Wobble: A non progressive oscillation. For example, due to an out of balance tire or a loose Telelever ball joint. Generally not dangerous but disconcerting.
Headshake: A progressive oscillation. Caused by an unstable geometry. Dangerous to the point of crashing. Fear inducing.
Headshake: This may be due to certain front-end geometries and weight distributions. (A similar phenomenon occurs on some bicycles. My Schwinn use to do this when coasting down hill. It would stop when my weight was moved back on the saddle or I started peddling.) A progressive oscillation is characteristic and occurs while coasting with little bar input and when riding in loosely packed gravel. It can be separated from out-of-balance tires. The latter causes a non-progressive wobble. However, if a bike has susceptible front-end geometry, a combination of the two may exist and separating things out may be difficult. The progressive oscillation is sometimes associated with certain tire types.
When riding at high speed, the front end of the bike is forced down by wind pressure on the front end (windscreen and fairing). When riding under power, this is partially offset by the pushing forces from the back wheel (rear suspension compression or lifting of the front end). However when coasting at high speed, there is greater compression of the front suspension such that the fork angle, relative to the pavement, increases and the resultant geometry is unstable. The progressive oscillation/wobble may get worse if the rider tries to hold the bars still to stop it. The best approach is to apply some throttle to level out the suspension or move your weight further back on the bike. Your weight relative to that of the bike will determine the effectiveness of the latter maneuver. The bike’s susceptibility to oscillation increases when you are traveling downhill as that puts additional weight on the front suspension causing further compression and a steeper fork angle. Additionally, using the front brake during front-end oscillation will further compress the front suspension, which further increases the fork angle, and may make matters worse (tank slap?). Using the back brake causes the opposite effect and may halt the oscillation.
Another cause of increased front end weight is the added down force applied by a taller screen at speed due to wind pressure (this may be considerable). This makes front end geometry steeper. Note that a heavy rider will be less affected by this than a lighter rider. To make up for this added down force, lower the back shock absorber preload and/or decrease back tire pressure and/or increase front tire pressure. Also note that running the tires at high speed will result in greater tire friction and heat and this will further increase tire pressure. Seasonal adjustments may be necessary. And perhaps even adjustments for altitude.
It is important to realize that the bike's high speed stability is affected by the system cases and front end wind protection. Non-progressive oscillations will occur at speed due to ambient air turbulence. Therefore, the GT version may be more susceptible to traffic induced turbulence than the RS. Furthermore, headshake may also occur at the same time so that separating things out may be even more difficult.
If headshake develops during high speed sweepers, this may be helped by keeping on the throttle during the curve. The logic is as above.
Some tire types may be more susceptible to headshake. The wheel/tire radius of some tires is more susceptible to change per given air pressure than others and furthermore, this change may be more disproportional between the front and back tires for a given tire type. Thickness and width of the tire may vary by type also and be front/back disproportional. The latter may account for headshake in high speed curves that some riders experience and others do not. Remember to roll on the throttle when going through a curve.
If you are experiencing high speed wobble or headshake, remember to make a log of each change made, make only one change at a time, and test only under identical conditions (speed, pavement, wind conditions, etc.). You may consider having another rider also test your bike, each time a change is made, and compare notes.
ABS and Washboard
Braking on a washboard road surface may confuse the ABS and this may result in poor handling/braking.
Gravel
Progressive oscillation occurs in loosely packed gravel with the K12RS (personal experience). Try less pressure on the bars and more weight on the pegs. Some recommend standing on the pegs.
Silicone Muffler Protection
Apply before and after trips (catch the muffler while it's still hot after a trip for best results). My aluminum looks better and better.
Removing the Stock Cover
See: IBMWR Heat Shield
See IBMWR K-Tech page.
Removal and replacement is not recommended unless there is significant damage to the existing cover.
Wudo Voodoo
Wudo sells a stainless steel muffler cover for $257. A polished muffler tip is also available.
Cleaning
Try Mother's Aluminum Polish. This also spiffs up the stainless steel exhaust components.
Warranty Replacement Muffler
This is stainless steel with a black tip.
After Market
See IBMWR K-Tech page.
The current Staintune sport and touring systems (about $1300), consist of a number of slip-together components. These have oxygen sensors, but not catalytic converters. Poor idling and backfiring with deceleration reported with the sport system. Modified systems are rumored to be in the works.
The Remus has a single slip fitting and costs less than the Staintune ($689). Sport and touring systems are available. Reported to sound totally cool and deep throated. No catalytic converter - - four into a collector box/pre-muffler and then into a single exhaust pipe. The cost is slightly over $1,000.