spgtech

Hi Cobie, A strain gauge on the pinch bolt for the clip on should do it. I have a Starlane quickshifter that has a little metal doughnut about 5mm thick and 10mm in diameter which sits under the head of the shift arm pinch bolt where it clamps to the splined shaft on the transmission. The increased tension on the bolt is sensed and the shifter activated. No reason this type of sensor couldn't work for the pinch bolt for the replaceable handlebar tubes on most aftermarket clip ons. I would guess a strain gauge, a signal conditioner and a data logger. Calibrate with a spring scale. Should be pretty cheap and easy. -Sean

Give this link a try... http://www.redbull.com/cs/Satellite/en_INT/RBRC-Riders-en_INT/001242988798094#7 -Sean

To the OP; To me, it seems like you are asking how to set your braking start points, while admitting that your braking actions may be inconsistent. I'll be starting my 3rd year racing next year, and up until the middle of last year I didn't have braking start points. In many corners, I still don't. What I have been using are braking end points (my turn point). If my attention is focused down the track, and I know how fast I want to be when I get to my turn point, the control of speed becomes much easier to modulate. Granted, this doesn't have me using 100% braking all the time, but it does usually have me releasing the brake lever as I tip the bike in. The timing is much easier. Otherwise, you need to accurately pick your start point, consistently apply your brakes exactly at some pre-determined level, and hopefully do it perfectly to end up at your tip-in point. Unfortunately, you end up focusing on your braking application instead of your entry speed, and the final outcome is much harder to manage. Mid season, I added using start points as a gentle reminder on blind corners (still on the track). I see the start point, start applying the brakes to get the process rolling, and keep my attention focused on spotting my turn point and relaeasing the brakes just as I tip in. If the corner isn't blind I still don't bother with a start point. On bigger bikes I still struggle with over braking the entry, but mostly due to not riding them enough to build consistency. The higher straightline speeds makes me feel the need to shed a little more than necessary, and they slow down quicker than I expect. -Sean

Nice work Greg. Turn 4 caught me this year as well. Looking forward to next year already! -Sean WMRRA #76

I have been pretty impressed with the new gloves from Insurrection Racing. These will probably be my next set. I especially like the two piece knuckle armor and the Scaphoid slider. Also priced pretty well at $160 and very easy to move in. http://www.insurrection-racing.com/insurrection-race-gloves.html -Sean

Here is a recent video of a few laps on a Motorcycle. This should give the CSS crew and students an idea of what things look like up here. http://www.youtube.c...=2&feature=plcp -Sean

Pacific Raceways near Seattle. -Sean

Minus whatever the rear tire should be carrying for cornering loads...

A picture (thanks to Darren Beatty Photography!) from last weekends WMRRA racing. It shows shows the #1 plate holder, Eli Edwards, doing a bit of trail braking past the apex of Turn 5. Pretty amazing level of grip for not only the cornering loads but the stoppie as well. I guess for this instance, getting on the gas "as soon as possible" would involve waiting for the rear tire to touch down... -Sean

So Hotfoot, Are you actually running an O-ring chain on your Moriwaki? If not, degrease with whatever solvent you like, and (when Will isn't looking) grab some Silkolene lube and lube the rollers. When done, immediately wipe the excess off the chain with a rag and let the stuff thicken. Repeat after each track or race day. My favorite solvent these days is Zep Brake Wash which is alcohol based, cleans everything but doesnt damage o-rings or paint. Great stuff, I use it on everything. It is great for cleaning all the earlier chain ###### off of your bodywork, wheels, tires, boots, etc. -Sean

I agree with Will that there are a lot of bikes where the forks are being lengthened for increased trail and feel based on the riding style (in his example trailing the brakes). My example for lowering the back or the front were meant to compare the differences between ends of the bike. They will of course still hold true for raising one end or the other. In addition, choosing to raise or lower the bike as a whole will change CG and the resulting turn and transition quickness and fore/aft pitch moment, as shown in the link from ktk-ace. It all comes down to ballancing the effect you are looking for, with the other items which will be affected as a result of the change. There are very few settings on a motorcycle that act in isolation.

Higher swingarm angle gives more anti-squat. In other words, the tail section of the motorcycle lifts when power is applied. This ideally is roughly balanced by the rearward weight transfer, which helps keep the chassis stable, the suspension in it's sweet spot, and the rear tire firmly planted to the ground. -Sean

Hi Dave, I used to think that front and rear height adjustments accomplished the same thing as far as pitching the bike forward or back, and it does to a point but not entirely. So, what follows is probably an over simplification, but here we go... Say you want to quicken handling; If you drop the front end (slide fork tubes up in clamps and make the triples closer to the ground), you reduce trail, steepen steering head, shorten wheelbase, reduce ground clearance and REDUCE swingarm angle. So, in contrast, raising the rear to pitch the bike forward, the effects of steering head angle, and trail are the same, but you are raising ground clearance and INCREASING the swingarm angle. With dropping the front, the swingarm angle changes are slight, but with raising the rear, they can be pronounced. Swingarm angle is related to the anti squat tendencies of the bike and can have a pronounced effect on how well the bike finishes the corner (as does rake and trail) So, if you know what handling changes you want with steering head angle and trail, you can decide which end to use based on desired swingarm angle (increase or decrease), and ground clearance (making the bike taller or shorter). Hope this helps. -Sean

Well, on some bikes the rear is not bigger. Several vintage (race) bikes run equal tire widths, and last year a lot of 250 Ninjas either ran 110/120 or 120/120 combinations. Kinda fun when you can rotate your tires front to back and side to side. As others have said, lower horsepower reduces the need for large contact patch to reduce tearing. As for cornering loads, they seemed to carry the riders to the top of the podium with little trouble. -Sean

A 60 degree lean angle (of the CG of rider and bike), should net a 2G force compressing the suspension and a lateral force of 1.7Gs. A two G lateral force from tire grip alone, (instead of banking, train tracks, etc) would be pretty impressive for a motorcycle. And yes Eirik, I think the braking and acceleration force is limited by the high CG which causes the tendency to wheelie or endo, while when cornering the horizontal force is held in check by the downward force against the counterbalanced mass. -Sean

To rephrase what I think Eirik was saying: A given motorcycle (say a liter bike) can stop with equal or greater force than it can accelerate. This stopping relies on the narrower tire than the acceleration does. If the bike is stopping with only the front wheel on the ground, and accelerating with only the rear wheel on the ground, each example has the same downforce and it would imply that the amount of traction is not directly related to the contact patch size. -Sean

And it looks like there is a 2 day camp for July 16-17 at The Ridge! Awesome!

This new track is The Ridge Motorsports Park, and is in Shelton, WA. Two hours North of Portland, an Hour and a half SW of Seattle. Pavement just down on the 6th. Trackdays and Racing scheduled for Spring 20121. Maybe CSS will be willing to come up north for a West Coast tour. (Dylan? Cobie?) Video of a car running three laps in HD. Enjoy!

Information on The Ridge Motorsports Park can be found here: http://www.ridgemotorsportspark.com/masterplan/ Maybe with a new and safer track, CSS would be willing to come back up this way???

Hi Ozzyp, Pacific does have some shortcomings, there is no doubt. That said, it is a somewhat technical track which can be a lot of fun. Some trackdays (2Fast for one) and the race organization use airfence on the most troubling areas, and they have removed the tire wall outside of T2. Bringing a little awareness of places to be conservative in should make for a safe and fun day at the track. Next race weekeing is on Oct 1,and 2, stop on by and see what you think. You can also bring your bike and for $20 do "taste of racing" during the lunch break (register early). It gives you 20 minutes of time on the track for $20, not a bad deal. I am however looking forward to the new track in Shelton opening next year. They should have a challenging track with lots of runout and no airfence required. It has also been designed from the start with motorcycles in mind, has a separate drag area, camping facilities, pits with power, etc. I still love Streets though... can't wait to go back in October. -Sean

Photos from this last race weekend at Pacific. Great weather, great fun, and some personal best lap times! -Sean

pbrown, Just out of curiosity, what are you doing with the throttle before step 3? That incidentally, is what I was wondering about earlier; I would crack the throttle to balance the bike in step 2, but would then feel like I couldn't add any additional lean angle because I was already "on" the throttle. Not that it felt dangerous or was leaning too far, just that it was "wrong". Thanks in advance. -Sean

So, maybe I have been doing this wrong and I am certain I have some confusion on this. Several questions; First, does the throttle roll on mean 10%, 20%, 30%, 40%, 50%... ->... %100? If so, I have probably not done it right, especially on long flat sweepers. I would turn in, let the bike settle/reach the desired corner speed, crack the throttle and add it until the bike no longer slows and starts to slowly accelerate, transferring weight back. The throttle is held pretty constant for this part. For a long sweeper, this is pretty slow acceleration until the drive out; I would call it maintenance throttle. Towards the end, where the turn starts to open up, I obviously start the drive. Shorter corners, this all takes place quickly and the turn in, crack, maintenance, and drive all pretty much run together. Second, does the rule (strong discouragement) of "adding throttle and lean angle" apply to a constant throttle setting which is still accelerating the bike, or only to twisting the grip more? After my last time at the school, I happened across this rule for the first time. Afterwards, I would find myself in a corner, perhaps running a little wide, I would have plenty of lean available, but would think, "Cr*p!, I cracked the throttle already, I shouldn't add any more lean..." Also, in Keith's Soft Science book, he talks about cornering plans. In the World Plan, there is stated a need for throttle and lean angle adjustments throughout the corner. I am assuming each angle adjustment is not accompanied by a throttle roll off, that wouldn't be very smooth... If adding/adjusting lean angle while at maintenance throttle/acceleration is OK, then that certainly opens up some options for me. Similar to number two, is this rule primarily to discourage adding throttle during initial turn in? That I can understand is a good rule. Finally (hopefully), What about a series of turns (like 4,5,6 at streets), where you are accelerating through the turns? If you are pinned going from 5 into 6, while you technically aren't "adding" throttle, you are certainly accelerating and adding RPM's as you turn in. Thanks in advance. -Sean

For what it's worth, if you look at the horizon for a reference; you avoid the rider, tip in a little far, bring it back up, and then add the gas and walk the back end out. Once the back end starts to slide, the camera points in towards the inside of the turn, and you hear the throttle chop. After the chop, the camera angle abruptly changes as you get chucked off of the bike. I'm sure it's no surprise but while the cause of the initial slide is undetermined, the actual crash was caused by the throttle chop. Hope you came out of it OK. -Sean

Wow Hotfoot, talk about on point! I do have that book and I'll go back and read that section (and the rest of the book as well). Much appreciated. -Sean