Wednesday, July 25, 2007

Stewart Ross's SR500 Cafe Racer.

From The Thumper page:

"I currently own two SR500's, an 'E' and a 'H', and have owned several other SR and XT 500's over the years. My first SR (the subject of this article) was bought in Adelaide in 1980. I bought it from Basham Yamaha, with a total of 5,000 kms on it. The previous owner, an old chap, had put a sidecar on it but had found the lack of power a little too much. He had traded it on something with a bit more zap, an XS 850.

I really loved the bike from the start. Though it was not a powerhouse. It didn't take much modification to release some stray ponies. The addition of an after-market muffler and removing the airbox cover transformed the bike, and allowed an increase of 1 tooth larger on the countershaft sprocket.

Being a diehard café racer I soon got around to modifying the looks of the bike as well. A Ducati SS fairing and seat, together with homemade rearsets and Magura clip-ons were duly attached to the bike. I also found some secondhand Mulholland shocks from an RD350 in the wreckers for the rear. These shocks are still on the bike today. I also installed an extra disc and caliper (XS250) on the front operated by a standard 'E' model rear brake hose.

The first incarnation.

The bike stayed as it was for about two and a half years and was a lot of fun to ride. I actually tried to sell it at one stage, shameful I know, but when the bloke interested in it took it for a ride he was scared off when he stalled it and couldn't get it going again. He was gone for so long I thought he'd crashed it! When I eventually found him he was fairly red faced and exasperated from kicking the engine over. After I then started it with one kick he left muttering never to return.

The never-ending 'call of the bike modifier' kept on though, and in late '82 I started on it again. This time I searched out and found what I had really wanted all along. An aluminium racing tank. I thought of using Manx tanks and others, but finally luck provided me with a slightly rough TZ 'A' tank for $25.00. Staying with the genuine Yamaha theme, I then sourced an RD350LC front mudguard and chain guard, and a TZ 'G' model seat. I modified the seat, making it longer to try and avoid having to have a rear mudguard. I also installed a Wiseco 88.5mm piston and a TZ 350 powerjet carb, with the powerjet blocked off with solder to simplify jetting on the four stroke.

I swapped the bits I'd used to make the original to Milo, a mate of mine in Adelaide, who'd recently bought a new 'H' model. From this deal I ended up with another new SS fairing to go on with.

In the interim I'd been down to Mac Park at Mt Gambier to watch the bike races, and it was here that I saw a racing SR from Eltham Yamaha in Victoria. It had some Tingate racing stuff on it, pipe, rearsets etc. They looked great. I took down Rod's contact details from the SR rider and I was away. Rod, being the helpful chap he is, listened to my request and supplied me with a black chromed pipe and alloy megga and some rearsets. These parts arrived in March of '83. (Since that time, Rod has helped me out with numerous bits and pieces for several different bikes, including parts for a Honda CYB 350 racer replica).

The bike had been coming together and by the time the pipe arrived I was ready for the finishing touches.

Mark two:

As you can see there were other little details like gold coloured wheels, and I had removed the side covers.

As time went on the modifier in me stirred again. This time ('92 I think) I was mainly satisfied with the overall look of the bike but I felt it needed something extra, so I undertook some smaller changes. I had a front wheel left over from my Honda racer project. This comprised an Akront rim laced to a 4 leading shoe Suzuki 750 drum brake. I had replaced this wheel on the Honda when I happened across a Yamaha TR/TZ drum. I then searched for a nice large drum brake for the rear (heavy), finally deciding on one from a TX 750 Yamaha. This wheel was duly polished, and after some bearing spacer modification to fit the SR's 17mm axle and backing plate modification to accept cable operation, I fitted it and the front wheel to the bike. The gearing now is 17/38 due to being able to fit a smaller rear sprocket on the TX rear wheel. I've also fitted a 525 chain after machining the sprockets narrower to suit.

I had always hated the battery. 'Any unnecessary items on the bike, that it doesn't really need, shouldn't be there!'. (Café racers creed). I fitted a large capacitor under the seat and removed the battery box and battery. The rest of the electrics attached to the battery box, went onto an alloy plate bolted to the underside of the side cover attaching points, under the seat. I knew I hadn't cut them off for a reason!

The results looked much lighter and very 'Café'.

1 comment:

Skylar said...

Gold lesters fit the 70's bodywork much better. Plus they match the two-tone