Spare tire carrier for the Vespa GTS step-by-step walk thru

Discussion in 'Battle Scooters' started by klm4755, Jun 26, 2013.

  1. klm4755

    klm4755 Been here awhile

    Joined:
    Jun 19, 2006
    Oddometer:
    577
    Enclosed is a step-by-step walk thru outlining the fabrication and process for installation of a spare tire on a Vespa GTS 250ie. Note that the Vespa GTS rims are interchangeable. It is OEM recommended that the rear tire (130-70/12) be slightly larger than the front tire (12070-12), but a rear wheel/tire combo can be installed on the front hub without issue. Therefore, if you are to carry a spare wheel tire it is recommended to carry the rear tire size on the spare. The thread will be separated into 5 parts:
    1. Spare tire placement options
    2. Attach bracket Mock-up and proof of concept
    3. Bracket fabrication
    4. Wheel installation
    5. Horn relocation. Guess where the wheel will be mounted?
    6. Review and observations

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    wheel placement option 1, in wheel well...loose quite abit of storage and foot placement

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    wheel placement option 2, on rear rack, loose aft storage

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    wheel placement option 3, upright on rear rack, not ascetically pleasing, would need to fabricate a bracket to mount

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    wheel placement option 4, on scooter side---like a pannier this would occupy the space of a pannier as pannier space is more valuable and would make the bike asymmetric.
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    wheel placement option 5, front faring mount. This location provides a few challenges. The challenges include:
    1. clearance with front wheel faring
    2. wheel attachment to scooter
    3. Horn relocation
    4. loss of front load carrying capability
    5. headlight visability

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    headlight is partially blocked, I'll need to "rake" the wheel as to limit headlight beam blockage

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    will mount on OEM front rack

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    disassemble rack, won't need these parts

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    re-install rack

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    quick wheel fit check, wheel contacts post

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    trim post, need to tuck wheel as close as possible to scooter

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    make bracket from aluminum rectangle bar stock

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    fit about here

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    drill oversized hole matching the front bracket

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    trim attach flanges

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    light deburr all mounting holes

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    rough machined bracket, repeat process

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    break edges with deburr tool

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    add loop adhesive velcro to the bracket to front rack contact/touch points as to spare the finish of the front rack

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    mount check

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    wheel base-plate out of wood first, then metal

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    trim with band saw

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    wheel check

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    attach base-mount to bracket interface to front rack

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    attach to scooter

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    mount wheel to baseplate

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    scooter fit check

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    no front fender contact

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    still some headlight blockage, need to rake the wheel and will try another mount approach

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    vespa GTS front wheel hub ($30 from e-bay)

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    opposite side of hub, these hole attach to your front brake disc

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    need to trim off small tabs to make a flush surface, easy-peasy as hub is aluminum

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    trimmed hub

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    trim down the large disc to accept the hub

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    remove front decorative trim as the tire will tuck to a lower position, plug holes with fastener

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    aluminum sheet stock, 6061-T4 .125 inch gage

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    outline transfer from wood to metal

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    blend corners at 1.5 inch radii

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    cut on band saw

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    deburr

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    mount on bracket

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    mount assembly on rack

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    prime (2x coats) + paint (2x coats) the wheel hub

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    mount assembly on scooter

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    front view, notice the assembly blocks the horn and running light

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    countersink fasteners

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    attach hub with course thread M6 fastener, use blue loctite paste

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    fit check, no tire contact with scooter or bracket, only hub

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    front fender check, no issues

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    view from top

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    remove stebel horn from cavity. Stable horn install can be found here:
    [topic114292]

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    will mount the horn here

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    need additional hose and elbow hose couplers

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    bond straight coupler into stebel nozzle

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    mount with fastener here

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    straight connecter bonded in horn hole

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    thread nozzle hole thru bracket

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    horn as attached

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    horn/hose backside view

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    assembly on scooter

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    assembly front view

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    need to thread horn hose thru plastic trim, no real other option

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    connect horn hose with hose elbow connector, easy to disconnect if assembly needs to be removed

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    horn mounted

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    wheel clearance to top of front fender

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    front 1/4 view, closer tucked wheel, no headlight blockage

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    outside front view

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    side view

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    front 1/4 view

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    horn mount side view

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    horn front view

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    headlight view from ground

    Mod review and observations:
    1. Additional piece of mind if need to conduct fix a flat where plug is insufficient
    2. Certainly will mount for any long distance riding
    3. No additional noise at hi-way speeds
    4. Stebel horn is perceived to be ~30% louder, from re-location
    5. assembly weight ~ 20 lbs, this will have benefit in cross wind conditions
    6. some increase in front impact crash worthiness
    7. benefit to other vespa riders if touring with GTS scooters
    Enjoy!
    Keithm
    #1
  2. JerseyBiker

    JerseyBiker Living the life!

    Joined:
    Jan 31, 2007
    Oddometer:
    2,732
    Location:
    Asheville, NC
    Outstanding!!

    This would have been great to have on my last Vespa. Once I added a top case in the rear the scoot developed a front tire wobble - I'm guessing due to the weight being so far back. This weight in the front might have cancelled out the wobble.

    In any event, an absolute fantastic job and terrific step by step instructions!

    :clap:clap
    #2
  3. rpclark

    rpclark Been here awhile

    Joined:
    Aug 25, 2008
    Oddometer:
    172
    Location:
    Central OH
    Will it fit on the back?
    #3
  4. gogogordy

    gogogordy Long timer

    Joined:
    Feb 25, 2009
    Oddometer:
    2,028
    Location:
    Winchester, Southern California
    As usual Keith very well done farkle.

    I'd make 2 suggestions:

    1) Protective "clear bra" circles on the paint, under the rubber cups

    2) Your voltage regulator's already minimal airflow has just been reduced even further...they get plenty hot in normal use with just the small amount of airflow the horncast allows in. On my GTS, I drilled several air holes in the plastic shroud the VR mounts above, on the throttle side radiator. Can't hurt and did I mention that VR gets hot as hell?
    #4
  5. klm4755

    klm4755 Been here awhile

    Joined:
    Jun 19, 2006
    Oddometer:
    577
    Good comments, I'll take alook at directing some flow to the cavity, unaware the cavity usage was for VR cooling. I'll also need to add aux front turn signals as the tire/wheel blocks view from head on.
    Keithm
    #5
  6. klm4755

    klm4755 Been here awhile

    Joined:
    Jun 19, 2006
    Oddometer:
    577
    Yes, the wheel would fit on the back rack, but at the loss of the racks cargo carry ability.
    Keithm
    #6
  7. gogogordy

    gogogordy Long timer

    Joined:
    Feb 25, 2009
    Oddometer:
    2,028
    Location:
    Winchester, Southern California
    The VR lives on top of the black plastic right-side radiator shroud and gets very little cooling air.

    I'm certain you know how much electonics like heat...and Im not saying the VR wouldnt fail otherwise, but on the Vespas they are buried so uncharacteristically deep when compared to most other PTW's I dont see a down side to adding some cooling.

    Anyway...great mod (I mounted my Rotopax up front in a similar fashion) and very well executed and documented. thanks for sharing.
    #7
  8. gogogordy

    gogogordy Long timer

    Joined:
    Feb 25, 2009
    Oddometer:
    2,028
    Location:
    Winchester, Southern California
    Add'l benefit: The add'l weight up front from my gas or your spare actually improves the ride and handling/braking IMO.
    #8
  9. conchscooter

    conchscooter Long timer

    Joined:
    Feb 3, 2007
    Oddometer:
    2,308
    Location:
    Florida Keys
    Thats a very clever and well thought out piece of work. From my own experience with a GTS removing the rear wheel is unnecessarily complicated and difficult- dealing with the exhaust and the fragile bushing (I used the Moto Amore bushing which I'm told also crumbles after a while) and the impossible to move bearing in the support plate for the wheel. I loved riding the GTS but the original vespa concept of simplicity seemed to have got left behind on these four stroke machines.
    #9
  10. Warney

    Warney Been here awhile

    Joined:
    Jun 6, 2010
    Oddometer:
    568
    Location:
    Omaha, Ne
    Excellent fabricating skills and a clever solution.:clap Changing a rear tire on the side of the road on a Vespa GTS is impossible without pliers, a breaker bar, multiple sockets, hex bit socket, torx bit socket, a socket wrench, extensions, and a torque wrench. Who carries all that? Then there is the matter of that fragile graphite bearing...

    Vespaman video
    http://www.youtube.com/watch?v=eUNXDSvpN7I
    Alternate method requiring even more tools
    http://www.youtube.com/watch?v=iSvFcNRFEuM
    #10
  11. klm4755

    klm4755 Been here awhile

    Joined:
    Jun 19, 2006
    Oddometer:
    577
    Good point, I'd suspect it would be desirable to carry these tools while in touring mode. I'm in the process of fabricating a lockable metal pannier for storage. Here are a couple of shots of concept:
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    pannier rack
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    rack + metal ammo can
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    left side of scooter, not yet fabricated rack to can mount....

    I plan on carrying the tool list listed within the pannier.
    Keithm
    #11