Stuff I don't know: suspension settings

Random unrelated cool motorcycle picture
I may have mentioned before that I am a fourth-generation journalist. My great-grandfather was editor of a newspaper in Concho County, Texas, my grandfather was a sportswriter in San Antonio, my father was an anchorman in Austin, and I have worked just about every side of the field imaginable from North Dakota to California to Wales.

One of the little tricks you pick up with such a pedigree is the automatic ability to speak/write with an authoritative voice. When I talk about something -- pretty much anything -- I have a tendency to make it sound as if I really know what I'm talking about. Even when I really, really don't. I once managed to convince a friend that Jimi Hendrix was the original lead guitarist for Metallica.

It's a useful little trick that serves me well in job interviews or managerial situations, but it can backfire at times and result in my being totally ignorant about something that, really, would be helpful to know. A person will hear me speaking on a subject and assume I'm already aware of whatever fact they might have to contribute. Or, worse yet, I'll start to buy into my own nonsense, start to think I really am as knowledgeable as I sound, and I'll forget to ask questions.

I think the latter happened to me just a little bit in the past few weeks. I've been writing gear reviews and broad overview posts about given classes of motorcycle (eg. ADV bikes), and that has somehow accidentally given voice to that deep, dark Wes Siler that lurks within all of us and says: "I Know All The Things."

But then Bob Skoot happened to make a comment about his DL650 burning oil when being run at high RPM and I suddenly thought: "Oooooooooh. My bike does that, too."

Not too long ago I had discovered the CBF600 was a quart shy of oil. I filled it back up but I didn't take the time to ask myself why it was a quart shy. There are no signs of oil leaking from the bike, so where did it go? That is a good question to ask. If oil just sort of disappears from your bike, you really, really should understand the reason. You should understand why it goes and how fast it goes. Failing to do so could result in it being gone and your standing on the roadside in the middle of nowhere.

We could all stand to learn a little more...
But I didn't even think to ask those questions. Perhaps because, with the swagger of a whopping 2,700 miles of riding under my belt and a head full of words, I had unintentionally told myself I was a Knower Of All The Things.

I'm not. Not even close. I'm a newbie, and it's quite possible I will never know even as much as someone like Steve Johnson has forgotten (and I'm pretty sure he would tell you he doesn't know all that much).

The underlying purpose of this blog has always been about learning. So, I'd like to get back to that right now and ask you guys a question:

Suspension. What's the deal with that stuff?

According to my manual, the rear monoshock of my CBF600 has seven different settings. And the bike comes with a nifty little tool to allow me to adjust those settings. But I've never messed with them because I have no idea what I'd be trying to achieve. Nor how any given setting is supposed to affect the ride. When I try to read up on suspension settings I too quickly get lost in technical lingo and talk of sag and suggestions of having three blokes sit on my bike and blahblahblahblah white noise, and I end up needing a nice cup of tea and a sit down.

I am stupid, but I at least understand the concept of hard and soft. So, I'm hoping you can help me fill in the blanks:
- When I'm riding a typically uneven, pot-hole-laden British road my suspension should be _____.
- When I'm riding on the motorway at speeds up to 90 70 mph, my suspension should be_____.
- When I'm riding on a really curvy road my suspension should be _____.
- When Jenn joins me on the bike and we carry luggage my suspension should be _____.

I'd appreciate your help. Thanks.

Comments

  1. I don't know exact setting but I do know it depends on type of roads and your weight as well as weight of luggage and/or passenger when setting suspension; ie- preload and dampening. Geoff James over at Confessions of an Aging Motorcyclist blog send me a pdf on how to set preload and dampening and it did wonders when I changed the setting after I put the GSXR rear shock in my Gladius. I looked for the literature but cannot find it now.

    Check the forum for your specific bike and they'll probably walk you through it in detail. Or one of the gurus out in blogger land should be able to help.

    ReplyDelete
  2. Yeah, it's the preload settings. It's so you can increase or decrease the amount of travel in the shock, based on the weight you put on the bike, so that you don't bottom out. If you set the preload to maximize travel, and you're still bottoming out, you can always buy a stiffer shock spring.

    ReplyDelete
  3. PRELOAD
    ========

    Preload (ie: Spring Pre-tension) is directly related to motorcycle gross weight (ie: you, your clothing, passenger, luggage, dog, etc.) that will be loading down your bike when you are riding it.

    Preload should not be confused with 'stiffness' of suspension. It primarily affects RIDE HEIGHT - it does NOT affect the spring's 'stiffness'. Typically, the Rear Preload is to do with the amount that a rear suspension monoshock spring is put under 'Pre-tension' or amount of constant spring tension, off-load.

    On cheap motorbikes, the Front Preload may be fixed, ie: not easily adjustable. Regarding an adjustable Rear Preload setting, simply changing it to a lower number will not make the suspension 'softer' nor 'more comfortable' on bumpy roads. If anything, the suspension may 'bottom out' and then you WILL notice it!

    For Rear Preload, it should generally be set for a 'Rider Sag' or 'drop' of around 1/4 to 1/3 of the total 'Rear Wheel Travel' (measured at the rear axle nut) quoted in the bike's chassis specification. For example, if the 'Rear Wheel Travel' is quoted as 125 mm (4.9") then when you and your luggage, pillion, etc., sit on the bike, the rear of the bike should sag between 30 to 40 mm (1.2" to 1.6") depending on your own particular riding style (closer to 30mm (1.2") for track or aggressive sport riding, closer to 40mm (1.6") for long-distance touring or commuting).

    For 'ramp-type adjustment' rear monoshock systems, if 'Rider Sag' is too much, typically you would use the Preload tool supplied in the tool kit to increase the Preload number by turning the upper slotted ring of the monoshock clockwise to a higher number.

    Conversely, if there was not enough sag, you would turn the upper slotted ring anti-clockwise to a lower number. The number set would normally be the number aligned with a small metal boss on the side of the monoshock.

    If the Rear Preload is already on the very highest number and the suspension still bottoms out on bumpy roads or potholes then either lose rear weight, try to move weight forward or upgrade your shock from the standard stock.

    TIP

    To measure 'Rider Sag', you can get a friend to hold a steel rule against the rear wheel axle nut and a point on the rear mudguard directly above the rear wheel axle nut and measure that 'Rider Sag' which should occur when you sit down on the bike with your feet on the pegs and with one hand outstretched onto a brick wall to stop the bike falling over.

    ReplyDelete
  4. I believe your CBF600 has a 'Rear Wheel Travel' of 125 mm. With a default 'Rear Preload' setting of '3', you would generally leave it set at '3' even when taking your good wife to the pub. On the other hand, if you are thinking of bolting on ally boxes, a tent bag, a couple of water containers, a Camping Gaz stove, etc., and a pillion as well to go on a trek to the Sahara then you might consider notching it up to '5', '6' or '7' (the max) and checking that the rear suspension doesn't 'bottom out' on potholes. If it does then you'll have to upgrade the spring stiffness, ie: you would usually change the shock.

    ReplyDelete
    Replies
    1. That is exactly the sort of advice I was hoping for. Huge thanks!

      Delete
  5. Chris:

    Your first photo was taken in Vancouver on the lower road in our inner harbour.. I couldn't figure out why you came to town and didn't let me know ahead of time.

    another thing about bikes like the DL650. I have a long suspension travel on the front forks so the forks are not completely parallel when you go on uneven/bumpy roads, or when you turn into a parking lot onto the curb (uneven pavement transitions). I installed a Richland Rich fork brace and it made a big difference in stability on uneven roads. It also helped with wind buffeting on the freeway (ie: motorways in UK talk)

    Most often your front suspension is not adjustable. You may have to fill with a heavier oil

    See, I am like you. It appears that I may know what I am talking about but it's all "smoke and mirrors"

    bob
    Riding the Wet Coast

    ReplyDelete
  6. Nice post Chris. I have pre-load settings on my Sportster as well but don''t have as much adjustment as you do. I learned that I need to "stiffen" things up the first time Sherry rode two-up with me. Thankfully she forgave me for that first ride.

    I'm surprised that your wife hasn't said anything to you about how it feels when you go over even the slightest bump...but then again, maybe your factory pre-load settings are high to begin with.

    Cheers,
    Curt
    Live Free. Ride Hard. Be Happy
    www.curtcarter.com

    ReplyDelete
  7. I love this post because I relate to you so well.

    I know nothing, it seems, of the mechanics of the motorcycle. What I realize is that I tend to wave a hand, turn my face, and say, "Oh Honey, just make it work for me, OK?" in my best Marilyn Monroe voice. I've always been that way, until I had to learn.

    In my early 20's I had a Toyota Pickup that I ran ragged. I learned to work on that truck, changed the oil, replace the bumpers (I drank alot and crashed into things), fixed little things under the hood with help from my brother or a boyfriend, replaced my battery, things like that. I got pretty hands-on with that truck because I never feared that I would break it.

    This brings me to the point that I probably should start learning about my motorcycle. Just like you want to do. It's so easy to lean on Steve and his knowledge and just go paint my nails instead, but totally setting myself up for victimhood and failure. Ha ha ha!!

    I must say I've been incredibly blessed to ride with someone so knowledgeable and skilled. And you're right. He's so humble it would blow your mind. He had a riding buddy who he looked up to, Brian. Brian doesn't ride with Steve anymore, but Steve will always see Brian as the pinnacle of riders, I believe.

    Smooches,
    Sash
    SashMouth

    ReplyDelete
  8. Hi all, I'd like to add to Walter Cronenburg's 'tip' about measuring rider-sag on his very informative post.

    Whilst this method of measuring the amount of rider-sag is the most typical (and probably best) method, it should be noted that a completely-unloaded measurement needs to be taken first. This is easy if you have a centre/main stand, just pop the bike onto the stand and the rear wheel will be elevated, with a side stand you need a helper to tilt the bike onto the stand to elevate the wheel off the ground.

    The amount of rider-sag (sag with rider, or rider & pillion, on board) will be determined based on the unloaded measurement.

    If the unloaded measurement was 500mm and you wanted 40mm of rider-sag then the measurement with you on board should be 460mm.

    If you take the initial measurement with the bike's own weight on the wheel (static-sag), the bike will already be compressing the suspension unit to some degree, let's say 10mm for discussion purposes, so now you'll have a measurement of 490mm and shooting for 40mm of rider-sag would leave you at 450mm, this would be verging on too much sag and would make for a loose and sloppy-feeling ride.

    My motto for today is...one click back from too much is the right amount.

    I hope this helps.

    ReplyDelete
  9. I came across this dandy little PDF article from Bikers Oracle on setting up suspension as the season came to an end in October here.. have to try it as soon as Mother Nature farks off and quits dumping the cold/white stuff on us this "spring" in Atlantic Canada.
    Suspension Education Program - from T595.net
    http://www.bikersoracle.com/cbr600/forum/attachment.php?attachmentid=6277&d=1332336984

    ReplyDelete

Post a Comment

Popular Posts