UPDATE: Speed Racer v6.2 - Lower and Faster

Discussion in 'Recumbent bicycles' started by B. Sanders, Jan 22, 2003.

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  1. B. Sanders

    B. Sanders Guest

    After some thought about aerodynamics vs. "streetability", I have modified the Speed Racer quite a
    bit. It's still streetable; but it presents far fewer speed compromises, and yet retains steering
    stability and minimal turning radius.

    Here's a GIF image of the new design:

    http://bsanders.net/SpeedRacer6.2.gif

    Design highlights for this version:
    - No rear suspension = maximum power transfer
    - Extra-low seat height (lower than M5, Jester or Baron)
    - M5-style fiberglass rigid seat
    - Short wheelbase gives tighter turning radius
    - Shallow head tube angle and plenty of trail
    - Seat angle is steeper than the M5, Jester or Baron
    - Non-power side chain routed to avoid leg interference
    - Crank height is similar to M5 - lower than Jester, Baron
    - Barnett Williams' chainstay design (1.5" pipe, brazed on)
    - Avid mechanical disc brakes (V-brakes on test bike)

    The steeper seat angle, shallow head angle, increased trail, minimal chain interference, disc brakes
    and shorter wheelbase were all on my wish list after owning an M5 Low Racer. The 1.5" tubular steel
    chainstays won't be quite as brutally rigid as the M5's massive sculptured steel stays; but should
    be plenty efficient. This design (after it is tweaked a bit) could be as fast and stable as any bike
    out there: Any speed deficiencies will be in the engine compartment, not from the bike design. I may
    spec a monoblade instead of the BMX fork for later builds.

    I think this one looks like a winner, and should be fairly easy to build. I'm going to have to
    experiment a bit with the chain idlers quite a bit, it would seem; but the rest of it appears fairly
    straightforward. Seat mounting should be a piece 'o cake.

    Comments welcomed as always.

    -Barry
     
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  2. John Foltz

    John Foltz Guest

    B. Sanders wrote:
    > After some thought about aerodynamics vs. "streetability", I have modified the Speed Racer quite a
    > bit. It's still streetable; but it presents far fewer speed compromises, and yet retains steering
    > stability and minimal turning radius.
    >
    > Here's a GIF image of the new design:
    >
    > http://bsanders.net/SpeedRacer6.2.gif
    >

    Hmm... sure looks like a Baron/Jester derivative to me... Not that that's bad...

    --

    John Foltz --- O _ Baron --- _O _ V-Rex 24/63 --- _\\/\-%)
    _________(_)`=()___________________(_)= (_)_____
     
  3. Bentbiker

    Bentbiker Guest

    reminded me a lot of a Zephyr, which seems like a very reasonable priced lowracer, that I rarely
    seem mentioned here.

    John Foltz wrote:
    > B. Sanders wrote:
    >
    >> After some thought about aerodynamics vs. "streetability", I have modified the Speed Racer quite
    >> a bit. It's still streetable; but it presents far fewer speed compromises, and yet retains
    >> steering stability and minimal turning radius.
    >>
    >> Here's a GIF image of the new design:
    >>
    >> http://bsanders.net/SpeedRacer6.2.gif
    >>
    >
    > Hmm... sure looks like a Baron/Jester derivative to me... Not that that's bad...
     
  4. B. Sanders

    B. Sanders Guest

    "bentbiker" <[email protected]> wrote in message news:[email protected]...
    > reminded me a lot of a Zephyr, which seems like a very reasonable priced lowracer, that I rarely
    > seem mentioned here.
    >
    > John Foltz wrote:
    > > B. Sanders wrote:
    > >
    > >> After some thought about aerodynamics vs. "streetability", I have modified the Speed Racer
    > >> quite a bit. It's still streetable; but it presents
    far
    > >> fewer speed compromises, and yet retains steering stability and minimal turning radius.
    > >>
    > >> Here's a GIF image of the new design:
    > >>
    > >> http://bsanders.net/SpeedRacer6.2.gif
    > >>
    > >
    > > Hmm... sure looks like a Baron/Jester derivative to me... Not that that's bad...

    Yes, it does doesn't it? This one is quite a bit lower, however. I've since raised the seat a bit on
    v6.3, making it even more like an Optima Baron; but with a slightly lower seat height and slightly
    steeper seat angle. This change should make it even more "streetable" than a Baron, but much faster
    than a SpeedMachine, Taifun, Stinger, Shockproof, etc. That is my design goal. I want stable
    handling at all speeds, but excellent aerodynamics, too. Why compromise if you don't have to?

    I'm thinking of going ahead with either 2 1/4" stainless steel or possibly 3" 6061-T6 tubing (again,
    similar to the Baron and Jester). It will depend upon who ends up doing the bending and the welding.
    I'll definitely want mandrel-bent tubes with the 3" aluminum tubing.

    -Barry
     
  5. B. Sanders

    B. Sanders Guest

    "bentbiker" <[email protected]> wrote in message news:[email protected]...
    > reminded me a lot of a Zephyr, which seems like a very reasonable priced lowracer, that I rarely
    > seem mentioned here.

    It's not a bad price at all, and the plans (blueprints) for it are posted for free on the Zephyr
    website. I did take notes from the Zephyr design; but decided that the Baron, Jester and M5 are my
    design ideals (with some tweaks for better low-speed handling).

    -Barry
     
  6. Jeff Wills

    Jeff Wills Guest

    "B. Sanders" <[email protected]> wrote in message news:<[email protected]>...
    > > > Hmm... sure looks like a Baron/Jester derivative to me... Not that that's bad...
    >
    > Yes, it does doesn't it? This one is quite a bit lower, however. I've since raised the seat a
    > bit on v6.3, making it even more like an Optima Baron; but with a slightly lower seat height and
    > slightly steeper seat angle. This change should make it even more "streetable" than a Baron, but
    > much faster than a SpeedMachine, Taifun, Stinger, Shockproof, etc. That is my design goal. I
    > want stable handling at all speeds, but excellent aerodynamics, too. Why compromise if you don't
    > have to?
    >

    B-

    How many rideable prototypes have you built so far?

    Jeff
     
  7. B. Sanders

    B. Sanders Guest

    "Jeff Wills" <[email protected]> wrote in message
    news:[email protected]...
    > "B. Sanders" <[email protected]> wrote in message
    news:<[email protected]>...
    > > > > Hmm... sure looks like a Baron/Jester derivative to me... Not that that's bad...
    > >
    > > Yes, it does doesn't it? This one is quite a bit lower, however. I've since raised the seat a
    > > bit on v6.3, making it even more like an Optima Baron; but with a slightly lower seat height and
    > > slightly steeper seat angle. This change should make it even more "streetable" than a Baron,
    but
    > > much faster than a SpeedMachine, Taifun, Stinger, Shockproof, etc. That
    is
    > > my design goal. I want stable handling at all speeds, but excellent aerodynamics, too. Why
    > > compromise if you don't have to?
    >
    > B-
    >
    > How many rideable prototypes have you built so far?

    Zero. I'm using the known ride qualities and aerodynamic characteristics of existing designs to
    minimize the number of prototypes. The first one will be as close to perfect as possible, based upon
    as much data as I can gather. It will be a prototype, by its nature, and I intend to tweak the
    design and build a follow-on design.

    Why do you ask? Do you think I should go into production with this design? The thought has
    definitely crossed my mind. Aside from George Reynolds' bikes, no other lowracers are being produced
    on this side of the pond that I know of. I'm pretty sure that this frameset could be produced at a
    very competitive price, probably in line with the Zephyr. The business model for lowracers isn't
    that great, however. It's a business for people who aren't out to make money - just to have fun. (I
    need an income.)

    Cheers,

    Barry Sanders From the Frosty Midwest USA
     
  8. Jeff Wills

    Jeff Wills Guest

    "B. Sanders" <[email protected]> wrote in message news:<[email protected]>... <snip>
    > Why do you ask? Do you think I should go into production with this design? The thought has
    > definitely crossed my mind. Aside from George Reynolds' bikes, no other lowracers are being
    > produced on this side of the pond that I know of. I'm pretty sure that this frameset could be
    > produced at a very competitive price, probably in line with the Zephyr. The business model for
    > lowracers isn't that great, however. It's a business for people who aren't out to make money -
    > just to have fun. (I need an income.)
    >

    I think you're on the right track with building a prototype, but...

    Don't think about mandrel-bent tubes. Don't think about aluminum. Close the carbon-fiber catalogs
    and tape them shut.

    Build a frame out of mild steel, something like 1.5" to 2" square,
    1/16" wall. This should cost something like $20 in materials. *Make sure* everything works the way
    *you* like. If something's messed up, you can chop it up or build a second prototype for the same
    minimal cost. Building real ridable bikes will teach you 100 times as much as making drawings.

    We of the OHPV (Oregon Human Powered Vehicles) are building chassis to go into full fairings. The
    frames are 1.5" square steel. We're going through this process with the aim of having several
    streamliners ready for our races in May.

    Jeff
     
  9. Tom Sherman

    Tom Sherman Guest

    Jeff Wills wrote:
    >
    > I think you're on the right track with building a prototype, but...
    >
    > Don't think about mandrel-bent tubes. Don't think about aluminum. Close the carbon-fiber catalogs
    > and tape them shut.
    >
    > Build a frame out of mild steel, something like 1.5" to 2" square,
    > 1/16" wall. This should cost something like $20 in materials. *Make sure* everything works the way
    > *you* like. If something's messed up, you can chop it up or build a second prototype for the
    > same minimal cost. Building real ridable bikes will teach you 100 times as much as making
    > drawings....

    Jeff,

    What about using some large diameter exhaust tubing ('muffler moly") bent (pun intended) at a local
    muffler shop? This should be inexpensive, and the weight will not be a concern on a prototype.

    I have thought about having a frame custom built from large diameter titanium alloy tubing. Getting
    it right would be easy, since the frame geometry would be an exact copy of the Earth Cycles Sunset
    Lowracer [TM]. :)

    Tom Sherman - Quad Cities USA (Illinois side) RANS "Wavewind" and Rocket, Earth Cycles Sunset and
    Dragonflyer
     
  10. B. Sanders

    B. Sanders Guest

    "Jeff Wills" <[email protected]> wrote in message
    news:[email protected]...
    > "B. Sanders" <[email protected]> wrote in message
    news:<[email protected]>...
    > <snip>
    > > Why do you ask?
    >
    > I think you're on the right track with building a prototype, but...
    >
    > Don't think about mandrel-bent tubes. Don't think about aluminum. Close the carbon-fiber catalogs
    > and tape them shut.

    > Build a frame out of mild steel, something like 1.5" to 2" square,
    > 1/16" wall. This should cost something like $20 in materials. *Make sure* everything works the way
    > *you* like. If something's messed up, you can chop it up or build a second prototype for the
    > same minimal cost. Building real ridable bikes will teach you 100 times as much as making
    > drawings.

    Hmm. I appreciate what you're suggesting; but I question it. For one thing, I don't see how you can
    expect to build a bike that handles well without examining other bikes that handle well, and
    designing carefully. That's what I'm doing. Also: Speed isn't my only goal. I want my bike to look
    great, too.

    Believe me, I'm not eager to spend money. I'm not dreaming of carbon fiber just yet - though my
    neighbor across the alley built carbon fiber wheelchairs that took gold medals at the Olympics. He
    knows a thing or two about fabricating with carbon fiber, so carbon is probably in my future. It's
    not terribly expensive, compared to the price of a new Optima Baron! (that's how I look at it)

    > We of the OHPV (Oregon Human Powered Vehicles) are building chassis to go into full fairings. The
    > frames are 1.5" square steel. We're going through this process with the aim of having several
    > streamliners ready for our races in May.

    Are you running a 1.5" square unsupported frame tube from end to end of the entire bike, without
    reinforcement? Doesn't your bike exhibit some flexiness? That's what I was concerned about with
    thin-walled 2" steel tubing.

    -Barry
     
  11. Jon Meinecke

    Jon Meinecke Guest

    On Sat, 25 Jan 2003 06:19:28 GMT, "B. Sanders" <[email protected]> wrote:

    Barry,

    I like the drawings you've posted and incorporating ideas from other bikes seems quite reasonable. I
    look forward to hearing about how the project works out, particularly the fabrication details. More
    power to you!

    >"Jeff Wills" <[email protected]> wrote in message
    >>
    >> Don't think about mandrel-bent tubes. Don't think about aluminum. Close the carbon-fiber catalogs
    >> and tape them shut. [...] Building real ridable bikes will teach you 100 times as much as making
    >> drawings.

    In the software development industry there's a truism that "running code trumps an unimplemented,
    superior design".

    I think Jeff's point was about not worrying too much about the finer details on the first prototype,
    but rather get something you can ride and tweak then make another, better design, incorporating what
    you've learned in an iterative fashion. In a sense, starting from an existing design inherits many
    iterations, but there's still probably much to learn for oneself. That's probably part of the fun!

    In terms of a 'business' plan, if you come up with a design that works well and can be made by
    hobbyists, you might consider selling plans. (Consult a lawyer about liability...)

    Jon Meinecke
     
  12. Jeff Wills

    Jeff Wills Guest

    Tom Sherman <[email protected]> wrote in message news:<[email protected]>...
    > Jeff,
    >
    > What about using some large diameter exhaust tubing ('muffler moly") bent (pun intended) at a
    > local muffler shop? This should be inexpensive, and the weight will not be a concern on a
    > prototype.
    >

    I did this on a lowracer in, umm... 1991. 2" diameter muffler pipe, bent and then welded to a rear
    triangle from an upright. 17" front wheel, Lightning seat. The only reinforcement to the bent tube
    was under the seat, where a plate gusset spanned the bend.

    Despite having the front and rear wheels in different dimensions, much less the same plane, the bike
    was quite rideable. Too bad I never pursued the design further- it looked a lot like Ed Gin's
    20/700C Festina.

    Jeff
     
  13. Jeff Wills

    Jeff Wills Guest

    "B. Sanders" <[email protected]> wrote in message news:<Q%[email protected]>...
    > > We of the OHPV (Oregon Human Powered Vehicles) are building chassis to go into full fairings.
    > > The frames are 1.5" square steel. We're going through this process with the aim of having
    > > several streamliners ready for our races in May.
    >
    > Are you running a 1.5" square unsupported frame tube from end to end of the entire bike, without
    > reinforcement? Doesn't your bike exhibit some flexiness? That's what I was concerned about with
    > thin-walled 2" steel tubing.
    >

    Take a look at the ZOX FWD bikes: http://www.zoxbikes.com/index_e.html
    . Their frames are 1.5" square mild steel. If it's good enough for Sergio, it's good enough for us.

    Our frames are reinforced with small gussets at the (cut and welded) bends. However, I can't tell
    you how they ride... the frames are still being fabricated. If things go bad, I'll report it here.

    Jeff
     
  14. Jeff Wills

    Jeff Wills Guest

    Jon Meinecke <[email protected]> wrote in message
    news:<[email protected]>...
    >
    > In the software development industry there's a truism that "running code trumps an unimplemented,
    > superior design".
    >
    > I think Jeff's point was about not worrying too much about the finer details on the first
    > prototype, but rather get something you can ride and tweak then make another, better design,
    > incorporating what you've learned in an iterative fashion. In a sense, starting from an existing
    > design inherits many iterations, but there's still probably much to learn for oneself. That's
    > probably part of the fun!
    >

    Exactly, Jon. Like I said, you'll learn far more by *building* and *riding* than you will by
    contemplating drawings. Even building copies of an existing design will teach you far more about it
    than just taking measurements.

    FWIW: my "real life" is software testing/QA . You'd be amazed at the number of bugs that get found
    *after* the "final code" gets delivered.

    Jeff
     
  15. "Jeff Wills" skrev...
    > Take a look at the ZOX FWD bikes: http://www.zoxbikes.com/index_e.html
    > . Their frames are 1.5" square mild steel. If it's good enough for Sergio, it's good enough
    > for us.

    I actually had a chance to look at some brand new Zox-20 clones last weekend. Pretty cool bikes and
    looked fairly easy to make. If we get a local building group started here that might be fun to try.
    Unfortunately I didn't bring my digicam.

    There were also some nifty CNC-drilled (?) chainrings. Up to 72 teeth and you can even get your name
    on them. Cheap too at ~50-60 usd. They hadn't yet tested how well the rings held up, but I just need
    one for the annual 200 m sprint anyway. Addys here if anyone wants to know more.
    http://hpvklub.dk/kontakt.htm

    Mikael
     
  16. Jon Meinecke

    Jon Meinecke Guest

    On 27 Jan 2003 16:09:23 -0800, [email protected] (Jeff Wills) wrote:

    > contemplating drawings.

    This can be fun, too, though. People approach creative tasks in many ways...

    >FWIW: my "real life" is software testing/QA . You'd be amazed at the number of bugs that get found
    >*after* the "final code" gets delivered.

    No, I wouldn't be surprised.

    We put those behaviors into the code so that 'you guys' will have something to do. %^P

    S/W development is iterative, too. It all about tolerances.

    Jon Meinecke
     
  17. Jeff Wills

    Jeff Wills Guest

    Jon Meinecke <[email protected]> wrote in message
    news:<[email protected]>...
    > On 27 Jan 2003 16:09:23 -0800, [email protected] (Jeff Wills) wrote:
    >
    > > contemplating drawings.
    >
    > This can be fun, too, though. People approach creative tasks in many ways...
    >
    > >FWIW: my "real life" is software testing/QA . You'd be amazed at the number of bugs that get
    > >found *after* the "final code" gets delivered.
    >
    > No, I wouldn't be surprised.
    >
    > We put those behaviors into the code so that 'you guys' will have something to do. %^P
    >
    > S/W development is iterative, too. It all about tolerances.
    >
    > Jon Meinecke

    Yup- which developers you can *tolerate*, and which aren't worth the space they occupy. :)

    (FWIW: not only am I a QA guy, I'm *married* to a software engineer. She wrestles with firmware
    code... Yikes! She's also prettier than me. )

    Jeff
     
  18. Tom Sherman

    Tom Sherman Guest

    Jeff Wills wrote:
    > ... Despite having the front and rear wheels in different dimensions, much less the same plane,
    > the bike was quite rideable. Too bad I never pursued the design further- it looked a lot like Ed
    > Gin's 20/700C Festina.

    Jeff,

    As far as I know, Ed has only had stock framed Ross Festinas (Festine?). You may be thinking of
    Warren Beauchamp's Barracuda, which was basically a Festina clone with some significant
    modifications:

    Indirect steering Monoblade [2] instead of the Festina's fork with a bend in the right blade Step-up
    jackshaft [2]

    [1] < http://www.wisil.recumbents.com/wisil/barracuda/barracudaframe.htm
    >
    [2] These in turn were apparently copied by Earth Cycles for the Sunset Lowracer - the monoblades
    appear practically identical.

    Tom Sherman - Quad Cities USA (Illinois side) RANS "Wavewind" and Rocket, Earth Cycles Sunset and
    Dragonflyer
     
  19. Ed *has* recently had a rear triangle transplant on his Festina.

    Dave Larrington - http://legslarry.crosswinds.net/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  20. Tom Sherman

    Tom Sherman Guest

    Dave Larrington wrote:
    >
    > Ed *has* recently had a rear triangle transplant on his Festina.

    Ed *has not* recently updated his Festina page, however.

    < http://home.earthlink.net/~gkpsol/festina.html >

    Tom Sherman - Quad Cities USA (Illinois side) RANS "Wavewind" and Rocket, Earth Cycles Sunset and
    Dragonflyer
     
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