Aftermarket Suspension Linkages
A lot has been touted and talked about with the aftermarket linkages. Originally available from Moriwaki and then from Kyle Racing the linkage alters the rising rate of the swingarm making its travel much more linear.
The OEM link by default is designed to carry both a rider and a passenger so having a more progressive curve insures that the bike can handle a much broader range of rider weights. Installing an aftermarket linkage ultimately gives the rider a better tuned suspension for riding solo and more compliance from the rear wheel which translates into more grip while on the throttle exiting the turn.
There has been a lot of misconceptions about the link so after 10 years of listening to rumors on the message forums I finally decided to come back to the old website here and set a few things straight:
1. The purpose of the link is to alter the rising rate of the swingarm period. It is true that it also increases the rear ride height by about 14mm, but this is purely a by-product of design not the original intention.
2. The link does work with the stock shock, but the stock shock is a piece of crap not even worth its weight as a boat anchor. You would be much better off with an aftermarket shock without the linkage than trying to use the linkage with the stock shock.
3. The link works best on the SP1 swingarm. It does offer positive benefits on the SP2 swingarm as well, but it really shines on the original 2000-2001 designed swingarm.
4. The link does not work as well with other brands of aftermarket shocks as it does with the Ohlins. I get accused a lot of being biased about this and trying to sell more Ohlins shocks, but I assure you that is not the case. I have tested the link extensively with Penske shocks and the contrast to the Ohlins is HUGE. It's not that the link is a detriment to the handling when using a different brand than Ohlins it is simply that it does not offer the same benefits as it does with the Ohlins. It took me years to figure out why, but I have pretty much narrowed it down to the fact that the Ohlins shock uses an internal top-out spring while the other brands of shock do not.
5. If you install an aftermarket link you will need a stiffer spring rate than you currently use on your Ohlins shock. One rate higher will be sufficient.
6. As you approach the rider weight of about 220lbs (without gear) or more the effect of the link starts to work against you. For starters it becomes increasingly difficult to find a spring stiff enough to compensate for the more linear rate of the linkage. Springs of that heavier rate have thicker coils and sometimes the larger coils tend to rub the inside of the swingarm and grind away at it, in some cases coil bind has been a problem as well. This effect is increased as the spring compresses and bulges out of its normal shape. Additionally due to the heavier rider weight riders will find that with the link they can get their rider sag numbers set properly while sitting static on a flat level surface, but when the bike is in motion the shock ends up riding in a different area of the stroke causing issues with the rear end squatting to much which in return causes the front end to rake out. Ground clearance issues can also occur as a result of this.