To answer the question, does the momentum+yamaha motor spin the armature with your feet unpowered? The answer is no. With the new security chain (abus 1/2"x10' wrapped, grainger.com $390) I took PakYak outside today and locked it to a stepladder and a 8.25x14" tire. I put the pedals on and sat on it. The motor does not whirr when pedaled. The dropper post does not move when I sit on it. I suppose I am too light at 153 lb. I thought sitting on it would make it power up, but no combination of button pushes+sitting on it makes the display light up. There was a wire to the bottom of the dropper post.
I painted the flat black rear fender, rear rack, and front rack, Rustoleum Marigold Yellow today. Ends of bike were very black, and I am not a member of the "kill me ASAP, I welcome death" club. Needless to say, with the display off, the lights don't work either. I took the battery out. It has 5 blobs when you push the button, which I guess means full charge. The outer two pins were 1.2 v on a 36 v battery. Probably requires a communications handshake before the battery will turn on. Battery is CE rated, which means I guess I cannot take this bike in an Amtrak baggage car. They require UL rating. I have not yet found the external charger port discussed on the electricbikereview of the 2021 model.
I cerakoted (wax) the middle. The "orange" paint is very nice for a used bike. Upway.com sold it to me. Nicely packed, no dings, the only complaint is that the presta valves the stem retainer nuts were not screwed down, the pin lock nuts were not screwed down, and there are no plastic anti-rock covers.
It did take 12 days for package to get here from Upway Brooklyn. Sat in the Seko warehouse in Louisville 8 days. When seko logistics lists a delivery date on the website, they do not actually put it on the truck and bring it to your house. I sat here by the front door 7 AM -7:30 PM 12 days and the truck never came. Upway website said it was coming 9/7, but nothing. The Seko website said it was coming on 9/11, but when I called that day at 06:30 nobody knew anything except bike was at the Louisville warehouse. Louisville did not answer the phone until 09:30, and they told me all the trucks had left already without my bike on them since I did not "make an appointment". Next appointment was 9/15. When I told the lady that holding my package for 16 days (shipped 8/31) because I do not have enough Chinese electronic communication toys was extremely weird, She ran a special van out for me at 12:30.
Edit 9/27/26 The sun is out today, so I can see the black on black controls. There are two buttons on the front side of the display, away from the rider. Circle with slash and light bulb with radial rays. The first does turn the display on and off. The second turns the lights on but does not turn them off. As I am going to ride 23 of 30 miiles unpowered on the flat. I will have to buy new front and rear lights that are battery powered.
The cards in the accessory package from Upway, one explains the dropper post. I am supposed to be able to pull the lever on the post to adjust strength of the spring. I have not seen any such lever. Close inspection in the sunshine does allow me to see the hard as a brick Selle Royale seat has rails held by a clamp. So perhaps I can replace it with a $35 evo seat that has actual foam padding. After I spend some hours with a needle file on the boogered allen socket. 6 mm allen wrench goes in the socket only 1/32". Burrs insode the socket prevent using the full depth with a wrench. I have had 2 evo seats stolen one: one 9/20 by burglar who was convicted. Another stolen by a burglar on the Yuba bodaboda bike 8/22/26. I've invested $1050 in steel wrapped doors this year, and I still have 3 wood ones to replace.
Edit 10/17/26. I installed a steel case as a pannier so I could carry 2 tubes, an air pump, a tool box, my helmet bag, a rain jacket, a water bottle. I have completed 3 rides - 6 miles, 13 miles, 8 miles. The first trip was without power and it was really difficult to get up a 1% one block grade with 52:28 the lowest ratio available. The IGH lowest speed is 1:1. The 13 mile trip had some ~5% grades where I had to use level 2 power to get up them at 6 mph. Advantage of PakYak, the controller has an "off" level where I can turn power on and off with the up/down buttons instead of using the on button on the front and waiting 5 seconds for the internal check. Another advantage of PakYak, the power comes on tenths of second after I start pedaling, instead of after 1/2 turn of the crank on my previous controllers. It must have something to do with sensing the chain tensioner after the crank. Disadvantage of PakYak, yesterday I hit a gas valve hole, 5" diameter, and broke a front spoke. 8 mph and I only weigh 158 lb. There was a 21 lb security chain in the front rack. I would think on a bicycle with $4700 OEM price, that Momentum would use DT Swiss or Sapim spokes instead of scrap metal garbage. Spokes don't appear to be necked down in the middle as all the premium DT swiss spokes on the Universalcycle website. The bargain grade are 2mm all the way. I will change all 36, instead of just the one.
The temperature has just changed from 96 last Tuesday to 52 today, 35 low, with 36 mph winds, so I wouldn't be out riding these days anyway.
Edit 10/19/26 The front spoke did not break, the head popped off the brass spoke nipple. Lots of ways to save a penny & screw the customer. I found a 2 mm spoke nipple in stock, and tried to install it. Bound up after 4 turns. The spokes on the PakYak are not 2 mm, they are 2.15 mm. .088" instead of .082" on other bikes. I will be replacing all 32 OEM spokes with DT Swiss 2 mm straight shank spokes, with standard nipples. Only way to get rid of the batch of trash originally installed.
BTW, the front axle will not unscrew to let the tube & tire off. Not with a 1/4" Dewalt impact wrench on a 6 mm hex bit. Not with cheater torque multiplier wrenches on two 6 mm hex wrenches. If you have a flat tire on a Momentum bike, you need to call AAA to tow it to your Momentum dealer. (*&^$##@
A recount of sprockets with the bike upside down gets 46 tooth front, 25 tooth rear. Still too high to pedal 8% grade without electricity. In my current out of shape state, I stall on 2% grades without elecricity. I am looking at replacing the heavy 5 spd Shmano IGH with a freewheel 7 speed 32 to 16. I don't think the frame cuts are compatible with a derailleur.
Edit 10 PM. Universalcycles sells DT swiss nipples in 14 ga and 13 ga. 13 ga turns out to be 2.34 mm which is .090". I ordered some, I'll see if they fit the .088" spokes on the PakYak. E-bikes have a lot of 2.5 mm spokes and nipples, and one of those spun on the PakYak spoke but would not tension the spoke. Amazing now many hub drive ebikes are sold and the majors won't sell spokes for them. Only Ebay, aliexp, amazon. From the source of all garbage.
Edit 10/20/26 Taking a bernzomatic torch (previous 5 stolen, one bought at HD today) to the front axle ends to burn any lok-tite freed the bolt up for removal. It is one piece, threaded into the aluminum fork on the small end. I had tried to unscrew the two allen socket ends in the opposite directions, as the basket mount has a bolt on one end going into a sleeved nut inserted from the other end. Those two ends unscrew 2 opposite directions both counterclockwise. The front axle being one piece, the small end unscrews clockwise. Good thing the torque limit is a figment of their imagination, as I put a 300 ftlb dewalt impact tool on the small end and tried to unscrew counterclockwise before giving up and trying clockwise in desperation. So now possibly I can change a punctured tube out on the road, with only two 6 mm allen keys.
I've taken the 6 open end wrenches I used on the yuba bodaboda with 15, 17, 18, & 19 mm axle nuts, out of the tool kit to save weight. The seat clamp bolt & nut were 14 mm and the seat column nut was 13 mm. TBD if I can unscrew the wallowed out PakYak seat clamp bolt and salvage the threads in the no-head end. I have a 6 mm LH drilll to remove the head end, but it takes a .205" lh drill to go through the bolt threads to not damage the threads in the headless end. As long as I am riding <20 miles the hard as a brick seat with a gel pad may continue to be acceptable. Universalcycle does not sell gel covered evo cruiser or cloud9 seats, anyway.
