Yamaha R1-z(Two stroke 250cc)

  Engine Type: Parallel Twin , liquid cooled, 2-Stroke, crankcase reed valve
Capacity: 249cc
Bore and Stroke: 56.4mm x 50.0mm
Compression Ratio: 6.4:1
Fuel system: Carburetor, 2 x 28mm, Mikuni TM 28SS
Starting: Kick starter
Maximum Power: 45PS @ 9500 rpm
Maximum Torque: 3,7 kg-m @ 8500 rpm  

transmission

  Clutch: Wet multi-plate type
Transmission: 6-speed constant mesh
Gearshift pattern: 1-down , 5-up
Primary reduction: 2.545(56/22)
Final reduction: 3.214 (45/14)
Gear ratios 1st: 2.333 (35/15)
2nd: 1.647 (28/17)
3rd: 1.315
4th: 1.083
5th: 0.961
6th: 0.875 (21/24)
Drive chain: DID 520 or RK 520  

dimensions

  Length: 2005mm
Width: 
700mm
Height:
 1040mm
Wheelbase: 
1380mm
Seat Height: 775mm
Ground Clearance: 135mm
Dry Weight: 133 Kg  
r11 

The original format of the R1-Z is aimed squarely at creating a bike around a strict budget for a limited market. It looks plenty trick enough but, scrape off the outer layers of your initial attraction and you soon find that Yamaha haven’t gone too far into town when gracing the bike with modern construction techniques and procedures. Each half of the Ducati like frame is made up of six straight lengths of steel that when welded together make the trellis while the swing arm is of a similar, basic construction in tubular steel, if it has to be compared to any series of machines it is akin to being a two-stroke Diversion. Even though basic by design a well ridden R1-Z will make an impression on most other machines thanks to its great engine and overall lightweight, particularly the rest of the grey-import line up, it being far easier to get the best out of when compared to the more popular VFR and FZR 400’s.
Fred Castor of Long Eaton, on the outskirts of Nottingham, has had a keen eye on the type for some time having been attracted by images of the highly modified bikes on the many Japanese websites dedicated to the type. Like many other R1-Z owners, he has taken the basic format and added to it creating a cracking little street racer that not only looks good but goes well too.

Having ridden both a standard version and now Fred’s hotted up model the latter is by far the better bike and getting back on a standard model came as quite a shock after a day riding some a good deal better. Despite putting on a few pounds, thanks to the extra mass of the forks and swing arm, Freds bike feels lighter and more alive, as if the engine has been tuned which, to date it hasn’t. Whether by accident or design the end result is a sharp handling and exciting bike to be on, with its peaky powerful engine and cackling exhaust pipes the ride is racer like while still maintaining some level of road legality. On board every part of the commuter styled R1-Z has been lost and the seating position now feels more like supermoto than lazy street machine.
The TZR rear end has jacked ride height up by a good few millimetres which has, in turn, sharpened the already keen steering found on the standard R1Z. The front end, also on loan from the race replica, is now quick to react to even the smallest of inputs, making the bike agile but without compromising the handling in any adverse way. This is balanced out by an extra bit of length added to the wheelbase, around 25mm of increased distance between the wheel centres, is provided by the swing arm, effectively keeping the bike from becoming twitchy once the taps are opened. Braking is shockingly effective, with little weight and race track like calipers and discs now doing their work on the front wheel, even the gentlest of touches on the front brake lever has the bike diving under the strain and the rear wheel hopping about barely in contact the tarmac. Once off the brakes, the fun really begins as, this machine loves pushing the front end to the limits of the tyres abilities. Get it tipped over and on its side before adding a touch of gas to get the bike where it is happiest, the four-stroke like power delivery that the YPVS system delivers make light work of getting into and out of corners as fast as possible. The harder you apply the throttle the faster she digs in and pulls the front end around the rears axis, it is a great sensation and one that has you hunting out twisty back roads in favour of the straighter or more direct route.
If Yamaha had continued to make a 250LC for the UK market then, had it been some thing along these lines, it would, without a doubt, have been a popular machine. The engine pulls strongly throughout the rev range thanks to the power valve system and the carburetion is spot on making for a proper Superbike eater around the twists and turns and up to its top speed around the 120mph mark. To cap it all it looks the business too, the chassis mods haven’t lost the original look of the R1-Z but, simply make it appear meaner and leaner, which of course it is while the Kenny Roberts inspired paint job puts the finishing touches to a biking master piece. The end result is a usable bike on a day-to-day basis that will turn heads, as indeed it does at any bike show or rally throughout the summer months.

This bike proves that you do not have to stick to the established norm when choosing a bike to turn into a special or be too respectful when choosing a donor machine to rob parts off, after all most would rather end up with a tricked up TZR250 than a similarly attired R1-Z but look who’s laughing now.

yamaha-r1-z-cross-chamber-type-2-k2-tec-japan-4052522d64ea67b987d99160e06b69ea
The story of this special begins in 2003, Fred bought an R1Z and had a pretty good idea how he wanted a bike based upon this model to look. He has seen several of the Japanese specials and this sparked an idea which he committed to paper but, if the final bike was to look anything like the images in his mind, also meant acquiring several hard if not impossible to find components. The forks, wheels and swingarm he intended to use also came from a machine not natural at all to the UK, the TZR250R. This race replica machine has a GP like banana swing arm and hefty upside down front end but who would have one to sell, let along be breaking it for parts?

The RD community (Fred, know as Fred Gee to his mates, has a tidy RD500 as well as this special) is a close one and help is usually to hand, regular meets at the New Inn, Shardlow, serves to form a tight knit community where help and advice is freely swapped, along with the odd jar of the local brew. This was the case when searching for a suitable TZR to rob parts off and a damaged one was found belonging to another R owner. This was acquired and stripped down, with all of the unneeded parts being sold on to part fund the rest of the project, and specials builder Nigel Kimber of NK racing, Nigel has a long history of producing stunning and spectacular machines and being local to Fred his help was enlisted to get the TZR parts fitted to the R1Z. Once the modified parts were returned Fred set about offering up the various components in the form of a dry build. This highlighted where old brackets etc were no longer needed and could be removed, as well as showing were others needed to be attached for the new components. The rear Brembo brake caliper was slung underneath the swing arm, greatly tidying the rear end while the top yolk was suitably drilled to accept a set of conventional handlebars. With the TZR rear end being much larger the battery and two stroke oil tank had to be repositioned and space was found for these a little higher up in the seat hump, although it did require a new tank to be fabricated out of aluminium as the original plastic one was far too much of an awkward shape to fit in such a confine.
With the bike complete but not assembled the components were then shot blasted ready for powder coating, yet again a local firm, the Bosworth Brothers of Ilkeston, showed great interest in Fred’s requirements and also carried out the work with much care and to great effect.

With the painted and coated parts now back in the shed and the bike now beginning to look something like, it was time to think about the final paint scheme, the original idea was to paint it in the traditional TZ race colours of white with a single red stripe running the length of the bike straight down the centre line, however, with a mint red and white RD500 already in the garage, for Fred there could be only one other paintjob worthy of this machine, and a tribute to Kenny Roberts was soon sketched up. The result is the American eagle logo’d side panels and large speed blocked tank that far from being garish, works well with the grey of the engine making the bike look as if it is doing 100mph while stood still.

r1-z_1

The engine was placed in the ever growing chassis and cables and pipes connected, thankfully all except the wiring for the ignition fitted in place without modification although it soon became clear that the standard pipes would no longer fit with the TZR swinging arm as the exhaust fouled the huge alloy casting that now holds the rear wheel in place. A set of aftermarket SPEX pipes had been bought and imported from Japan, and these were modded to create more clearance and then fitted on to the R1Z.

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