Ok, I have an 09 S and as we all know they come stock with Dunlop D605 tires. I mainly use the bike for tooling around town with some high speeds on the highway. The problem I was having was the front end wants to start walking side to side at around 75 indicated on the speedo. I originally thought this was due to have a tire more geared towards dirt riding than street. So today I have put on a set of Kenda K761 tires and went out for a short ride. I'm still getting the same affect and the same speeds even with a tire more geared towards street riding. I ran the stock tires at the recomended pressure of 22 psi front and rear. The Kenda's have a max load of about 32 psi front and rear. I think I still need to play with the pressure a bit but not 100% sure. I started out with 25 psi front and rear. Should I run a higher pressure or should I go back to the lower pressure? Will this make that big of difference with the feel of the bike on the road?

I have also put a Kouba KLX2 lowering link on the rear and moved the front forks up as far as they can go which is 5/8". This means I have a 1/8" difference between the front and rear height of the bike. Can this have a huge affect on how the bike handles at speed? I was looking to go with a low bar and a 1" riser to maintain the overall height of the stock bars but allow me to push the front forks up the full 3/4" that the link lowered the rear. I have thought about coming up on the reload on the rear spring but the whole idea of lowering the bike was to get a little better stance on the ground since I'm vertically challenged. Is there a bar riser out there that would not require me changing out the top triple clamp since out are part of the clamp? Anyone know of an easy fix or do I just need to slow down and accept the limits of the bike at higher speeds?

 

Honestly, if you are planning on running 75 mph indicated around town, you may have the wrong tool for the job. A Ninja 250 or Rebel 250 would probably do this much better than a KLX250. The Street version KLX might be better too. It sure wouldn't hurt to put more air in the tires. Changing to street tires may or may not help. You're sitting on almost 10 inches of travel up front, when many street bikes have half of that....perched up on those sticks on a light bike is a recipe for some unsteadiness at speed, especially on grooved pavement.

Yes, the geometric relationship of the front and rear can certainly affect handling...especially at high speeds or very low speeds. Best to try and keep the original geometry

When all is said and done, I think you may find you are stuck with a knife that's not quite right for the job....it will still cut, but, not as precisely as others would. It's a FINE small DUAL-sport....it's not a fine 75mph on-road bike.

 

Ordered all the parts necessary to get the same amount of lowering in the front as I did in the rear. Renthal ultra low rise bars and a 1 1/2" bar riser along with some other bits and pieces. I know this is not a bike to be running 70 - 75 mph all day on but there are times and places where it is nice to be able to do this. After installing the risers and the bars I was able to get the full 3/4" lower in the front. Tested my new set up and was very happy. Now going the higher speeds I no longer get the front end walk bakc and forth unless a big wind comes along. Plus now I have the added benefit of having a little more footing on the ground when at a stop.

 

I ran at an indicated 70 mph last night for about 10 miles on a highway and was thinking about this thread.

70 mph is 7000rpm, knobby tires, and full dirt setup. It's not fun. Definitely hold on with two hands. The knobbies howling is loud, the intake is loud. Between the wind gusts making your head shake, and the bike shake, your handlebars appear to be kind of moving around when you want them to be still.

It is nice to be able to do it. The bike can do it. It is also nice to be able to release the pucker from the seat and to stop holding your breath.

I've spent plenty of time on big road bikes at much higher speeds. Yamaha Vmax and GSXR600 mostly. Those bikes got nice and smooth with speed. Terrible off-road bikes.

 

As I was coming down an overpass with a good tail wind I hit about 90 indicated. With the 80/20 street tires on the bike it was nice and solid. Now, would I ride at these speeds all the time? No. We just picked up a 2001 SV650 for those times where I feel the need to get out and speed. The 250 with the current set up will do exactly what I need it to do so I'm happy. I have one more piece coming in tomorrow and I will be done doing mods on the bike until IMS finishes the tank for the 09's and up. Then I will just wait until Christmas and get me the 351 kit and maybe a new carb.

 

I Had a thread about this last summer...

at 120kms i definitely get a wobble too.. my KLX is bone stock except for tires (trackmaster knobbies) - and earplugs

I just hang out in the slow lane doing about 105-109km/h indicated and it's not too bad...

it's much better if you loosen your grip a bit... counterintuitive for sure, but it certainly helps..

I'm a novice rider and have only been on the HWY <10 times.