Aprilia RS250 RZ500 project

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spook · #1 Post by **spook** » Thu Aug 06, 2009 5:45 am

Well it has been a while, but I finally have the big bits I need to get on with this project. The RS250 I obtained is a nice low K (6000) 2000 year bike. It is almost a shame to pull it to pieces and turn it into something else, however, it has to be done

I'm amazed at how well these bikes handle, and look, they really are a well engineered bike. So it is going to be the RZV500 engine into the RS chassis. I can't find any reference to this having been done as yet, though it appears that quite a few have had the RG500 engine grafted into them.

I still have to sell the RS250 engine, until that happens it will remain in the bike. It goes like a scolded cat above 7000 rpm... lol.

So if there is any interest I will keep you posted... truth is I'll probably have more questions than answers... Here's a pic of the RS and the engine. Must say I'm looking forward to getting started on it, though I've got a shed full of projects, so it will happen over time. Cheers.

gus · #2 Post by **gus** » Thu Aug 06, 2009 1:58 pm

thats a pretty popular bike I thought, you'll need to scour the past posts its kinda fun on boring days that is how I spend my time

#3 Post by **rztom** » Thu Aug 06, 2009 3:34 pm

Looking forward to your progress updates, Spook....

BASH · #4 Post by **BASH** » Thu Aug 06, 2009 5:48 pm

spook wrote:Well it has been a while, but I finally have the big bits I need to get on with this project. The RS250 I obtained is a nice low K (6000) 2000 year bike. It is almost a shame to pull it to pieces and turn it into something else, however, it has to be done

I'm amazed at how well these bikes handle, and look, they really are a well engineered bike. So it is going to be the RZV500 engine into the RS chassis. I can't find any reference to this having been done as yet, though it appears that quite a few have had the RG500 engine grafted into them.

I still have to sell the RS250 engine, until that happens it will remain in the bike. It goes like a scolded cat above 7000 rpm... lol.

So if there is any interest I will keep you posted... truth is I'll probably have more questions than answers... Here's a pic of the RS and the engine. Must say I'm looking forward to getting started on it, though I've got a shed full of projects, so it will happen over time. Cheers.

Hi Spook

Nice I cant wait to see it. I have a reference for you the following link is someone who has build a RD500 engine in a RS250 body. http://www.rd350.be/inhoud//specials/rd ... 0siebe.htm
You only have to translate with google or some other program, its written in the dutch language.

Cheers Bash

geosot · #5 Post by **geosot** » Fri Aug 07, 2009 5:32 am

Two more RS-RD500 (Italian)

http://www.2t-special.it/forum/viewtopi ... =14&t=1265

Most of the pictures are from a mobile, therefore cr***py.

BTW They should ban the cellulars with camera.

We all will be blind after a few years.

Either a proper picture or nothing.

spook · #6 Post by **spook** » Fri Aug 07, 2009 11:17 am

Cheers Guys, The dutch Google translation is kind of funny...

"A person here in the Netherlands, the naughty shoes and provided a RD500! blok in een Aprillia RS250 frame gehangen. block in a frame hung Aprillia RS250"

Hmmm, only in the Netherlands... lol. Actually gives me some comfort that the engine actually fits. Also I reckon that there wont be too much need for frame hacking with the RZ500. There is already a hole in the frame (access for shock mount bolt) that may well just accommodate the kick starter. I want to use it on the road as well as track, so it will be necessary.

Just had a quick look at the German site. Hell some useful info there

Looking forward to getting started as I said, I may seek to pick your brains Gus in the future re: engine stuff... I've been looking at Banshee sleeves (liners) on ebay... Heads spinning at 100mph... in an orderly sort of fashion, lol.

I'll keep you posted as I move forward with it. Cheers.

beek · #7 Post by **beek** » Sat Aug 08, 2009 11:28 am

Looking at the pics and links posted it looks like there is some thinking to enable the use of the kick start. the rd500 has a large clutch/ kickstart cover that sticks out a lot so will not be easy.
There is a possibility of the kickstart shaft passing through the frame but it would have to be in passed through the frame once the engine was in. not sure if this is viable. The other would be to extend the shaft with some sort of spline this could go through the frame once engine was in. what ever decision if id put the engine as close to the front wheel as possible so it gave more room at the kick start area. so id build first with bolt on mounts until id got it exactly right. then who knows the kick start may not be such a problem afterall

solex27 · #8 Post by **solex27** » Wed Aug 19, 2009 2:41 pm

Hello,
I come back after a long period on an other project (250 RGV complete rebuild)
As you, I started to build a RS-RD 500 3 month ago. I stopped my old project based on the original steel frame with R1 fairings.
So I decided to cut the RS 250 frame in the kick area and to make reinforcement in the cutted area.
I think it's the better way. the very interesting point is that we could keep the upper mounting brackets with few modification! just need to make 2 new holes at 25 mm from the two originals ones, cut the brackets from 25mm and make a 10mm bushing between the case and the right bracket.
The front sprocket will be in line with the rear.
I will post photos when I will be at home next week.

For a good damper setup I chose to switch to a gsxr 750 03 shock (+15mm length) with 600 bandit brackets (+5mm length) to correct partialy the extra damper length. Result is 10mm rear increase and that's OK.
I will also transfert my R1 2000 complete fork on the frame.
Just need to machine the triple tree tube mainly to swap to a 28-52-16 inner bearing.

@+
Franck

solex27 · #9 Post by **solex27** » Wed Aug 26, 2009 5:53 pm

See photos:

You can see the frame mod for the kick.
You need to cut a part of the subframe mount points. The front hole is removed.

The engine in position in the frame. The engine need to be higher in the frame from 10mm. The sprocket is not in good position for the chain working on the arm

the mod of the 2 upper brackets. You can see the aluminium bushing between the right bracket and the engine. Holes have been moved up from 15mm but it's not enough (need 25mm). I'm modifying them.

If you have any question please send me a mail.
@+
Franck

wolfgangh · #10 Post by **wolfgangh** » Thu Aug 27, 2009 4:13 am

Solex27,
that cutout at the right frame rail for the kickstart looks dangerous. It weakens frame stiffness a lot I believe. A frame is only as stiff as its weakest point. Try to weld up some bracing around the kickstart hole even if it makes engine removal difficult. Thats the case with my Micoproducts frame as well.

solex27 · #11 Post by **solex27** » Thu Aug 27, 2009 4:51 am

Wolfgangh,
One member of our french 500RD club made this mod without any problem.
His bike run well. I understand the stiffness will decrease but compared to an orginal alu RZV frame which is a shame nowadays ?

If I remember, the result was nearly the same on your RZ500 Rainey 91 replica after modifying the original steel frame !

I don't cut only the frame. I also renforced the frame in the aera cutted (see photo before welding).

Also the lower engine mount brackets:

geosot · #12 Post by **geosot** » Thu Aug 27, 2009 5:01 am

You can weld a 8 mm alloy cutting and keep also the OEM frame look.

Look at this Italian RG500 RS250 conversion.

He chopped a great amount of frame side and weld a 8 mm cutting to give again the OEM look.

Nota Bene: The lower frame mount look like 5 mm, why do you use 8 mm or better 10 mm?

Also why don't you remove the top mount and weld new?

George

geosot · #13 Post by **geosot** » Thu Aug 27, 2009 5:07 am

wolfgangh wrote:Solex27,
that cutout at the right frame rail for the kickstart looks dangerous. It weakens frame stiffness a lot I believe. A frame is only as stiff as its weakest point. Try to weld up some bracing around the kickstart hole even if it makes engine removal difficult. Thats the case with my Micoproducts frame as well.

I had always that question. How do you remove an engine from a Micoproducts frame.

I think that you slide it left and it down in order to get it out.

solex27 · #14 Post by **solex27** » Thu Aug 27, 2009 7:54 am

Geosot,
OK but there's no kick on your solutions and for me that's a big issue.
Same for removing the clutch cover.
If I keep the kick, I can't weld up some bracing around the kickstart because the clutch cover is in line with the frame, not inside.

solex27 · #15 Post by **solex27** » Thu Aug 27, 2009 8:56 am

You are OK, lower brackets are in 5mm. It's too thin.
Now I'm making 2 news brackets in 10 mm depth for the lower mount. (because need to move up the engine from 10mm)

For the upper, why removing the original brackets for new ones if they fit well ? They are well positioned, just need to shortened from 25 mm, make 2 new holes and making a small bushing and it's OK.
I also need to make a new hole on the left side of the frame to fit the srew of the upper mount and obstruct the original hole.

500 Two-Stroke Tech

Aprilia RS250 RZ500 project

Aprilia RS250 RZ500 project

Re: Aprilia RS250 RZ500 project