Front forks

[knockdolian]

Hi all, hope everyone had a great Christmas. Now I’ve fitted the air ride system to m6 trike and fitted Brembo 4 piston callipers I get a knock when hard breaking. I’m guessing it’s the front forks bottoming out. When I jack the front up I’m supprised how much of the fork tube comes out the sliders. Any one ever beefed up the front forks. I have the 2” conventional forks not the 64mm inverted. I’ve changed the fork oil. I can live with it just wondered if there was was a spring upgrade. Thanks

[Grand Canard]

The later model front suspension (at least from 2007)spring tension is adjustable; if you have that, it should solve your problem.
Look on top of your triple tree, above each fork tube for a machined hole (might have a removable cap covering hole) that will have an allen screw inside. Turn it clock-wise with an allen key to increase tension on fork springs.
Rick

[Orlando606VetteTrike]

On my previous 2000 Big Block which had the conventional front end, I added a longer preload rod which gave me more spring preload which corrected my fender hitting the fan issue. When you unscrew the allen cap which has long threads, there is a steel rod that the threaded allen screw/cap pushes down on creating more spring preload. Pull out the that rod, and cut one longer, drop it in, and reinstall the cap. You'll see it takes a little more strength when pushing that cap back in to start the threads. At the time i did this, there was no spring upgrades that i knew of, hence the choice to length that preload rod.

[knockdolian]

Thanks Orlando. That I think that’s the way ahead. I believe the early forks were bespoke so finding stiffer springs like progressive would be difficult. Do you remember how much longer you made them ?. I’ll have a look at the weekend. Thanks again.

[knockdolian]

The later model front suspension (at least from 2007)spring tension is adjustable; if you have that, it should solve your problem.
Look on top of your triple tree, above each fork tube for a machined hole (might have a removable cap covering hole) that will have an allen screw inside. Turn it clock-wise with an allen key to increase tension on fork springs.
Rick

Thanks Rick, unfortunately I have the old forks. No preload adjustments.

[502wingman]

You may try to "overfill" the forks by 100ml and use a heavier forkoil. Worked pretty good on my own and other bikes.

[Orlando606VetteTrike]

No unfortunately i don't remember the total length. I might have added about 1/2 in.

Good luck.

[knockdolian]

Just for an update I lifted the front and measured the fork fully extended then dropped the weight back down. I went for a quick ride with Zip ties around the forks. The results are. There is 3” of sag stationary and I have 1” of dive with heavy breaking. No wonder I’m bottoming out !!! Bit of experimenting I think. Thanks to all.

[Paul H]

Seems like to me you should be riding at about half
or less of the full travel. If it's dropping 3 of the 4 inches
of travel you have maybe you should add a spacer
over the spring to bring it back to the middle of travel
or a little above the middle. In the old HD glides
a 350 Honda fork tube was just right.

Paul H

[knockdolian]

Seems like to me you should be riding at about half
or less of the full travel. If it's dropping 3 of the 4 inches
of travel you have maybe you should add a spacer
over the spring to bring it back to the middle of travel
or a little above the middle. In the old HD glides
a 350 Honda fork tube was just right.

Paul H

Thanks Paul. That’s pretty much what I thought and what others have said. So today I went about it. I cut two .6 spacers from some 1.5” tubing I had. I did the R leg and reassembled. When I did the left leg the spring had a plug cap on it. I assumed they would be the same. I left it where it was and added the spacer. I will also add more oil. It’s done the job . Brought the front up another 1.5”. Any ideas thoughts or opinions on the cap appreciated.

[knockdolian]

No reply’s to my question about the spring cap so I’m going to assume there should be one both sides so I’m going to get a pair made with the added 1/2 “ unless someone has one available ??