Do I need this locking groove to make this work?

[Nvreloader]

Guys,
I know this site is mainly ebike related,
but I have a problem I am attempting to fix, Old school bike repair>

I have a Rigid front fork 26" with a threaded 1-1/8" x 26 tpi at approximately 6-1/4" stem length, with 2" of threaded stem, for the locking nuts to hold the head stem bearings on the frame.

I am replacing this rigid fork with this Suntour suspension front fork,

SR SUNTOUR FORK SRST 26 XCM COIL 1-1/8 180/55 QR9 M-BK DISC/CANTI 2013 SF13-XCM- V3 26
SR SUNTOUR
SKU: 10-28376

All the OEM spec's of the Suntour suspension fork fit the Rigid fork, EXCEPT,
there is NO locking groove cut into/thru the threads, on the replacement suspension fork,
This locking groove is for the locking nuts and tabbed flat washer that fits between the 2 locking nuts.

Do I need this locking groove on this new susp fork? To lock this susp fork down and hold the required setting for the bearings?

There is a 1" goose neck locking handle bar stem that fits inside the 1-1/8" threaded fork stem.

The machine shop wants $50/75 to cut this locking groove in the suspension fork.

I have been told that I can drill/tap 3 cone pointed set screws in the top locking nut to hold the setting needed, after final adjustments of the stem etc.

Your thought's or suggestions
Tia,

 

[Chalo]

Those headset washer tabs fail more often than not anyway. Don't bother. Use a plain non-tabbed washer or file the tab out of the one you have. Use a plate wrench to hold it in place while you tighten the top nut with a big crescent wrench.

When I set up a bike whose steer tube is a little short, the first thing I delete is the tabbed washer. It's a convenience feature that isn't actually very convenient.

 

[Nvreloader]

Chalo
Thank you for the info.
I was thinking that there is not much torque pressure on those nuts, as the bearing are turning when they are moving etc.