Inner beauty!
By TMX Archives on 14th Jul 05
Barely halfway through 2005 and we're already testing 2006 model bikes - crazy! But despite the seemingly premature launch it seems that KTM have done everything it takes to make the zero-sixers as competitive as possible.And it all starts with Barely halfway through 2005 and we're already testing 2006 model bikes - crazy! But despite the seemingly premature launch it seems that KTM have done everything it takes to make the zero-sixers as competitive as possible.And it all starts with a small makeover. It appears that orange is still very much en vogue and black is back! Black rims, black fork tubes and black frames matched up with a new richer orange make these machines sexy.There are changes on the inside too - after all, inner beauty is what it's all about. The 125 SX has an all-new cylinder that's claimed to be similar to last year's works version as well as a V-Force 3 reed-valve taking care of the inlet side of things while an SXS style pipe and silencer gets rid of burnt gas.Down in the depths of the new crankcases sits a new six-speed gearbox which comes with closer spacing between gears while a new clutch offers less weight but more reliability.The 250 SX has a new lighter piston and changes to the powervalve which along with a smaller carburettor and new CDI unit should help smooth out the power and offer added rideability.The new pup in the KTM pride is the 250 SX-F which is claimed to pump out a whopping 39 ponies at 11,000 RPM while weighing in at around 98-and-a-half kilos. Awesome!While much of KTM's attention has gone in to the 250F the 450 SX hasn't been forgotten as an all-new stiffer crank and valve stem guides should improve reliability - which to be honest has never been an issue - while a new carb offers increased throttle response.The whole range gets a new, stiffer swingarm with a re-worked PDS shock while new more progressive front forks, improved clutches and new rear brake master cylinders help finish off the overall package.125 SXThe 125 KTM seems to have been dominating the world championships for the past few years. They've come a long way with their eighth-litre machine but obviously in the last few years the four-strokes have come along and sort of taken over. But the 125 KTM is still a very competitive production machine. This year the 125 comes with a new V-Force reed block and cylinder - I feel this is a result of feedback from the GP teams.My first impressions are that it doesn't feel majorly different from last year's machine although it does feel like the power delivery is that little bit stronger and more usable.The first thing you notice is how well jetted it feels - if I hadn't been told differently I'd swear this thing was running on race fuel and not pump gas. I've never known a production bike to feel so good straight out of the crate. With good jetting comes good engine power and the engine on this bike felt as strong as any of my GP race bikes (from a good few years back) it was just so clean and positive.The power delivery is sharper and more responsive than the '05 and the initial punch is there right from the bottom. The mid-range to top-end power is awesome. It seems to rev on and the harder you ride this bike - without over-revving it - the better performance you get back from it.The chassis is a good all-round package and wherever I put the front end the rear end would follow. At speed it's very stable and even on the fast turns the bike feels very positive - I think sharp is the best way of describing it.The riding position is very similar to the '05. The harder seat is still here and I feel it gives you a very positive riding position. As an overall package I think the 2006 KTM 125 will take some beating.250 SXThe 250cc two-strokes have never been a strong favourite of mine purely because of my small size and build. I find the 250 strokers a harder bike to ride as they're very aggressive.This is the case with the KTM too. I never felt all that confident on this bike because of the on/off power this bike delivers as it's very difficult to be smooth around the turns. If you're a big rider that likes to be aggressive out of turns then this would be the ideal bike for you! If I was to ride a bigger bike I'd prefer an easier, more usable powerband than the KTM offers.I was also struggling with the front end on this bike. The rear end is great and soaks up big hits no problem but in long turns I felt that the front end was pushing out if I tried to increase my pace. In the slower turns the front end is faultless and in braking bumps and stuff the bike handles perfectly - no problems there.250 SX-FKTM's 250 four-stroke makes its long-overdue arrival to the 2006 range. We all thought it would be out for 2005 but they held it back another year which seems like it was a good move as this is an excellent bike.The technicians claim that they've mastered the reliability problems of the 250 four-stroke but I guess only time will tell on that. They've been testing a standard bike at Lommel in Belgium which is a deep sand track. After 10 hours they go inside and check everything out and they reckon that in 40 hours of riding they've never had to adjust or replace any of the valves.When I first rode the bike I was quite shocked by how the motor felt. It feels very sluggish at first but once you pick the RPM up the feel completely changes. I think this bike will be good for all class of riders - it can be ridden using the low-end power but the best comes when you pick the revs up.I think this engine works perfectly with the chassis and out of the whole range it feels the best - they work great together and it surprised me how quickly I felt right at home on this bike even though it feels very different to the Japanese 250Fs.The motor feels much torquier and feels to have more engine braking which is what four-strokes are meant to be all about. The top-end is more than enough for me. Jetting is absolutely spot on and I hope that it feels as good when it reaches our side of the channel.The bike feels so well balanced and that's partially down to the great suspension but also the power delivery. The PDS suspension feels great to me - I know not everyone shares that opinion - and I reckon it gets better and better each year. I didn't have any issues with any of the bikes on the rear end.I love this bike and I would love to spend a lot more time with one back at home. I think it looks great and rides well too.450 SXI don't think this bike's changed much from last year. Minor improvements include a stronger crankshaft and also new valve guides - I guess this is more down to durability than anything else.The only problem I found on the 450 was jetting related. I found that while I was stationary if I held the throttle at a certain position the revs would change - I would imagine a tweak on the air screw would sort that right out.This bike would suit any class of riders as the power spread is just so big. You also get great feeling from the throttle down to the ground and you can really make the bike hook up on slippery surfaces without spinning up the back.The bike starts okay even for a short arse like me and even when it's hot but you do need to think about it and use the right technique - follow the correct protocol and you'll be fine, treat it like a two-stroke and you'll suffer.specificationsSX125Capacity: 124.8ccBore and stroke: 54mm x 54.5mmTransmission: Six-speedCarburettor: Keihin PWK39Front suspension: WP 48mm USD (300mm travel)Rear suspension: WP-PDS shock (335mm travel)Steering head angle: 63Front brake: 260mm discRear brake: 220mm discWheelbase: 1471mmSeat height: 925mmDry weight: 92.4kgSX250Capacity: 249ccBore and stroke: 66.4mm x 72mmTransmission: Five-speedCarburettor: Keihin PWK 36 S AGFront suspension: WP 48mm USD (300mm travel)Rear suspension: WP-PDS shock (335mm travel)Steering head angle: 63.5Front brake: 260mm discRear brake: 220mm discWheelbase: 1475mmSeat height: 925mmDry weight: 97.7kg250 SX-FCapacity: 249.5ccBore and stroke: 76mm x 55mmTransmission: Six-speedCarburettor: Keihin PWK39Front suspension: WP 48mm USD (300mm travel)Rear suspension: WP-PDS shock (335mm travel)Steering head angle: 63.5Front brake: 260mm discRear brake: 220mm discWheelbase: 1481mmSeat height: 925mmDry weight: 98.5kg450 SXCapacity: 449.4ccBore and stroke: 95mm x 63.4mmTransmission: Four-speedCarburettor: Keihin MX FCR 41Front suspension: WP 48mm USD (300mm travel)Rear suspension: WP-PDS shock (335mm travel)Steering head angle: 63.5Front brake: 260mm discRear brake: 220mm discWheelbase: 1481mmSeat height: 925mmDry weight: 105.2kgWhere's the beast?Has the 525 disappeared?The quick answer is no sirree but yes kind of! Confused? Read on...The 525 isn't officially imported into Britain anymore as most people see it as a bike without a class - in the UK at least - as it's ineligible for use in the British championships which follows the MX1 capacity rules laid down by the FIM.And, let's be honest, it's probably too brutal for any of us mere mortals to ride in anger. In many ways it's just like the 450, except it carries a little extra weight (almost a kilo) and that little extra punch - a little extra that makes it just a little too much.525 SXCapacity: 510.4ccBore and stroke: 95mm x 72mmTransmission: Four-speedCarburettor: Keihin MX FCR 41Front suspension: WP 48mm USD (300mm travel)Rear suspension: WP-PDS shock (335mm travel)Steering head angle: 63.5Front brake: 260mm discRear brake: 220mm discWheelbase: 1481mmSeat height: 925mmDry weight: 106kg