Exhibit 4.2

IN THE EVENT THAT THE  SHAREHOLDERS OF THE COMPANY DO NOT APPROVE AN INCREASE IN
ITS AUTHORIZED  SHARE CAPITAL AT THE COMPANY'S  ANNUAL GENERAL MEETING THAT WILL
TAKE PLACE ON  DECEMBER  10,  2004,  THE  COMPANY  HAS  COMMITTED  TO REDEEM THE
CONVERTIBLE  DEBENTURE  PLUS A 5%  PENALTY  WITHIN  90 DAYS FROM THE DATE OF THE
DEBENTURE.

EVEN THOUGH THE  COMPANY HAS  RESERVED  30 MILLION  SHARES FOR  INVESTORS  TO BE
UTILIZED UPON CONVERSION OF THE CONVERTIBLE  DEBENTURES,  A PRICE DECLINE IN THE
COMPANY'S SHARES WOULD RESULT IN THE COMPANY HAVING  INSUFFICIENT SHARES FOR THE
CONVERSION OF YOUR CONVERTIBLE DEBENTURE.

THERE IS A RISK THAT THE  COMPANY  WILL NOT BE ABLE TO REDDEM  YOUR  CONVERTIBLE
DEBENTURE AS COMMITTED AS THE COMPANY  CURRENTLY DOES NOT HAVE SUFFICIENT  FUNDS
TO REDEEM YOUR  CONVERTIBLE  DEBENTURE  AND IT IS UNLIKELY THAT IS WILL GENERATE
SUFFICIENT CASH FROM OPERATIONS TO REDEEM YOUR CONVERTIBLE  DEBENTURE.  AS SUCH,
IF REQUIRED TO REDEEM YOUR CONVERTIBLE  DEBENTURE,  THE COMPANY WILL BE REQUIRED
TO  RAISE  ADDITIONAL  CAPITAL  TO  FUND  THE  REDEMPTION  OF  YOUR  CONVERTIBLE
DEBENTURE.

NEITHER  THIS  DEBENTURE  NOR  THE  SECURITIES  INTO  WHICH  THIS  DEBENTURE  IS
CONVERTIBLE  HAVE BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE "ACT") OR ANY STATE  SECURITIES  LAWS AND NEITHER  THIS  DEBENTURE  NOR ANY
INTEREST THEREIN NOR THE SECURITIES INTO WHICH THIS DEBENTURE IS CONVERTIBLE MAY
BE OFFERED, SOLD, TRANSFERRED,  PLEDGED OR OTHERWISE DISPOSED OF EXCEPT PURSUANT
TO AN  EFFECTIVE  REGISTRATION  STATEMENT  UNDER  SUCH ACT AND  SUCH  LAWS OR AN
EXEMPTION FROM  REGISTRATION  UNDER SUCH ACT AND SUCH LAWS WHICH, IN THE OPINION
OF COUNSEL SATISFACTORY TO THE COMPANY, IS AVAILABLE.

                        5% SECURED CONVERTIBLE DEBENTURE

$________                                                      December 15, 2004

         FOR  VALUE  RECEIVED,   SMARTIRE  SYSTEMS,   INC.,  a  Yukon  Territory
corporation (the "Company"), hereby promises to pay to ____________________ (the
"Holder") having an address at _______________________, two years after the date
hereof,  or earlier upon  prepayment of this Debenture as provided  herein,  the
principal sum of  _______________  Dollars  ($__________),  together with simple
interest  (computed on the basis of a 360-day year of twelve  30-day  months) on
the unpaid balance at the rate of five percent (5%) per annum  beginning six (6)



months from the date of the last closing of this  Offering in arrears  until the
principal hereof shall have been paid.

         The Company shall pay interest  semi-annually in arrears  beginning six
(6) months from the date of the last  closing of this  Offering and the last day
of every  subsequent  sixth  (6)  month of each  year  that any  portion  of the
principal balance is unpaid.

         All payments of principal  and interest  shall be made to the Holder in
lawful  currency of the United  States of America to the address set forth above
or such other address as to which the Holder shall notify the Company in writing
ten (10) days  prior to the due date of any  payment or upon any  prepayment  of
this Debenture as provided herein.

         Subject to and in compliance  with the  provisions  hereof,  the Holder
may, at its option,  convert  all or any  portion of the  outstanding  principal
balance of this Debenture, and all or any portion of the interest accrued hereon
to such date,  into shares of common stock of the  Company,  par value $.01 (the
"Common  Stock") at a conversion  price (the  "Conversion  Price")  equal to the
lesser of 80% of the lowest closing prices of the Common Stock for the 5 trading
days  preceding the date on which the notice of conversion is sent via facsimile
to the Company or 120% of the closing bid price of the Common  Stock as reported
by Bloomberg,  L.P. for the OTC Bulletin  Board for the trading day  immediately
preceding  the date that the  Holder's  funds are  released  from  escrow by the
escrow agent to the Company.  The Holder hereof shall  communicate its intention
to convert all or any portion of the principal  amount of this Debenture and all
or any portion of interest  accrued through such conversion date by surrendering
this  Debenture,  with the Form of Notice of  Election  to Convert  attached  as
EXHIBIT "A" hereto duly completed and signed,  to the Company at its address for
notice set forth elsewhere herein.

         The  Holder  shall  not be  entitled  to  convert  such  amount  of the
Debenture in  connection  with such number of shares of Common Stock which would
be in excess of the sum of (i) the number of shares of Common Stock beneficially
owned by the Holder and its affiliates on a conversion date, and (ii) the number
of shares of Common Stock  issuable upon the  conversion of the Debenture  which
would result in  beneficial  ownership by the Holder and its  affiliates of more
than  4.99% of the  outstanding  shares of common  stock of the  Company on such
conversion date. For purposes of the preceding  sentence,  beneficial  ownership
shall be  determined  in accordance  with Section  13(d) of the  Securities  and
Exchange Act of 1934, as amended,  and Regulation 13d-3  thereunder.  Subject to
the foregoing,  the Holder shall not be limited to aggregate conversions of only
4.99% and aggregate  conversions by the Holder may exceed 4.99%.  The Holder may
void the  conversion  limitation  described in this paragraph upon and effective
after 61 days prior written notice to the Company. The Holder may allocate which
of the equity of the Company  deemed  beneficially  owned by the Holder shall be
included in the 4.99%  amount  described  in this  paragraph  and which shall be
allocated to the excess above 4.99%.

         The  Company  may,  at its  option,  redeem  all or any  portion of the
Debentures with 3 business days advanced notice.

         If the Holder elects to convert less than the entire  principal  amount
of this  Debenture  and  interest  accrued to the date of such  conversion,  the
Company  shall issue or cause to be issued and  delivered to the Holder,  at its


                                       2


expense,  a new Debenture  evidencing  the  outstanding  amount of principal due
hereunder  after giving effect to the amount  applied to the  conversion,  which
such Debenture shall, except as to the principal amount thereof, be identical to
this Debenture in all respects.

         If the Company,  at any time while this Debenture is outstanding  shall
(a) pay a stock dividend or otherwise make a distribution  or  distributions  on
shares of its Common Stock or any other equity or equity  equivalent  securities
payable in shares of Common Stock,  (b) subdivide  outstanding  shares of Common
Stock into a larger number of shares,  (c) combine  (including by way of reverse
stock split) outstanding shares of Common Stock into a smaller number of shares,
or (d) issue by  reclassification  of shares of the  Common  Stock any shares of
capital  stock of the Company,  then the  Conversion  Price shall be adjusted to
offset any of the  aforementioned.  Any adjustment made pursuant to this Section
shall become effective  immediately  after the record date for the determination
of  stockholders  entitled to receive such  dividend or  distribution  and shall
become  effective  immediately  after  the  effective  date  in  the  case  of a
subdivision, combination or re-classification.

         If the  Company  shall  (i)  fail to make a  payment  of  principal  or
interest  when due; or (ii) make an  assignment  for the  benefit of  creditors,
files a petition in bankruptcy, be adjudicated insolvent or bankrupt, suffers an
order for relief  under any  federal  bankruptcy  law,  petition or apply to any
tribunal for the  appointment  of a  custodian,  receiver or any trustee for the
Company or any substantial part of its assets,  or (iii) commence any proceeding
under  any  bankruptcy,  reorganization,   arrangement,  readjustment  of  debt,
dissolution or  liquidation  law or statue of any  jurisdiction,  whether now or
hereafter in effect;  or (iv) have been filed any such petition or  application,
or any such  proceeding  shall have been  commenced  against the Company,  which
remains  undismissed,  unstayed or unbonded  for a period of thirty (30) days or
more;  or (v) by any act or  omission  shall  indicate  consent  to,  approve or
acquiescence in any such petition,  application or proceeding or the appointment
of a custodian,  receiver or any trustee for all or any substantial  part of its
properties,  or (vi) allow such custodianship,  receivership,  or trusteeship to
continue undischarged,  unstayed or unbonded for a period of thirty (30) days or
more, or (vii) violate any term or provision of this  Debenture  then and in any
such event, the outstanding  principal  amount of this Debenture,  together with
all accrued and unpaid interest thereon, shall be and become immediately due and
payable.

         All notices and other communications  provided for herein shall be sent
by certified mail,  return receipt  requested,  or by personal  delivery or by a
nationally  recognized  overnight courier to the Holder or the Company, at their
respective  addresses as set forth herein,  or to such other address as to which
either  party  may  advise  the other by notice  given in  accordance  with this
provision. All such notices shall be deemed given upon the earlier of receipt or
within five (5) business days of mailing if receipt is refused.

         Notwithstanding  any other provision of this Debenture,  interest under
this  Debenture  shall not exceed the maximum rate  permitted by law; and if any
amount is paid under this  Debenture as interest in excess of such maximum rate,
then the  amount so paid will not  constitute  interest  but will  constitute  a
prepayment on account of the principal amount of this Debenture.  If at any time
the  interest  rate under this  Debenture  would,  but for the  provision of the


                                       3


preceding  sentence,  exceed  the  maximum  rate  permitted  by  law,  then  the
outstanding  principal  balance of this Debenture shall, on demand by the Holder
of this Debenture, become and be due and payable.

         All payments under this Debenture  shall be made without  deduction for
any taxes of any nature now or hereafter imposed.

         The  provisions  of this  Debenture  shall in all respects be construed
according to, and the rights and  liabilities of the parties hereto and shall in
all respects be governed by, the laws of the Province of British Columbia.  This
Debenture  shall be deemed a  contract  made under the laws of the  Province  of
British  Columbia  to be  fully  performed  therein,  and the  validity  of this
Debenture and all rights and liabilities hereunder shall be determined under the
laws of said  Province  without  reference to the  conflicts of laws  provisions
thereof.  For purposes of any proceeding  involving this Debenture,  the Company
and the Holder hereby submit to the exclusive  jurisdiction of the courts of the
Province of British Columbia and of Canada having jurisdiction, and agree not to
raise and waive any  objection  to or  defense  based upon the venue of any such
court or based upon forum non conveniens.

         In the event this  Debenture  is placed in the hands of an attorney for
collection or for enforcement or protection of the security, or if Holder incurs
any costs incident to the collection of the indebtedness evidenced hereby or the
enforcement  or protection of the security,  the Company agrees to pay to Holder
all reasonable  attorneys'  fees so incurred,  all court and other costs and the
reasonable costs of any other collection  efforts,  including all costs incurred
in collecting  any judgment and in any appellate or bankruptcy  proceeding.  The
Company agrees to pay any  documentary  stamp taxes,  intangible  taxes or other
taxes which may now or hereafter  apply to this Debenture or any payment made in
respect of this Debenture.

         No delay or omission  on the part of the Holder in the  exercise of any
right  hereunder  shall  operate as a waiver of such right or of any other right
under this Debenture. A waiver by the Holder of any right or remedy conferred to
it hereunder  on any one occasion  shall not be construed as a bar to, or waiver
of, any such right and/or remedy as to any future occasion.  The Company and all
persons now or hereafter  becoming obligated or liable for the payment hereof do
jointly and severally waive demand,  notice of non-payment,  protest,  notice of
dishonor and presentment.  No failure to accelerate the  indebtedness  evidenced
hereby by reason of default hereunder,  acceptance of a past-due  installment or
other indulgences granted from time to time, shall be construed as a novation of
this Debenture or as a waiver of such right of  acceleration  or of the right of
the Holder  thereafter to insist upon strict  compliance  with the terms of this
Debenture or to prevent the exercise of such right of  acceleration or any other
right granted hereunder or by applicable law.

         This Debenture may be amended only by a written instrument  executed by
the Company and the Holder.

         THE COMPANY HEREBY KNOWINGLY,  VOLUNTARILY AND INTENTIONALLY WAIVES THE
RIGHT WHICH IT MAY HAVE TO A TRIAL BY JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE
OF ACTION BASED HEREON,  OR ARISING OUT OF, UNDER OR IN ANY WAY  CONNECTED  WITH


                                       4


THE  DEALINGS  BETWEEN  THE  HOLDER  AND THE  COMPANY,  THIS  DEBENTURE,  OR ANY
DOCUMENTS EXECUTED IN CONNECTION HEREWITH,  OR ANY COURSE OF CONDUCT,  COURSE OF
DEALING,  STATEMENTS (WHETHER ORAL OR WRITTEN) OR ACTIONS OF ANY PARTY HERETO OR
THERETO IN EACH CASE WHETHER NOW EXISTING OR HEREAFTER  ARISING,  AND WHETHER IN
CONTRACT, TORT, EQUITY OR OTHERWISE. THIS PROVISION IS A MATERIAL INDUCEMENT FOR
THE HOLDERS EXTENDING THE LOAN EVIDENCED BY THIS DEBENTURE.

                   REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                             SIGNATURE PAGE FOLLOWS



                                       5


         IN WITNESS WHEREOF,  SMARTIRE SYSTEMS,  INC. has caused this 5% Secured
Convertible  Debenture to be executed in its  corporate  name by its  President,
thereunto duly authorized.

Dated:   December 15, 2004

                                                    THE COMPANY:

                                                    SMARTIRE SYSTEMS, INC.


                                                    By: /s/Robert Rudman
                                                        -----------------------

                                                    HOLDER:


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



                                       5


                                   EXHIBIT "A"

                              NOTICE OF CONVERSION


(To be Executed by the Holder
in order to Convert this Debenture)

The  undersigned  hereby  elects to convert the attached 5% Secured  Convertible
Debenture into shares of common stock, par value $.01 (the "Common  Stock"),  of
SmarTire Systems, Inc. (the "Company") according to the conditions hereof, as of
the date written below. If shares are to be issued in the name of a person other
than the  undersigned,  the undersigned will pay all transfer taxes payable with
respect  thereto and is delivering  herewith such  certificates  and opinions as
reasonably  requested  by the Company in  accordance  therewith.  No fee will be
charged to the holder for any  conversion,  except for such transfer  taxes,  if
any.


Conversion calculations:        ---------------------------------------
                                Date to Effect Conversion


                                ---------------------------------------
                                Principal Amount of Debenture to be Converted

                                Payment of Interest in Kind   |_| Yes
                                                              |_| No

                                    If yes, $ _______   of Interest Accrued on
                                                        Account of Conversion at
                                                        Issue

                                ---------------------------------------
                                Number of shares of Common Stock to be Issued

                                ---------------------------------------
                                Applicable Conversion Price

                                ---------------------------------------
                                Signature

                                ---------------------------------------
                                Name

                                ---------------------------------------
                                Address