VStrom Knuckle Guards on an ST1300 - STRider's take...

[STRider]

So I went and did it. I installed DL650 VStrom knuckle covers on my ST1300.

As others have done, including the Bellevue, WA motor police, I used the optional Knuckle Covers for the Suzuki DL650 VStrom, p/n 57300-27841-291.



There are a couple of obstacles to fitting these covers to the ST beyond the obvious "crossing of the brands".

The ST has a hydraulic clutch as well as front brake. The VStrom has a hydraulic brake but a cable operated clutch. The key difference becomes the thickness of the lever pivot and the length of the replacement pivot bolts Suzuki supplies to attach the covers to the levers. The diameter of the plain bearing surfaces on the Suzuki bolts are correct, however because the clutch lever pivot is thinner owing to being a cable design, it's unsuitable for the ST1300.

Knuckle Cover kit 57300-27841-291



All components in place per the destructions. Note the difference in design between the cable clutch (left) and the hydraulic front brake (right). The plain bearing surface for the lever to pivot in particular.


So I began researching fasteners - including shoulder bolts, smaller bolts passing through a spacer - but I took a cue from the Suzuki replacement brake lever bolt and the work I did to make the bolts for the bar risers for @dlim. Need riser bolts! Please someone help!!!

The unthreaded portion of an M8-1.25 bolt is almost a perfect match to the OEM Honda pivot bolt's bearing section. It's about 0.030" 0.005"/0.14mm smaller (don't quote that, I'll check again later ). Checked! and boy was I off!! A tiny bit looser than OEM, but far from sloppy.

So I searched for suitable bolts that I could modify by adjusting the length of the bearing and threaded portions as well as drilling and threading for the retaining screw. I found M8-1.25 x 50mm bolts were the best option. On the Suzuki bolts, the brake side used a tall hex section which was drilled and threaded for the retaining screw. On the clutch side a hex section of typical thickness was employed, but instead of a threaded hole for screws, a short M6 stud extends from the bolt allowing an acorn nut to retain the knuckle cover unlike the brake side.



Drilling and tapping the head of the bolt for the retaining screw was easy, turning down the section threaded with M8-1.25 and cutting the M6-1.0 threads was the biggest challenge. The jaws of the lathe were too deep to grasp the shank of the bolt directly because of the 12mm bolt head, so I turned a collar to the correct diameter and drilled a hole for a close fit of the bolt to support it while removing the M8 threads and shortening the shank.

Obligatory shop photos...

Bolt in the collar, removing the M8 threads and shortening the plain shank. I turned the collar a couple thousandths too large, so the strip of Dr. Pepper can was used as a shim around the bolt head so everything was clamped tightly in the three jaw of the lathe.



Cutting the M6-1.0 threads. Note the shoulder cut on the underside of the bolt head.



Tapping the hole for the knuckle cover retaining screw.


L-R, Finished modified clutch lever bolt, Honda OEM clutch lever bolt, Suzuki replacement front brake lever bolt.


My favorite detail is the shoulder cut into the underside of the head. The Honda OEM master cylinders for both the clutch and brake are countersunk for the head of their bolts. If I were to mount an unmodified bolt, the underside of the hex head would bottom on the outer surface of the pivot perch and scratch where it contacted the casting. I measured the OEM bolt head and turned the underside of the modified bolt so it would bottom in the countersink rather than on the perch.

Shoulder cut on underside of bolt head to engage countersink in the clutch lever perch pivot bolt hole.



New bolt fully in place with no contact to the paint surface on the lever perch.


The brake side using the Suzuki replacement bolt would do the same thing without a shoulder, but I didn't want to turn that bolt and tear up the chrome plating. So after I finished the custom bolt I turned some spacers from the support collar (spacer shown being test fitted in the clutch lever perch).


Clutch side knuckle cover in place. Note, it's not connected to the bar-end... yet!


Front brake side knuckle cover in place.


View from the front.


View from the saddle. With the MCL risers and my seating position they hardly affect the view in the mirrors at all.


The covers fit amazingly well considering we're crossing brands. It does require spreading the brake cover a little more than Suzuki intended, but it fits and I expect with time and temperature cycling, the plastic will conform to its Honda home.

What I haven't completed is the interface to the bar end. On the Suzuki a spacer is inserted between the bar-end and bar-end weight which is nominally the inner diameter of the 7/8" handlebar on one end and turned down on the other to engage the C-shaped end of the knuckle cover.

The bar ends of the ST1300 however have a protrusion which extends into the bar end several millimeters and has a shoulder cut into its face so once tightened it won't rotate. Unfortunately that protrusion is a larger dimeter than the C-shaped end of the cover so rather than butchering the plastic of the cover, I plan to return to the shop later and turn some custom spacers to fit between the OEM Honda bar-end weights and the handlebars.

As usual, no OEM factory parts have been modified in this project. The entire installation is reversible and the Suzuki kit could be easily installed on an unsuspecting VStrom later.

For now I'll be riding it with the ends of the covers not retained at the bar end. They're pretty solidly in place as is. And while this version used a garden variety zinc-plated steel bolt, I also have a chrome version with a much nicer unthreaded portion which I may upgrade to later.

Hopefully these will add a few degrees of comfort on the backs of my hands and reduce reduce the impact of rain. And when the weather turns nice, they currently come off with two screws.

UPDATE: Corrected the M8 bolt dimensions; M8-1.25 x 50mm NOT M8-1.0 x 60mm. Bolt shank is 0.005"/0.14mm smaller than the OEM clutch pivot bolt... Not 0.030"!! What was I thinking? I know, I live in the metric system and my intuitive grasp of 'thou' versus microns is still weak.

 

[dduelin]

Nice detail work on the fasteners.

 

[Kevcules]

Really good work! Good job!

 

[DeanR]

You are gonna like these Tom. Nice job.

On my 1100, I just tighten the bar end weight/screw up against the plastic of the guard end. Not great but has worked fine for a long time.

 

[Willsmotorcycle]

Top notch. Thanks for sharing.

 

[Honda-st-team]

Nice !!!!! When do you start production ???? Lol

 

[STRider]

Nice !!!!! When do you start production ???? Lol

Who's askin'?

 

[ToddC]

Leave it to a robot builder to figure that out....!!! Nicely done sir..!!
T

 

[STRider]

When we last visited this mod, the mounts using the lever pivot bolts were finished and the bar end of the guards remained unattached.

Unlike the VStrom where the bar-end weights are flush on the end and the place where they're screwed into the bar is close to the opening, those on the ST1300 have a cylinder which inserts into the bar end about 3/4" and the internal handlebar weight is recessed a corresponding amount. In addition, there's a half-moon shaped shoulder on the bar-end weight that keys into the internal one to keep the whole mess from rotating as it's tightened. This made for a rather ungainly collection of washers to assemble those parts.

The spacers included with the knuckle guards also have a shoulder which the end of the knuckle guard snaps onto, but it's just the diameter of the bar on the larger side and the guard is captured between the bar-end weight and that space when installed on the VStrom.

That stupid cylinder on the ST1300 bar end weight is complicating things. First I go new M6-1.0x105mm socket head screws to replace the 70mm stock ones. Properly spaced out, the OEM bar end weights will sit significantly farther away from the bar. But before hitting the machine shop I mocked up the final configuration using a stack of washers inside each bar-end opening to keep the internal weight in the same position; about 8 I think. Then another washer between the bar-end weight and the knuckle guard to keep that half moon shaped shoulder from gouging the plastic before I finished making my parts.

Here's what the throttle side looked like.



So I need spacers that copy the shape of that cylinder on the bar-end weight.



The center was drilled with clearance for a 6mm bolt. Parted to length, then had one half of the should milled away so it can key into the internal weight. This does nothing for the rotation but does avoid uneven clamping pressure when tightened.



Next are the collars that the bar-end weights will mate with. I center drilled again and made a 7/8" hole with a silver deming drill. My intent was to bore the hole so its floor could be flat and the overall length of the space would be slight shorter. But, my boring skills are still developing and I'm using a shop inhabited by high school kids. A serviceable boring bar was not to be found. And the interior wall finish is atrocious! But once assembled no one will ever see it.

The finished parts. A little deburring and we're done. Almost...




They look pretty good just like this.






But it does need something to fill in the abrupt step between the bar-end weight and the spacer.

Perfect application for.... 3D printing!

I had one of our robotics students CAD a simple cylinder of the right dimensions, got ready to print and . . . . No black filament! Seems I failed to restock after running off a bunch of zumo XT mount covers for someone.

But I did have other colors. A little sidetrack here. I made my set of luggage key knobs. They work great, except I cut the key shanks just a few thou short and they required some selective milling with a Dremel to work reliably but still each one works best in a specific lockset. So how to tell them apart? Left from right? Forward locking compartment? A big 'L' or 'R' on the knob would be to obvious and crude. How else do we tell left from right? port from starboard? That's it!! Colors. Boats use marker lights - red for port, green for starboard. So I put some red paint on the left bag's key knob and green on the right's. So when I saw what colors I had the choice was obvious.

 

[SMSW]

Outstanding!

And you have a good way to remind you which is right and which is left. Except, its Red on the right (mnemonic is red right returning).

 

[core-aggie]

And you have a good way to remind you which is right and which is left. Except, its Red on the right (mnemonic is red right returning).

Be cautious about those mnemonics !! ...

It's good for North America, Central America and South America, the Philippines, Japan and Korea.

However, in Europe, Australia, New Zealand, portions of Africa and most of Asia - when entering a harbor there, marks to port are red and marks to starboard are green

 

[Sadlsor]

Dang, Tom, that's quite a lot of detailed work.
Perhaps you just like a challenge, perhaps you truly are OCD, perhaps you just wanted some excuse to play with cool machines and power tools. Whatever, it's obvious you appreciate things "done right".
One might surmise you are very close to Satan.
(for reference: "the devil is in the details." Or at least that's what we're told...)
Nicely done, my friend.
Color me impressed.

 

[STRider]

Outstanding!

And you have a good way to remind you which is right and which is left. Except, its Red on the right (mnemonic is red right returning).

True, but isn't that from the perspective of an observer? A boat with the 'red right returning' is the one you see in the distance and if red is on the right to you, it's on the left, port, side of the approaching vessel.

Dang, Tom, that's quite a lot of detailed work.
Perhaps you just like a challenge, perhaps you truly are OCD, perhaps you just wanted some excuse to play with cool machines and power tools. Whatever, it's obvious you appreciate things "done right".
One might surmise you are very close to Satan.
(for reference: "the devil is in the details." Or at least that's what we're told...)
Nicely done, my friend.
Color me impressed.

Which color @Sadlsor ? Red or green? Though I won't deny I have minor OCD tendencies, it's really about playing with tools and developing skills. I aspire to have Allen Millyard's skills with Jay Leno's workshop.

 

[ST Gui]

I think I'll just stay with heavy heated gloves.