Converting to adjustable CNC hand levers

Brake and clutch levers on a motorcycle should be adjustable to suit the rider's hands perfectly. All it takes is a simple conversion.

Converting to adjustable CNC hand levers
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Important: Hand levers that work properly are essential for your safety on the road. A sticking brake lever, for example, could have fatal consequences. So this conversion is a job that you need to do with great care, and it does require a good understanding of how the individual components function. If you haven't got the necessary skills, you should leave this job to a professional workshop instead. 

Converting to adjustable CNC hand levers

Precision-machined CNC hand levers with a high-quality anodised finished give any modern motorbike a touch of luxury, and make it stand out from the crowd. As well as lending your bike a really distinctive look, right in your line of sight, they can also be adapted to suit your hand size by multiple adjustment of the distance between lever and handlebar. This is particularly good news for all bikers with smaller hands, who often have difficulties with OEM levers. What's more, these levers also come in a stylish short version for sporty bikers. They're specially designed to make it easier to control the exact amount of pressure you exert on the lever.

Important: On motorbikes with a hydraulic clutch, the clutch lever is installed in the same way as a hydraulic brake lever.

On most motorbikes, converting to CNC-machined hand levers is really quite easy for DIY mechanics to do themselves. All you need is a good socket wrench set and suitable screwdrivers. Some grease is also required for lubricating the moving parts. 


Converting to adjustable CNC hand levers – now let's get started

Step 1: Slacken and release the clutch cable

Step 1: Slacken and release the clutch cable

01 – Slacken and release the clutch cable

Before you remove the clutch lever, the clutch cable must be slackened off and released from the lever. The lever must have a small amount of free-play so that the clutch doesn't slip yet still disengages perfectly. There may well be an optimum amount of free-play that you're accustomed to, and you'll want to make sure this doesn't change. So it's best to measure the free-play using a caliper gauge before you turn the adjuster in order to slacken and release the cable. You can only release the cable when the slot on the adjustment wheel is aligned with both the adjuster and the clutch assembly.


Step 2, Fig. 1: Release the clutch cable using gentle force

Step 2, Fig. 1: Release the clutch cable using gentle force

02 – Disconnecting the clutch cable

Usually you need to use a degree of force (pull the lever, grip the cable firmly with your other hand, pull the end ferrule out of the adjuster while slowly releasing the lever, and detach the cable from the adjuster). Releasing the cable is sometimes made easier if the lever's bearing pin is unscrewed beforehand. 

Step 2, Fig. 2: If necessary, slacken off the cable slightly at the engine

Step 2, Fig. 2: If necessary, slacken off the cable slightly at the engine

Otherwise, the long adjuster will also need to be slackened off slightly at the cable or at the engine. In order to loosen the bearing screw of the lever on the motorcycle shown in our example, we first had to remove the clutch switch because it is located just behind the lock nut. The old lever can then be removed along with its bearing. There may also be a thin spacer inside, which sits between the assembly and the lever, and whose purpose is to compensate for free-play. Take care not to lose this spacer. 


Step 3: Check whether the long bush may need to be re-used

Step 3: Check whether the long bush may need to be re-used

03 – Check long bush

Before installing the new lever, check whether the original bearing bush needs to be re-used, as is the case here. Clean and lubricate the bearing bush thoroughly before inserting it into the new lever.


Step 4: Clean, lubricate and insert the clutch cable

Step 4: Clean, lubricate and insert the clutch cable

04 – Cleaning the clutch cable

Also grease the new lever lightly top and bottom at the points of contact with the assembly so that it moves freely and wear is minimised. Likewise, clean and freshly lubricate the end of the clutch cable before inserting it into the new lever. You can now insert the new lever (with spacer, if fitted) into the assembly and retighten the bearing pin. Do this gently. The lever must not be jammed in. If there is a nut, it should always be self-locking.

If you had to remove the clutch switch, you can now reinstall it, taking care to avoid damaging or jamming the movable pressure pin (usually made of plastic). Applying gentle force, pull the cable out of its black casing (if necessary, you can support the silver end ferrule against the adjustment wheel) and insert the cable into the adjuster.


Step 5: Adjust the clutch free-play as previously measured

Step 5: Adjust the clutch free-play as previously measured

05 – Clutch play adjustment

Now adjust the clutch free-play as previously measured. Free-play of approx. 3 mm between the lever edge and the assembly is normal. Then adjust the distance between the lever and the handlebar so that you can grip the lever comfortably in the riding position. Check all of the functions again before using your motorbike. Is the clutch working properly? Does the clutch switch work? Does the clutch operate smoothly and easily? Does the lever stick, snag or rattle?


Step 6: Install the lever using bearing screw and bearing bush

Step 6: Install the lever using bearing screw and bearing bush

06 – Brake lever conversion

The hydraulic brake lever does not have a cable, so it is quicker to replace. It's especially important to make absolutely sure that the brake is working properly!

First unscrew and remove the bearing pin. It may be held by a thread in the assembly in addition to the lock nut. When you remove the lever from the assembly, check whether it is fitted with a thin spacer that prevents rattling. If a bearing bush from the original lever has to be re-used, you should give it a good clean. Grease the bush and the bearing pin lightly. Likewise the part of the new lever that actuates the piston in the brake assembly (cam) and the points on the top and bottom surfaces of the lever that are in contact with the assembly.


Step 7: Check the pressure pin of the brake light switch

Step 7: Check the pressure pin of the brake light switch

07 – Note the pressure pin of the brake light switch

Some motorbike models have a setting screw on the cam. This screw needs to be adjusted to give a small amount of free-play so that the lever does not press continuously against the piston (e.g. in the case of BMW).  When installing the new lever in the assembly, also check the pressure pin of the brake light switch. If it is jammed, it may become damaged, and the brake lever may also jam! So please be very careful!


Step 8: Set the lever-to-handlebar distance at the adjuster

Step 8: Set the lever-to-handlebar distance at the adjuster

08 – Adjusting the lever position

Tighten the new lever carefully and without jamming it, then adjust the distance between the lever and the handlebar so that you can operate the brake optimally when sitting on your motorbike. Check one more time that the brake works properly with the new lever before you take your bike on the road again: Does it move smoothly and freely without any rattling? Is there a little free-play on the piston so that it is not permanently under load? Is the brake light switch working properly?



The Louis Technical Centre

If you have a technical question about your motorbike, please contact our Technical Centre, where they have endless experience, reference books and contacts.

Please note!

These tips for DIY mechanics contain general recommendations that may not apply to all vehicles or all individual components. As local conditions may vary considerably, we are unable to guarantee the correctness of information in these tips for DIY mechanics.

Thank you for your understanding.