First, I thought there was a sticky for tricks and tips and such, but couldn't find it for this.

If you are considering going heavier or softer on your rear shock spring to compensate for harder riding or added equipment weight, or if you need a lighter spring, being a lighter rider I have a way for you to save money on the whole thing, making it affordable for sure without compromising in quality.

I did some research back when working with my 650 getting a DRz400 shock to fit it. I learned a lot about springs, since most aftermarket springs for the specific application cost a small fortune. But I found I could get a good price on standard size/rate springs. The standard size springs for coil over shocks is 10". I am guessing the KLX250 has a 10.5 inch spring because the KLX300 has one. I have not done the spring on my 250 so I have no idea how much the adjuster threads can take up, so a spacer may be needed. Here is what I found when doing some leg work for a rider in the ADVrider forum. I felt it was worth posting here for sure.

Measure the ID and length of the KLX250 spring, consider how much adjustment you have available since there may be some difference with the spring. See if you can find out what the spring rate is for the 250 spring. If you find it matches the following dimensions from the KLX300 please post that in this thread.

I did research on the Eibach site (Eibach lists the springs by metric OD/ID/length/rate.) on applications, no KLX250, but there was the KLX300. The spring for the KLX300 is probably the same size as the 250, but with measurement you can verify the spring size. Eibach lists the size in metrics, but I did some conversion. Those metrics convert very close to 2.5"x10.5" 63.1x60.6x270 mm and the stock KLX300 spring rate is about 440 lb-in 5.08 kg-m. Seems a lot of bike shocks run 2.5"x10.5" springs and have a bunch of thread for adjustment.

The reason is because springs are springs. Seems you can get springs from some rather odd sources.

In an ebay search there is nothing in 10.5", but there are 10" springs and either enough threads or a 1/2" spacer will do the trick. Seems sprint cars use the same size on coil overs... and a spring is a spring as long as dimension fit.

I did do calculation for coil bind on the 2.5"x10" 475 lb-in spring and it has roughly 4.5" spring travel, my 2009 250 has a bit under 4" shock travel, so it is not likely to hit coil bind unless you use a lot of pre-load, but I'd think if the spring has proper rate there will not be much pre-load.

Now to get a spring. Go to ebay and a search for 2.5 x10 coil 450 with the last number being the spring rate you want. that search will find all springs 2.5x10 450 lb-in. I found a 450 in-lb spring for $25.99, a shade stronger than the KLX300. A 500 lb-in is the same money. There are lighter and heavier springs with ratings in 25 lb-in increments, prices may vary.

Now you know how you can save a buck on springs.

I learned this when setting up to do the DRz400 shock swap for the KLX650C. It requires a higher rate spring. For my roughly 200 lb it would take a 2.5 ID 10" long spring in a 475-500 lb-in spring (obviously converted from metric). I went softer since I'm not super aggressive off road with the 650. I found a 2.5"x10" 475 lb-in spring on ebay for about $30. Used on a sprint car coil over shock. The guy got a new sponsor and sold off his old springs. It is 1/2" shorter than the Suzuki spring, but there's plenty of adjustment to deal with it.

 

One kind of off hand tip for those who have a license place registration slip and insurance card that, by law, needs to be with the bike.

If you have a crossbar pad you can put the registration and insurance card in a sandwich bag, then put it under the cover that wraps around the foam on the cross bar. Out of sight and no risk of being waterlogged. I used to put them in the tool bag, but this just made more sense. Someone is far more likely to screw with the tool bag and lose the stuff.

At first I tucked the zip part in the split in the foam, but oddly enough it made the foam roll big enough the cover didn't want to fit easily or right. Today I pulled the cover and just laid the baggie in around the foam, the cover went on virtually perfect.

Then there is the tip I saw in Dirt Rider where a race mechanic puts some of the adhesive back velcro hook tape on the crossbar before installing the roll - keeps the roll in one position. Why? As he said, it makes the bar sponsors happy. Just a thought if you don't like the pad moving. I haven't done it yet, but may. I don't like the attachment seam being up all the time. Looks kinda ugly.

 

I think your math may be off, a quick google conversion shows 440lbs/in to be 7.857kg/mm, not the 5.08kg/mm youve calculated, just dont want anyone to order a spring too heavy for them.

 

Type this into google: 440 lb/in to kg/mm

It gives 7.857 kg/mm. Unless the way the springs are measured are different and it somehow throws off the calculation/conversion?

This page also converts to the same # as google: kg/mm to lb/in Converter, Chart -- EndMemo

 

Then I must have screwed up using the convertor, that's what I used. Glad you caught it. I will go back and look to find where I made the error.

Edit, did a few and shows 284. No idea why I got 440. A good reason for taking tips and researching the heck out of them. You clearly did. Again thank you for finding the error. The springs can be had on ebay either way. I guarantee you no one is running sprint car coil overs with junk springs.

 

Good idea. I'm going to do it. Now can you suggest a way to get temperatures under 100F so I can get out on the bike without frying?

 

Mark, I use the 6.0 Eibach for a KLX300 on my '06 KLX250S. It will also fit the '07 model...not sure about the '09 and later models. The KLX300 spring is a little taller, and when you install it on an '06/'07 model you get the impression that it will dig into the airbox. However, once any preload is cranked into the spring which has to occur, no clearance issues will exist.

 

Mooch space from some friend with an air conditioned garage or shop - use beer to bribe them.

I should say we aren't dealing with the 100 degrees, just the daily rain and some days so muggy you break into a sweat at 73 degrees when you step outside.

 

Having grown up near Bowling Green, OH I know the feeling well. And I experienced it mostly on the end of a hoe in the middle of a beanfield. When I wasn't baling hay, that is.

 

And leaning into the wind on those days? I had a friend at BGSU that told me about how they had traffic patterns for the winter so students weren't exposed to the cold and wind on the extreme winter days.