Real World "Rain Riding Survival Skills/Techniques Checklist"

[Gary J]

I'm not sure that I agree with this one if you're riding a powerful bike like my KTM 990. It's too easy to slide the rear tire at higher engine speeds both from giving it a little too much throttle or from engine braking if you let off too much. I don't have the same issue with my XR650L.

I understand Scott, and agree regarding different engine displacements and engine/bike types, having a unique "sweet spot" for the optimum RPM to have the engine working while going through corners in the wet.

Certainly on a torquey, powerful 990cc twin-cylinder machine like the KTM, my generic reference to being in a "lower" gear, to work the optimum RPM range, needs to looked at as it pans out into actual numbers for that bike.

The key is to have the bike in whatever gear will allow the motor to be working in an RPM that allows for the most even and linear degree of power application/control to the rear wheel (for "smoothness"!) by the rider.

You definitely do not want that gear selection, and resultant RPM, to be at a range where the power delivery on a particular bike's engine is abrupt or hard to smoothly modulate.

Just as a ballpark example of my vision of likely optimum working RPM ranges would be:

(NOTE: This is in reference more to riding corners on the backroads where you, the bike and the turns are the bulk of the focus. Though keeping the bike working in a way that minimizes the chances of overloading the front tire's grip in the wet is equally important, it should be noted that riding done when navigating around town and general city streets, requires a high focus and consideration on all the other factors around you!

- 990cc twin with 100+ HP and 60+ Ft/Lb of torque: ................ 4K-5K (?)

- 600cc inline-four: ......................... 6K-8K (?)

- 250cc inline-four - (Ninja 250): ................. 7K-9K (?)

These are just ballpark examples, for consideration and discussion.

One of the other reasons (besides the linear power control) for consciously avoiding riding with the engine way down in the low near-lug-it range, is that the increased rotational speed of the faster spinning mass of the bike's engine parts (crank, flywheel, etc) provides an increased amount of gyroscopic effect. This force helps to keep the bike wanting to stay upright on two wheels, in working against the forces that are wanting the tires to slide out from under it on the wet pavement.

The more forces that are working to propel the bike in the direction its tires are pointing (and the rider wants it to go), and the more force (gyro) at work trying to keep the bike from rotating on it's center (tires sliding out), the less the chances of the bike going down.

As with anything, if you personally find that something different works best for you, on your type/size bike, for your kind of riding in the wet, by all means stick with it! :thumbup

However I do have extreme confidence that the techniques I'm sharing on wet weather riding do have validity, and do work (if done properly). Learning by real world experimentation and testing of going in every possible direction (including the wrong way ....... OUCH!) on these things, and then letting the dust settle to what proved from the final outcome to work.

100K+ miles of extreme wet weather riding, while staying mostly upright, at some pretty "spirited for conditions" paces at times, during some of the worst possible weather conditions both on and off the track, on a wide range of different bike and tires, have provided that validation. :ride

 

[Razel]

One reason to go for the slightly over-inflated profile is that you are exerting more downward force against a wet surface with a slightly smaller contact patch, keeping you in better contact with the road surface.
If you can't move the water away, it will lift the tire off the surface. With the weight of the bike over a smaller area, you push the water away better.

Deeper tread will also give the water somewhere else to go as well.

 

[Gary J]

Where/how would one determine the optimum PSI (solo, 2-up, 2-up plus bags)?

Good questions Mehran. Unfortunately in the world of motorcycles there's so many different variables that it's really impossible to ever come up with any finite number that is the "perfect" tire pressure.

There's general guidelines where approximate PSI numbers can be derived by taking into consideration certain key factors. A few of those being:

• 1) The total amount of gross weight (rider/bike/passenger/baggage/etc) each tire will have to bear.
  
  2) The riding conditions to be encountered (dry? wet? hot? cold? freeway? backroad? racetrack?, etc.)
  
  3) The construction of the tire (bias-ply? radial? soft-carcass? etc.)

With regards to your specific questions on 2-Up an 2-Up with baggage, the amount of additional weight of those entities would dictate the amount of additional PSI to add. The closer to the "maximum gross weight" that is on a tire (the rear being the one of focus for the factors mentioned above), the more pressure added from that which worked best when riding solo.

Due to mostly rearward weight distribution (front vs. rear) of the added mass when adding passenger and/or luggage, the front tire generally doesn't need much adjustment. Going up anywhere from 3-8 PSI in the rear to adjust for the added load is generally the range.

For the rain, again the lack of much temperature rise, and the resultant reduction in the amount of garage vs. on-the-road pressure rise, still produces a need for bumping a few PSI up from warm/dry riding "cold" (in the garage before a ride) starting numbers.

In the example above, PSI went from 32 to 35 after some riding. Is the "delta" of 3 PSI a measure for "optimum" initial PSI? Or perhaps the 10% increase is a more universal measure? Or is it something else :teeth?

The amount (delta) of PSI rise is again totally dependent upon all of the environmental and riding condition variables mentioned above. The numbers can vary over a large range, where at the track a 20% pressure rise is not uncommon; all the way to in the rain where none ..... to little ..... PSI change can occur.

That's the reason "cold" starting pressures for trackday riding (in the dry/warm) are generally 4-6 PSI lower than starting pressures used for street use .... even if the same tire brand/model are being used. And the reason rain riding pressures have been found to work better when set in the higher PSI direction (at least from my personal testing).

 

[Gary856]

• BIKE /BODY POSITIONING:

o Less bike lean angle achieved via getting body position shifted an exaggerated amount off the inside (for turns)

Gary, what's your take on weighing the inside foot peg vs. the outside peg while turning in the rain? I've often seen contradicting opinions on this.

 

[Gary J]

Gary, what's your take on weighing the inside foot peg vs. the outside peg while turning in the rain? I've often seen contradicting opinions on this.

I think the term you're actually referring to Gary, is "weighting" of one of the footpegs, vs. "weighing". Not a big deal, but just thought I'd clarify as it seems to be an oft misused term.

As to your question on a conscious effort of trying to induce a higher percentage of force onto the outside peg, vs. the inside peg ("weighting") when riding in the rain, I'd say my answer would be "only to a small degree".

Because of the bike being consciously kept so close to a near vertical angle for this form of rain riding on roadbikes, unlike dirtbike riding where the bike is pushed under the rider ..... and they get their body on top of the bike, the formula is different. In the push-the-bike-under dirtbike technique, the lion's share of weight/force is directed down on the outside peg for slide control.

On the streetbike, as mentioned in the list items from the original post, the focus on a firm, planted foot/ankle contact with the bike is actually done at both legs. Anchoring to the bike via the heels, ankles, etc digging into the frame, heel-guards and such, on both the inside and outside peg areas, is my approach.

Along with this anchoring of the lower legs/feet to the bike in these contact areas, there is certainly some pressure/force being kept in a downward vector direction on the outside peg. So hence, some outside peg "weighting" is going on.

If the rear tire loses a bit of grip and does slip sideways when cornering, a conscious effort to direct a higher percentage of that combined inside/outside peg contact force ...... to the "outside" peg ...... does come into play. The objective being to resist the bike's tendency to rotate around its center axis (e.g. lose some of its near vertical attitude), as a result of the tire's outward lateral movement.

The high wear on the ankle bone areas, on the inside of both of my boots (and rain booties), is a clear indicator of the amount of tight grip that I consciously exert on the bike at those two contact points during spirited wet weather backroad riding. :ride

 

[UDRider]

Great post and clarifications. Thank You!

 

[HRCrider]

This is a great sticky thread. The only thing that I think would help a little bit more, and can be a big part of having fun, or down right miserable time. Is what would be the propper gear or most effective things to wear when going for a rain ride. Everything from footwear, gloves, suit, to what to put on the visor.

 

[Gary856]

Gary, thanks for the feedback on "weighting" the pegs.

The technique of wedging/locking the boots against the heel guards feels unnatural to me - need to practice that.

 

[Mel]

Gary J, thanks for putting up your great consolidated rain riding guidelines. I actually cut and pasted it and printed it out to use as a checklist. I can run a fairly decent spirited pace in the rain, but need to work on and fine tune some of the items in your guidelines to improve my wet weather performance. Looking forward to riding with you on your True Grit rides:thumbup.

Mel

 

[Banjoboy]

All great advise.
Hanging off is good as long as you can do it smoothly. (I know the cops think it's cool.) :cool
As far as tire pressures go; basically the more psi the better your tire will hold it's shape, cut through puddles & deep standing water giving better traction and control.
But if it's just cold and damp, (Light rain) less psi can give you a larger contact patch, more heat in the tire, and better grip. (As long as the tire isn't hydroplaning.)
Since I ride a real manly-man bike (660+ lbs.) I just keep 39f/41r year round, but do soften up the suspension. :thumbup

 

[Gary J]

Wouldn't increasing the tire pressure decrease the amount of contact patch? (image attached)

Arent' the "over" and "under" inflation example illustrations reversed form the headings in that illustration??

If I'm remembering correctly, exessive middle contact/wear is "over" inflation, and wearing on the opposing edges is "under" inflation. Am I missing something or are those illustrations reversed in that drawing??

 

[Lunch Box]

Arent' the "over" and "under" inflation example illustrations reversed form the headings in that illustration??

If I'm remembering correctly, exessive middle contact/wear is "over" inflation, and wearing on the opposing edges is "under" inflation. Am I missing something or are those illustrations reversed in that drawing??

You are spot on, Gary. The outer two tread examples should be swapped.

 

[Brown81]

I think it shows that white area as being the wear. Seems right.

 

[Gary J]

I think it shows that white area as being the wear. Seems right.

I thought about that, but if that were their intent in the illustration, with the white representing the "wear area" where rubber does meet the road, shouldn't the "correct" tire pressure example in the middle be shown as basically "all white" .... rather than nearly all blackish, as it is?

 

[UDRider]

I have a follow up question, about this.

o If bike starts to lose traction, in pushing the front tire, immediately apply additional throttle (light roll-on) to potentially recover by moving the greater load/force bearing to the rear tire

So my understanding is that if front starts to slide lightly rolling on the throttle might save it. I understand that it will unload the front, but how will it prevent the slide out? Does the bike straightens out? Seems like taking load from the front will make it more difficult to find traction again.

Thank You

 

[Gary J]

So my understanding is that if front starts to slide lightly rolling on the throttle might save it. I understand that it will unload the front, but how will it prevent the slide out? Does the bike straightens out? Seems like taking load from the front will make it more difficult to find traction again.

Let me see if I can help clarify on this Alex. If the resultant direction of force (for weight on the front tire) were totally straight up-n-down, with the tire pressing directly into the pavement, at 90 degrees to that surface, then more would always be better; even if riding in the rain. Because of this aspect in some ways a heavier bike can actually provide better traction in the wet, than a light one, in some circumstances.

Unfortunately as soon as the bike begins to take a turn, and the direction of travel of the bike is being asked to change, cornering loads begin directing force less downward, and more outward. The result being the more load/force pushing in this off-angle direction, the higher the probability of exceeding the available traction level, and the tire beginning to slide.

As an extreme example of how throttle can be used to aid in the reduction of front end slides in these slippery rain conditions, think of what would happen if a stunter were taking a turn while doing a complete wheelie (front tire not even touching the ground). Obviously problems with front tire sliding out on the wet pavement, while taking the corner in this manner, would not be a factor. :laughing

Well looking at the situation from a more realistic perspective where the front tire is on the ground, the same “less is better” applies, when it comes to the amount of outward directed force the front tire is producing.

For a worst-case example, if you enter a wet turn with the throttle totally chopped (off), a large amount of the combined weight of the bike/rider will be directed forward, and the outward component of that force will surely cause the front tire to exceed available traction, slide outward, and the bike to crash.

By having the optimum amount of throttle applied when first entering, and while navigating a wet corner, a greatly reduced amount of that combined bike/rider weight will be on the front tire, with the rear doing the lion’s share. The end result being the front tire not exerting outward force at a level that exceeds the current traction limits, and the tire not sliding out.

If the magic number for when the front tire will exceed current traction limits and begin to slide is say 31, if a rider detects the initial onset of the slip VERY early, and give the bike a bit more throttle to take a little more load off the front end of the bike to a point where that demanded force drops to say 28 (or below), the tire may regain grip in time to prevent the crash.

No guarantees once a front tire starts to slide in the wet, but it’s the best chance of a save. Of course the best action being a defensive one, in having good wet weather cornering throttle control in the first place, to never allow the traction limits of the front tire to be exceeded.

Hope that helps clarify things Alex.

 

[Brown81]

I thought about that, but if that were their intent in the illustration, with the white representing the "wear area" where rubber does meet the road, shouldn't the "correct" tire pressure example in the middle be shown as basically "all white" .... rather than nearly all blackish, as it is?

It is rather confusing, and not the way I would have done it!:laughing

 

[Gary J]

As a result of closely analyzing all of the most subtle nuances of things I was doing in controlling the bike during a couple hundred miles of "True Grit" rain riding today, I've added a few updates to the tips and techniques content within the original posting in this tread.

Please revisit if you have an interest in doing so. Thanks.

 

[UDRider]

Kewl, thanks. I saw you ride through STP parking lot today. How do you keep that bike so clean?

Actually I have a follow up question about front tire slipping. How do you detect the initial slip? When I was riding on 84 few weeks back I felt like the front just dropped from under me. I was able to save it mainly through luck and not going too fast by straitening the bike. I am assuming that is passed the initial feeling of it starting to slip?

 

[Gary J]

Actually I have a follow up question about front tire slipping. How do you detect the initial slip? When I was riding ....... I felt like the front just dropped from under me

I am assuming that is passed the initial feeling of it starting to slip?

Let's see what I can share for you on this question Alex.

---------------------------------------------------------------

First off, it's important everyone reading this thread fully understand that even the slightest amount of front tire slippage in a corner, when riding on wet pavement, carries a serious risk of a crash, no matter the skill level of the rider!

The fact that any front tire slippage (even the slightest bit) does occur, is in most cases a huge red flag of an already big "FAIL" on the part of the rider regarding effectively applying one or more of the traction control techniques mentioned in this thread.

I don't want anyone to come away from this tread with the misimpression that detecting a slipping front tire when riding in the rain, and then making some bike controls to catch it and save it, is a targeted aquired skill. Learning the skill to avoid ever having the slipping front tire in the first place, is the skill I hope to get other riders to learn from this tread (and the practice that follows, after now knowing what to do).

With that said, when things do go wrong, here's my take on the detection of front tire slippage.

Instantaneous detection is the key to a long-shot possible save. Just a few tenths of second will be the difference in an immediate slam to the pavement, vs. some quick adjustments with a butt pucker moment ..... and potentially continuing to ride on.

The key to the following detection aspect is "being incredibly loose on the handebars". Without that, this subtle change in the bike won't be detectable until things are so far gone that a crash is nearly sure.

What I notice when the front tire first begins to slip, are the following things:

• 1) The direction the front wheel is pointing (and subsequently the position of the handlebars) will suddenly be slightly more INTO the direction of the turn. Kind of like an auto-pilot where someone has slightly rotated the steering in that direction (caused by the reaction of the tire pushing outward).
  
  2) A recognition that the trajectory of the bike's line of travel suddenly changes, with the line just beginning to run wide. Bascially the direction you're looking through the turn and the direction the bike is just beginning to travel, are suddenly becoming different.
  
  3) A slight (unrequested) increase in lean angle of the previously near-vertical attitude of the bike.

All of the above are incredibly subtle changes, and require a lot of experience in riding in slippery conditions at pace to even begin to detect early enough to be able to have any chance of reacting and catching. Hence the prevention approach to keeping the front tire from slipping in the first place as being the golden rule! :thumbup

There are some extremely advanced rain riding techniques that can potentially be applied as a final bullet to try to save a front tire push that's gotten pretty far out there; but as that such techniques are beyond what's in the realm of 99% of those reading the information in this tread I will keep that in the archives for now.