For those who are building cafe racers, brats, or any of the numerous other styles, a bikes suspension can play a huge part in the final performance of your machine. In fact, suspension ultimately is one of the most important factors in how your bike performs. Sure, a smoking fast engine is great, but if you are afraid of your bikes handling you will never get take advantage of that sweet horsepower. And while sorting electrical issues or fine tuning carburetion is a great way to make your bike work well, suspension is what keeps your tires on the road and and helps prevent your body from close encounters of the asphalt kind. Moreover, if you get out for a ride and find yourself uncomfortable, whether that is from a physical discomfort or a mental one, your riding experience is going to suffer. But suspension is generally misunderstood, especially in the sense that people are more often than not of the opinion that throwing money at it is the only way to improve it. That simply is not the case, and in this article I am going to go over some of the ways we can do refine our suspension and the ride quality of our machines without the budget a modern MotoGP team.
Suspension is important, this is true no matter the age of your bike, but with that in mind, there is generally a lot that can be done to your suspension that can be done in a budget friendly way. This may especially be needed if you are riding on twenty or thirty year old components and even more so if your bike has components that are even older yet. Some of the advice here is going to apply more to older bikes than it is to new ones, as older bikes generally have more to gain from these low level changes, though the principals found here a fundamental and as such should be considered no matter the age of your bike.
Probably the cheapest way you can improve your suspension is via rigorous setup. While many bikes, especially older ones, have fairly rudimentary adjustments there still remains a fair amount of improvement to be found in the details. Let’s start with basics, and by basics, I mean the standard items you should be inspecting and maintaining as a part of your normal maintenance schedule. Your swing arm should be greased properly and you should flush your fork oil regularly. If your fork seals are leaking, they should be replaced, this can usually be done for less than $50 if you can do the work yourself. If you do not know how to service your forks, find a forum that is specific to your bikes make and model and I am willing to bet that someone has already cooked up a tutorial for you. If you have any questions about how long it has been since the swingarm bushings have been checked, it is time to check. Leaving items unquestioned can mean that there is room left for improvement.
Another basic and often overlooked aspect is wheel alignment. That’s right, wheel alignment is critical on your motorcycle. Most DIY mechanics just eyeball wheel alignment either by checking that the tire tire is centered inside the swingarm or by using the hash marks on the swingarm at the adjusters. Believe it or not, your 30 year old frame, swingarm, and components may not be all that straight. So its best to check it, if only once to establish that you can truly rely on the hash marks. And if your bike is newer, it stil isn’t a wise move to trust those hash marks. Checking your alignment is fairly easy, here is a great tutorial on how to do it.
Checking the alignment establishes whether or not those hash marks are correct. If they are correct, it is okay to trust them in the future. If they are not correct, you must align the rear wheel properly, and then maintain that alignment even after chain tension adjustments. That just means you will have to move both of the chain adjusters the same amount during chain tensioning. In addition to properly aligning your wheel and helping your bike ride better, aligning the wheel also gets your chain to run nice and true across your sprockets and will increase the life of the those components. That makes checking wheel alignment an even better time investment.
Remember when I mentioned swingarm bushings above? The topic of slop or free play is here again, it’s an important issue! You can vastly improve your suspension by removing unwanted slop or movement in components. Older components are especially prone to have a lot of wear from years of use and abuse. At the rear of the bike, one of the easiest and cheapest ways to do this is to fit a new set of swingarm bushings or bearings. Swingarm bushings are there to allow for low friction movement of the swingarm. Many bikes, especially those from the 70’s and 80’s came with some damn cheesy swingarm bushings too, so if your machine is from this era you should take note. As the bushings wear they allow the swingarm to move not just rotationally, but you might also get lateral movement. This lateral movement actually translates into a rear tire that steers and misaligns. If you had issues getting good wheel alignment using the method described before, then it is time to look at your bushings.Moreover, can sloppy bushings lead to some rear wheel steer, but it does so unpredictably. This means that the bikes alignment can change dramatically when you change inputs such as going from throttle to brake application.
Checking for slop in the swingarm can be as easy as raising the rear of the bike off the ground and then manually attempting to pull the rear wheel side to side, though in some cases you might want to disassemble the swingarm completely and inspect it closely. For those out there with a center stand, there is no reason not to check for lateral play in the swingarm as it’s as easy as putting your bike up on the stand and trying to wiggle the wheel from side to side. If you find slop, it’s time for new bushings or bearings. For many bikes this upgrade can be done for under $50. Again, consult the forum that applies to your bikes make and model and there will likely be a nice tutorial on how to perform the parts swap as well as the best suppliers for the parts you need. There are also roller bearing upgrades for many bikes with bushings. Roller bearings, while they generally reduce friction, they also tend to be higher maintenance, slightly less precise (can have more slop even new), and generally are more expensive than bushings. Keep that in mind when shopping.
Moving on, another major spot for slop on your rear suspension can be found in the eyelets or the clevises of your coil over shocks. If you running around on 40 year old shocks, there is a good chance that the rubber bushings are long in need of replacing. This extra movement creates motion where your suspension is no longer damped or sprung. That of course has many ramifications, but again, uncontrolled movements are a bad thing. If these shock bushings can be found, go for it, but more often than not this scenario is unfortunately one that requires new shocks all together. That said, there are many great options out there today, they are spread across the gambit price wise.
At the front the bike, you can find unwanted play in several places. The stem bearings are highly loaded and can get dirty which cause nasty feeling steering but bearing slop and eventually wheel misalignment. Tapered roller bearing kits are generally less than $35 for your vintage bike over at AllBalls.com. Tapered roller bearings are great because they take advantage of the taper to reduce slop, something those old loose ball bearings do not do well. That said, just cleaning and properly setting up the old ball bearings can make a huge improvement too, so assuming the bearings and races are in good condition you might be able make this upgrade for free. Finally, take a look at those wheel bearings. While wheel bearing failures are surprisingly low, but new bearings reduce rolling resistance and further tighten up the components at the front of your bike. Should you find that the bearings need replaced, you can usually get them for less than $30.
Fork swaps are a popular though somewhat advanced way to upgrade your front end. Many guys lust after modern upside down forks and huge brakes. When done right, these can indeed offer a significant upgrade. Unfortunately, doing them right is often very expensive and timely. Since transplanted forks come from bikes with different geometries and weights you end up changing springs. Once this is done, you are then facing valving changes, and beyond that many other parts might need worked on as well. If you wish to get better forks from a more modern bike it is first best to do some research on a forum that supports your specific model of motorcycle. Usually you can find common swaps that are not only an upgrade but can be done easily and cheaply. For example, I swapped FZR600 front end onto my RD350. Having keenly watched Craigslist I got a stem, triple clamps, brake calipers, rotors, and fender, and I only paid $100. Replacing my pitted fork tubes to get my stock forks in working order would have cost $200 or more. It is important to note that I had to do the machine work to adapt the forks to my frame, but the fork stanchions grew 4mm in diameter, and I got a modern front caliper and rotor. It was a big upgrade, especially in the brake department, where the modern rotor saved me several pounds and added significant stopping power. Swaps like this are common and with a moderate level of mechanical ability can be done with low expense. Or in my case, I actually saved some cash!
There are many other small refinements that can be made. For example, removal of friction in your suspension can make a huge difference. In fact, many large racing teams have found in testing that simply lubing mounting/hinge points with a light oil can provide one of the most significant improvements to a suspension system, so take note of those bushings. You can get pretty extreme here, and I’ve glossed over many of the finest details, but keep this in mind when you are exploring the health and condition of your suspension. Moreover, there are many fine details to setup, sag, compression and rebound damping, and spring rates, and they are all important. However, once you start adjusting those you are looking at spending more cash. So for the sake of this article they have been left out. Feel free to post and questions or comments below. Suspension is a growing and evolving topic and for us DIY guys but by making sure that we closely check our suspensions most basic variables we can generally improve the performance of our bikes drastically.