Prolink front spring rate

[Jeff Bennetts]

Rick just a quick refresh please, what are the current components you’re running on the front end?

[Warwick Biggs]

OK Jeff, my current front end has Prolink forks modified as follows:-

Stock springs with the softer dual rate section cut off and 6" spacer tubes inserted to preload front. Stock damper rods with oil holes welded up and drilled smaller (sorry I don't have the precise dimensions) by race suspension expert Trevor Manley who raced Roly's Beast, is a multiple Oz national champion and worked with Nicco Bakker in Europe developing suspensions. 30 weight Motul fork oil at stock recommended level. Air caps set at around 15 psi.

Steering head rake modified from around 28 degrees to 24 degrees. Front forks dropped to approximately 8 mms above the top yoke.

17" Honda VTR1000 front wheel (shod with 120 Bridgestone slick) and modified VTR rotors with stock Prolink 4 piston calipers (with alloy spacers) and dual carbon ceramic race pads.

Rear has retained Prolink arm and also been significantly lifted with custom dogbones on Wilbers adjustable shock. 17" Kawasaki ZZR rear wheel (shod with 165 Michelin slick).

Current wet weight (with 5.5 litres oil and some fuel) on front is 113 kgs and 106 kgs on rear.

Roly is adamant that the current fork set up is fine, emulators are unnecessary and that the motor needs to be lifted in the frame to overcome ground clearance issues. However, that mod is beyond my skill set and was really developed on his earlier twin shock 'Beast'. My Prolink has followed more conventional practice simply by steepening the rake and lifting front and rear shocks to the maximum (rear arm at 13 degrees).

[Jeff Bennetts]

Okay, let me take some pictures and I’ll be back.
Jeff

[EMS]

17" Honda VTR1000 front wheel (shod with 120 Bridgestone slick) and modified VTR rotors with stock Prolink 4 piston calipers (with alloy spacers) and dual carbon ceramic race pads.

I forgot about the 17" VTR wheel and the effort you had to go through to get the rotors accepted by the rules committee. So, I hate to bring that up, but a 18" front could help too.

[Warwick Biggs]

Reluctant t go backwards EMS

[Warwick Biggs]

Warning about using Racetech recommended front fork springs in Prolinks. See my blog 'CBX Racing' for the details.

[Warwick Biggs]

I am somewhat ignorant of early 80's bikes because I was working in the jungles of PNG thru' that period and apart from the odd holiday my biking was restricted to a Honda 125 trail bike. So, perhaps forum regulars could assist we with information on and their opinions of the front forks of that period.

From my limited knowledge it seems that a good contender as a significant straight forward upgrade to the Prolink forks is the Honda CB1100RC fork. It was the same 39 mm diameter, had rebound damping control but not the hinged calipers of the TRAC anti dive. But were the forks the same length and would the Prolink calipers fit the fork legs? Was the axle the same diameter? On some CB1100R's I have also seen a pivoting quick release for the axle replacing the primitive CBX projecting studs that make quick wheel changes more complicated than they should be.