive (which they are) but more the fact the (US) manufacturer makes batches and may not have stock when something happens.

So with that in mind I decided that I needed to build something from a larger straight through cut down silencer, I just needed to make it small enough to look ok, but also large enough to reduce the volume to help keep the cops looking elsewhere for their scalps.

I also needed something that looked well made, even delicate, and perhaps a little ‘old skool’ as the modern profiles and end caps can seen incongruous on older bikes. Polished alloy or stainless would be good too... And not cost a small fortune as Id already invested heavily in the Kedo unit.

So... I spent quite a bit of time looking at photos, websites and the local bike shops and found 2 things:

1, Modern silencers are all long or fat, or both and Carbon would look wrong on this bike, even though its offers more sound deadening.
2, XTs really do look silly with huge, fat, long mufflers...

I even searched for an older aftermarket system from back in the day, but they were either in horrible condition or people were holding onto them. I should probably have kept the (now collectable probably) Aussie Muffler (its a brand, really!) from my XLR, but it sounded so good on the Honda that was tuned to run with it fitted. It was probably too restrictive for the hotted up XTs motor anyway if im honest, but I looked anyway.

Finally after hours of looking I decided to take the plunge with a brand new unit from ebay with the view that I would cut down the silencer body to a more manageable size and working with new parts was infinitely preferable to those covered in soot and oil gunk, especially when fabbing/welding.

I picked up this CRD QP system as the manufacturer designed it to quieten down the noise from a CRF250X which makes around 30bhp from its peaky little 4T motor. I chose this unit as it has a huge flange for its intake (52mm) which is larger than even my oversize Kedo font pipe (44mm), the thinking was that the might of my larger cc wouldn’t be dulled by the muffler, and it should still muffle the bark. If I wanted to get creative the CRD system comes delivered with 3 end plates with different sized outlets for tuning (the noise, not the bike really) as well.

Image

Came with all the bits (except the springs bizarrely):
Image

Including 3 inserts like this (one is already in the pipe) that control the noise:
Image

I should say really, this is a very nice muffler, it bolts together and is very well made and impressed me with its quality when I pulled it apart.

Image

I figured I needed to cut 10cm out of it, about 3 in the fat end, 7 in the pipe:

Image

Its actually so nice that I suffered a crisis of conscience and couldn’t bring myself to cut it up as I started to understand that the inner workings (the actual silencing) would be somewhat compromised anyway... And, when I thought about it some more I kept being drawn back to my favourite of all the solutions; the underseat cut down muffler I showed earlier. I really like the look, mostly since there is no ‘look’ as its hidden. This allows the small XT to become even slimmer, which is perfect for a city bike, ie. what a motard is all about of course, and there is nothing to scrape up if you go over, plus ist not like everyone has one :)

Of course, that design is not without its engineering problems, not least in heat proofing the seat and the wiring for the taillight, as well keeping the up pipe away from the back of my overly large airfilter on its extended manifold, although its already compromised in this run as the filter sits over the exhaust header and on my bike the rear brake master is under the header as well. All of these items need heat proofing of course. I would also needed to avoid the travel of the rear wheel (easier with a 17inch ‘motard wheel than an knobbly 18 of course) and the swingarm arc, as well as making sure the exhaust gasses didnt heat up and burn the paint on the rear guard which contains the tailight. Packaging is a real problem on an XT, did I mention its a small bike...?

Anyway I did some looking on these and found that only a couple had been built. The famous xt500 builder Dave Newitt (RIP), who built the yellow TT in the pic I posted earlier, obviously struggled with the same issues as me, and in two of his builds utilised an underseat solution. A black bike with a system that actually included a working EXUP valve using two round pipes that exited gasses from the back of the bike under the mudguard and the other solution on the yellow bike (as per the picture) that used what was said to be a custom (cut down I’ll say) silencer that excited half way under the mudguard over the tyre. These bikes were built a few years back, Dave left us over 5 years back now I think and the pics and info is a bit scant now sadly. Pics here (the specs are misleading with the photos, the yellow bike I believe is Phase3 and the orange one is Phase1 but the black one has Phase2 on the photo, yet I believe the specs with the powerbomb and exup refer to the the black bike not the yellow one, hmm) http://www.xt500.de/daves-toys/dave-phase3.htm" onclick="window.open(this.href);return false; the yellow bike is here: http://www.supermotoaustralia.com/8069/ ... supermoto/" onclick="window.open(this.href);return false;

So.... Its with heavy heart that I consign my expense on the CRD pipe to experience, and I did learn quite a bit about how it was built and what to do to make a bike quiet if im honest, so it wasn’t wasted. But I also have a spring in my step as Ive decided that side pipes are nice, but they don’t really work on the XT and that if im going to devote effort to making a muffler then I should damn well make the one I want, right?!

With that in mind I did some measuring, bought some more mandrel bends and took the plunge to buy yet another silencer (a Gianelli oval unit from a local bike shop that has stopped selling the brand) and set about turning the brand new, ex display unit into its component parts.

I showed LB my plans, parts and mock up design when he was here earlier in the week and I think he approved. I showed another mate the same and he told me to bring him the parts when i had them ready so he could tig them as he welds nicer than me, so looks like Ive a way to make the underseat muffler setup. Can’t say it will happen overnight, but I’ll stick up some pics as I go...
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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South_Oz
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Re: My new project... XT500 supermoto

Post by South_Oz »

Hey Jon, I bought one of these off evilbay

Image

and turned it into this to fit my BMW R1100S. Cost less than $100 and a cpl of hours.

Image

Image

Image

Image

You can buy them as a single, there's hundreds of similar ones on there. Might be some thing you can adapt.

http://www.ebay.com.au/sch/i.html?_from ... c=50&rt=nc" onclick="window.open(this.href);return false;

Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)


http://www.dlra.org.au/index.htm" onclick="window.open(this.href);return false;
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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

Haha, thats brilliant Dave! Nice work! What is bizarre is that I actually saw one of those on the floor by the welding bench at a mates workshop the other day, I did wonder where it came from, mystery solved :)

Ive actually already sourced my new silencer, Ive already cut it up and will report on the work when its done... watch this space...
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com
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JonW
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Re: My new project... XT500 supermoto

Post by JonW »

Ok, its done... you'll have to wait a bit for a real write up, but lets just say its been a bit of a labour of love to get what i wanted, however it sounds great and you cant really see it... which is as intended. :)

(and it even contains a bit of an LC in it... the plot thickens!)
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com
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