September 21, 2018 • Tim Technical Support Specialist

Gotta Bounce! But Under Control, talkin about suspension systems!

Welcome to this week’s tech talk at Venom Motorsports!

We are getting excited here at Venom. The snow is almost gone and we are looking forward to taking out the new x22 for a ride! The spring in Canada is a great time to test out our suspension systems on our bikes. We have pot holes here that could swallow a truck...scary! So we really rely on our suspension systems to smooth things out.

This is a good time of year to check your suspension system over and adjust as required. This will ensure that your bike is a good comfy height for you and also has the right amount of “SAG” to ensure that your bike handles well.

To help with your understanding of “suspension systems” please click on the various “suspension system” video links below. These will help you understand the different types of components in a suspension systems and maintenance guidelines.

Again a big Thank You! to my fellow “youtube” posters!

Keep in mind that this information applies to all of our bikes that have suspension systems! Uhmm your right that would be all of them LOL.

Time to bounce now and get right to the topic!

Tim...Do my tires affect the handling of my bike?

Your tires, front forks and rear spring make up the three main components of your suspension system. The sidewall area of the tire that bridges the tread and bead is very important in terms of the bikes suspension system. A small part of the tire, it is vitally important. It gives the tire much of its handling and load transfer characteristics. This is the part of the tire we’re talking about when we reference height, profile, or aspect ratio. Typically, a shorter sidewall yields a stiffer sidewall, which tends to flex less. To a rider, this means better handling and turning, worse bump absorption, and more difficult mounting. This section greatly contributes to the tire’s role in the suspension. That’s right — the tire is a suspension component! If you want a really soft comfy ride a large sidewall can help with that, but the downside is a sloppy feel when turning. Sidewall area is a bit of a trade off in terms of comfy ride verses performance in the turns.

Tim...How do my front shocks...absorb movement after I go over a bump?

When you go over a bump in the road that energy is transferred first to the spring to take up the brunt of the force and then to the oil inside the fork that acts as a shock absorber. The shock absorbing effect of the oil in the fork smoothes out the oscillations of the springs. If you had no hydraulic oil in the forks shock absorbers your bike would bounce for a while before coming back to a neutral plane. With the shock absorbing effect of the hydraulic fluid the amount of deflection or travel in the fork is greatly reduced. So after going over a bump the bike undergoes a very small deflection or movement before returning back to a normal “preloaded” position.

“Preloading” is an important concept as it referrers to the amount of tension the springs are under before you sit on your bike. It is a physical distance somewhere between 30 to 40 mm measured before and after you sit on your bike. Think of it as the distance the bike sinks as you sit on it, also referred to as “SAG”.

You can watch the “youtube” video’s below for a complete visual explanation of what “preloading” is and how it can be set.

Keep in mind that not all bikes have fork designs in which the “preloading” setting can be changed. On some bikes only the position of the triple clamp on top of the forks can be changed or adjusted for height only.

Some of the rear springs are also factory set and cannot be moved. This will be clear as the lock nut on the spring will be spot welded to one position only.

Tim...Can the rear spring setting on my bike change the height of the seat?

In a word...yes! However, it is a little more complicated than that. The rear swing arm is connected to the rear seat frame of the bike via the rear spring and shock assembly. So by adjusting the “preload” setting of the spring you can in effect change the height of the seat. Keep in mind that you are looking for a “preload” setting if somewhere between 30 to 40 mm. If the preload is too low the bike will feel very soft and sloppy. Sort of like riding a couch. On the other hand too high and the “preload” will feel very stiff...and you will feel every little crack in the road.

“Preload” than becomes an adjustment you can make yourself and is a very personalized adjustment based on the type of feel you want your bike to have..and of course the amount of “mass” you carry. Sometime we have too much mass for too little bike. The amount of “SAG” is crazy and the suspension bottoms out. To give you a visual, imagine a 300 pound person on an x15 pocket bike. That’s a lot of sag...lol so to speak.

You can also change out the existing spring and shock absorber assembly and refit to a comfortable size for yourself. It really is all about personal comfort. Some riders like to have both feet firmly on the ground at a stop light. Others are happy to lean to one side..or stand on the tips of their toes.

Tim...Is it easy to change the amount of “preload” on my bike?

Yes! It is a very straightforward sort of task. However keep in mind that most of our bikes to not have adjustable front forks. They are set at the factory. However, most of our bikes do have adjustable rear springs.

You can watch the “youtube” video below and follow the instruction if you would like to change the “preload” in your rear spring. Again keep in mind that you are looking for a comfortable ride that still allows you to feel the road. The feel of the bike is very important. This is very clear at higher speeds.

Tim...Have you found any good video’s on “suspension systems” for our bikes?

Yes! gotta love “youtube”, thank you fellow youtubers for sharing your videos.

The video’s listed below are some of my favorites. Just click on the link below!

How do the front forks operate?

https://www.youtube.com/watch?v=aOlDGxTN9vI

How to rebuild your fork.

https://www.youtube.com/watch?v=k884DfM2LsU

Motorcycle SAG adjustment.

https://www.youtube.com/watch?v=t4m4ahZLRMY

How to measure and adjust rear preload.

https://www.youtube.com/watch?v=TMDCEU98_9w

How to adjust Motorcycle Suspension.