F700gs fork raising

After buying a comfort seat for my f700gs I find the extra 15mm height means I feel a little unstable especially with a passenger. I was thinking of raising the forks maybe 8-10mm to help lower the bike at the front and also reducing the rear shock pre-load to the minimum setting to help lower it at the back. Would this be safe to do - all my riding is with a passenger, 18 stone (280lbs) between us.

Whilst I don't think the front forks on your F700GS have any inbuilt adjustment, they should perform Ok as they are. Some riders play around with progressive springs & different weight fork oil to change the damping characteristics, but I doubt this is actually the issue here. The seat height change is minimal 5/8 in/15mm. I assume you have the standard chassis height, so why do you need to be looking at lowering the ride height? I've seen it done, but frankly, if you are tip toe & uncomfortable you need to think about swopping to an OE low model.

Setting the suspension up correctly is pretty straightforward on these. Looking at your weights & assuming there are no defects with the machine mechanically (tyre pressures/head bearings/wheel bearings/swing arm/front forks level in the top yokes, not dropped above) I suspect the instability issue is with the rear shock. Far from slackening off the preload, I would expect you to need at least 2/3 of the available preload dialled in, with a pillion, as well as an increase in damping. Thus I suggest you take the settings back to factory standard. The tool required is under the nose of the seat. My Rider's manual shows this under 'operations(4) - adjusting spring pre-load, then over the page to the basic damper setting, probably 2 turns out. Then road test the bike solo - all should be well. Then, once you are happy solo, you can get to it & increase the preload to take account of the extra load of the pillion &/or luggage. One way is to sit on the bike solo, headlight on pointing at a wall on dip - mark the wall with say tape at the dip cut-off. Then wind up the preload, add the extra load & see where your beam sits now. Carry on adjusting until the beam cut off is corrected with your full load on board. Then wind up the damping progessively until you are happy with its characteristics, say a couple of turns at a time, then road test.

I hope this helps, indeed have I understood the problem correctly?

Ride Safe ...................... KEN

You could maybe take 20ml of oil out of ach fork which would effectively "reduce the preload" and ncrease the static sag of the forks - because ir is compressible but oil isn't. Downside of this is you may get more fork dive under heavy front brake use.

Sorry if my query sounds vague. I mean that I feel unstable due to the taller seat - not the bike feels unstable. I'm basically on tiptoe in other words and want the security of flat footing at a standstill. I just need to get back to the original seat height of 820mm rather than the 835mm of the comfort seat. I want to lower the bike by 15mm. I don't think removing 20 mls of fork oil will do anything - the springs control the fork length at rest rather than the oil - I would need to cut down the plastic pre-load tubes to effectively reduce fork length. My understanding is that rear shock preload adjusts the ride height according to rider/passenger weight. Thus I am assuming with no preload the bike will be lower at the rear and by raising the forks will be lower at the front. This would hopefully keep the original steering geometry intact. I have ESA and keep it on comfort (soft damping). I'm going to try this and will let you know the result.

Trust me. I've just fitted some doo-dads in my wife's 650GS twin.

I cut down the spacers by the length of the gadgets I'd fitted but when I reassembled the forks I put in the standard oil fill.

Hers is a lowered bike and I found I had inadvertently brought the front back up to standard height.

I had to reduce the oil fill by 30mm each side to get it back down again. This increases the volume of air in each leg - air is compressible - ergo when she sits on the bike, the static sag means that the front sits approx 25mm lower than standard.

Now, if you just slide your forks through by 15mm you will also decrease the "trail" i.e. The distance between the head bearing centre line and the front wheel bearing centre. This will make your bike turn in much quicker than it does now. This might make the handling awkward on such a soft fork. From you first post ... 8 to 10mm would have a lesser effect and is easier to try first.

If you do go for oil removal and as you live in rural Devon..... find a farm supplies shop and get a sheep drenching syringe with tubing. Makes the job easy

Hi I fitted hyperpro lowering spring and then found that the cut down seat was very uncomfortable after 50 miles so opted for the comfort seat .Comfort cured the advantage I gained by lowering was lost lol . Anyway run the rear suspension fairly soft to allow my little legs to reach the ground ,but this made the bike sit down too much at rear ,so as you suggest pushed the forks through 12mm handles fine and seems to balance the front to rear aspect . Still use Daytona raise boots and manage fine .Hope this shines some light on your problem .

Reporting back - I raised the forks by 9mm yesterday and set the rear pre-load to zero. With the weight of my 8 stone partner on the back I found I could again flat - foot it to the ground. Indeed it felt the same as with the standard 820mm seat. Went for a 50 mile ride and found no difference to the handling and steering.

Hedgetrimmer said:

Reporting back - I raised the forks by 9mm yesterday and set the rear pre-load to zero. With the weight of my 8 stone partner on the back I found I could again flat - foot it to the ground. Indeed it felt the same as with the standard 820mm seat. Went for a 50 mile ride and found no difference to the handling and steering.

Click to expand...

Two up, with zero pre-load - surely it will be bottoming out regularly & stressing the rear suspension unit & it's mounts??

It's unfortunate that we dont have 'bones' on the F series rear end, so if this is the way you want it, I would suggest you talk to a suspension specialist & get some height out of the rear end. Either a shorter unit or a re-spring. Maybe someone on here can clarify how the low chassis models achieve this at the rear.

I think you may find this link answers the question, a hyperpro rear lowering kit ................ https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=72&Ct=KA&SbCt=BA_15_72_KA_62

This will give you a 30mm height reduction & uses a stronger but progressive spring rate. Other vendors of similar products are available.

I hope this helps ................. KEN

ShakeyBMW said:

You could maybe take 20ml of oil out of ach fork which would effectively "reduce the preload" and ncrease the static sag of the forks -

Click to expand...

That's not true, you have an air gap which gets compressed before the load comes fully onto the oil....increasing that air gap is often a way of reducing the 'chop' riding over stones etc.

Timolgra said:

That's not true, you have an air gap which gets compressed before the load comes fully onto the oil....increasing that air gap is often a way of reducing the 'chop' riding over stones etc.

Click to expand...

So more air = more compression. Hence I said "effectively reducing the preload" as it has the same effect i.e. Increasing the sag. If it didn't, I doubt BMW would have used it as their technique to drop the front ride height.

Does'nt seem to be bottoming out although it is probably using most of it's 170mm of travel on some rough rural roads. We are only 18 stone combined weight so not loading the shock that much. I might give it 5 turns of pre-load to see it makes much difference to the ride height.