MadRhino
100 GW
tolkaNo said:Build a giant dh comp/team
The GT DHI that the OP has found is a better frame. A bit more work to build than a Giant, but well worth it.
tolkaNo said:Build a giant dh comp/team
MadRhino said:tolkaNo said:Build a giant dh comp/team
The GT DHI that the OP has found is a better frame. A bit more work to build than a Giant, but well worth it.
tolkaNo said:Why is the GT a better frame?
Callbrin said:I am planing to build a powerful ebike [my 2nd one] but I not sure what I need.
First I'm either gonna need a fat bike or a regular bike with 150mm dropout for obvious reasons but I'm not sure what to get as I dont want any of those frames that look like dirt bikes like the grey borg or stealth bomber.
List of Bikes For possible use:
https://www.amazon.com/Huffy-Mens-Fortress-Mid-Fat-Mountain/dp/B01EWSEBSM/ref=cm_cr_arp_d_product_top?ie=UTF8 [already have andf it is 155mm rear dropout but is a cheap walmart bike]
https://www.amazon.com/Firmstrong-Deluxe-Stretch-Cruiser-Bicycle/dp/B00DOIGUUY?ref_=Oct_MWishedForC_110798011_1&pf_rd_r=2WEBJ60WVDEJ10MCFT5E&pf_rd_p=6b50b771-b2fd-5318-9f17-f9259842a6dc&pf_rd_s=merchandised-search-6&pf_rd_t=101&pf_rd_i=110798011&pf_rd_m=ATVPDKIKX0DER&th=1 [Rear Dropout width is unknown but its made of steel so I might be able to stretch it]
https://www.ebay.com/itm/Schwinn-Stingray-Bike-OCC-Chopper-Black-Chrome-20/123561071437?hash=item1cc4d0534d:g:FVIAAOSwsqxb-J8y:rk:10f:0 [Looks cool but unsure if its worth it to get this]
List of Possible Kits
https://ncyclebike.en.made-in-china.com/product/OyinDdCuLHht/China-Super-Power-72V-8000W-8kw-8000-Watt-Electric-Bike-Hub-Motor-Kit.html [8000w]
https://www.aliexpress.com/item/48v-72v-26-5kw-hub-motor-electric-bike-conversion-kit-5000w-programmable-sinewave-controller/32234864092.html?spm=2114.search0104.3.42.7c05e977gyZyr1&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10130_10890_10547_319_10546_317_10548_10545_10696_453_10084_454_10083_10618_10307_537_536_10059_10884_10887_100031_321_322_10103,searchweb201603_2,ppcSwitch_0&algo_expid=9e494284-d90c-4916-a345-c6266fbaab20-9&algo_pvid=9e494284-d90c-4916-a345-c6266fbaab20 [5000w]
https://www.amazon.com/theebikemotor-3000W-Motor-Electric-Conversion/dp/B01GSR8MLW [3000w Has option for fat wheel]
Now The Problems:
Rear dropout width
battery size [thinking maybe running 96v instead of 72v]
Trusted kits [I want a lot of torque but I dont want to overspend. Do I even need 5kw? The torque is rated at 190nm and around 65mph so the 5kw looks best bust the battery sizing is and issue then.
Possible Batteries For Diy Battery
https://www.imrbatteries.com/samsung-30q-18650-3000mah-15a-flat-top-battery/ [3000mah 5C]
https://www.imrbatteries.com/samsung-50e-21700-5000mah-9-8a-battery/ [21700 Cell, 5000mah 1.95C]
https://www.imrbatteries.com/lg-mh1-18650-3200mah-10a-flat-top-battery/ [3200mah 3.125C]
I dont want a lot of voltage sag but I want the batteries to not struggle giving full power and then some to the motor
markz said:Dude, just dont go 65mph on a fuckking bicycle man, just dont. Just because others do it, dont follow suit. Bicycles are not meant for that kind of fibration or stress. Might as well just buy a motorcycle frame and put some fake pedals on it. I doubt even them motorcycle looking ebike frames are capable of hitting a pothole on a road at 65mph.
MadRhino said:Good DH frames are made to ride that speed, down wild mountain trails. Don’t worry, the bike is capable. The rider is the only concern.
Chalo said:MadRhino said:Good DH frames are made to ride that speed, down wild mountain trails. Don’t worry, the bike is capable. The rider is the only concern.
Those are short events. And racers who reach such speeds don't keep running the same bike season after season. Maybe the bikes can tolerate routine motorcycle-like use, and maybe not. Their intended purpose is different.
n3glv said:Whatever you do, get the thickest spokes you can, or use moped wheels.
BC eventually at some point you'll rip the spokes out of the rim.. Cheers.
n3glv said:Whatever you do, get the thickest spokes you can, or use moped wheels.
BC eventually at some point you'll rip the spokes out of the rim.. Cheers.
Absolutely - with a live load (a ~180lb rider using his legs as part of his suspension) they do very well. Taking those impacts with ~100lbs of dead weight affixed rigidly to the frame (i.e. a battery, controller, motor) is a whole different story.MadRhino said:Good DH frames are made to ride that speed, down wild mountain trails.
billvon said:Absolutely - with a live load (a ~180lb rider using his legs as part of his suspension) they do very well. Taking those impacts with ~100lbs of dead weight affixed rigidly to the frame (i.e. a battery, controller, motor) is a whole different story.MadRhino said:Good DH frames are made to ride that speed, down wild mountain trails.
MadRhino said:Good DH frames are made to ride that speed, down wild mountain trails. Don’t worry, the bike is capable. The rider is the only concern.
Agreed - but if the goal is "a powerful ebike" you're going to be tending towards heavier batteries. (And he said he wants a large battery.)MadRhino said:First, dead weight added to the bike doesn’t need to be 100 lbs. I do it with 50 lbs max, even less with short range lipo pack.
Right. But DH riders don't plant their butts on the seats when they are going downhill. They are on their pedals, using their legs to absorb much of the impact. That greatly reduces the loads that the frame sees, and puts the load where the bike is designed to handle it (the bottom bracket.)Second, many DH riders are 200+ lbs big guys. A 165 lbs rider plus build weight does match, and the old school DH bikes that we are building on, are overbuilt frames.
billvon said:Agreed - but if the goal is "a powerful ebike" you're going to be tending towards heavier batteries. (And he said he wants a large battery.)MadRhino said:First, dead weight added to the bike doesn’t need to be 100 lbs. I do it with 50 lbs max, even less with short range lipo pack.
Right. But DH riders don't plant their butts on the seats when they are going downhill. They are on their pedals, using their legs to absorb much of the impact. That greatly reduces the loads that the frame sees, and puts the load where the bike is designed to handle it (the bottom bracket.)Second, many DH riders are 200+ lbs big guys. A 165 lbs rider plus build weight does match, and the old school DH bikes that we are building on, are overbuilt frames.
Now compare that to a battery. Most are completely dead loads, without any suspension internally. If you see a 10G bump on a 50lb battery, that means 500 lbs on a part of the frame that was NOT designed to handle that load. With the design margins built into a DH frame you are usually OK. But it's not just like bombing down a steep trail with a heavy rider.
Callbrin said:This was going to be my 2nd ebike but I figure I would rather upgrade the battery instead on my first and the brakes as well. Currently its a 1500w voilamart kit from eBay with a 52v 20ah battery.
[...]
My plan was to increase the battery capacity to around 30-35ah and I wanted to use the same cells I am using now [Samsung 25r].
Callbrin said:OK wow its been a few days and i see this has gotten some attention. So after some thought and ready the replies I think I might not go with the 3kw kit on a normal bike as what other replies have said with the problems it would have. This was going to be my 2nd ebike but I figure I would rather upgrade the battery instead on my first and the brakes as well. Currently its a 1500w voilamart kit from eBay with a 52v 20ah battery. and going probably around 25-28mph on it I get around 10miles [20%-80%] so i would say on a full charge around 18miles.
My plan was to increase the battery capacity to around 30-35ah and I wanted to use the same cells I am using now [Samsung 25r].
I would build a frame case for the center to even out weight distribution and more room but IDK the best way to go about this so...
1. whats the best way to attach the box frame to the bike frame for my batteries
2. I wanted to save money by buying more 25r's but is it worth it?
3.is there any heating problems I should worry about for the motor since @ 35ah it the battery would be @ 1820wh
4. The controller get pretty warm, bag [no airflow] so it would defiantly over heat from this so should I get something like the 60amp controller from lunacycle?
also thanks to everyone who replied for the info and help
2old said:The kit info states it's capable of 34 mph @ 48V, but is restricted to 24 for street use, and should be capable of more @ 52V especially with the cells you're using. Have you removed the restriction in which case they're information is faulty? I ask because my YESCOM kit goes 33+ mph with a 30 amp controller @ 52V (I realize the motors could be wound differently).
brone said:Lol 18miles on a 20Ah battery? That battery is definitely not 20Ah