Installing a Throttlemeister throttle lock on a Ducati Multistrada

I’ve had Throttlemeister throttle-locks on two previous bikes, and like them a lot. They provide gentle pressure to lock the throttle in a set position for right-hand release, and can be set to hold the throttle wherever you put it while permitting speed adjustments. On top of that, they are a beautifully-machined piece of kit and look great on the bike.

I ordered the standard size, standard chrome finish model. That’s model FT & AZ5 (AZ5 refers to the mounting mechanism, and is the correct one for the Multistrada handlebars.)

Here’s the install process:

Warning

I am not a mechanic or a representative of Ducati or anything else official. This page is only my notes on doing this procedure myself. Although I believe what I have documented here is correct, I make no promises and you do this at your own risk.

Tools Required

• 5 mm Hex Wrench to remove the stock bar-end weights.
• 6 mm Hex Wrench for the socket screws in the Throttlemeister.
• Screwdriver or prying tool, tape to cover it with, and a hammer or other object to tap it with.
• Sharp utility knife.
• Optional: rotary burr or rotary sanding drum in a rotary tool or drill.
• Sandpaper.
• Blue LocTite #242 (supplied with Throttlemeister).

Difficulties & Warnings

Fairly easy. Things to watch out for:

• Warning: throttle locks are potentially dangerous. Not for beginners, know what you’re doing, don’t be stupid, etc.
• Requires cutting a small plastic ridge off the bike’s internal throttle tube. You’re working near the grip heaters and need care not to nick them.
• Removing the stock bar-end weights requires care or a jam-nut can fall off and end up loose inside the handlebar.
• Careful adjustment of the spacing of the Throttlemeister is necessary to ensure the throttle operates freely when the lock is not engaged.

Procedure

The Throttlemeister replaces the stock bar-end plug, shown circled in yellow here.

Care is needed when removing the stock bar-end. It uses an internal “jam nut” and if the retaining screw is removed all the way, the jam nut will fall off and be left loose inside the handlebar.

So, using a 5mm hex key, back off the retaining screw 2 turns only. Then give the now-protruding screw a tap with a hammer. This will drive it back inward slightly, which will free up the internal jam nut.

Now we’re going to pry the bar-end plug away from the handlebar. To avoid marking the bar, wrap the blade of a slotted screwdriver in some electrical tape.

Get the blade behind the bar-end plug,

then gently tap it with a hammer. The plug will pop loose.

Now, with a bit of wiggling, the plug can be pulled out of the bar.

Here, as the plug comes out, you can see the jam nut, which is still attached because we didn’t remove the screw all the way out.

Next, this “friction tube”, supplied with the Throttlemeister, needs to be slipped over the throttle tube, under the handgrip. We’ll roll the rubber handgrip back a centimetre or two to facilitate this.

To make it easier to roll the handgrip, we start the bike engine and turn on the heated grips. Give them a couple of minutes to warm up, then shut down.

Now with firm pressure you can roll the end of the rubber grip back onto itself.

Just roll back enough to leave room for the length of that friction tube.

Note that we’ve uncovered the heater foil of the heated grips here. We’ll want to be careful not to damage that in the following steps.

We’d like the friction tube to slide on to the end of the now-uncovered plastic throttle tube. Unfortunately, the throttle tube has a “lip” on the outer end, a rim designed to retain the rubber handgrip in place. This lip has to be trimmed away.

We start with a sharp utility knife, carefully trimming away the lip, approximately down to the level of the throttle tube, and being very careful not to damage the exposed heater foil.

This takes a while, working slowly and carefully all the way around the throttle tube.

Once I had done what I could with the knife, I used a grinder burr in a hand-held drill to smooth the lip down a little more.

Then I switched to a small sanding drum, continuing to smooth the lip down.

Finally, I used coarse emery paper, pulled around the throttle tube in a back-and-forth motion, . . .

followed by fine emery paper, to finish the job.

Now the throttle tube is a continuous smooth cylinder, with no protruding lip.

The Throttlemeister friction tube now slips on to the throttle tube.

With a bit of wiggling back and forth, work it all the way down the tube.

Make sure it is firmly pressed onto the throttle tube as far as it will go.

Then roll the handgrip back into position, covering the new friction tube.

You’ll have got some plastic dust inside the handlebar tube. Clean it out with a rolled cloth dampened slightly with alcohol.

The right-hand Throttlemeister consists of the bar-end weight with an internal bronze pressure piston, an mounting bushing that fits into the handlebar, and a hex-socket screw.

Throttlemeister recommends putting Loc-tite on the screw, and supplies a small tube of it. (This is not the supplied tube, it’s my own workshop bottle.)

Be sure you use blue loc-tite, number 242, which is non-permanent. Don’t use one of the stronger permanent locking agents such as Red 262, or you will never be able to remove or adjust the unit.

Assemble the screw through the bar-end and into the bushing, with the pair of O-rings at the far end.

Insert this assembly into the handlebar tube and push it in almost all the way — leave it about 0.5 cm1/4-inch from fully-inserted.

Now you need to determine the right amount of insertion by trial and error. Tighten the hex screw (6mm wrench) and check the operation of the Throttlemeister. Turned fully clockwise (top toward front of bike), the unit is “off” and the throttle should move freely exactly as normal. Turned about 1/4-turn counter-clockwise (top toward the rear of the bike), the bronze piston should press on the throttle friction tube and prevent it from turning.

If the throttle turns freely without locking even with the unit fuly “on”, you need to loosen the screw and move the unit in slightly. If the throttle is locked or partially locked with the unit fully “off”, you need to loosen the screw and momve the unit out slightly.

After each adjustment, re-tighten the bolt and check again.

Finally, start the engine, turn on the heated grips, and check the operation with the handgrips warm. (If you have the tolerance too tight, the expansion resulting from heating the grips may lock the throttle. You are looking for the “sweet spot” where it operates freely, or holds the throttle, whether the handgrip is cold or hot.)

here is the finished install, in the “off” position.

When the bar-end weight is rotated counter-clockwise, the internal bronze piston extends and presses on the throttle, holding it in place. You can just see the bronze piston in this photo, and the tip of the arrow.

You can set the unit in-between the “on” and “off” position, and it will hold the throttle where you put it without preventing you from moving it to another position.

Now we repeat with the matching left-hand unit. It has no mechanism inside, and is just a decorative bar-end weight. The stock bar-end plug has to come out.

As before, loosen the retaining screw 2 turns only, then tap it inward to release the jam nut.

Pry the plug out, tapping the screwdriver with a hammer if necessary.

One it comes free, pull the bar-end plug out of the handlebar.

Be sure you get the attached jam nut too.

Clean the inside of the handlebar.

The Throttlemeister for this side has no internal mechanism.

As before, assemble the bar-end, screw, and bushing.

Slide the assembled unit into the handlebar.

And push it in as far as it will go.

There is no mechanical action on this side, so no adjustment is necessary. Just tighten the screw securely.

And here is the finished left-hand installation.

You’ll want a 6mm hex wrench with you on the road in case the right-hand unit requires any adjustment. There isn’t one supplied with your bike’s tool kit, so add one to the pouch.