F650GS squirrelly handling on dirt. - BMW F800 Riders Forum & Registry



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  1. #1
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    Searched but could not find any threads on this issue.

    New to me F650GS. With both street and knobby tires, the front doesn't track well on dirt roads when there is even a 1" ridge of dirt to ride over.

    Don't know if I am explaining this well. My dirt bikes' front wheels do not wobble when crossing loose dirt lines left by cars/trucks on the local roads here. The F650GS' front wheel wobbles, jerks?, side-to-side when crossing these little ridges of dirt. Seems like it should plow through them.

    I must be missing something. It does the same with road or knobby tires.

    Anyone know what I am missing?

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  3. #2
    Richard230's Avatar
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    Perhaps the steering bearings need to be adjusted. The F650GS is mostly designed for riding on the street and well maintained dirt roads. Its 19" front tire is a bit wide for off-road riding, compared with more dirt orientated thinner 21" tires that are used on most off-road optimized motorcycles. You might also try reducing your tire pressures when riding the F650GS off road. I guess you could also try installing an after-market steering damper.
    Richard - Current bikes: 2016 BMW R1200RS, 2018 16.6 kWh Zero S, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2020 KTM 390 Duke, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior. 

  4. #3
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    Quote Originally Posted by Richard230 View Post
    Perhaps the steering bearings need to be adjusted. The F650GS is mostly designed for riding on the street and well maintained dirt roads. Its 19" front tire is a bit wide for off-road riding, compared with more dirt orientated thinner 21" tires that are used on most off-road optimized motorcycles. You might also try reducing your tire pressures when riding the F650GS off road. I guess you could also try installing an after-market steering damper.
    I've got the front tire at 26 psi. Which is the lower limit that doesn't have the TPMS alarm yellow triangle constantly displayed. I don't know how low I can go on the stock cast aluminum rim before risking pressure loss.

    I'll try the steering damper. I had not thought of that. Thanks.

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  6. #4
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    You have a dirt bike, so it's not new off road riding nerves and 26 psi sounds good, maybe experiment with a 20 psi and 30 psi. The description that it " jerks from side to side" is weird. Hold the front wheel stationary and rock the bars back and forth, any play or slop? Maybe there's too much forward bias weight on the front. Check your rear preload and make sure it's not maxed out stiff. Check your sag. A dirt bike has about 50% front and 50% rear weight bias and a sport bike has kinda 60% front and 40% rear. I don't know what a F650GS is, but if the fronts heavy it might feel like it's pushing in the corners and tends to follow and track ridges instead of roll over them. Check your front forks, make sure someone hasn't dropped the front to make the bike shorter. Kinda sounds like it's not balanced right for dirt roads. Any improvement with speed, does it get better or worse. I don't have an adventure bike so not much experience with this.

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    Richard230's Avatar
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    Quote Originally Posted by XR1000 View Post
    You have a dirt bike, so it's not new off road riding nerves and 26 psi sounds good, maybe experiment with a 20 psi and 30 psi. The description that it " jerks from side to side" is weird. Hold the front wheel stationary and rock the bars back and forth, any play or slop? Maybe there's too much forward bias weight on the front. Check your rear preload and make sure it's not maxed out stiff. Check your sag. A dirt bike has about 50% front and 50% rear weight bias and a sport bike has kinda 60% front and 40% rear. I don't know what a F650GS is, but if the fronts heavy it might feel like it's pushing in the corners and tends to follow and track ridges instead of roll over them. Check your front forks, make sure someone hasn't dropped the front to make the bike shorter. Kinda sounds like it's not balanced right for dirt roads. Any improvement with speed, does it get better or worse. I don't have an adventure bike so not much experience with this.
    I have weighed my 2009 F650GS using two electronic scales. There is 220 pounds on the front wheel and 266 pounds on the rear wheel, for a total weight with a full tank of gas of 486 pounds.
    Richard - Current bikes: 2016 BMW R1200RS, 2018 16.6 kWh Zero S, 2011 Royal Enfield Bullet 500 Classic, 2009 BMW F650GS, 2020 KTM 390 Duke, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior. 

  8. #6
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    That's good info. Fuel tank location on the F bikes is kinda rearward, so that supports your numbers.

  9. #7
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    Quote Originally Posted by XR1000 View Post
    You have a dirt bike, so it's not new off road riding nerves and 26 psi sounds good, maybe experiment with a 20 psi and 30 psi. The description that it " jerks from side to side" is weird. Hold the front wheel stationary and rock the bars back and forth, any play or slop? Maybe there's too much forward bias weight on the front. Check your rear preload and make sure it's not maxed out stiff. Check your sag. A dirt bike has about 50% front and 50% rear weight bias and a sport bike has kinda 60% front and 40% rear. I don't know what a F650GS is, but if the fronts heavy it might feel like it's pushing in the corners and tends to follow and track ridges instead of roll over them. Check your front forks, make sure someone hasn't dropped the front to make the bike shorter. Kinda sounds like it's not balanced right for dirt roads. Any improvement with speed, does it get better or worse. I don't have an adventure bike so not much experience with this.
    The steering bearings are tight. No problems there. The tire is a 110/80. Which is the same size as the ones on my dirt bikes. Should not make a difference. I think I am expecting too much from the bike. It gets me where I want to go. I've been down some difficult jeep roads with it and have had minimum problems. Any problems were caused by my skill level, not the bike's.

  10. #8
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    You could be right, maybe more seat time will work it out. It's like riding in sand or snow. The first 1/4 mile really sucks, then you remember to slide your ass back, no front brake and steer with your feet and repeat over and over.... I will not crash!

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