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Classic Bike Trackdays

RS500 Special Build

 
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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 12:46 pm    Post subject: RS500 Special Build Reply with quote

Hi,

I thought I would post you guys my RS500 special build, I am based in the UK - West Midlands, so hello to everyone - hope you enjoy the build journey.

This is the start of my new project an RS500
A couple of years ago I purchased a Suzuki RG500, a bike I have always wanted. The plan was to try and drag it into the 21st Century by updating and modernising where I could, this is the bike as I purchased it.



A Japanese import RG500, totally standard apart from the seat hump and pushing out about 74bhp. The engine underwent a full engine rebuild, gas flowed and ported, tripod filters, bored 31.5mm diameter carbs, bespoke expansion chambers and Zeeltronic programmable ignition. Plus new body work, wheels, suspension, dash etc. This was the end result.



I was pleased with the results, a modern looking bike that handles and now making 112.5bhp. One thing that always bugged me were the two rocket launchers (sorry expansion chambers) on display under the seat. As I wanted to keep the frame intact this was the only option I had, if I had cut the rear sub-frame and raised it several inches I could of hidden the under seat exhaust, err under the seat!
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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 12:49 pm    Post subject: Reply with quote

So it was always on my mind, what could I have achieved if I did not have any restrictions or barriers, so the idea of the RS500 was born. An Aprilia RS 250 frame married with a RG500 engine, tuned and modern suspension, wheels etc.







To be continued………………………
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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 12:57 pm    Post subject: Reply with quote

The Engine as purchased is a RG400 that was imported from Japan by Suzuki Race based in Ashbourne. Alan goes out to Japan for 2 or 3 months a year and buys up bikes, engines and parts – fills a container then ships them back to the UK and sells them as complete bikes and engines, or strips them and sells parts. This particular engine was low mileage, approx. 7,500km (and when stripped the internal condition confirmed this).







Luckily enough when I had finished the Walter Wolf modernisation, I managed to pick up a second hand set of RG500 barrels and cylinder heads – which were very low mileage and in very good condition, these are very difficult to find and very expensive! I actually purchased them from Darren Lane, who is an RG500 bike builder of some repute.

Before anything could happen to the engine it was initially used to match up to the Aprilia RS 250, to allow the necessary modifications, new engine mounting brackets and bespoke engine cradle, plus frame spar clearance for carburettors, but this will be covered later.
The engine RG400 was stripped completely and all external parts and the RG500 barrels and cylinder heads were sent for vapour blasting at Projex Motorcycle Engineers.





The rebuild and engine tuning was entrusted to Mark Dent of Performance Fabrications, who is the guru on these engines. The full engine spec is;
All new bearings and seals, genuine Suzuki full gasket set, crank strip and rebuild, full engine tune, engine gas flow, crank web ignition pick up slot widened to allow greater static advance, modified carbon rotary valves, billet disc valve covers, complete Nova transmission and straight cut primary gears, TTW cougar red clutch, offset carburettor bore to 31.5mm and carb splitters plus a new generator
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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 1:06 pm    Post subject: Reply with quote

RS 250 Frame Modifications

Initially you need to remove the original engine mountings from the frame, then you can dress and clean the areas back and remove the anodising, locally to where the new engine mount brackets will need to be welded. Once this has been completed the RG engine can be offered up to the frame, the clutch cover needs to be first removed as this will clash with the RS frame. I tried to position the engine as far back as possible and as high in the frame as I could, whilst fitting the engine centrally within the frame.
Another main area to consider is chain run, so basically the position of engine output sprocket in relation to the swing arm pivot and rear wheel spindle – during its suspension travel. This took a fair amount of time to find the best position for the engine in relation to the frame, this is always going to be something of a compromise. Then once the exact position is known new upper and lower engine mounting brackets can be fabricated and welded in position. One of the engine mounting bolts will need to be inserted and removed through a frame spar due to limited access, so an aluminium boss was turned and welded into the frame.







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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 1:11 pm    Post subject: Reply with quote

The next area to look at is the inside of the frame in relation to the clutch cover, I purchased a 3 piece billet cover from Performance Fabrications which is narrower than the standard cover, and will allow clutch removal with the engine in situ. The inside of the RS frame can be marked in relation to the clutch cover, the engine removed and then the inside ‘skin’ of the frame cut away to give clearance and then the inside can be strengthened by an aluminium fabricated section being manufactured and welded in place. Also a cast hole in either side of the RS frame was ‘filled’ with an aluminium plug welded into position and dressed back.





The RG engine has its carburettors mounted on the side of the engine, the rear carburettors will hit the RS frame spars, so the frame requires modification to allow the carburettors to mount and also give clearance for the throttle cable exit. Again the frame was marked in the correct areas, the frame spars were cut and modified then aluminium sheet cut and formed and welded in position to close and strengthen the frame spars.







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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 1:14 pm    Post subject: Reply with quote

The last item to be made was a bespoke engine cradle. The RG engine is mounted at the rear of the engine in 2 positions, the front engine mount is via rubber vibration mounts and a bespoke engine cradle – similar to how the engine is mounted in the original RG frame. Other schools of thought are not to use an engine cradle and instead to have a bracket from the frame mounting to the cylinder head bolts via rubber vibration mounts. I preferred the engine cradle which will give the main frame some additional strength, especially as the main frame has been cut and shut in a few areas (carb cut outs and clutch cut outs). Also the engine cradle is in two halves, and either side can be removed independently, it also gives an area to locate brackets for radiator mounting.







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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 1:23 pm    Post subject: Reply with quote

Other modifications to the frame;

Power Valve / battery mounting lugs



Steering damper mounting lug



Fairing mounting bracket plate



Frame hole plugged and welded



Radiator mounting bracket



Engine mounting brackets, bolts and nuts



Plus a couple of items purchased from Performance Fabrications

Stainless Steel expansion chambers and carbon end cans



Pace core curved high capacity radiator

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500RG



Joined: 27 Jun 2017
Posts: 8

PostPosted: Wed Jun 28, 2017 1:28 pm    Post subject: Reply with quote

Now the frame has been prepped to accept the RG500 engine, the next stage was to send the engine away for tuning, gas flowing and rebuild. I decided to keep the engine self-colour as vapour blasted and to treat with ACF50 to help prevent corrosion. The engine went off to Mark Dent and came back fully rebuilt and tuned along with bored carburettors.
This is how the engine looked when I collected it.










I added a few goodies I had purchased, a Gamma sprocket cover which also incorporates a shift shaft support, a carbon fibre magneto cover and a Cougar Red clutch.





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Top-shaggy
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Joined: 05 Mar 2011
Posts: 1665
Location: Derbyshire

PostPosted: Wed Jun 28, 2017 3:44 pm    Post subject: Reply with quote

Wow !! Looking forward to seeing this build come together Smile
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Bitacticus



Joined: 13 Apr 2009
Posts: 265
Location: Netherlands

PostPosted: Wed Jun 28, 2017 8:10 pm    Post subject: Reply with quote

what an outstanding job.
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vestanpance



Joined: 20 Oct 2012
Posts: 64
Location: Birmingham

PostPosted: Wed Jun 28, 2017 8:46 pm    Post subject: Reply with quote

Fantastic stuff!
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andyw114
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Joined: 01 Jan 2014
Posts: 236
Location: Near Kidderminster

PostPosted: Thu Jun 29, 2017 12:53 pm    Post subject: Reply with quote

Beautiful.
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steezin_and_wheezin



Joined: 07 Jul 2015
Posts: 63
Location: Radford, VA(USA)

PostPosted: Thu Jun 29, 2017 2:23 pm    Post subject: Reply with quote

Unreal, can't wait to watch the progress of this one!!
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DSBBadmin
Site Admin


Joined: 13 Nov 2006
Posts: 520

PostPosted: Thu Jun 29, 2017 2:28 pm    Post subject: Reply with quote

Note to all members : this is how you introduce yourself on this forum. Thumbs Up

Epic stuff, keep it coming please. Oh, and welcome ! Very Happy
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