Improving Fork Action.

[fourex]

I've got an '84 300 which currently wears Magicals springs and pre-load adjusters which has been ok for the past few years but could be better.

I am curious if any of you have succeeded in making the 35mm Zokes perform closer to a modern day fork mainly in regard to plushness. I'm aware of the HFS product out there but this doesn't seem to address oil damping.

Has anyone successfully grafted Racetech emulators into a Trials fork, specifically the Fantic, as they don't have any Trials bikes listed on their website application guide.

http://www.racetech.com/page/title/Emulators

 

 

[feetupfun]

Have Racetech gold valves in 34mm Yamaha-Kayaba TY250 forks on 250 Godden Majesty. Better than standard forks but I wouldn't claim them to work better than well set up 35mm trials Marzocchis.

Racetech don't list TY250 forks either but Yamaha MX bikes with 34mm forks of the same era have the same design damping internals as the TY250.

[fourex]

1 hour ago, feetupfun said:

Have Racetech gold valves in 34mm Yamaha-Kayaba TY250 forks on 250 Godden Majesty. Better than standard forks but I wouldn't claim them to work better than well set up 35mm trials Marzocchis.

Racetech don't list TY250 forks either but Yamaha MX bikes with 34mm forks of the same era have the same design damping internals as the TY250.

Thanks David, but how do you set up 35mm Zokes "well".  I was gobsmacked by the rough holes drilled into the damping tubes when I first dis-assembled a few years ago, it was as if the apprentice was given an 8mm drill bit and told to drill some holes in this tube and don't worry about de-burring. I have since tidied this up, added the Magicals and experimented with 5/ 7.5/ 10 wt oils in varying quantities. It's not until I jump on my modern bike that I realise how ordinary those forks are, somewhere in between would be a good compromise if possible.

[feetupfun]

On 7/1/2018 at 8:38 PM, fourex said:

Thanks David, but how do you set up 35mm Zokes "well".  I was gobsmacked by the rough holes drilled into the damping tubes when I first dis-assembled a few years ago, it was as if the apprentice was given an 8mm drill bit and told to drill some holes in this tube and don't worry about de-burring. I have since tidied this up, added the Magicals and experimented with 5/ 7.5/ 10 wt oils in varying quantities. It's not until I jump on my modern bike that I realise how ordinary those forks are, somewhere in between would be a good compromise if possible.

I don't know what Greg Harding did to his Fantic 240 forks but that is what I'm comparing mine to.

[fourex]

On 04/07/2018 at 3:40 PM, feetupfun said:

I don't know what Greg Harding did to his Fantic 240 forks but that is what I'm comparing mine to.

I spoke to Greg a couple of weeks ago, sounds like all std. I never rode my Fantic in the bush when it 1st arrived, I just went straight into re-furb (not restoration) mode after riding it around my suburban yard and local park, so it was basically replace everything that was possibly 1984 like bearings, bushes, cables, seals, brake shoes, carby jetting and front fork springs etc, the motor remained intact because it still sounds so good. I think the magicals springs are just too firm and springy for me regardless of pre-load adjustment and the different oils I've tried.  This gold valve thing is getting too complicated for a simpleton like me especially when they don't make anything specific for a 35mm Marzocchi Trials fork, so I've splurged out on the HFS air/spring conversion which I will fit within the next couple of weeks and see where that takes me. Cheers.

Edited July 29, 2018 by fourex

[feetupfun]

I recently bought a set of magicals springs for TY250 forks. They are dual rate of a similar design to the standard TY250 springs. On the magicals, the first rate is a bit stiffer than standard springs and the second rate comes in earlier in the stroke than the second rate on the standard springs. I found the magicals springs made otherwise standard TY250 and KT250 forks feel even more under-damped. Very good in combination with Majesty damper rods though which provide more damping.

Rod after reading your last post I was wondering did you check how good was the piston/bore sealing in your Marzocchi forks. Yours may have a ring for all I know - I haven't worked on Marzocchis from a 240 Fantic, but Betors from the same era have sealing rings on the damper rod pistons.

I'll be very interested in what you find with the HFS setup.

[fourex]

18 hours ago, feetupfun said:

I recently bought a set of magicals springs for TY250 forks. They are dual rate of a similar design to the standard TY250 springs. On the magicals, the first rate is a bit stiffer than standard springs and the second rate comes in earlier in the stroke than the second rate on the standard springs. I found the magicals springs made otherwise standard TY250 and KT250 forks feel even more under-damped. Very good in combination with Majesty damper rods though which provide more damping.

Rod after reading your last post I was wondering did you check how good was the piston/bore sealing in your Marzocchi forks. Yours may have a ring for all I know - I haven't worked on Marzocchis from a 240 Fantic, but Betors from the same era have sealing rings on the damper rod pistons.

I'll be very interested in what you find with the HFS setup.

I would have fitted the HFS kit weekend just gone if not for other distractions, you can take it for a ride yourself on 18/19 August if your coming down. Cheers.

[feetupfun]

1 hour ago, fourex said:

I would have fitted the HFS kit weekend just gone if not for other distractions, you can take it for a ride yourself on 18/19 August if your coming down. Cheers.

Excellent thanks and you are welcome to try out my bikes. Yes I'm coming down and planning to ride Open Twinshock blue line

[axulsuv]

So is the HFS kit worthwhile , ? I asked about them a few years ago and didn't hear anything positive ...

[fourex]

On 20/08/2018 at 3:29 AM, axulsuv said:

So is the HFS kit worthwhile , ? I asked about them a few years ago and didn't hear anything positive ...

I think so, I've just riden a 2 day event over here in Australia on what we refer to as 'C' grade lines and I quite liked the fork action, much better than anything previously and I'm happy enough to leave it alone now, running 7.5wt at 175cc per leg (basically just enough to cover bottom of springs), about 2.75 bar per leg, combination of 1x hard spring and 1x medium spring for 90 kg me.

The only issue I encountered was the supplied 50mm alloy spacer was far too long to achieve the desired 28mm between top of fork tube and underside of fork cap, I solved this by re-using the adjustable magicals pre-load adjuster that I was pulling out.

Some pics attached that may explain what I'm trying to say.