Throttle sticking/Handle bars

[Oconner]

Throttle sticks. PO said that he put new bars on (see attached) and that he had them powder coated. The coating is what he says creates the problem. Do you think I can remove the grip ect and sand off the coating and reinstall the grip ect. to solve the problem? Don't mind the "cruise control" but would like more control.
Gracias!

[Barry]

Are they the correct size bars i.e. 22mm rather than 7/8" which is slightly bigger and causes problems which powder coating will only add to.

Sanding off the powder coating may help. It's usual to lubricate the bars with a little grease before sliding on the throttle sleeve.

[montmil]

Try sanding off just a small section at the end of the bars. Use a micrometer to accurately measure the bar's diameter. Should be 22 mike mike as barry states. 7/8" bars are an invitation to cracking the lever perch assembly.

[mrclubike]

The "O" rings on the throttle shafts can swell and cause issues also.

[Mike V]

You may try disconnecting the cables at the handlebar handgrip and make sure the cable is free by pulling and checking the release action of the cable.  I can think of many things that may be causing this situation downstream of the twist grip.

Process of elimination to point you in the right direction.

[Oconner]

Yes the bars are 22mm measured, so maybe the PO didn't know what he was talking about. I will disconnect the cable and see where that leads me. Thanks

[Bob_Roller]

Another place to check, is inside the throttle housing on the handle bar .
The teeth on the metal tube the grip fits over and the cam gear with the chain attached to it, are made from a pot metal and wear /deform with use .
You can try cleaning them up with a file, but usually you need to replace both parts .
Also, if you do replace them, you need a new cover that goes over these parts, the design was changed on the cam or ring gear, the hole in the middle of it is a larger diameter, you can't make the old cover work with the new parts .

[montmil]

There is one item that could be causing the sticky throttle... Confirm the entire perch/switch assembly has not be pushed so far onto the new bars that the rubber hand grip is dragging on the handlebar end and creating the drag issue. This may be due to the PO's install. Easy check. Don't cost nuttin'.

[Oconner]

Checked the throttle cable and its good.  Someone had already sanded off all of the black powder coating. Grip turns perfectly on that. The 'drag' is being caused by the housing that the grip slides into, the hole so to speak. It seems to be off just a mm or so creating the drag, hang up. I don't see how to adjust. By the way whats the small hex underneath for. Seems to tighten and make the drag even worse when turned. Greased everything up, was late so didn't get a chance to test ride. Seems better though.

[montmil]

Checked the throttle cable and its good.  Someone had already sanded off all of the black powder coating. Grip turns perfectly on that. The 'drag' is being caused by the housing that the grip slides into, the hole so to speak. It seems to be off just a mm or so creating the drag, hang up. I don't see how to adjust. By the way whats the small hex underneath for. Seems to tighten and make the drag even worse when turned. Greased everything up, was late so didn't get a chance to test ride. Seems better though.

The hexhead machine screw is what tightens the perch assembly to the handlebar. The Magura control assembly, depending on model year, utilizes a small, triangular-shaped steel wedge the limits the amount of compression that can be exerted on the handlebars. This prevents overtightening and cracking the perch, thereby rendering the control assembly useless -not to mention dangerous. It also prevents the rotating throttle tube assembly from binding.

Your control assembly may be missing the wedge. This vital component is often missed and lost during a change out of handlebars. You will need to remove the throttle assembly to check. The first photo is of the wedge.



This photo indicates where the wedge fits. The Allen screw passes over a rounded cutout in the wedge and secures it in place... until an unknowing owner removes the throttle assembly and the wedge disappears into another parallel universe.



There's no way of knowing if your perch requires the wedge or not as newer Magura controls were manufactured to eliminate this pesky part. BMW still sells them for $11-12.00 each!

Post up what you discover.

[Oconner]

WOW! Thanks Monte. Will do!