Rear suspension

[j.newton1]

I recently read an article by an engineer who has motor cycles. He said that adjusting the rear shocks to a firmer setting ( pillion etc ) does not stiffen the springs. If you compress a spring by 1 inch the same force will be required to compress the spring 3 inches. The resistance of the spring stays the same regardless of the force put on it. What does happen is that by stiffening the suspension, you alter the attitude of the bike when sat on the road. If you raise the suspension settings you will put more weight on the front of the bike, the reverse is also true. To confirm this, when my scooter is on its centre stand the rear wheel is clear of the ground, if I wind the adjusters at the rear to a higher setting the rear wheel in now in contact with the ground. My scooter is fitted with 16 inch wheels but the bike has not felt as stable on corners as a motor cycle. I have wound the rear shocks up by about 1/2 inch, this has really made a difference when cornering, as I am more able to feel what the front end is doing. I have ridden bikes and scooters since I was 16 years old and I am now 71, but I have never read this explanation before. If you already are aware of the above, sorry to waste your time.

[Data]

j.newton1, good post. And definitely not wasting anyone's time. We all love this sort of more technical post. The article you read is correct, mostly. What it doesn't explain fully enough is the way the 'preloading' of the shock spring in that way alters the suspension dynamics. It alters not just the preload, but also affects by default the rebound and of course, as you say the ride height. So it has in actual fact, quite an effect. Once extra preload has been applied it also, in practice, alters the actual amount of initial force required to overcome the spring inertia to begin further compression. There are several dynamic reasons for that. So the ride will feel slighty stiffer. But in fact the spring will still only be capable of resisting in totality to the same force as prior to more preload being applied. Ignoring initial inertia, the spring resistance is constant throughout whatever the preload setting. In other words the springs total poundage load rating remains the same. It's just the initial force to allow compression to begin that changes. You can test this yourself by going to the softest setting and going for a ride. It'll be bouncier. Then put the suspension setting to it's hardest. It'll feel harder and bumpier. The thing that will affect the feel of the bike after applying preload is a slight increase in damping from the hydraulics of the shock. This becomes extended. Many are 'rising rate' and will automatically stiffen the damping further if more preload is applied. That's not the same for all bikes though. So in practice there are quite a few things that change to alter the suspension effect with more preload.

PS. if anyone can add anything to this, or thinks I've got it wrong, do chip in. But that's as I understand it from my misspent studies as a 'yoof'.

[burgerman]

So with settings on the Wing from 1 to 5, does that mean that 5 is the firmest, i.e with pillion, and 1 is the softest?

(Sent from a very non-technical mind!!)

[Data]

Yes, that's right. It will have the effect of firming up the suspension and stops wallowing on long sweeping bends. You may need to alter the headlight beams slightly if you jump from a low setting to a high setting as the back of the bike will raise slightly and point your headlights down a bit.

[burgerman]

Thanks for that Data, much appreciated

[michaelphillips]

Yes, that's right. It will have the effect of firming up the suspension and stops wallowing on long sweeping bends. You may need to alter the headlight beams slightly if you jump from a low setting to a high setting as the back of the bike will raise slightly and point your headlights down a bit.

i know my nexus is old, yet i really like the idea of a separate ride height with 14 different levels being separate to the single shock absorber, i have adjusted the shock to mid setting and also i use the ride height about in the middle as mixed road riding, if i adjust the ride height to the bottom the scoot sits lower and idea if you on motorways etc and if at the top setting the scoot is very agile, what i like is the ease of doing this, just twist the ride height to whatever setting you want within seconds.. not sure why all scoots with a single shock dont implement this type of setup

[spaceprobe]

Excellent past J.Newton and of course input from Data is always 1st class and welcome. Scoots and bikes tend to have a default setting on the midway mark and since all machines are different it is about experimenting. With the Maxsym I have found having it on the hardest setting 5 suits me best. This as slowed the rear bounce and reduced the amount of shock waves travelling up my spine. As stated the other change is to the front end which is now well planted and the scoot will now take corners superbly and its easy to see how those boys in Thailand get their knees down has they love to show you in their YouTube vids. Its a shame that when Frankie rented a Maxsym in Portugal he did not have the opportunity to adjust the rear shocks he may have enjoyed the experience more.

[Brubaker]

It's hardly rocket science adjusting a pair of rear shocks after a quick glance at the relevant page in the scooters rider handbook if needed. You can usually turn them by hand and it takes a few seconds, on the Silver Wing it's 3 for solo riding and 5 for riding with a passenger and a bit more pressure in the rear tyre. Nothing technical at all and who really adjusts their headlight beam when it means digging about inside the bodywork.

[Data]

That's a good point you make spaceprobe, about the front end feeling more planted. It sure does. In fact, by raising the back end it has the effect of reducing trail at the front, altering the steering sensitivity etc. And of course, helping to pushing weight forward on the bike by just a little.

Bru, we're not talking about rocket science, just the effects of altering the rear suspension, not how to. Sometimes altering the suspension will make a huge difference to the headlight setting depending how well they were set up in the first place. This is only really relevant if you ride at night out of town I suppose. But when I went from 3 to 5 on my Burgman the main beam was so low it slowed me considerably on country roads. It's a 5 minute job on the Burgman to bring it up again. Of course, if two up riding, it won't be required as the extra weight will raise the lights. But if you ride solo most of the time and like to ride in a spirited way and you use the bike in the dark, you may well NEED to raise the lights whether you want to or not. On your Wing, as with most scoots, it's easy, not much digging around.