Answer seem obvious to me:
Increase the rear shock preload when loaded. Probably need a couple of clicks of rebound too.
Increase the rear shock preload when loaded. Probably need a couple of clicks of rebound too.
GSPD 100 wobble ( again )
- Thread starter Captain Black
- Start date
So MOT'd today , millichamp cocktail makes the front feel much firmer, I like it. Tyres at 32/36 psi and after 100 mile test ride its a dream to ride ( solo no luggage ), feisty lanes , low high speed, motorway high / higher speed hands off , sweeping left / right bends at motorway speeds hands off , brilliant runs true and no wobbles at the bars !! I'm going to check my suspension at weekend do some measurements as per the above chart, ( thanks red boots ).
Got a few questions as I've been to my mates garage ( cars but knows his stuff ) he reckons my back end off stand no rider looks low, but the free travel when you lift the rear isn't very much. Can I wind the spring down to lift the rear ? Does it matter if I've no free play lift pulling up on the suspension minus rider/ luggage ? As once I'm sat on it it will compress and allow some free lift or will I be hitting the end of the suspension travel ? My mate thinks the rear needs to come up and or the forks dropping in the yokes , only about half inch available on forks or they'll hit the bars . They are set currently at their full length, ie no fork showing above the top yoke but flush with it. I've softened my rebound as well. Maybe when I'd do the measurement as per red boots chart ( two man job ) that will give a clearer picture ? Does it matter where I measure to from the centre of the rear hub to a point on the bike ? If I'm measuring tat the same as red boots I'll ( GSPD ?? ) I'll get a better picture.
Jeepus its great solo , just want to achieve the same for pillion / luggage as well if its possible. I'd like to see another PD to see how high it sits at the back ...
I'll repeat myself... Your headbearings need adjusting. The old BMW twins have such a narrow "perfect" spot in the headbearing adjustment.
It's more noticeable on the GS models due to the long fork travel.
As little as an eighth of a turn can transform the handling.
Adjust, ride it, re-adjust ride it, continue until happy then leave it... usually needs doing again within 6 months if you're a stickler like me .
There's a special genuine BMW steering headbearing friction measuring tool.
I'll repeat myself... Your headbearings need adjusting. The old BMW twins have such a narrow "perfect" spot in the headbearing adjustment.
It's more noticeable on the GS models due to the long fork travel.
As little as an eighth of a turn can transform the handling.
Adjust, ride it, re-adjust ride it, continue until happy then leave it... usually needs doing again within 6 months if you're a stickler like me .
There's a special genuine BMW steering headbearing friction measuring tool.
Message received and understood.
I've got a breaker bar and the correct socket , do I need any special tools or just brute force and tighten the knurled rings a little at a time , test and repeat .
I won't be buying the friction tool I'll use my amazing sense of judgement in small increments until I achieve PD nirvana
may have a crack at my lads first as there's a bit of unwanted free movement in the forks on his basic.
Sean Kelly
Registered user
New, correctly adjusted head bearings eliminated my wobble courtesy of BMurr's bearing puller
airhead_eire
Registered user
+1 Steering head bearings. Had the exact same problem when loaded with luggage to the rear.
I'll repeat myself... Your headbearings need adjusting. The old BMW twins have such a narrow "perfect" spot in the headbearing adjustment.
It's more noticeable on the GS models due to the long fork travel.
As little as an eighth of a turn can transform the handling.
Adjust, ride it, re-adjust ride it, continue until happy then leave it... usually needs doing again within 6 months if you're a stickler like me .
There's a special genuine BMW steering headbearing friction measuring tool.
Its your accent Neil. The northern Monkeys can't understand you...SPEAK..SLOWLY
Beemerboff
Registered user
Depends on the bike, the GS has a grey plastic tube, comes in two lengths, stock and a 10 mm longer on for the PD.
A piece of plastic pipe around the same OD as the spring can usually be used , fine tuned with a few washers
Generally slightly softer at the front than the back works best, 60/55 mm for soft roaders, 50/45 mm for road bikes is a starting point , then fine tune from there, adjusting whatever end is easiest to adjust, as you are mainly setting balance, back to front.
When you are getting close you will find that an adjustment at one end makes both ends feel better.
Best to decide on what tires/pressures you intend to use and fit them first- you dont want to start again when you change to a different tire.
All figures relate to sag with the rider on the bike as that is how most folks ride them---------------.
A piece of plastic pipe around the same OD as the spring can usually be used , fine tuned with a few washers
Generally slightly softer at the front than the back works best, 60/55 mm for soft roaders, 50/45 mm for road bikes is a starting point , then fine tune from there, adjusting whatever end is easiest to adjust, as you are mainly setting balance, back to front.
When you are getting close you will find that an adjustment at one end makes both ends feel better.
Best to decide on what tires/pressures you intend to use and fit them first- you dont want to start again when you change to a different tire.
All figures relate to sag with the rider on the bike as that is how most folks ride them---------------.
Beemerboff
Registered user
Rob Farmer added 10 mm more preload to one of his GS's and was happy with the result
I have HPN inserts which give around 60 mm rider sag which is probably around the mark.
Rear spring is a 450 lb on an Ohlins with 16 mm preload, a couple less than Ohlins recommend.
I think Hyperpro list the special springs that are in the HPN inserts, if packing OEM gets you nowhere.
I have HPN inserts which give around 60 mm rider sag which is probably around the mark.
Rear spring is a 450 lb on an Ohlins with 16 mm preload, a couple less than Ohlins recommend.
I think Hyperpro list the special springs that are in the HPN inserts, if packing OEM gets you nowhere.
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