Yellow Fever!
Published: 15th December 2006
Author: Words by Tony Marshall Photos by Redeye
DBR's chief test rider has never found the four-stroke Suzukis the most exciting bikes to ride - that is until he throws his little leg over the '07 RM-Z250 and finds himself breaking out into a sweat
Cards on the table time. The Suzuki four-strokes haven't been bikes I've been in a big hurry to test over the last few years. That's not because they've been bad bikes - far from it - but because I've found them, er, not the most exciting of the new wave of thumpers on the market.
The German GP track at Teutschenthal was a pretty long way to go to test a pair of four-poppers that I wasn't sure I was even going to enjoy riding. So it was a good job for me that the revamped RM-Z250 turned out to be a little beauty!
What a bike! While I enjoy riding four-strokes, my first love has always been eighth-litre strokers - even though the four-strokes are easier to ride for me at least you can't beat the feel of a light and snappy two-stroke. But the RM-Z250 is some fun bike to ride!
With it being the lightest 250 four-banger on the market it felt like I was riding the old 125 with 250Z performance. And what a combination! This bike just felt right from the beginning. With the track starting on the damp and greasy side in the morning I was finding grip where I was least expecting it. The RM-Z250 tracked well under load and felt like there was no grip going to waste.
With a very nice pull and great feel from the bottom coming out of turns all this motor wanted was to be ridden hard. Mid-range felt strong going through to the top-end with a nice spread of power which just seemed to go on and on. Gearing felt spot on and with Teutschenthal being well-known as a fast track I never felt I was looking for gears.
The front end on this bike was awesome and as the track dried out I was starting to get a better feel for it as the damp parts of the track were a bit unpredictable early on. With four-strokes I've always found them that little bit harder to get into turns compared to a 125 - with that bit of extra weight and the transfer of power it tends to put more load on the front end which can help in some turns but not others. But with the RM-Z250 it just felt like I could turn this bike wherever and whenever I wanted.
The rear shock seemed just right for me too. It's not as if Teutschenthal was the roughest of tracks for our test but there were some big hard landings off some of the jumps which the shock simply soaked right up. And the rear shock also worked well coming into corners over some pretty bad-ass braking bumps.
So with the rear shock and front forks working well together this made the bike feel very balanced to suit the nice riding position.
Controls felt smooth and precise, the brakes were exactly what you'd expect on a modern Japanese motocrosser and Renthal bars as stock all add up to a great overall package for '07.
Moving up now to the RM-Z450. It's a bike that's always been a bit of a mystery machine for me in the sense that it has a great feel to it - everything just feels right - until I really try to pick up the pace and ride it hard and fast!
It must have the strongest motor of all the 450s - it's soooo strong it feels like it's harking back to the old days of the 500s. The 450 runs a four-speed box but when out on the track this turns into a two-speed box! Confused? What I mean is that I've ridden this bike on both hardpack and sand tracks but I still only use third and fourth gears which to my mind means Suzuki have got it wrong.
With the motor being so strong I'm sure it's possible to make the gears a little wider apart so riders can make more use of the rest of the box. I know Suzuki are looking to suit all standard of riders but I've never been on a bike where I was double shifting in the air which put me into top.
The front end did feel a bit better than the '06 RM-Z450 but I seemed to struggle with keeping the front end where I wanted it in the turns - especially on the corners where I was able to carry more speed. I really can't put my finger on it so I can't say whether I would need to soften or harden the spring rate - there are so many things this could be down to. But then again, what do I know - one of the fastest riders in the world rides one. I would like more time on this bike because I am sure there is room for improvement on the front.
The rear shock on the other hand felt spot on - no complaints there at all. It makes good traction coming out of the turns, is very stable over braking bumps and makes hard landings from even the biggest jumps feel like I was landing on the downside of a tabletop.
The clutch felt smooth with no fade or need for adjustment even when just playriding which is always hard on the clutch and the riding position feels the same as the 250 which I really like. And for '07 Suzuki have included a gripper seat as standard which is one less aftermarket goodie to put on your Christmas list!
Spec RM-Z250
Capacity: 249cc
Bore and stroke: 77mm x 53.6mm
Transmission: Five-speed
Carburettor: Keihin FCR 37
Front suspension: Showa 47mm USD
Rear suspension: Showa
Front brake: disc
Rear brake: disc
Wheelbase: 1465mm
Seat height: 955mm
Dry weight: 92kg
RM-Z450
Capacity: 449cc
Bore and stroke: 95.5mm x 62.8mm
Transmission: Four-speed
Carburettor: Keihin FCR 40 MX
Front suspension: Showa 47mm USD
Rear suspension: Showa
Front brake: disc
Rear brake: disc
Wheelbase: 1480mm
Seat height: 955mm
Dry weight: 100kg