Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Show off your E-Scooter or Motorcycle creation here.
User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Oct 06 2020 7:55am

John in CR wrote:
Oct 04 2020 5:41pm
The overheating means you need a smaller rear sprocket, not a larger one. You seem to keep forgetting that it's a relatively low power motor in that casing. What's the no-load current of the entire drive train in low gear vs high gear?
ya but it hasn't overheated and i'm doing mostly road riding no crazy climbing and I want more top speed. I want the motor to overheat so I can replace it with a better one. I've been doing good with starting only in 1st and 2nd rolling

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Oct 06 2020 8:01am

So I finally got pulled over by the cops one town over from where I live. I was riding slow down the right side of a main road with no helmet when he stopped in front of me. I shut it down said hello, got off and handed him my license per his request. I told him I can have it picked up with a truck since I could tell he wasn't letting me ride it home. He asked if I could pull it over by the library we were near and get it off the road. He did not write me up and gave me a verbal warning and handed back my license.

He asked how fast it was and I said around 35mph, he said I could probably get it licensed as a moped if I get all the lights working. They are almost all working now just need to fix the rear brake lights. But MA moped laws state they cannot have more than one gear so I would have to technically lie on the form. Thoughts?

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Oct 06 2020 8:05am

skeetab5780 wrote:
Oct 06 2020 7:55am
John in CR wrote:
Oct 04 2020 5:41pm
The overheating means you need a smaller rear sprocket, not a larger one. You seem to keep forgetting that it's a relatively low power motor in that casing. What's the no-load current of the entire drive train in low gear vs high gear?

edit: I do own the new LRHDD XL motor that is a beast and same physical size

John in CR   100 GW

100 GW
Posts: 15225
Joined: May 20 2008 12:58am
Location: Paradise

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by John in CR » Oct 06 2020 12:29pm

skeetab5780 wrote:
Oct 06 2020 7:55am
John in CR wrote:
Oct 04 2020 5:41pm
The overheating means you need a smaller rear sprocket, not a larger one. You seem to keep forgetting that it's a relatively low power motor in that casing. What's the no-load current of the entire drive train in low gear vs high gear?

edit: I do own the new LRHDD XL motor that is a beast and same physical size
Hopefully the new one can handle more. Gearing is so important. To set the goals posts out there for you, I just got a escooter/emoto going with a pair of Nuc's pushing a HubMonster. This is my lightest HubMonster in service, but I still run the same wheel size, about 19.5" OD. With speed limit set to 100% and no field weakening, I get 101kph no-load with a full 16s battery. Full for me because I choose cycle life as important is 65V. It took it out on the highway and got a 94kph top speed in both going and returning, which surprised even me, especially in just a normal upright riding position.

goatman   1 GW

1 GW
Posts: 3065
Joined: Jun 23 2019 6:50pm
Location: Surrey, B.C.

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by goatman » Oct 06 2020 8:54pm

id select a gear that the bike will start in like 2nd or 3rd, take the shifter off, go through inspection and then put it back on after inspection but thats me :) no different than programming a controller to 3000 watts for inspection and then bumping it to 5000 watts afterward

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Oct 09 2020 1:14pm

goatman wrote:
Oct 06 2020 8:54pm
id select a gear that the bike will start in like 2nd or 3rd, take the shifter off, go through inspection and then put it back on after inspection but thats me :) no different than programming a controller to 3000 watts for inspection and then bumping it to 5000 watts afterward
then the top speed would be 25mph in 4th gear wide open with a huge 84v 35ah battery....that sounds real fun

goatman   1 GW

1 GW
Posts: 3065
Joined: Jun 23 2019 6:50pm
Location: Surrey, B.C.

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by goatman » Oct 09 2020 2:18pm

thats why you put the shifter back on after inspection but if your going through the bother of legalising it you could also just register it like a street legal enduro

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Oct 12 2020 9:14am

goatman wrote:
Oct 09 2020 2:18pm
thats why you put the shifter back on after inspection but if your going through the bother of legalising it you could also just register it like a street legal enduro
Oh I misunderstood you, I thought you were saying to gear it like that forever...not just to pass inspection. That would work if we had to inspect it, but in my state MA, mopeds are registered with one simple form and you yourself are responsible if you get pulled over not meeting the moped criteria

-under 30mph
-49cc or less
-one speed transmission
-blah blah

User avatar
mannydantyla   10 W

10 W
Posts: 76
Joined: Dec 04 2020 12:38pm

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by mannydantyla » Jan 05 2021 12:07pm

Thank you skeetab for this very helpful thread, it was fun reading through it all and it helped me decide on what motor I need for my project.

I love the form factor of this gearbox but I have decided that it is not for me and my project (a small, classic Honda ev conversion). The one they're selling now has a 4kw motor and from what I've seen on youtube, it can get top speeds of 110 mph! I only need a top speed of around 60mph. Faster would be nicer but not with 50-year old hub breaks lol.

Or if I could use the gearbox to get away with a smaller, weaker battery pack then that could make it worth it but the shifting is still not great even with a clutch, and I'm building the bike for my wife to ride and she refuses to learn how to use a manual transmission. That's actually one of the reasons I chose an EV motor for her bike.

The Denzel is a very cool product and part of me wishes it would be what I need. Thank you again for documenting and sharing your build.

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Apr 07 2021 8:09am

mannydantyla wrote:
Jan 05 2021 12:07pm
Thank you skeetab for this very helpful thread, it was fun reading through it all and it helped me decide on what motor I need for my project.

I love the form factor of this gearbox but I have decided that it is not for me and my project (a small, classic Honda ev conversion). The one they're selling now has a 4kw motor and from what I've seen on youtube, it can get top speeds of 110 mph! I only need a top speed of around 60mph. Faster would be nicer but not with 50-year old hub breaks lol.

Or if I could use the gearbox to get away with a smaller, weaker battery pack then that could make it worth it but the shifting is still not great even with a clutch, and I'm building the bike for my wife to ride and she refuses to learn how to use a manual transmission. That's actually one of the reasons I chose an EV motor for her bike.

The Denzel is a very cool product and part of me wishes it would be what I need. Thank you again for documenting and sharing your build.
Thanks for the kind words, i still love this dirt dike even though i can only take it out on trails now the cops are nice about it but dont want me riding it on the streets anymore so typically take a more bicycle looking bike when i ride with the kids.

This drive is sort of like a tank though and i have a feeling they will last for a very long time, bullet proof besides overheating motor if feeding it way too much power or your a fool riding in wrong gear. This bike has no clutch but you need to know what your doing.

Going 110mph on a coverted bike seems crazy, i am aiming for 50mph on the Honda CRF im converting now with the Denzel D9000M motor. That is plenty fast for me unless your commuting hwy everyday
Last edited by skeetab5780 on Apr 08 2021 5:42am, edited 1 time in total.

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Apr 07 2021 1:27pm

I also want to make a note that the Ebay BTR 72v 35Ah battery i purchased is a big pile of crap and it was another bad investment. I only got a month or two out of it then stored it for the winter. After only 3 months i go to use the bike and it does nothing, i go to charge it and it doesnt charge...i end up opening it up to find that it is made from 20s1p lipo pouch cells and one of the cells right in the middle of the pack has a huge puncture it is swelling and leaking chemicals all over the rest of the cells. This was not done by me so it happened from sitting dormant 3 months i guess. Also the negative battery terminal had a really bad cold solder joint that just fell off the cell pouch tab making the bms shut down randomly since the connection was intermittent.

I am not sure if i can revive the battery but very big waste of money. Im sure the other 19cells will work but removing the one pouch in the middle will not be fun since each pouch has a positive on one end and the negative on other, so there is solder joint on both end of battery, the bms also will not work with 19s only

I did shop this battery and bought it when it was over 10% off paid just under $700 and its worth over $800 new

User avatar
skeetab5780   10 MW

10 MW
Posts: 2459
Joined: Jun 15 2009 10:58pm
Location: MA
Contact:

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by skeetab5780 » Apr 26 2021 7:44am

So here are some pics of the junk BTR Ebay battery you should never buy! And never keep in your house!

Also I would like to note that I paid a little bit extra to get the 35ah version over the 30ah since this dirt bike was heavy and I wanted good range, but if you look at the pictures of the cells you can see they are clearly labeled 30ah cells!!!

Here is the picture process of me removing the bad cell and trying to put it back into a usable 19s battery pack...can you get a 19s BMS? Not sure
Attachments
IMG_5969.JPG
IMG_5969.JPG (2.8 MiB) Viewed 205 times
IMG_5970.JPG
IMG_5970.JPG (2.2 MiB) Viewed 205 times
IMG_5971.JPG
IMG_5971.JPG (2.55 MiB) Viewed 205 times
IMG_5972.JPG
IMG_5972.JPG (2.71 MiB) Viewed 205 times
IMG_5973.JPG
IMG_5973.JPG (2.65 MiB) Viewed 205 times
IMG_5974.JPG
IMG_5974.JPG (2.59 MiB) Viewed 205 times
IMG_5975.JPG
IMG_5975.JPG (2.97 MiB) Viewed 205 times
IMG_5976.JPG
IMG_5976.JPG (2.31 MiB) Viewed 205 times
IMG_5977.JPG
IMG_5977.JPG (1.63 MiB) Viewed 205 times
IMG_5978.JPG
IMG_5978.JPG (1.76 MiB) Viewed 205 times
IMG_5979.JPG
IMG_5979.JPG (2.93 MiB) Viewed 205 times
IMG_5980.JPG
IMG_5980.JPG (2.87 MiB) Viewed 205 times
IMG_5981.JPG
IMG_5981.JPG (3.8 MiB) Viewed 205 times
IMG_5982.JPG
IMG_5982.JPG (2.93 MiB) Viewed 205 times
IMG_5983.JPG
IMG_5983.JPG (2.49 MiB) Viewed 205 times
IMG_5984.JPG
IMG_5984.JPG (2.71 MiB) Viewed 205 times
IMG_5985.JPG
IMG_5985.JPG (2.25 MiB) Viewed 205 times
IMG_5986.JPG
IMG_5986.JPG (2.61 MiB) Viewed 205 times
IMG_5987.JPG
IMG_5987.JPG (2.37 MiB) Viewed 205 times
IMG_5988.JPG
IMG_5988.JPG (2.64 MiB) Viewed 205 times

larsb   10 MW

10 MW
Posts: 2194
Joined: Dec 10 2014 5:12am
Location: Gothenburg, Sweden

Re: Denzel 72v 4-spd Gearbox Build 125cc Dual Sport

Post by larsb » Apr 26 2021 11:22am

I feel sorry for you.. would recommend getting some used hybrid auto cells. Top quality, low price.
I paid 150usd for 10s25Ah modules in the past. Still ride them. If you find the right seller then you could get even more wh for that price

Post Reply