BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

I bought a near new 2012 R1200RT SE to which the PO had fitted a Hyperpro lowering kit ie replacing the OEM linear springs with Hyperpro progressive springs. I was also given the OEM springs when I bought the bike. Unfortunately I didn't take any pics of the OEM springs but below are the Hyperpros.


The rear spring is on the left & the front on the right
These springs are the same length as the OEM springs (as they need to be to replace them on the struts) but you can see that the coils get progressively further apart. The first part of the spring is very soft and then gets progressively harder.
They lower the bike because the weight of the bike itself & the riders weight easily compress the first soft part of the spring. Thus laden the bike seat sits lower to the ground. Great in theory but absolutely terrible in practice! So much so that my wife - an experienced pillion - refused to ride with me.
I wasn't happy either. No amount of ESA fiddling could stop the bike feeling like a sponge, bottoming out and the centre stand scraping - and I don't ride aggressively!
Luckily I had the OEM springs and was able to get a m/c suspension shop to refit them. The mechanic said that he would refuse to fit a lowering kit to a 1200 if asked because they were potentially dangerous. They bottomed out so easily and the collar that fits on top to secure the spring could fall out if the bike were ridden over a crest at speed causing the spring to momentarily float.

Thinking of fitting an aftermarket lowering kit to your 1200 - don't!

Ian

Ian,

It sounds as if the PO was sold the wrong springs or he rode solo and was much lighter then you. Springs are rated by spring-rate, the amount of force needed to compress the spring XX distance. The springs should be selected to match your weight. And if you have a pillion passenger frequently - the combined weight of both of you and anything you carry on the bike (like clothing, camping gear, etc.)

Lowering a bike by lowering the spring rate is the WRONG way to do it. Ideally - you want to limit the maximum extension of the shock, while maintaining the minimum compressed length. Your mechanic may be a fine fellow - but BMW sells a lowered R1200R that does exactly that. IMHO, he's not being entirely clear. If what he meant was he wouldn't lower a bike by putting softer springs on it - then he's 100% correct.

Using a shorter fully extended shock means the bike is lower when the suspension is uncompressed, but the same distance from the ground when it is fully compressed. This results in less suspension travel - which generally means a higher spring rate spring is needed to prevent the shocks from hitting the fully compressed length in normal use. It also means that nothing will touch down any sooner than with the stock length suspension.

I'm on the fence about progressive springs. I have a full Hyperpro suspension that was built to my rather exact spec's - and then modified to make it even a better match to my riding style. That was possible because I'm a good friend of the US importer of Hyperpro, and he was willing to spend some time with me, and toss ideas around as to how to do this. I originally had the progressive springs on front and rear - and ended up with a progressive front spring, and a linear rear spring. I simply couldn't seem to get the preload correct with the rear progressive.

The first linear spring I tried was too soft, and the suspension felt harsh because of that (due to it bottoming out.) I went up one step in spring rate and things improved. I also very carefully adjusted the dynamic sag (the amount the suspension settles with my weight on the bike) to about 1/3rd the travel of the suspension. That made a BIG difference.

Just throwing softer springs at BMW's marginal shocks in the hopes of lowering a bike is really the wrong way to go about lowering a bike - and whoever sold you those did you a disservice IMHO. Dunno who the Oz distributor of Hyperpro is, but if you bought the springs through a dealer, it might be worth talking directly to them about what you want to achieve and how you use the bike. Correctly lowered - you can get a comfortable ride and your tootsies can reach the ground.

I do not suggest trying to lower an R12R any more than about 3/4" (which is what BMW lowers it.) Every fraction of an inch you lower it comes directly out of the suspension travel (on a normal lowered suspension - mine is a bit different, but we'll leave that for another day), and that means you're more likely to bottom out the suspension, making it much less comfortable. Note that 3/4" at the wheel is NOT 3/4" at the shock, there is a lever multiplication factor between wheel travel and shock travel (or stroke..) and it's different on the front and rear. Luckily, it's easy to calculate with a simple tape measure.

BMW greatly overstates the actual travel of their suspension, by at least 20%. The travel they quote would only be true if the rubber bumper on the shock wasn't there or magically became infinitely thin when the shock neared full compression. Problem is - the bumper IS there and for it to protect the shock - it can't become infinitely thin. This means you have less travel to play with (by lowering it and reducing the travel.)

I had the opportunity to ride a friends R12R that had Wilbers shocks on it that lowered it 2". It was simply awful and IMHO unsafe to ride. We swapped bikes - and he couldn't believe the difference. He ended up getting a normal height Hyperpro suspension since he didn't need the lower suspension (the bike was used and had come with it) and he was then a very happy camper.

For more on setting up suspension, I've condensed a number of long posts I made here some years ago - on my website. You can find it here: http://www.eilenberger.net/Suspension/suspension.htm

If you have any questions on suspension, I'll try to help as best I can. I'm not a professional, but I have spent a lot of time on multiple bikes figuring out what works, and what doesn't. The first lesson I learned was using a softer spring to lower a bike is not going to be satisfactory. I've been quite happy with my current suspension for about 60,000 miles now, and see no reason to change anything on it. It's lower and comfortable, and really gives a great controlled ride.

Best,

Thanks Don for your detailed reply.
It got me thinking - What are the different ways to lower a BMW and what are the Pros & Cons of each?

Ian

garr2 wrote:Thanks Don for your detailed reply.
It got me thinking - What are the different ways to lower a BMW and what are the Pros & Cons of each?

Ian

Hi Ian!

Wow - that could be about as long a reply.. I'll try to keep it brief, and if you have more questions, please ask:

1 - Low seat. BMW makes one. It is actually more comfortable in some ways then the stock height one - the butt area on it is better shaped for support, meaning your tail doesn't get tired or sore as fast. It's also narrower in front which means your legs are straighter toward the ground (effectively meaning they get longer) when you come to a stop. That's the upsides. The downside is - it won't be as comfortable as a custom seat (which tends to be taller and a bit wider) and it can result in cramped legs on long slab rides (I've been known to get some really bad "charley-horse" problems after riding lots of hours without getting off the bike and walking around. You can gain about 3/4" of leg with a low seat.

I'm currently running one I sent to Sargent and had them rework. It remains about the height of the BMW seat, but when combined with a FreedomAir cushion, it's probably fairly close to a stock height seat. The advantage of reduced width remains even with the cushion, and with the cushion and some LD underwear, I can ride 7-8 hours without excessive butt pain.

2 - Shortened suspension. It's what BMW offers. Theirs (and mine) lowers the bike by about 3/4". The way BMW does it, whatever you lower the bike is removed from the total suspension travel available. They do not reduce the minimum ground clearance, and the minimum compressed shock length remains the same. All that changes with BMW's is the maximum fully extended shock length. That works at the cost of a slightly harsher ride, since you need more preload in order to keep the shocks from bottoming out.

What I did was have Hyperpro (actually Klaus at EPM who is the US Hyperpro importer and an old friend) redesign their lower shocks to maintain full suspension travel. We did this after some rather extensive tests to make certain nothing "hits" when the suspension is fully compressed (by mounting the modified shocks to the bikes without springs, then compressing the suspension fully and moving things around so we were certain nothing hit.) This design ends up leaving the same suspension travel, which aids in comfort. The downside is reduced ground clearance if fully compressed. I'm not a 10/10ths rider. Some people think I'm more around a 4/10ths, I'd rate myself at 6/10ths when I'm feeling frisky. I've never touched anything down riding the way I do. If you're someone who regularly grinds footpeg feelers (hi Joe!) then this isn't the route to go. If you usually have 1/2"-3/4" "chicken strips" on your rear tire, it will probably work just fine.

My goals with my suspension (in order of priority) were:

1 - A comfortable ride. A harsh ride is tiring, and my butt just won't take it for too long. BTDT and I rode less because of it.
2 - A controlled ride. I want the tire to have good contact with the pavement, and the bike not to pogo or float, that requires the correct springs and damping settings to achieve.
3 - A lower seat height. I have 27" inseams on a long day. I like to be able to touch at least both toes down to the ground when coming to a stop. More would be nice, but toes work OK for me.

I've managed this with the use of both the modified seat and the modified suspension. So far I've put about 60,000 miles on the current setup, and can't think of anything I really want to change. I'm hoping to put another 65,000 miles on it - at which time I'll have to consider if I'm still capable of riding safely. My goal this summer is around 15,000 miles, and that wouldn't be possible or even thinkable without the modifications I made.

HTH, and feel free to ask about any specifics.