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Stiff throttle springs


14kmtnman

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I have had several people comment on how stiff my throttle is. Other BMW riders, Vstromer's, sport bikers, etc. I have wondered why my right forearm has been getting sore on longer rides. Are there lighter pull springs available? Or is there an adjustment for the spring tension?

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I have had several people comment on how stiff my throttle is. Other BMW riders, Vstromer's, sport bikers, etc. I have wondered why my right forearm has been getting sore on longer rides. Are there lighter pull springs available? Or is there an adjustment for the spring tension?

 

 

14kmtnman. Problem is those are torsion springs not pull springs They are wound behind the throttle cams.. BMW uses (2) throttle bodies (one on each side) so you are holding 2 springs that need enough tension to return large throttle plates & all the cables including twist grip..

Next BMW doesn’t use a return cable so the only primary means of throttle return if something sticks or goes wrong is those torsion springs..

Next the later BMW’s use a splitter box to allow one throttle cable to pull on two throttle bodies so that adds friction & drag to the throttle system..

 

You can lube the twist grip & cable itself (use a non petroleum lube like Tri-Flow) or it can damage the inner cable liner.. That usually makes a little difference..

You might also pull the splitter box out clean that & the parts inside (a little gunk in that box can really stiffen up the throttle action)..

 

If you want to get real inventive you can add a rubber band or spring to the twist grip itself to aide twisting the throttle in the open direction.. That shouldn’t hinder safety as you can always manually close the throttle if a problem shows up..

 

 

Twisty

 

 

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Unhofliche_Gesundheit

you can also get one of those little paddles that attach to the throttle grip so you can use the heel of your hand to open throttle - can be done with the lightest of grips (dont forget to hang on though so you dont loose control on a bump)

 

my bike came with one of these doodads - they cost about 10$

 

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Thanks. Cleaning & lubing cable junctions, etc is always a good idea. Too bad I never thought of it before this. Next time I have the sides off, that will be on the list of things to do. Good idea! I do have one of those throttle paddles. I know it works well on real long rides. Maybe I just need to use it more often.

 

Thanks again for the ideas!

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It could just be that the cables are worn out (still on the original?). If so, just replace them, and consider replacing the junction box as well.

 

On my '02 I replaced the cables, cleaned the junction box, and greased the twist grip (all at 69,000 miles). It helped.

 

Stan

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A new set of cables on a set with more than 30K miles does wonders for a lighter throttle pull.

Sometimes I guess... but I just replaced my throttle cable at 100k miles and couldn't really tell any difference at all. Maybe because I have the earlier design without the junction box, dunno...

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Yeeha! Stephen

Might wanna check the junction box for crud.

 

I pulled mine apart after experiencing a stiff throttle, expecting frayed cables and found the box was full of grit and gunk. Looks like some one had sprayed lube in there, and attracted a lot of dirtiness.

 

Cleaned it and my cables and everything was fine again.

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A new set of cables on a set with more than 30K miles does wonders for a lighter throttle pull.

Sometimes I guess... but I just replaced my throttle cable at 100k miles and couldn't really tell any difference at all. Maybe because I have the earlier design without the junction box, dunno...

 

Guess we all can't be as lucky as you but then maybe that is why you are the tech mod. I can only say on both bikes I have had with the junction box cable replacement made a big difference in throttle pull. I didn't replace the junction box, only cleaned it.

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i have a '02 r1150rt with 54k on the original cables. i would like to replace the cables, junction box, and whatever else that would improve my throttle pull. but i need help with 2 things...

 

1. does anyone have any procedures on replacing cables, junction box, etc?

 

2. what are all the parts i need and where can i purchase them?

 

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I can only say on both bikes I have had with the junction box cable replacement made a big difference in throttle pull.

Please understand that I'm not doubting you at all. I was only suggesting that cleaning/replacing the junction box may be more effective than replacing the cable.

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Procedure is here. The 1150 is same procedure as the junction box equipped 1100 but a little more difficult to slide the junction box out in my experience.

 

http://ibmwr.org/r-tech/oilheads/R11throttlecables.shtml

 

BMW dealer should be able to set you up with the 3 cables you need and a junction box if you wish to replace rather than clean. You'll need some zip ties too.

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