[RoyB]

I have a Mk3 with very soft front suspension. It almost bottoms just when I sit on the bike. What’s the best way to firm it up? I have seen somewhere that you can cut some of the rubber/spring off, and replace with the same length of rod. Or is it better to put in a short length of rod, to compress (preload) the spring?

[stan ellison]

Hi RoyB

I wonder if you could have the wrong size springs inside. I have a mark 1 and a mark3 both with 16″ wheels. I also have the frame for a super 4 which had 14″ wheels. I measured the stem posts and the mark 1 and 3 were 14″ long but the super 4 is only 13″. If springs from a 13″ stem were put in a 14″ stem then might that cause this softness? Are they actually different parts or just fitted differently? I’ve yet to sample the joys of fork dis assembly but perhaps you should check out the info elsewhere on this site and have a look. If it’s an improper assembly or broken spring it can be fixed.

[RoyB]

Hi Stan
Thanks for the reply. I think the spring/ rubber is correct. I have to compress it to get the brake bolt through, so it seems to be the right length. The rest of the bike appeared pretty original, so I’m guessing the suspension is the same. Maybe the rubber has just lost some stiffness over 40 years. I’ll try preloading it with a bit of rod to see if that helps.

[Paul Grogan]

Hi Roy.
Before you start cutting up the spring / adding rods, etc. try adding one or two tap washers to the end of rubber/spring when re-assembling. This effectively lengthens the rubber column, so should stop the suspension bottoming out. It usually works and is non-destructive!

[RoyB]

Hi Paul. Thanks – I was just going to add a bit of rod or dowelling without cutting anything. That should compress the spring/rubber and make it stiffer. I don’t think it needs much (an inch?). I won’t go down the cutting route just yet!
Cheers
Roy

[RoyB]

Hi Paul
£1.79 and 3 tap washers later, I think it’s worked. Seems to hold the suspension when I sit on the bike, and there is plenty of travel when I push down. A test ride will confirm , but it’s too dark now. Thanks for the advice. What a valuable forum this is!
Cheers
Roy

[Author]

Posts