markz
100 TW
Thread is "probably" just a day dream post, no money in the bank account syndrome.
E-HP said:
Will this bike work for a 16KW build?
- Thread starter Haien
- Start date
Buying this 2014 Giant Glory 2 for $700 tomorrow. 150mm thru-axle dropouts and 26" wheels. More expensive, but definitely better than the other bikes I have considered.
I will try to get in touch with someone with a CNC cutter to machine out clamping dropouts which I can bolt onto the thru-axle holes and attach to the chainstay.
litespeed
100 kW
Great bike for the intended use. You will be happy with that one.
Tom
Tom
The battery cells are now paid, will see if I can get my hands on them this month.
I got in contact with QS Motor to order the 205 V3TI laced to a rim, an unlocked Sabvoton 72150, thumb throttle for regen, display for the Sabvoton, ferrofluid, and a twist throttle with "ignition" (3 speed apparently).
Although I said I wanted a rim made for 2.25 inch tires, they said the narrowest moped rim they have is a 1.6 inch one made for 2.75 inch tires. I measured the swingarm on my Giant Glory, and it seems to be about 3.5 inches wide at its narrowest, do you know if a 2.75 inch tire will fit?
I got in contact with QS Motor to order the 205 V3TI laced to a rim, an unlocked Sabvoton 72150, thumb throttle for regen, display for the Sabvoton, ferrofluid, and a twist throttle with "ignition" (3 speed apparently).
Although I said I wanted a rim made for 2.25 inch tires, they said the narrowest moped rim they have is a 1.6 inch one made for 2.75 inch tires. I measured the swingarm on my Giant Glory, and it seems to be about 3.5 inches wide at its narrowest, do you know if a 2.75 inch tire will fit?
Chalo
100 TW
Haien said:
26" bicycle rims are 22" in diameter. Whether you get a smaller or larger diameter overall depends on the size tire you use.
litespeed
100 kW
I’d tell you to go to a 17” rear and a 2.75 wide tire is about 3 1/4 inches wide.
A 1.6 or 1.85 rim will be fine for that size tire.
Tom
A 1.6 or 1.85 rim will be fine for that size tire.
Tom
litespeed said:
But wouldn't that look very off if I have a 26" bike wheel in the front (which I may have to change too though)? If you recommend smaller, then 18" might be better than 19".
I know it is generally not recommended, but do you know if I could get away with having a 2.5 wide tire on a 1.6 rim if the clearence of the 2.75 one is too small?
litespeed
100 kW
I run a 19 front and 17 rear. You can do a 18 or 19” rear but your motor (all hub motors!) will be happier in a smaller wheel.
I can’t answer on the width of the rim vs that size tire……I’ve never done a skinny tire.
Tom
I can’t answer on the width of the rim vs that size tire……I’ve never done a skinny tire.
Tom
Well this is a pretty late update, but I did manage to machine new dropouts:
They work very well, probably capable of supporting double the torque I have the motor produce at 80V 200A battery, 550A phase.
Pretty happy with the bike, when it's working well it's about what I imagined, very fun and almost too powerful. Though I have some problems. Firstly, as some of you thought, the backpack is very heavy, for short rides it's fine with a very good backpack, but not for longer ones, which i's why I'm getting a support for it mounted to the seatpost soon.
Secondly, as I managed to put everything together over a year after ordering the motor, the ferrofluid QS applied had dried out, and when spinning the motor suspened in the air you can hear some sort of rubbing a few times a revolution, sounding a bit like a brake rotor rubbing (although it isn't). I managed to disassemble the motor to check, and apart from some iron shavings from the dried up ferrofluid, I could not find anything abnormal.
The last and worst problem is that I have started experiencing some cogging and "clicking". Had none of that when I had just finished the build, but now when going past like half throttle at speeds over like 15mph I can feel a "click", almost like a chain skipping a tooth, loosing some power, and I think I can feel it isn't as zippy. One time during a ride when it was happening I switched to the other hall set, which made it much worse, cogging all the time, to then switch back to the first hall set, and this time it worked like it should, no clicking, cogging, ultra smooth and zippy. What can be the cause of this? Shouldn't be bad hall sensors right? (At least one of the sets), but maybe the controller?
They work very well, probably capable of supporting double the torque I have the motor produce at 80V 200A battery, 550A phase.
Pretty happy with the bike, when it's working well it's about what I imagined, very fun and almost too powerful. Though I have some problems. Firstly, as some of you thought, the backpack is very heavy, for short rides it's fine with a very good backpack, but not for longer ones, which i's why I'm getting a support for it mounted to the seatpost soon.
Secondly, as I managed to put everything together over a year after ordering the motor, the ferrofluid QS applied had dried out, and when spinning the motor suspened in the air you can hear some sort of rubbing a few times a revolution, sounding a bit like a brake rotor rubbing (although it isn't). I managed to disassemble the motor to check, and apart from some iron shavings from the dried up ferrofluid, I could not find anything abnormal.
The last and worst problem is that I have started experiencing some cogging and "clicking". Had none of that when I had just finished the build, but now when going past like half throttle at speeds over like 15mph I can feel a "click", almost like a chain skipping a tooth, loosing some power, and I think I can feel it isn't as zippy. One time during a ride when it was happening I switched to the other hall set, which made it much worse, cogging all the time, to then switch back to the first hall set, and this time it worked like it should, no clicking, cogging, ultra smooth and zippy. What can be the cause of this? Shouldn't be bad hall sensors right? (At least one of the sets), but maybe the controller?
Chalo
100 TW
You will break your seatpost. If that's what you want, go for it.
As it's holding up my weight + the backpack when sitting on the back edge of it just fine, it will not be a problem, it will just take off some of the weight from my back.
Chalo
100 TW
Your body serves as suspension when you carry the battery on your back. It doesn't when you hard connect the battery to a rack on the seatpost. Peak forces on the post will be much higher, even at the same static load.
It might be fine, but we'd just like you to be aware of the potential for failure; it's no fun to suddenly not have a seat under you and have to go back and pick up your battery hoping it hasn't been damaged by the fall, and that the connector(s) came unplugged cleanly instead of ripping loose. (ask Dogman about this sort of thing, for one example here on ES).
The seat post is taking a load more or less "straight thru it" when you're sitting on it even on the back edge, with or without a backpack on; it's designed for this (and even so, there are plenty of people that have broken seatposts without any racks on them, and sometimes the frame instead).
A rack clamped to the post is putting a cantilevered load on it along it's length (rather than at the end), which it isn't designed for. (the frame isn't designed to take that kind of load from the seatpost either).
What Chalo said is also true, because the hard connection of the rack to the post transfers that cantilevered load to it fully at the moment of impact/etc, and the farther out from the post the load is mounted, the greater the force applied to the post is, making it worse.
The seat post is taking a load more or less "straight thru it" when you're sitting on it even on the back edge, with or without a backpack on; it's designed for this (and even so, there are plenty of people that have broken seatposts without any racks on them, and sometimes the frame instead).
A rack clamped to the post is putting a cantilevered load on it along it's length (rather than at the end), which it isn't designed for. (the frame isn't designed to take that kind of load from the seatpost either).
What Chalo said is also true, because the hard connection of the rack to the post transfers that cantilevered load to it fully at the moment of impact/etc, and the farther out from the post the load is mounted, the greater the force applied to the post is, making it worse.
No, you are misunderstanding what I mean by support. I am not mounting my pretty heavy battery directly to a rack attached to the seat post, of course that would be dumb. I have some understanding of physics.
I will still have the battery in the backpack on my back, but it will stick up behind the seat and "poke" the underside of my backpack to take some weight off my back. Between the fabric of the backpack and the battery there is even some cushioning foam, so the peak forces will not be that bad.
That might work better than what your previous description let us imagine. 
circuitsmith
10 W
- Joined
- Feb 27, 2008
- Messages
- 81
This reminds me of the kids who want 500hp in a Honda Civic.
Once OP grows up he might find his way to the concept of balance.
Once OP grows up he might find his way to the concept of balance.
I haven't seen Dogman online in a while. Hopefully just taking a break from the forum?
Frankly, I'd be terrified to ride with what amounts to a thermite charge strapped to my body, with a 'ripcord' to activate it in case of a crash...
But if you are ok with that, I think the greatest problem with backpack is, again, 'cantilever' and the fact that it puts all weight on your shoulders.
Splitting the pack in two and making it 'body hugging' and using a system of straps like a modern body armour that weights about as much (research it) and is supposed to be worn if not all day, than certainly for hours at a time should work. Using 3d printing and 3d scanning and some composites on top will help a lot and may even protect the battery and you in case of a crash - of course 'safety third' and all that, but I think there are easier and less painful options if you just want to kill yourself...
But if you are ok with that, I think the greatest problem with backpack is, again, 'cantilever' and the fact that it puts all weight on your shoulders.
Splitting the pack in two and making it 'body hugging' and using a system of straps like a modern body armour that weights about as much (research it) and is supposed to be worn if not all day, than certainly for hours at a time should work. Using 3d printing and 3d scanning and some composites on top will help a lot and may even protect the battery and you in case of a crash - of course 'safety third' and all that, but I think there are easier and less painful options if you just want to kill yourself...
