I learned something at Sears Point last round – I’m not that old or washed up.  We went into that weekend with four big problems and raced with virtually no Sears practice since August 2011, yet we ran only 1.5 seconds off the FP pace and came home with a win in Open Twins.  You ask me that’s a good weekend, especially considering we were slowed by lack of rear grip and hellacious chassis wobbles coming up the back straight.  But going fast despite our issues is not our goal – solving them is.  And while we did fix 50% of our issues (rear tire coming off the ground under braking, bike turning at too low mph), really we made no headway at all into solving the lack of rear grip or chassis wobbles.  Sure we left Sears with plenty of ideas, but the problem was many of these ideas were conflicting.  Also some of them, I felt, could cause worse problems in other areas than the ones they fixed.

One interesting thing we tried at Sears was padding the rear of our fuel tank – to push my weight rearward.  This was J.J.’s idea, and while I liked the thinking in it, it didn’t seem to change anything out on track – but the “rear-weight” seed was planted.  The next idea we considered was lowering the rear ride height to the bottom of it’s stroke, again, to put more weight on the rear/get the rear squatting, to improve rear grip.  This idea I did NOT like.  We have tried lowering the rear of this RC8R a few times now.  Each time I ride our bike like this I only last half a lap and come back in – it is terrible.  Ruins the whole character of the bike.  It steers wide, rear traction is awful, my feet drag on the ground, and it turns in lazy as hell.

We left Sears undecided on what to do next.  I wasn’t satisfied with this so I stepped outside our typical box and called our good friend Doug Chandler.

Doug Chandler Cagiva GP

Photo by Bill McMillan

Doug Chandler is still blazing fast on a motorcycle today.  He rides, he teaches, he is still very much into roadracing motorcycles.  But that’s not why I drove our bike down to his bicycle shop in Salinas.  There is another element to DC10 which most people don’t know about.  His looks are deceiving – easily you can picture him riding a horse to work, wearing a cowboy hat, and chewing tobacco all day long.  With this image you might also assume he’s not the sharpest marble in the pile.  And you would be wrong.  Easily Doug Chandler is the most unique thinker when it comes to bike/chassis/suspension setup that I have ever met.  Never in all the questions I have asked him has he answered in a way even relating to anyone else I have asked the same question to.  Personally I find that fascinating.  And once again that fascination of mine brought me to his bicycle kingdom seeking setup advice for our race bike.

Holding our RC8R’s grip in one hand Doug looked up at me and started asking questions.  I said it wallowed violently side to side.  He asked “In a straight  line or leaned over?”  Right away no one else ever asked me this.  I said, “Leaned over, hard on the throttle, going fast.”  He asked, “Turning to the right, to the left, or both?”  I had to think about this one, as yet again no one had ever asked me this question either.  I finally answered, “Hard exits turning left only.”  He said, “I bet your front wheel is set out to the right, out of line with your rear.”

You see why I drove down there yet?  Who talks like this?  Who says these things?  Who knows this stuff without ever riding the dam motorcycle, measuring the dam motorcycle, or even seeing it go..?

Just then I told him, “Well we do still have a problem with our triple clamp off-sets.  The steering stem holes are not quite perfectly in line with each other, which aims our front wheel out to the right.  This is a problem we are working on fixing by next round.”  He looked back at me with a crooked eye-brow and said, “Yea, get that fixed..”

Here is our problem with our off-sets:

Line up perfectly on the outside, as you see here the way they sit inside both the upper and lower triple clamps….

….the inside holes for the steering stem are actually not in line, which aims our front wheel off to the right

So there, this is good news.  Possibly now three out of the original four problems we have with our bike will be solved by next round.  Now on to the fourth problem, rear tire traction..

Like I said, Doug is a fascinating guy.  Once we started talking about rear grip he proved his worth again.  He asked me about front grip, “What’s it like mid-turn?”  …try to follow this now:

GoGo: “I thought we were talking about rear traction.”

DC10: “We are.”

GoGo: “So why are you asking me about the front mid-turn?”

DC10: “I’m not, I’m asking you about the rear.”

GoGo: “Doesn’t sound like you’re asking me about the rear.”

DC10: “Answer the question.”

GoGo: “I hate you.  …But anyway it feels great.  …Except for when I lose the rear a bit mid-turn, like in turn 2 at Thunderhill.  When I do that and I have to make a correction with the throttle, maybe to back out of it just a hair, I instantly lose the front for a bit.  It’s weird yet exciting, makes me feel like a superhero.”

DC10: “Why do you think you’re losing the front mid-turn?”

GoGo: “I don’t know, that’s why I came here.”

DC10: “It’s cause you’ve got too much weight on the front.  Which is also why you’ve got no rear grip.  You need to move the weight back.”

 

Right at this point my brain starts to hurt.  “How the hell are we supposed to do that – move the weight back?”

DC10: “Move your rear axle forward, change your front off-set to move it forward too, keep your wheelbase the same – if you like it how it is.  To me it seems long, which also puts more weight up front.  You might try shortening the wheelbase up a bit too..”

 

So there you have it, a man goes to a bicycle shop in Salinas to sort out a roadrace bike set to run next AFM round some 300 miles away.  How about that for a WTF moment?

Here is Doug’s idea in a graphic, on how to move our bike’s weight rearward.
For reference, the “Frontheavy” version is how we’ve raced our bike since day one.

 This article will remain a work-in-progress.  We are set to test these changes, AND also our new race bike for the second half of this season, up at Thunderhill around the 23rd of this July during a Keigwins track day.  DC10 has offered to come help us set both bikes up, experiment, and test.  All I have to do is find him one student to take his riding school that Sunday, July 22 2012, and he will make the trip.  It’s a good deal, he works with you all day, gives you video and tons of attention/help.  If you are interested please email me “gogo at gotagteam.com”.  We’ll have a go-fast-party!

 

  1. Mattacme says:

    Amazing guy, such great questions. Also, WTF were you thinking with those steering stem offsets like that? Can’t wait to see you ride it once it’s set up comfortably.

  2. GoGo says:

    LMAO… That was our first set of off-sets. The second set, which we have in there now, are also out of alignment, only not as much. What can I say, this is a work in progress!

  3. mattacme says:

    With Ducati twins, particularly the old air heads, we had a hard time getting the weight balanced because we couldn’t move the front tire back far enough – it would hit the horizontal cylinder head (not good). We were always trying to get more of the balance to the front and so the only way left to do it was to extend the swinging arm, which of course increased the wheelbase. It worked but like everything, at a price. I found a compromise between ideal traction characteristics and turning ease to be the best to live with. It was never perfect (and that’s not even discussing the spring rates or dampening) but it was really very rideable, which is all you can really ask for. I am certain that you can find a happy medium and then just ride that thing like you stole it, instead of wondering how high it’s going to toss you like a dwarf out of the next almost highside.

    Best of luck Gogo! It looks like a few of my son’s pals and I will invade your garage at he September 1-2 Sears round.

  4. GoGo says:

    It’s actually pretty funny how those “off-set” off-sets were discovered to be off-set. The guys at the shop installed them, I guess it was a mistake to assume they were straight? Anyway the bike was so hard to ride last year. Totally f’d with my head – I was trying so hard out there and just couldn’t produce. I thought for sure I was just no good. Then mid-way through a race weekend last year I asked that we change the off-sets from 27mm to 26mm. I stood by fiddling with the 26mm off-sets in my hands while a machinist pressed the 27mm off-sets out of the triple clamps. Mid way through a conversation with Mike who was also standing by waiting, I slid my pinky through the two steering stem holes as they were lined up like in this picture. I couldn’t believe what I felt. No one could believe what I felt. We were all in shock. But you wanna know the worst part of it all? I had to race the bike that way the next day – we had no other off-sets so we had no other choice.. Talk about head games! We took a second like that.

    • Ed Molijn says:

      OK, am I being dumb here but it almost looks like if you turned the top insert 180 degrees it would line up and give you your …. offset ?

  5. GoGo says:

    “Almost” being the key word here, Ed. Truth is I had the same thought, and I tried this about nine times in all sorts of different configurations. This one is the closest they come to being aligned. Problem is the clamps themselves were designed and fabricated all with computers and CNC, but the offsets were made free-hand on a lathe – old school style. Something got twisted on the free-hand end of the build that is being sorted now – via the same computers and CNC system that built the clamps.

  6. mattacme says:

    Offset inserts are not uncommon, but the offset is in a single plane, front to back, and never side to side. Eric, in the interest of making certain that the inserts provided are at fault you might want to check that the triple clamps and the areas that receive the inserts are in alignment. Why? Maybe the CNC triple clamps were produced with insert holes that are not in alignment and the machinist who made then inserts corrected the misalignment with them. It’s an easy check that requires the triple clamps to be removed from the bike and either sighted against each other or measured in a reference plate and compared, something that should have been done prior to assembly anyway. Make sense?

  7. mattacme says:

    ^^^I would add, don’t rely on a visual check, make the measurements.

  8. Bob Cotter says:

    Glad you spotted those gloves hanging in the garage a few years ago…it’s been quite a trip since

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