Le Mans Mk1 fork springs

[dylan]

Hi all

First post here, although a VERY long time lurker. I used to post a bit on Roperville (Guzzi Exchange) but that's a little quiet these days.

I've recently been re-doing the front end on my Le Mans 1, it had quite a bit of sag with the original springs so I had some new springs put in to tighten it all up. I wanted to get progressive springs, either Wirth or Ikons but apparently it's not that easy to get them for the Mk1 due to the one off size (I'm confirming this with Ikon though, just need to get the measurements to them). So instead the mechanic installed a set of one piece heavy duty springs (with the yellow paint) and a 1cm spacer. This certainly helped the sag but they are still pretty stiff, not moving a whole lot over small bumps.

Video of stiction/bind issues: https://www.youtube.com/watch?v=1sYKsuDfpuw

I had lots of stiction which took me quite a while to fix, it ended up being mainly caused by having a slight bend in one of the stanchions and both triple clamps being out of whack. I have FAC dampers fitted which are working correctly but I changed the fluid anyway, 70ml in each from memory). I run no air pressure in the forks. 120mm of ATF in each leg. I also installed some new (black) single two lip seals. I don't believe there is a stiction issue any more, but they are still pretty stiff over small bumps.

These are new springs, and I know they will loosen over time, but does anyone know if the progressive springs would be that much better over small bumps, or am I just being a Nanna?

Overall I'm happy with the way it rides at pace (it corners extremely well), it's just that it's so firm my glasses wobble in my helmet and I find I have to adjust the way I ride to stop that which is giving my core muscles a really good work out over long distances.

Cheers, and sorry for the long winded first post.

Interested to hear anyone opinions or experience.

Cheers
Dylan

[Antietam Classic Cycle]

Wirth fork springs for the Le Mans 850:
http://www.mgcycle.com/index.php?main_page=product_info&cPath=197_199&products_id=1145

I've often wondered why the spec. for the Le Mans 850 is 120 cc of atf when the (internally identical) fork of the 850-T is only 50 cc. The extra 70 cc would certainly make the front end much stiffer. Maybe experiment with different amounts of atf and see if that helps ride quality?

[dylan]

Hi Antietam Classic Cycle

Great idea, reducing the air volume would certainly affect preload. I wonder how the AFT level would interact the hole in the stanchion as well, I understand that is a breather hole.

Easy to find out, I'll report back.

Cheers
Dylan

[dylan]

Well that was it! I removed around 50ml of ATF from each leg and they are much softer now - I'm happy. I can measure weighted sag and rider sag on the front end which is something I couldn't do before. They are lots more compliant over small bumps as well, and the good thing is I now know I can adjust the amount pre load by the quantity of oil AND air from the FAC dampers.  ;D

I don't think I have a need to move to progressive springs at this stage.

Cheers for your help, and thanks to the guys over at Guzzi Exchange.

Dylan