Replacement Wilbers fork spring doesn't fit?

[Doubleyoupee]

Hi all,

I just bought replacement fork springs (progressive) for my XT600Z 3AJ '88. These ones to be specific:
https://www.wilbers.de/shop/en/Motorcyc ... ?year=1988

I tried to install them this weekend but I can't get the fork cap back on.
The springs are 3-4cm longer so they protrude about 8cm above the fork. Combined with the fact that they are way stiffer, even with my full weight on top I cannot push them down enough to engage the cap thread.



The inner tube is fully up.



I am not using any spacers etc. as the 3AJ doesn't have them, unlike the XT600E.

When I look at videos of regular XT600's, the fork spring seems to be protrude only 1-2cms above the fork.
This also makes more sense to me because after compressing the spring by 8cm there is hardly any stroke left.

Am I missing something or did I receive the wrong springs?

Thanks

[Peen]

Hi,

I also bought the Wilbers fork springs for my 3AJ a couple of years ago and remember in being incredibly difficult to get the caps back on, they did get launched across the room on a couple of occasions, but I managed in the end.

If you think they've sent the wrong springs, whoever you bought them from should be able to tell you what the free length of the springs should be and you can compare.

I actually have my forks apart at the moment, so my Wilbers springs are out and I also have my original springs somewhere. I can measure them and compare later if you want?

Thanks

Peen

[Doubleyoupee]

Hi,

I also bought the Wilbers fork springs for my 3AJ a couple of years ago and remember in being incredibly difficult to get the caps back on, they did get launched across the room on a couple of occasions, but I managed in the end.

If you think they've sent the wrong springs, whoever you bought them from should be able to tell you what the free length of the springs should be and you can compare.

I actually have my forks apart at the moment, so my Wilbers springs are out and I also have my original springs somewhere. I can measure them and compare later if you want?

Thanks

Peen

Hi, yes indeed, I've already contacted the shop. Was hoping I would find someone here that has bought the same (or similar) progressive springs, because there might also be something different/wrong with my current forks. The 3AJ is 35 years old so who knows what happened in the past!
If you're willing to measure that would be perfect . Also wondering if it's normal that they protrude so much above the fork before fitting the cap.
Thanks!!

[Peen]

Ok, Ill have a look when I get home tonight and let you know. Mine should be the same as yours as its also a '88 3aj and I think Wilbers only offer one set of fork springs for them?

[Doubleyoupee]

Ok, Ill have a look when I get home tonight and let you know. Mine should be the same as yours as its also a '88 3aj and I think Wilbers only offer one set of fork springs for them?

Thank you!
Yes, according to Wilber's website there is only one spring for the 3AJ year 88-91 (Article 600-0160-01)

[XT3DS]

I have the same fork springs and yes they are quite difficult to install because of the extra length. Use a socket and extension on the fork cap and lean your body weight on your right arm to compress the spring. With your left hand rotate the fork tube to get the fork cap thread started. Wearing thick gloves helps.

[Peen]

Hi, been and measured my Wilbers springs, they are about 627mm long and the OEM springs are 605mm. Comparing images, yours do look a bit longer. The part number you mentioned matches mine.

Never thought I would ask a stranger this on the internet, but how long is yours?

[Doubleyoupee]

Hi, been and measured my Wilbers springs, they are about 627mm long and the OEM springs are 605mm. Comparing images, yours do look a bit longer. The part number you mentioned matches mine.

Never thought I would ask a stranger this on the internet, but how long is yours?

Thanks! Really helpful
I actually got word from the shop too. Apparently, the spring is supposed to be 620mm.

Mine is 633mm :



Weird that there is such a difference. I think 13mm difference is quite a lot in this situation. It is especially the last 1-2cm that I'm really struggling.

I have the same fork springs and yes they are quite difficult to install because of the extra length. Use a socket and extension on the fork cap and lean your body weight on your right arm to compress the spring. With your left hand rotate the fork tube to get the fork cap thread started. Wearing thick gloves helps.

I actually tried with socket and thick gloves, but the last cm is almost impossible. I'm wondering whether the 1-2cm extra length is the problem or whether I'm just too weak

[XT3DS]

A bit weird that specs seem to be a bit all over the place. They are supposed to be 620mm, but yours are 633 and Peen's are 627. I do not recall what mine were unfortunately, but the difference in length was deffinitely substantial.

[Doubleyoupee]

How are you guys liking the Wilbers springs for 3AJ?
Is it not too stiff? Apparently the spring rate is almost 2x the stock spring (4-6.5 vs 2-4.5 N/mm)
I am wondering for what rider weight the spring is designed for