Front shock

[kiwiaudio]

Can the spring be removed from the front shock on the 1100RTs? To avoid the front end slamming on anything resembling a decent dip in the road, i'd sure like to preload the spring with a big fat washer if I could.

The shock has around 20K on it and dampening feels OK, it just feels undersprung !

[russell_bynum]

What is the sag up front?

 

I'm guessing that you've probably lost compression damping up there and that's why it's bottoming out. If you measure sag and it is within acceptable limits, then that's your problem. If sag is too much, then you might be able to improve the situation with preload.

 

I don't know of anyone who's ever done that, btw. But first things first...let's figure out what's really going on.

[kiwiaudio]

I haven't measured "sag" Russell, but i'll look in the manuals and see how thats to be done.

[russell_bynum]

I haven't measured "sag" Russell, but i'll look in the manuals and see how thats to be done.

 

Sag is basically how far the suspension compresses when you're sitting on the bike in riding position, in your gear, with your full weight supported.

 

Easy way to do it:

Put a zip-tie around one of the fork tubes. Get a helper to steady the bike. Sit on the bike in your riding position, with your feet on the peg.

 

Carefully get off the bike try to do it without compressing the forks any more than they already are.

 

Put the bike up on the centerstand and make sure the front wheel is in the air (put some weight in your topcase or have your helper lean on the rear rack.

 

Measure the distance from the zip-tie to the rubber dust seal on the fork. That's your "rider sag"

 

When you add spacers to the front shock, you're adding spring preload, which reduces sag.

[T__]

Can the spring be removed from the front shock on the 1100RTs? To avoid the front end slamming on anything resembling a decent dip in the road, i'd sure like to preload the spring with a big fat washer if I could.

The shock has around 20K on it and dampening feels OK, it just feels undersprung !

 

Mark, on the STOCK R1150RT front shock (strut) there is no adjustment for compression dampening & the spring is not removable (at least easily or handily)..

 

You have a couple of options none of which will gain you whole lot..

 

The first & easiest is to change the front fork oil & when refilling add a couple of ounces extra.. That decreases the air space in the forks at full compression so the pressure build will be higher on compression.. Not a lot of extra force added but some.. Also be sure the air is neutralized at full fork extension.. Basically remove the top bleed plugs at full fork extension & allow the internal fork pressure to equalize with outside atmospheric pressure.. That will make the forks build pressure on compression (act like air forks).. At normal ride height the air in the forks adds very little spring load but as the forks go into compression the air pressure builds & adds spring load with an added slight rate increase to go with it.. Again not a lot but the above kept my 1100 from bottoming out on sharp edged road dips..

 

Another option would be to machine a spring spacer that looks like 2 overlapping horseshoes,, then compress the spring up the shock & install the double spacers between the spring & seat.. Lot of work & you should FULLY compress the shock/spring to make sure you aren’t then getting coil bind..

 

You could probably with some work grind the lower spring seat welds then weld on a tab & make the lower seat adjustable like the GS was.. (again lots of work for the gain involved)..

 

OK now a real quick thing to try.. Seeing as the upper fork bleed screws are so difficult to get to - put the bike on the center stand,, then make sure the front wheel is off the ground,, then lubricate a .003” feeler gage & slide it between the fork dust shield & fork seal (carefully so as to not damage the seal) ,, slide it all the way in until it slides past the seal top a little ways.. Then let it sit for a few minutes.. (do both sides).. That will allow more air to enter the forks so there is more air in there to compress at full compression.. If your forks have equalized at ride height (happens if bike is stored on the side stand for extended periods) this will help some (not much but possibly a little)..

 

Other than that you are looking at a new (aftermarket) shock/spring assembly or possibly a police unit..

 

Twisty

[kiwiaudio]

Ah Twisty, - always thinking !

Reminds me of the old days when we used to install tire valves on the top of our dirt bikes front fork caps and add a couple of PSI.

Hmmmmm ................. I wonder ??

 

By the way Russell, my sag using your method is 1 5/8 inches. I weigh 210, which although more than it should be (aren't we all !) is not a heavyweight by any means.

 

What do you think ?

[Davis]

That sag is only about 1/3 of the total travel of 4.72 inches.

I'd agree with Russell, it's not lack of preload, but compression damping that's root of the problem. I don't remember if Lindemann rebuilds the front stocker or not. I'd be looking at a quality aftermarket shock which is readily rebuilt when needed.

[russell_bynum]

That sag is only about 1/3 of the total travel of 4.72 inches.

I'd agree with Russell, it's not lack of preload, but compression damping that's root of the problem. I don't remember if Lindemann rebuilds the front stocker or not. I'd be looking at a quality aftermarket shock which is readily rebuilt when needed.

 

+1

[Woodie]

<lots of good suggestions snipped>

Other than that you are looking at a new (aftermarket) shock/spring assembly or possibly a police unit..

 

Twisty

What is different about the police units? Does this mean I have some sort of option for adjusting mine?? <hopefully!>

[T__]

<lots of good suggestions snipped>

Other than that you are looking at a new (aftermarket) shock/spring assembly or possibly a police unit..

 

Twisty

What is different about the police units? Does this mean I have some sort of option for adjusting mine?? <hopefully!>

 

Woodie, I’m not really sure what the difference is in the authority shock.. The authority bike carries more weight so I’m pretty sure the spring load would be higher & possibly the spring rate might be a bit higher.. Possibly the rebound dampening would also be a bit more firm to handle the higher spring rate.. BMW is not to forth coming on their spring & shock packages so without actual data from BMW it is difficult to know..

 

Twisty

[kiwiaudio]

I tend to agree with the compression damping diagnosis now that I spent a little more time feeling the bike out. This shock has about 20K on it though. Should it have lost its damping already? No wonder everyone talks about aftermarket shocks if this is the case.

What is the least expensive shock worth buying ?

[Davis]

While 20k is a little low, 25-30k is about the life of a shock before needing service. It isn't just the OEM's, quality aftermarket shocks will need to be rebuilt at about the same interval. The key is they are serviceable unlike the OEM's.

 

As far as aftermarket brands, Works is probably the cheapest; Ohlins probably has the best resell; Klaus is a really great guy that knows his stuff, but Hyperpros haven't been imported very long so there is little data available on them; Wilbers are on the same quality as Ohlins and were slightly cheaper when I got them from Klaus (Klaus is no longer the Wilbers distributor, they are now sold by MaxBMW among others).

[kiwiaudio]

Thanks Davis.

How do I contact Klaus ?

[Davis]

http://www.run-n-lites.com/index.asp

 

877-786-6543