The Vincent damper wasn't meant to work with the long eyebolts. They were made to work with the Armstrong dampers.
FF: Forks Modified Steering Stem
- Thread starter greg brillus
- Start date
Tim Vibrac, you have got to change the habit of a lifetime and read the instructions. It is there in bold red print. Inner and outer spring boxes.
Mac you need to check if the suspension is topped out with the bike sitting on its wheels only, that is can you still pull up on the bars. If you have not removed any coils off the springs, my experience is that it will have too much pre-load, remembering that the set up for each bike and rider is different, so it is near impossible to have a spring/shocker combination that is perfect for all bikes. With the 45 lb springs I have always had to cut off around 20 to 25 mm of length off each spring to reduce the pre-load whilst still keeping as much travel as I can with minimal sag. The length of the eyebolts is different now, as this sets up how the suspension sits at the start of its travel. It is possible that the short eye bolts may suit the original shocker if it is longer when fully extended, but I have done this mod to bikes using the original Vincent shocker and still used the long eyebolts which worked out fine.
This is a series D and it had an armstrong damper. I fitted a modified Vincent damper on advice from Ron Kemp when I rebuilt the bike previously. I have a set of short eye bolts so I could try them but given that there is negligible deflection at the shock with long eyebolts under the weight of the bike alone, I cant see how this would help.
I've not thought this through for long so this may not be the way to go but you might try removing the damper completely and then:
- Measure the static sag without rider. This will be only a small amount, maybe 1/4" - 1/2". If there is none at all you need to reduce pre-load. i.e. remove spacers if any or shorten spring.
- Next check the static sag with rider.
- If the sag is in the ballpark see what eyebolts fit best.
And here we see the problem. Greg can push a Comet front end up and down with 45lb springs. Over here fully laden twins, two up, seem happier with 36s. Please remember that the 45s have 2 inches of preloaded and all the others are intended to have 3 inches as supplied. The preloaded is there to ensure the correct height when stationary, the spring rate is supposed to allow maximum deflection over, up to, severe bumps. I can supply weaker strings for you to try when I'm back. Shortening or packing the springs to get the correct ride height seem OK to me. Altering the spring rates is something we need more feedback on.
luckily (or not) my maximum compression on the spring boxes was only 1-3/8" so not a problem. When I drag it all out of the naughty corner and strip it all down this autumn I will lop off the inner cover and then try and find why I have no movement with various dampers on a Comet with 30lb springs
Tim if you remove the damper you will be surprised how soft the springs are on their own.
My understanding is that Tim tried that already.