How to measure/cross match a spring

[Guest]

Hi everyone,

I recently started looking to find a neutral stop spring for my 1979 Suzuki gs850g. (had trouble going from 1st to neutral while stopped, had to rock the bike forward or go up to 2nd then hand down to get to neutral.)

While doing a search I found that Suzuki NO LONGER MAKES the spring I needed (part number 09440-06018).

I ended up purchasing a "new, old stock" spring from e-bay which helps me, but it does nothing for anyone else.

I would like to find a way to cross match the spring to inform others what they would need to buy in a spring to match the specs.

How do I do this ?


Thanks

sean

[cowboyup3371]

Does the NOS part still have a part number some place on the packaging? If so, you can go to http://www.alpha-sports.com/suzuki_p...q=suzuki-parts and then click on Special Tools, Part Finder: All to see if that number cross matches to anything

[Brendan W]

Generally a spring is specified with a number of measurements, the style of the end and the material type.
You could measure the outer diameter, the diameter of the wire, the overall length, the number of coils and note whether the end is open or ground flat for example. This will generally do it.
You could go further and worry about the material. It should be obvious if the spring is stainless or galvanised. A magnet will sort some of that out. A little ingenuity with a kitchen scales could even get you an estimate of the spring rate.
For the kind of springs we're talking about the measurements in the first paragraph should get you close enough for all practical purposes.

[tkent02]

I have had no trouble going into a hardware store and squeezing springs by hand until I found one about right. There's nothing critical here.

Somewhere in a town near you will be a shop or store with a ton of different springs.

You could also shim your old spring to get it a little tighter.

[seanarthurmachado]

OK. I checked and the part looks available there. All the other parts sites showed not available no order. (Z1, bikebandit, partsoutlaw, ect, ect).

I was thinking this would be a tough match up on this spring and needed to be documented for future owners.

I guess I was getting way too complicated in my thinking.

Sean

[tkent02]

Even if the original is available, a slightly stiffer spring will make it easier to find neutral, especially on an 850 that is known to have problems with it.

[BigD_83]

I'd like to step away from the question asked for a second, and ask a different but related question.

In Sean's original post, he says he has to rock the bike a bit to get the shifter to move into neutral while at a stop. I have a similar issue with the 650, and it feels like it is more of a "hard" shift, rather than just not being able to stop at neutral.

If there is a "hard" shift rather than just hunting for Neutral, wouldn't that imply there is a second problem unrelated to the spring?

In my mind, a hard shift would not be a result of the spring being soft, but a soft spring might result in passing through neutral more often (i.e. less positive engagement).

Maybe my thinking is faulty, but shouldn't a weak spring result in the neutral stop not engaging on the shift cam, and not affect the force with which one shifts?

[tkent02]

I didn't read it like that. You mean like it's so hard to get out of first that it flies past neutral into second? If the clutch is released completely it shouldn't require any force at all to get it out of gear.
Could be some clutch dragging causing that, seen it on a bunch of bikes with poorly adjusted clutches. Maybe something is worn in the shifter or shift drum or something associated with it.....

My habit is to put it in neutral (if I'm going to) as I'm still rolling to a stop, which makes neutral easy to find. All I have ever done is just put in a bigger neutral stopper spring and it works fine. Need to do it on my 450, it's a little bit hard to find neutral sometimes. You just need a really delicate toe, the neutral detent feels really wimpy on it, so I think the spring will fix it.

[BigD_83]

Sean, can you clarify your situation? Is your problem as I have described on my 650, or are you just hunting for neutral?

[seanarthurmachado]

The situation is that from neutral is easy to from from neutral to 1st, or 1st to 2nd as well as 2nd to neutral, but 1st to neutral is not easy to get into and bike needs to be rockedforward a couple inches when still.