Difference between revisions of "Drive Belt"

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See the [[Unofficial Service Manual#Belt|unofficial manual entry for the belt]].
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<onlyinclude>
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Zero uses a belt for primary transmission of torque to the rear wheel. It's quiet and lightweight but is a proprietary design that can wear out. If you plan to put a lot of miles on a Zero or risk the belt often, buy a spare belt ahead of time and mind its maintenance.
 +
 
 +
===Belt Risks===
 +
Belts fail by snapping or by stripping the teeth.
 +
 
 +
;On Landing
 +
: The most common situation for a belt snap is when going over a major bump or jump where the rear wheel leaves the ground.
 +
:*If, while airborne, the throttle is not immediately relaxed, the rear wheel will rapidly spin up.
 +
:*A wheel that is moving extremely quickly in the air will get jerked back to its regular speed on landing. This is transmitted to the belt through the rear sprocket and can easily strip teeth.
 +
 
 +
;From Debris
 +
: Gravel or sand that gets thrown between sprocket teeth and the belt will force the belt to expand quickly under load, and can cause it to snap.
 +
: Reportedly, sand is a much more reliable path to belt failure than gravel.
 +
: The sprocket tooth design is meant to deflect gravel to the inside of the swingarm towards the wheel.
 +
: The bike has an upper debris guard made of soft ABS plastic, but does not have a lower guard.
 +
 
 +
;From Mis-Alignment
 +
: An unaligned belt can wear really badly and break sooner.
 +
 
 +
===Belt Specifications===
 +
Zero's final drive is a custom-designed [http://www.gates.com/ Gates] [http://www.gates.com/products/industrial/industrial-belts/synchronous-belts/powergrip-htd-belts HTD (high torque drive)] [http://www.gates.com/products/industrial/industrial-belts/synchronous-belts/poly-chain-htd-belts Poly Chain Carbon] toothed carbon fiber belt.
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* It's never been available outside of Zero's parts system.
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* It's been the same part for 2012-2016 models.
 +
*: 2017 models shifted to a wider belt that can accommodate more torque/loading.
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 +
{| class="wikitable"
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!Years
 +
!Width
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!Pitch
 +
!Models
 +
!Sprockets
 +
!Number of Teeth
 +
!Length
 +
!OEM Part No.
 +
!Photo
 +
|-
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|[http://electricmotorcycleforum.com/boards/index.php?topic=7439.0 2010-2011]
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|rowspan="3"|14mm
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|rowspan="3"|8mm
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|S/DS
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|98T / 28T
 +
|200
 +
|
 +
|
 +
:30-02641
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|
 +
|-
 +
|rowspan="2"|2012-2016
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|S/SR
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|132T / 28T
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|rowspan="3"|220
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|rowspan="3"|
 +
|rowspan="3"|
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: 30-03673 (old logo)
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: 30-08084 (new logo)
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|rowspan="3"|[[File:ZM30-08084.png|300px|reference photo of belt]]
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|-
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|DS/DSR
 +
|130T / 28T
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|-
 +
|rowspan="2"|2017-2018
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|rowspan="2"|17mm
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|rowspan="2"|14mm
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|S 13.0
 +
|130T / 28T
 +
|-
 +
|
 +
: FX/FXS
 +
: DS/DSR
 +
: SR/S6.5
 +
|90T / 20T
 +
|158
 +
|
 +
|
 +
:30-08086
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|[[File:ZM30-08086.png|300px|reference photo of wide belt]]
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|}
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 +
;Part
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: [http://electricmotorcycleforum.com/boards/index.php?topic=5846 Gates GT Carbon, 14mm wide, 8mm pitch, 220 teeth].  It's only available from Zero.
 +
: P/N's are 30-03673 ("Belt Drive, 220T, 8mm Pitch, 14mm Wide") and also 30-08084 (same belt w/new Zero logo).
 +
: One rough match for reference: [http://www.biedlers-belts.com/gates-8mgt-1760-12-belt.html Gates 8MGT-1760-12 Belt]
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 +
===[[Belt Tension Check]]===
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{{:Belt Tension Check}}
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 +
===[[Belt Adjustment]]===
 +
An unaligned or mis-tensioned belt can wear really badly and break sooner.
 +
 
 +
{{:Belt Adjustment}}
 +
 
 +
===Belt Wear===
 +
Generally, watch for belt damage and try to anticipate when to replace the belt to avoid an incident on the road where the belt snaps.
 +
 
 +
;What to Check
 +
* Check the teeth for wear and cracks.
 +
*: If you see cracks in the tooth forming, the belt is getting old.
 +
*: If you see deep cracks starting, it's time to [[#Belt_Replacement|replace the belt]] ASAP.
 +
 
 +
;When to Replace
 +
* When it snaps.
 +
* When any teeth have been ground off.
 +
 
 +
;Hard Skips
 +
* If the belt experiences a "hard skip" from debris between the belt and a sprocket, it is likely to fail soon after. Watch it carefully if this happens.
 +
 
 +
;Tension with aging
 +
: Apparently, [http://electricmotorcycleforum.com/boards/index.php?topic=5693.msg42069#msg42069 per forum user JaimeC], belts don't wear like chains.
 +
: As they get older they'll actually get tighter, not looser like a chain.
 +
:* When a chain ages, the little bearing points between the links and rollers wear causing the chain to hang looser.
 +
:* When a belt ages, the rubber on the inner/toothed side begins to swell.
 +
: Since the Kevlar belt on the outer circumference won't stretch, the inner circumference will shrink making the belt tighter around the sprockets.
 +
: Generally, you want to make sure the belt hasn't gotten any tighter since you brought it home.
 +
 
 +
===[[Belt Replacement Procedure|Belt Replacement]]===
 +
{{:Belt Replacement Procedure}}
 +
</onlyinclude>
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 +
[[Category:Component]]

Latest revision as of 06:29, 7 November 2019

Zero uses a belt for primary transmission of torque to the rear wheel. It's quiet and lightweight but is a proprietary design that can wear out. If you plan to put a lot of miles on a Zero or risk the belt often, buy a spare belt ahead of time and mind its maintenance.

Belt Risks

Belts fail by snapping or by stripping the teeth.

On Landing
The most common situation for a belt snap is when going over a major bump or jump where the rear wheel leaves the ground.
  • If, while airborne, the throttle is not immediately relaxed, the rear wheel will rapidly spin up.
  • A wheel that is moving extremely quickly in the air will get jerked back to its regular speed on landing. This is transmitted to the belt through the rear sprocket and can easily strip teeth.
From Debris
Gravel or sand that gets thrown between sprocket teeth and the belt will force the belt to expand quickly under load, and can cause it to snap.
Reportedly, sand is a much more reliable path to belt failure than gravel.
The sprocket tooth design is meant to deflect gravel to the inside of the swingarm towards the wheel.
The bike has an upper debris guard made of soft ABS plastic, but does not have a lower guard.
From Mis-Alignment
An unaligned belt can wear really badly and break sooner.

Belt Specifications

Zero's final drive is a custom-designed Gates HTD (high torque drive) Poly Chain Carbon toothed carbon fiber belt.

  • It's never been available outside of Zero's parts system.
  • It's been the same part for 2012-2016 models.
    2017 models shifted to a wider belt that can accommodate more torque/loading.
Years Width Pitch Models Sprockets Number of Teeth Length OEM Part No. Photo
2010-2011 14mm 8mm S/DS 98T / 28T 200
30-02641
2012-2016 S/SR 132T / 28T 220
30-03673 (old logo)
30-08084 (new logo)
reference photo of belt
DS/DSR 130T / 28T
2017-2018 17mm 14mm S 13.0 130T / 28T
FX/FXS
DS/DSR
SR/S6.5
90T / 20T 158
30-08086
reference photo of wide belt
Part
Gates GT Carbon, 14mm wide, 8mm pitch, 220 teeth. It's only available from Zero.
P/N's are 30-03673 ("Belt Drive, 220T, 8mm Pitch, 14mm Wide") and also 30-08084 (same belt w/new Zero logo).
One rough match for reference: Gates 8MGT-1760-12 Belt

Belt Tension Check

Krikit Tension Gauge

Zero recommends the Gates Krikit belt tension gauge to check belt tension.

Krikit Tension Gauge invoice and box
Krikit Tension Gauge gauge and instructions
Video Guide
MostlyBonkers made a How-to video:
Tips
  • Turning the back wheel backwards before measuring will give different readout compared to turning the wheel forwards before measuring using the same spot.
    The difference may be significant to the (pre-2017) 20-30kg belt tension specification.
    For wide-belt 2017+ models, the tension specification is very wide (~25-75kg) and thus has a lot of leeway but seems worth a rotational check anyway.
  • The center of the belt can be reached from below, without removing the mudguard.
    This is described as a note in 5.14 in the 2015 manual
Steps
More detailed generic instructions for the Krikit deflection device
  1. Ensure the blue indicator arm is pressed down.
  2. Place the gauge in the center of the belt span, such that it is aligned longitudinally with the belt length.
  3. Place a finger on the blue pressure pad and depress this pressure pad.
  4. Keep pressing the blue pressure pad until you feel and hear a distinct 'click'. When this 'click' sound is heard, do not press any further.
  5. Remove the gauge and read the belt tension by observing the point where the top side of the blue indicator arm crosses the numbered scale on the gauge body.
  • Care must be taken to ensure that the gauge is not 'rocked' when pressing down on the blue pressure pad. The strap above the pressure bar is provided to attach snugly over the finger and prevent any 'rocking' motion.
  • Due to the fact that this device requires some amount of practice and operator skill, the accuracy and repeatability of the tension readings are not high.
Improvement
Because this procedure is not trivial to perform consistently, there is a modification to make the tension gauge easier to align
Gates' Carbon Drive mobile app
As of 2017, the Official Owners Manual also includes a procedure using Gates' Carbon Drive mobile app to check belt tension.
Usage
  • Use the application in a quiet environment.
  • Pluck the belt near the center of the lower belt span, so it vibrates like a guitar string.
Recommended Belt Tension
Belt Type Years Resonant Frequency Tension Range
Narrow 2013-2016 96.3 Hz – 124 Hz 20 – 30kg
Wide 2017+ (except S 13.0) 42.5 Hz – 73.6 Hz 25 – 76.5kg

The frequency can also be checked with instrument tuning apps such as Tuner-gStrings for Android.


Belt Adjustment

An unaligned or mis-tensioned belt can wear really badly and break sooner.


The official manual has a good procedure from which this is derived. Check that first.

Alignment of the belt is critically tough to get correct, and needs to be done everytime adjusting tension.

Video instruction
Zero SR: How To Adjust Your Belt on Youtube by NewZeroLand:
Tools
27mm hex socket
Breaker bar
Torque wrench set to 75ft/lbs or 102Nm
13mm open-end wrench
Instructions
  1. Place the motorcycle on a lift or rear stand so the wheel spins freely.
  2. Loosen the rear axle nut on the right side (27mm) with the breaker bar.
    Rear Axle Nut and right adjustment bolt Rear Axle Spacer and left adjustment bolt
  3. Loosen both left and right belt tension jam nuts (13mm) that face forward inside the adjusting gap.
    Rear Axle Nut and right adjustment bolt - loosened Rear Axle Spacer and left adjustment bolt - loosened
  4. Turn both left and right adjustment nuts (13mm) one quarter turn at a time to the desired belt tension.
    • Ensure that the alignment marks on either side of the swingarm indicate that the wheel and belt are aligned.
    • Roll the wheel forward and track it flush with inside of rear sprocket.
    • For proper alignment, the belt will track exactly centered on the wheel sprocket with a 1mm gap to either side of the belt relative to the sprocket.
      Once tension is set and tracking is flush to the inside, tightening the axle nut to 75ft-lbs will tend to nudge belt approximately 1mm to the outside.
    • Measure tension by rolling the wheel forward while plucking bottom side of belt or using tension gauge over several revolutions.
      Expect tension to vary slightly as wheel is rotated because front and rear sprockets are only round to a certain design tolerance.
  5. Check that the belt is aligned with belt tension in the right range.
  6. Re-tighten the left and right jam nuts (13mm).
  7. Tighten the axle nut (27mm) with the torque wrench (to 75ft-lbs).
References
Belt alignment discussion
How to Adjust Your Zero's Belt
Notes via Shadow


Belt Wear

Generally, watch for belt damage and try to anticipate when to replace the belt to avoid an incident on the road where the belt snaps.

What to Check
  • Check the teeth for wear and cracks.
    If you see cracks in the tooth forming, the belt is getting old.
    If you see deep cracks starting, it's time to replace the belt ASAP.
When to Replace
  • When it snaps.
  • When any teeth have been ground off.
Hard Skips
  • If the belt experiences a "hard skip" from debris between the belt and a sprocket, it is likely to fail soon after. Watch it carefully if this happens.
Tension with aging
Apparently, per forum user JaimeC, belts don't wear like chains.
As they get older they'll actually get tighter, not looser like a chain.
  • When a chain ages, the little bearing points between the links and rollers wear causing the chain to hang looser.
  • When a belt ages, the rubber on the inner/toothed side begins to swell.
Since the Kevlar belt on the outer circumference won't stretch, the inner circumference will shrink making the belt tighter around the sprockets.
Generally, you want to make sure the belt hasn't gotten any tighter since you brought it home.

Belt Replacement

Ask your dealer/Zero before replacing it.

They may perform it under warrantee if it happened prematurely; and they'll likely want to understand how and why it broke, anyway, for quality reasons.
Video Guide
Tools
  • Center lift.
  • 27mm socket.
  • 3mm Allen key.
  • 10mm Allen key socket
    Ensure at least 1" depth and a ⅜" drive sufficient to handle swingarm pivot bolt torques.
  • 15mm socket wrench (S models).
  • 13mm socket wrench (X models).
  • Torque wrench capable of setting 75ft-lbs and driving the 27mm socket and 10mm Allen key.
  • 2012-2013:
    • 2.5mm Allen key.
    • 24mm socket wrench.
Procedure
NOTE: For roadside belt swaps, particularly for an FX or FXS, setting the bike on its side should be possible for this work.
However, no effective procedure has been described for the process.
The following steps are suited to garage locations.
Bike on center lift
  1. Use a lift to raise the bike from the center.
    A sturdy wood crate may work in a pinch. Be safe.
    If the lift can be adjusted, lift the rear wheel just off the ground for ease of removal and replacement (lower than depicted but not in contact).
  2. Pull the wheel off (or slide it forward) by loosening the axle nut with a 27mm wrench.
  3. Pull off the rear tire fender by taking out the 4 hex bolts securing it with a 3mm Allen wrench.
    You can get away with removing only the left-side screws, to allow lifting the fender up enough to get the belt under.
    The right side fasteners also anchor the brake line to the rear calipers and a grounding strap, so mind them for re-attaching in the same way.
  4. Remove the brake pedal:
    This creates clearance for loosening the swingarm bolt above it (might be optional for pre-2015 models).
  5. Get the rear brake pedal out of the way of the right side swingarm pivot bolt.
    S platform: Use the 15mm hex socket to loosen or remove the bolt forming the pedal pivot.
    X platform:
    1. Remove the pin that attaches the brake pedal to the piston.
    2. Remove the two 13mm bolts that hold the grey piston bracket to the frame, and gently move the whole assembly to the left.
    Rear Brake Lever Bolt
  6. X platform: To access the left swingarm bolt, remove the lower left passenger peg bolt (13mm) and remove the grey cover piece.
  7. Remove the left and right swingarm bolts.
    2012-2013
    Remove the set screws from the swingarm bolts on both sides with a 2.5mm Allen wrench.
    The set screw is very difficult to find.
    It is located in one of the sides of the 24mm hex nut, perpendicular to the long axis of the 10mm allen bolts.
    It is actually on the edge of the nut.
    The best way to locate it is to use a small mirror and a strong flashlight.
    Then remove the bolts by holding the inside nut with a 24mm wrench, and a 10mm hex on the head.
    This was the hardest step, because there is not a lot of room to manipulate in the rear assembly - especially with a 24mm wrench!
    XU-2013
    sane as above, but needed a 23mm wrench and a 2mm Allen wrench instead of the 24mm wrench and 2.5mm allen wrench
    2014+
    Remove the left and right swing arm bolts with a 10mm Allen wrench.
    Swingarm Bolt
  8. Hang the swing arm with a strap on the tail section.
    The swingarm will pull back enough for the belt to fit through the frame.
    Pulling the Swingarm
    Swingarm Pulled
  9. Check the front sprocket for debris, and clean it with a firm but non-abrasive brush.
    If the sprocket is damaged somehow or the teeth are too worn to engage the belt, get it replaced to avoid damaging the new belt.
    The rear sprocket regularly deserves the same treatment.
  10. Slide the belt over the front sprocket.
  11. Replace the swingarm bolts.
  12. Slide the belt over the rear sprocket.
  13. Set/adjust belt tension accordingly.
  14. Install the rear wheel
  15. Re-check belt tension and alignment.
  16. Re-install the rear brake pedal.
  17. Re-install the rear tire fender.
  18. Extend the sidestand, then lower the bike carefully from the lift onto the sidestand.
References
2013 S Belt Replacement
2012 DS Belt Replacement, by User:DoctorBass
Swingarm Bolt Set Screw?
Facebook comments by Bobby Loo.