Springs 12 R1200R

[David R]

I have owned this bike enough to get a good feel for the suspension.

I set the rear sag at 1/3 the suspension travel which is supposed to be 140 mm which = 46mm.

Front is 41mm with no adjustment. One third of the 120mm of travel is 40mm.

All measurements are with me on the bike.

I have a couple of questions.

Does anyone get a true 120mm travel in the front? I put a Zip tie on the fork and for 4 weeks it never went
over 100 mm of travel. Even hitting some pretty good bumps.

Next is the rear spring. I loaded my girlfriend, side cases etc on the bike. Cranked the preload all the way
up and can not get the 46mm sag or even close. I am quite sure we were not up to the 500 lb load limit of
the bike.

We went on a weekend trip taking all "blue sign" county roads. It rode like a dream on all those back roads.

I am probably going to send the rear shock in for a slightly stiffer spring.

Comments appreciated.

[Woland]

I think the commonly accepted verdict on the stock suspension is that it's acceptable at best.

Basically I have three options for you:

1. Just ride the bike and don't worry about sag or suspension travel.

2. Live with the suspension as it is until its so so tired it has to be changed, then buy proper aftermarket shocks.

3. Buy proper aftermarket shocks now.

See how I made it all easy for you

For my bike I'm going for a combination of option 1 & 2, I've dialed in the shock as well as can be done, but @ 80k km's I'm mentally preparing to spend a boatload of money on Öhlins shocks in a year or two unless I change bike before that.

[deilenberger]

I have owned this bike enough to get a good feel for the suspension.

I set the rear sag at 1/3 the suspension travel which is supposed to be 140 mm which = 46mm.

Front is 41mm with no adjustment. One third of the 120mm of travel is 40mm.

All measurements are with me on the bike.

I have a couple of questions.

Does anyone get a true 120mm travel in the front? I put a Zip tie on the fork and for 4 weeks it never went
over 100 mm of travel. Even hitting some pretty good bumps.

Both the front and rear travel quoted by BMW on the R series bikes is "optimistic" - it discounts the rubber bumper on the shock shaft. The only way to get the 120mm travel would be to remove the bumper, which then lets the shock bottom out, potentially destroying it. In other words - BMW lies. 100mm is correct. I'd suggest about 30-35 MM sag with you on the bike and tippie toes balancing it.

Next is the rear spring. I loaded my girlfriend, side cases etc on the bike. Cranked the preload all the way
up and can not get the 46mm sag or even close. I am quite sure we were not up to the 500 lb load limit of
the bike.

Does this mean you're getting more or less then 46mm?

We went on a weekend trip taking all "blue sign" county roads. It rode like a dream on all those back roads.

I am probably going to send the rear shock in for a slightly stiffer spring.

Comments appreciated.

If the suspension feels better when loaded up (girlfriend and luggage/camping gear) - the springs are close to correct. They might be a tad on the stiff size. Dunno of sources for different rate springs for the stock shocks, but worth checking with EPM Performance - Klaus may have a source (and he has a machine to measure spring rates for unmarked springs.)

I'd suggest reading a bit at: http://www.eilenberger.net/Suspension/suspension.htm

I'd have to look it up on one of my spreadsheets - but the actual rear travel is NOT what BMW spec'd. It's less, by about 1" (35mm?)

[David R]

Thanks Don.

This is kind of what I thought about the front.

With the rear set at 46mm sag, I get 38" from the ground up to the top of the rear rack. The preload adjuster is on Normal.

With the preload cranked all the way up, saddle bags and the little woman, I get 36" to the top of the rear rack. Take off the bags and I get 37"

This is the only way I can measure it with me and the saddle bags on the bike.
Spring seems a little weak to me. BMW says I can carry
500 lbs. Yes I can with the headlight pointed up.

I am sure her and I with bags and stuff do not weigh 500 lbs.

I can buy a new spring installed for $110 p0lus shipping.

Once the snow files, I will.

David

[motoracer8]

The spring on the std Showa shock is 871lbs per inch travel and is pre loaded 10 mm.

The leverage ratio is 4 to 1

[David R]

The spring on the std Showa shock is 871lbs per inch travel and is pre loaded 10 mm.

The leverage ratio is 4 to 1

Thank you!

What spring do you have on the ohlins ?

David

[motoracer8]

David, when I recieved the Ohlins shock the installed spring was 1062 lbs per inch and a 8mm pre load, it was way too stiff, I fiddeled around with the damping adjustments and it did'nt make much difference. I called Ohlins and told them I had measured the spring and thought it to be too high of spring rate, they asked me to send the unit to them as it could have a probblem as they felt it had the right spring.

When I got the unit back it came with a note that said they put it on the dyno twice, had made an adjustment and said to be in good working order with it's original spring. It was still too stiff, too much compression dampning or the spring.

I ordered a aftermarket 900 lb spring and installed it with a 10mm preload, it's much better. I still think it has too much high speed compression dampning, I can only adjust the low speed on the unit I have.

The front Ohlins has been perfect, I messed with the ride hight some and played with the rebound alittle and otherwise have not had to touch it.

I'm going to ride it some before I mess with the rear unit any more, Ohlins said to send it back if I was unhappy, I may have them adjust the high speed compression dampning but for now I'm going to ride.

[David R]

Motoracer8 Thank you.

I think when I have the rear preload set all the way low, spring is too soft and letting the high speed compression do too much.

The result is the expansion joints (fast bumps) are way too rough.

When I turn the preload up to one past normal, the problem goes away. SO I think the spring its self is too weak.

Also since I cannot get the sag right with not a full load on the bike the spring is too weak.

I was thinking a 950 lb spring may be the correct compromise.

I will be doing this when the snow flies and there is no chance of riding the bike.

I appreciate the information.

Sometimes I think all the shock people want our bikes set up for racing. I want a good ride with control.

David

On my 2000 RT I put a shim in the stock shock spring to add a little more preload. It made the bike ride and handle much better. I may do the same with my 12 R1200R. Right now the front sag is 41mm. I get a true 102 mm travel on the front suspension measured at the forks with a zip tie. I would like 30% sag which would be 30mm. Perhaps even 35mm.

I never thought BMW suspension was crap, I just think it needs fine tuning to my taste like salt on food.

[motoracer8]

David, I made a 3/8" spacer for a friend of mine with a 08 RT, as he didn't want to spend the big bucks for a aftermarket shock. He would crank the preload to max and the sag was still a little low, with the spacer he was able to set the preload in the middle of the range.

The spacer just helped the ride height, I do think he could use alittle more spring for the load, or alittle more compression dampening.

The rebound is alittle soft on the Showa unit so more spring may make things worse.

Just my opinion and you know what that's worth.

[griffi]

[quote="motoracer8"]David, I made a 3/8" spacer for a friend of mine with a 08 RT, as he didn't want to spend the big bucks for a aftermarket shock....The spacer just helped the ride height...quote]

This is an interesting idea. I'd like to lower my R12R by an inch without spending a ton of cash. Could I get a 1/2" spacer for my rear shock and accomplish this? Would this create a handling or safety issue?

[David R]

Griffi,

The spacer would make your bike taller. Hyperpro makes a spring you may be looking for.

I added a 3.2 mm shim under the spring on the rear shock of my 12 R12000R

Before I had from 29 mm sag at max preload adjustment to 51 mm at minimum preload.

After the shim I have 45mm at minimum preload and 22 mm sag at max preload.

I also messed with the shock spring off.

The shock is nitrogen charged so it extends on its own.

With the rebound screw all the way out (S) it took 2 seconds for the shock to extend fully.
With the rebound screw all the way in (H), it took 9 seconds.

I have had the bike out once since. Seems to work great.
The front is next. I have a 3.2mm SS shim cut out ready to install. I expect to go from 41 mm sag to 35, at least that is my goal.

Think of it as a cat on its toes ready to pounce.

[motoracer8]

David, I have replaced the 900lb spring with a 800lb spring I recieved from Ohlins, I set the preload to 12mm and have about 25mm of sag with me on the bike, compression and rebound are Ohlins original settings. It feels pretty good now but I have'nt ridden it very far.

I'm going to round trip Phoenix in a couple of weeks, about 1800 miles, should be a good test.

Springs are easy to get for the Showa shock, they are a std 2 1/4" or 57mm ID spring. If I remember right the spring on the Showa shock was 180mm long with a 10mm preload. The probblem with the Showa shock there is no way to set the preload other than the hydraulic adjuster and they are a pita to take apart.

I spent several hours in a machine shop making a compressor. Remember thats a 850lb spring and you need to compress the spring about 1" to get the snap ring off, with the preload it's probbably around 1000lbs, I suggest you be very careful.

Ken G.

[David R]

Ken G.

I made the compressor out of automotive strut compressor. I don't have any problems using it. Everything is captured.

I went for a 300 mile ride yesterday. For the first half of the day I left the sag at 45mm. Then with out changing anything else, I turned it up 10 clicks which is 6mm sag so it was at 39-40 mm. I could tell the differnce. Rebound was at 1.5 turns out the whole time.

Anything over 45mm sag with me on it is a waste of suspension travel. This is why the shim. I measured the spring when it was off the shock. The spring is tilted one way a little so it was hard to measure. It was closer to 8mm preload. This plus the 3 I added makes 11mm.

Still need to get my passenger on and check the bike with max load. Its too cold here for her to ride.

Do you still have the 900 lb spring? I would try (buy) it.

David

[motoracer8]

David, I have the 900lb spring, it's a Hyperco, blue in color, 7" or 178mm long, 2 1/4" ID in as new condition.

I'd take $60 for it plus shipping.

Ken