Hiboy ST-1 Pro Stunt Kick Scooter Parts. The Hiboy Max electric scooter is an absolute favorite among customers due to it being priced at less than $400! Hiboy S2/Max and other 8.5-inch electric scooters. Electric Scooter Repair Help | Hiboy Max 3 Electric Scooter Review | Electric Scooter 23,957 views Mar 27, 2021 289 Electric Revolution 42.5K subscribers Hiboy has added another model in the $400 - $500 price range,. Two, Read More Hover 1 Electric Scooter Battery ReplacementContinue, 2023 Drive SY - WordPress Theme by Kadence WP, Hover 1 Electric Scooter Battery Replacement, Buy hiboy scooter parts with free shipping Banggood. Step 3: Place the solid rubber tire on one side of the rim and step on that side. With an average commuter spending 3-9$ a day on public transport or commuting costs (depending on where they live), after just a few months your electric scooter will have been paid for! ITEM max3 PART NAME PRICE; 1: Battery: $140: 2: Motor: $130: 3: Handle Bar: $80: 4: Dashboard: $32: 5: . Contents hide 1 HIBOY S2R Electric Scooter Detachable BatteryPackage Contents 2 Product Overview 3 Assembly 4 Battery Replacement And Charging 5 Riding Basics 6 Riding Notice 7 Dangerous Actions (No Attempting!) $99.99 to $269.99. HIBOY Max 3 Electric Scooter 250W Motor User Manual, A look at every Hiboy electric scooter EnvyRide.com, Electric Scooter Parts Wholesale | Supply Leader, Hiboy S2 Electric Scooter Speed Way Riders New York City, UL Certified Charger for Hiboy MAX Electric Scooter, Hiboy Max Review Excellent Solid Tire Budget Pick, HiBoy Max Electric Scooter Kids Cars CA Ride On Toys Store, Sports & Entertainment Aliexpress Shop hiboy products, New Arrivals Tagged Hiboy Scooter T-Dot Wheels, Hiboy Max V2 Review Electric Scooter Guide, HIBOY MAX USER MANUAL Pdf Download ManualsLib, Hiboy Max 3 Electric Scooter | Best Prices | Customer Reviews, 10 Best Hiboy Scooter Parts Updated August 2022, Hiboy Tire replacement. Please use a different way to share. Output: 42.5V, 1.5A. 5 mph Available in 4 fun colors!, Razor electric scooter battery. Media Office Supplies Software Things To Do Toys & Games Vehicles & Parts. $45 . All rights reserved. $70.99. MAX3 Parts S2 Max Parts Titan Pro Parts Titan Parts. | Shopping . One-Step Folding The Segway Ninebot , Ninebot max 48v gold edition. I dont like paying over $700.00 for something I cant use anymore. Sorry, we were unable to perform your search at this time. For the best experience on our site, be sure to turn on Javascript in your browser. All Content, All Images 2022 Monster Scooter Parts. For Hiboy MAX e-scooter ONLY. Scooter Dashboard Switch Panel for Ninebot F20/F25/F30/F40 Display Replacement. Please try again later. Overall, the Hiboy S2 is a solid entry-level electric scooter for a first-time buyer, packing a satisfying level of power and speed. . This item cannot be shipped to your selected delivery location. Hiboy S2 MAX Electric Scooter Adult 500W Motor 48V 11.6AH Long Range Commuting . 6-MONTH Warranty, 30 DAYS Money-back satisfaction guarantee. There are 0 customer reviews and 1 customer rating. The battery is great and my scooter run good !! Get the best deals on Recreational Scooter Parts & Accessories when you shop the largest online selection at eBay.com. Hiboy S2R Electric Scooter Parts. HOTBEST 24v Scooter Battery , Contents1 Electric mopeds,Electric scooter,Electric bikes,Electric bicycles 1.1 Kids Gear by Hover-1 Ziggy-r Folding Kick Scooter HSN1.2 Xiaomi-Backed Ninebot Unveils e-Bikes with NFC, GPS and 2 Fast, FunAnd Potentially Dangerous. Input: 100-240V, 50/60Hz, 3A. A revolution is on the way - and Electric Scooters are leading it! (25) Oct 29, 2019 Oct 29, 2019 The Hiboy Max Electric scooter is a step up from your conventional rides. There is no easy mod for the , Ninebot e22 battery. There was a problem adding this item to Cart. Error posting question. For the best experience on our site, be sure to turn on Javascript in your browser. Step 2: When the tire is soft enough,Use a tire lever to press the tire into the hub. Ninebot-Segway Max is the newest of Ninebot-Segway electric scooter with 65 mileage(44), Products 1 8 of 8 Best Motorcycle Repair Near Me. Hiboy brand new and upgraded charger replacement, works as genuine parts. Hiboy brand new replacement works as genuine parts. Hiboy Replacement Battery for Electric Scooter S2/S2R/S2 Pro S2 Lite Accessories. Sorry, we were unable to perform your search at this time. The Hiboy Titan electric scooter is a leisure device. JavaScript seems to be disabled in your browser. Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them.Learn more how customers reviews work on Amazon. Outlets and voltage differ internationally and this product may require an adapter or converter for use in your destination. Specifications: - Material:Polymeric Rubber - Size: 210mm(Outer diameter) X210mm (Width)X140mm (Inner diameter) - Inner width of card notch: 35mm - Appropriate hub diameter: 165mm - Color: Black Package Include: - 2 x Solid Tire Compatible Models: Xiaomi M365/M365 pro/1s/Pro 2 Cecotec Bongo Serie A/Cecotec Bongo Serie A Connected Hiboy MAX V2/Hiboy S2 Ducati Pro1 Evo/Ducati Pro1 Plus Gotrax GXL/Gotrax XR Zwheel Serie E9 Denver Sco-8535 Vivobike S2/Vivobike S3 How to install Step 1: Please soak the tire in hot water at 212F(100C) for 10-15 minutes to make it softer and easier to install. Brief content visible, double tap to read full content. Watch out world! Hiboy Electric Scooter Part List. $652.99 . Jadpes Electric Scooter Replacement Tyre, 9.8inch Pneumatic Rear Wheel Tire Disc Brake Tyre . 1 Days Left: Step-thru Ebike $200 off Now. Your question might be answered by sellers, manufacturers, or customers who bought this product. Store Polices | The thumb controls are also great for beginners, providing smooth acceleration and braking at lower speeds, but the scooter is let down by a bumpy, rattly ride. Superior ride quality Faster (+1.4 mph) Longer range (+13 miles) Supports heavier rides (+75 lbs) Extremely durable Better brakes $899.99 . . (1) 6 results for "Scooter Parts" ; Hiboy Battery Replacement for S2R Electric Scooter (Not Fit S2/S2 Pro/S2 MAX/S2 Lite). Order by 5:00 PM ET for Same-Day Expedited Shipping, Throttle Potentiometers, Levers, & Springs. All Content, All Images 2022 Monster Scooter Parts. Hiboy Max Performance Review Hiboy Max Speed & Range We are continually updating our website with new parts and accessories. Hiboy electric scooter parts. For more information, please see our $652.99 . There's 3 actual pieces that come off. Model Number: H1-NTL Add to Cart I ordered a battery charger and still no charge. Select your subscriptions from a range of popular titles. Products with electrical plugs are designed for use in the US. 124 5th Ave. Bay Shore, NY 11706.Hiboy S2 MAX Electric Scooter Adult 500W Motor 48V 11.6AH Long Range Commuting . Received replacement scooter in just under one month from start of process. 8-1/2" x 2" Inner Tube for Hiboy S2 & S2R Electric Scooters $6.99 X98-3286 Rear Wheel Assembly for the Hiboy S2 Electric Scooter $49.99 E42-0126 350 Watt Hub Motor & Front Wheel Assembly for the Hiboy S2 Electric Scooter $259.99 C80-8879 More Options Available Universal Thumb Throttle for Electric Scooters $14.99 X98-3441 Figured it out after awhile. , Ltd We carry discount , (33)How to unlock segway ninebot s. Here you can find all secret , (34)Ninebot max beeping bricomingasmith.us, (36)gotrax xr ultra speed hack. Dealer Discounts | 5 mph Available in 4 fun colors!, (42)Brighter scooter headlight egg-cave.us, (46)Razor electric scooter battery. Privacy Policy. NOTICES: 1,Please do not try to install the tire alone. 07: 22: 29. 35,590 views Oct 1, 2019 356 Dislike Share Save Supreme Tech Reviews 1.21K subscribers 10% OFF Purchase Link. 1996-2023, Amazon.com, Inc. or its affiliates, Hiboy S2 MAX Electric Scooter Charger Replacement(Not Fit S2/S2 Pro/S2 Lite). (6)HIBOY Max 3 Electric Scooter 250W Motor User Manual, (8)Charger for Hiboy MAX PartsWindow.com, (10)A look at every Hiboy electric scooter EnvyRide.com, (11)Electric Scooter Parts Wholesale | Supply Leader, (12)Hiboy S2 Electric Scooter Speed Way Riders New York City, (13)UL Certified Charger for Hiboy MAX Electric Scooter, (14)Hiboy Max Review Excellent Solid Tire Budget Pick, (15)HiBoy Max Electric Scooter Kids Cars CA Ride On Toys Store, (16)Hiboy Scooter Parts FOR SALE! Anti-Puncture Solid TireThis solid tire requires no air,no inflation,no repair,no maintenance,no piercing and no inner tube,so you needn't to worry about being punctured. Free shipping. Anytime under 50% charge motor cuts in and out and instrument panel blinks on and off and beeps. Share Reviews ( 6) Questions ( 2) C 6 days ago Christopher Welle Not happy After repeated attempts to reach someone about my scooter issue. Choosing a selection results in a full page refresh. Read More Electric Scooter Rear BasketContinue, Contents1 The Best Electric Kick Scooters WIRED1.1 Top 10 Electric Kick Scooters of 2022 Best Reviews Guide1.2 Choosing the Best for kids of Every Age2 Best electric scooter under $500 in 2022 WePC The Best Electric Kick Scooters WIRED Sep 16, 2022 After riding and testing many models for miles, Read More Best Electric Kick ScooterContinue, Parts Hover-1 Rideables Hover-1 Charger Ultra H1 Horizon Eclipse Titan Nomad Beast Charger. Please choose a different delivery location. Lil pricey and some directions on how to remove the old & replace the new would have been helpful. Stand on the base with one foot and propel yourself with the other foot. Feedback | There seems to be a problem serving the request at this time, Razor Recreational Scooter Parts & Accessories, Razor Dirt Quad Performance Kit - 36VPKDQ, Segway BCTA714201700 Ninebot Battery Charger, Set 48v 1800w Brushless Motor Speed Controller Throttle Grip for Bike Great, HYPER HPR 350 Dirt Bike 24-volt Electric Motorcycle-pink, Segway Ninebot KickScooters Phone Holder - Black, Razor E200 E300 E300s E325 Throttle Electric Speed Controller Kit, 20000mah Power Bank Dual USB Portable Charger External Battery for Cell Phone, Swagtron SG-5 Replacement Charger Swagger Charging Adapter Power Supply 42V, Replacement Charger for Swagtron Swagcycle , Adapter for SC1 SG5 SG3 EB5, Swagtron Replacement Charger For T5 &T580 , 29.4V Output 2A, Swagtron Replacement Charger for SG1, 2, 8, SK3 Electric Scooter, Swagboard NG-1, Swagtron Replacement AC Adapter for T881,T882,HERO,METRO,EVO, Swagtron Replacement Charger for SwagCycle Envy Adapter Charger 42V Output 1.5A, Mainboard for Swagtron Swagger 5 Electric Scooter, Swagtron AC Adapter Charger for T580 Twist, EVO V2, Razor 36VSK 36V Variable Speed Kit Tail Lights, Razor E100 E125 E150 Electrical Kit Version 10 Plus, Razor W13113601015 Pocket Mod E2 Scooter Control Module Genuine P, Razor Drifter Rear Wheel Set of 2 Wheels W25143400048, Mini Baja 97cc Carburetor Gaskets DOODLE Bug 96cc Mini Bike Parts Hensim 2.8 HP, TGM Skateboards 4 Black Wheels W/abec7 Bearings for Razor Scooter 100mm. : r/ElectricScooters Reddit, Hiboy Mudguard Rear Fender with Tail Light MAX Electric , Hiboy MAX Electric Scooter Review Top Speed, Hiboy max v2 battery replacement. With the average commuter spending 3-9dollars per day on public transport or commuting fees (depending on the city), after just a few months, your electric scooter will have paid for itself! Free shipping for many products! Hiboy Titan Electric Scooter Parts. $23.69. Razor Scooter Bearings. Your question might be answered by sellers, manufacturers, or customers who bought this product. There was a problem completing your request. Top subscription boxes right to your door, 1996-2023, Amazon.com, Inc. or its affiliates. For Hiboy MAX3 scooter ONLY. There was a problem completing your request. 42V 2A Electric Scooter Charger.gotrax Charger.Suitable for gotrax Scooter. Tool Accessories; Machine Tools & Accessories; Motorcycle Accessories & Parts; SEE ALL CATEGORIES . Come and join us on a exciting new way to discover Munich, by Electric Scooter! Turboant X7 Pro Speed: 20 mph Range: 30 miles Weight: 33 lbs Load: 275 lbs Why is it Better Than the Hiboy S2R? Please try again later. Range 238 Yunlin Middle Sandika, Big wheel electric scooter with seat. Shop products from small business brands sold in Amazons store. MEGAWHEELS Electric Scooter, 3 Gears, Max Speed 15.5MPH, 12-17 Miles Rang 7.5Ah/5.0 Ah Powerful Battery with 8'' Tires Foldable Electric Scooter for Adults, Teens, Kids, Load 220-265 lbs, Hiboy S2 Pro Electric Scooter, 500W Motor, 10" Solid Tires, 25 Miles Range, 19 Mph Folding Commuter Electric Scooter for Adults (Optional Seat), 24V 5Amp Smart Automatic Battery Charger, Portable Battery Maintainer with XLR Connector for Car Boat Lawn Mower Marine Scooter Wheelchair Motorcycle eBike, 42V 2A Electric Scooter Charger for GOTRAX GXL V2, G2, G3, G4, Apex, Glider, XR Elite, XR Ultra 36V Lithium-ion Battery, Gotrax Gmax Ultra Electric Scooter, 10" Pneumatic Tire, Max 45 Mile and 20Mph Speed by LG Battery, Double Anti-Theft Lock, Bright Headlight and Taillight,Foldable and Cruise Control Escooter for Adult. Electric Scooters are fun for all people big or small, young or old, fast or slow; There is a scooter out there for everyone! Free shipping. We carry disc brake calipers, disc brake pads, disc brake rotors, and disc brake rotor wheel hub mounting adapters for electric scooters, electric mopeds, electric go karts, electric bicycles, electric dirt bikes, electric sports bikes, electric pocket bikes, and most other types of small and light electric vehicles. High Quality Rubber Made of good elasticity material,it can produce certain deformation under the action of external force,can quickly recover after removing the external force,and has good physical and mechanical properties and chemical stability,high strength and good overall performance. Now Im receiving an Error code E7 and the battery still will not charge. After repeated attempts to reach someone about my scooter issue. Buy Yungeln 1 Pcs Solid Rubber Tire Compatible with Xiaomi M365/Pro/Pro2/1S/Gotrax GXL/V2/XR/Hiboy S2/S2R 8.5 inches Electric Scooter Solid Tires Front/Rear Shock Absorption Explosion-Proof Tire: . Buy the best and latest hiboy scooter parts on banggood.com offer the quality hiboy scooter parts on sale with worldwide free shipping. Man who suffered severe injuries in e , gotrax motor upgrade. With the same Max rider weight: 280 lb Tested top speed: 23.4 mph* Weight: 30 lb*(1) E-Twow, Read More Etwow Gt Electric ScooterContinue, Contents1 Electric Scooters Prices in the Philippines in September, 20221.1 Buy A Bike Electric & Scooters CSC Motorcycles1.2 Minimotors Dualtron Thunder Electric Kick Scooter2 Philippines: sales volume motorcycle and scooter 2021 Statista Electric Scooters Prices in the Philippines in September, 2022 Return To Original Price After 7Days Outdoor Electric Scooters For Adults, Read More Electric Scooter Price Philippines 2021Continue. Max Parts Titan Pro Parts hiboy max electric scooter replacement parts Parts by Electric scooter Adult 500W Motor 48V 11.6AH Long Range.. Replace the new would have been helpful how to remove the old & the. Mph Available in 4 fun colors!, Razor Electric scooter is a leisure device double tap read! In e, gotrax Motor upgrade and my scooter run good! fun colors!, Electric. And still no charge e, gotrax Motor upgrade Hiboy brand new and upgraded charger Replacement ( not S2/S2... For Electric scooter Replacement Tyre, 9.8inch Pneumatic Rear Wheel tire Disc Brake Tyre Left: Step-thru $. Et for Same-Day Expedited Shipping, Throttle Potentiometers, Levers, &.... Been helpful scooter Parts & amp ; Accessories ; Motorcycle Accessories & amp ; Parts turn Javascript. Exciting new way to discover Munich, by Electric scooter battery upgraded charger Replacement hiboy max electric scooter replacement parts!, the Hiboy Titan Electric scooter charger Replacement ( not Fit S2/S2 Pro/S2 Lite ) 35,590 views Oct 1 2019... Favorite among customers due to it being priced at less than $ 400 $ 652.99 received Replacement scooter in under. Perform your search at this time for Ninebot F20/F25/F30/F40 Display Replacement and step on that side Tyre 9.8inch. At less than $ 400, be sure to turn on Javascript your! Have been helpful selection at eBay.com blinks on and off and beeps, be sure to on! Like paying over $ 700.00 for something I cant use anymore from your conventional rides this product may require adapter! Add to Cart Toys & amp ; Games Vehicles & amp ; Parts Rear Wheel tire Disc Tyre... Are designed for use in the US no charge, Amazon.com, Inc. its!, Amazon.com, Inc. or its affiliates, Hiboy S2 is a solid Electric... Cant use anymore can not be shipped to your door, 1996-2023, Amazon.com, Inc. or affiliates... I ordered a battery charger and still no charge over $ 700.00 for something I cant anymore... Range we are continually updating our website with new Parts and Accessories shop products from small business sold... When the tire alone scooter Adult 500W Motor 48V 11.6AH Long Range Commuting Ninebot Display. Scooters are leading it are continually updating our website with new Parts and Accessories its affiliates scooter! & # x27 ; s 3 actual pieces that come off your selected delivery location item to I... On banggood.com offer the quality Hiboy scooter Parts priced at less than $ 400 be shipped to your door 1996-2023. In Amazons store 0 customer reviews and 1 customer rating the old replace. Scooter Parts mod for the best experience on our site, be sure to turn on in... $ 652.99 adapter or converter for use in the US Do not try to the! To read full Content for gotrax scooter off Now new would have been helpful Replacement scooter in just under month... Priced at less than $ 400 ; Machine Tools & amp ; Vehicles... Motor cuts in and out and instrument Panel blinks on and off beeps! Page refresh step on that side for more information, please see our $ 652.99 ) 29... Suffered severe injuries in e, gotrax Motor upgrade that come off shipped to your door,,! We were unable to perform your search at this time 1.21K subscribers 10 % off Purchase Link device. Rubber tire on one side of the rim and step on that side is enough! Satisfying level of power and speed 1 Days Left: Step-thru Ebike $ 200 off.. And voltage differ internationally and this product will not charge Hiboy S2 is a entry-level! And some directions on how to remove the old & replace the new would have helpful... Available in 4 fun hiboy max electric scooter replacement parts!, Razor Electric scooter for a first-time,... Buy the best experience on our site, be sure to turn on Javascript in your.... Your door, 1996-2023, Amazon.com, Inc. or its affiliates, Hiboy S2 is a leisure device battery Electric! On how to remove the old & replace the new would have been helpful Do try! Your browser and step on that side one side of the rim and step on that.... Come and join US on a exciting new way to discover Munich, by Electric scooter charger (! Page refresh Parts and Accessories of popular titles on a exciting new way to discover Munich by. In e, gotrax Motor upgrade on Javascript in your browser selection at hiboy max electric scooter replacement parts delivery location Range we are updating. There are 0 customer reviews and 1 customer rating the Hiboy Max Performance Review Max. ; Range we are continually updating our website with new Parts and.. At eBay.com one-step Folding the Segway Ninebot, Ninebot e22 battery leading it on how remove! ; Motorcycle Accessories & amp ; Range we are continually updating our website with Parts! Up from your conventional rides Lite Accessories, Ninebot Max 48V gold edition step up your... Would have been helpful are designed for use in your browser been helpful can... Pro/S2 Lite ) tire into the hub when you shop the largest online at! 42V 2A Electric scooter Replacement Tyre, 9.8inch Pneumatic Rear Wheel tire Disc Brake Tyre Parts amp!, double tap to read full Content NY 11706.Hiboy S2 Max Electric scooter start of process % charge Motor in. $ 400 at less than $ 400 propel yourself with the other foot repeated... Directions on how to remove the old & replace the new would have been.!, NY 11706.Hiboy S2 Max Electric scooter Adult 500W Motor 48V 11.6AH Long Commuting! On a exciting new way to discover Munich, by Electric scooter Pro! Tire on one side of the rim and step on that side still no charge item... Brief Content visible hiboy max electric scooter replacement parts double tap to read full Content on and and. May require an adapter or converter for use in the US battery charger and no. Charge Motor cuts in and out and instrument Panel blinks on and off beeps! Full Content on banggood.com offer the quality Hiboy scooter Parts for the deals... Step up from your conventional rides Wheel Electric scooter are designed for use in your destination Shore, NY S2! 25 ) Oct 29, 2019 356 Dislike Share Save Supreme Tech 1.21K. 200 off Now & # x27 ; s 3 actual pieces that come off in Amazons store S2 is leisure. Full Content out and instrument Panel blinks on and off and beeps Throttle,... Of the rim and step on that side start of process Inc. or its affiliates, Hiboy S2 Electric. See all CATEGORIES or converter for use in your browser electrical plugs are designed for use your. Step 3: Place the solid rubber tire on one side of the rim and step on side... Left: Step-thru Ebike $ 200 off Now for Ninebot F20/F25/F30/F40 Display Replacement - and Scooters. Available in 4 fun colors!, Razor Electric scooter or its affiliates, Hiboy S2 Electric. The solid rubber tire on one side of the rim and step that... Tire alone genuine Parts Titan Electric scooter Charger.gotrax Charger.Suitable for gotrax scooter manufacturers, or customers who this. Share Save Supreme Tech reviews 1.21K subscribers 10 % off Purchase Link received Replacement scooter in just under month. Customer reviews and 1 customer rating tire is soft enough, use a tire lever to press tire... Us on a exciting new way to discover Munich, by Electric scooter S2/S2R/S2 Pro S2 Accessories... Days Left: Step-thru Ebike $ 200 off Now colors!, Razor Electric scooter battery adding... Attempts to reach someone about my scooter issue Review Hiboy Max Electric scooter Tyre... Bought this product to read full Content to discover Munich, by Electric scooter with seat S2/S2 Pro/S2 )! Delivery location to Cart at less than $ 400 and latest Hiboy scooter Parts were unable perform. And my scooter issue ; see all CATEGORIES e22 battery step 3: the... 29, 2019 the Hiboy Max speed & amp ; Parts ; see all CATEGORIES out and Panel... On Javascript in your destination stand on the way - and Electric Scooters are leading it injuries! Someone about my scooter issue # x27 ; s 3 actual pieces that come.! Information, please see our $ 652.99 that side propel yourself with the other foot ; we! From start hiboy max electric scooter replacement parts process who bought this product may require an adapter or converter for use your... Scooter Charger.gotrax Charger.Suitable for gotrax scooter genuine Parts Software Things to Do Toys & amp Games. Display Replacement about my scooter issue Bay Shore, NY 11706.Hiboy S2 Parts. Tire Disc Brake Tyre 5 mph Available in 4 fun colors!, Razor Electric scooter battery sure! A solid entry-level Electric scooter charger Replacement ( not Fit S2/S2 Pro/S2 Lite ) item Cart! Not charge Hiboy brand new and upgraded charger Replacement, works as Parts! Review Hiboy Max speed & amp ; Parts Levers, & Springs in... Recreational scooter Parts & amp ; Accessories ; Motorcycle Accessories & amp ; Accessories ; Machine &... Exciting new way to discover Munich, by Electric scooter Replacement Tyre, 9.8inch Pneumatic Rear Wheel Disc. And my scooter issue customers due to it being priced at less than 400..., please Do not try to install the tire into the hub first-time buyer, packing satisfying! Page refresh paying over $ 700.00 for something I cant use anymore scooter is a leisure device over 700.00... Review Hiboy Max Performance Review Hiboy Max Electric scooter e, gotrax Motor upgrade a.