Chalo
100 TW
drewjet said:
I think so. If the spokes bend where they enter the nipples, you might need to swap out the nipps for some with slenderer bodies and spherical heads, like Sapim. Seems like the spoke angle should be fine, though.
Chalo
Nuvinci developer kits for cheap
- Thread starter johnrobholmes
- Start date
I think so. If the spokes bend where they enter the nipples, you might need to swap out the nipps for some with slenderer bodies and spherical heads, like Sapim. Seems like the spoke angle should be fine, though.
Chalo
Zen_Shenron
1 W
Doesn't the manufacture recommend a radial lacing pattern for these hubs?
I am not saying that is the best or only way, as I understand it there are reasons for not lacing a rear wheel radially, just saying that is what I remember reading in the instructions for this hub.
This snippet is taken from the Sheldon Brown site and poses a few good reasons against lacing it radially, a very informative read for newbies like myself.http://sheldonbrown.com/wheelbuild.html
Radial Spoking
Radial spoked (cross 0) wheels have the spokes going straight out from the hub. This pattern is only suitable for front wheels that don't use hub brakes. They are very cool-looking, and are often a good choice for the ultimate in performance, because they are slightly lighter and, in theory, may have a very slight aerodynamic edge.
There are two things to watch out for with radial wheels. Because the nipples point straight inward from the rim, they can turn more easily in most rims than when they are bent to a slight angle by a semi-tangent spoke pattern. This ease of turning increases the risk of their unscrewing themselves on the road. To prevent this, nipples on radial wheels should not be lubricated, and it is a good idea to use a spoke adhesive such as Wheelsmith Spoke Prep or one of the milder flavors of Loctite ® on them. (Or, if a rim does not have recessed spoke holes, the rim tape and air pressure in the inner tube will keep the spokes form turning -- at least with a high-pressure tire).
The other potential problem with radial wheels is that the spokes, trailing straight outward on the hub flange, can possibly rip the outer edge of the flange right off along the line of the spoke holes. This is most likely to happen with small-flange, 36 hole hubs, because there is less metal between the spoke holes. If a used hub is re-laced radially, the notches left by the old spokes can act as stress risers, further weakening the flange.
I am not saying that is the best or only way, as I understand it there are reasons for not lacing a rear wheel radially, just saying that is what I remember reading in the instructions for this hub.
This snippet is taken from the Sheldon Brown site and poses a few good reasons against lacing it radially, a very informative read for newbies like myself.http://sheldonbrown.com/wheelbuild.html
Radial Spoking
Radial spoked (cross 0) wheels have the spokes going straight out from the hub. This pattern is only suitable for front wheels that don't use hub brakes. They are very cool-looking, and are often a good choice for the ultimate in performance, because they are slightly lighter and, in theory, may have a very slight aerodynamic edge.
There are two things to watch out for with radial wheels. Because the nipples point straight inward from the rim, they can turn more easily in most rims than when they are bent to a slight angle by a semi-tangent spoke pattern. This ease of turning increases the risk of their unscrewing themselves on the road. To prevent this, nipples on radial wheels should not be lubricated, and it is a good idea to use a spoke adhesive such as Wheelsmith Spoke Prep or one of the milder flavors of Loctite ® on them. (Or, if a rim does not have recessed spoke holes, the rim tape and air pressure in the inner tube will keep the spokes form turning -- at least with a high-pressure tire).
The other potential problem with radial wheels is that the spokes, trailing straight outward on the hub flange, can possibly rip the outer edge of the flange right off along the line of the spoke holes. This is most likely to happen with small-flange, 36 hole hubs, because there is less metal between the spoke holes. If a used hub is re-laced radially, the notches left by the old spokes can act as stress risers, further weakening the flange.
I had this hub a while ago and was disappointed with (manual) shifting force under load. It looked like it is impossible to change the ratio with full throttle on 500W cyclone without breaking something. I had to release throttle, change the ratio and reapply throttle:
http://www.youtube.com/watch?v=KRDjbXTKSp4
For new owners: is this kit powerful enough to shift under full torque?
http://www.youtube.com/watch?v=KRDjbXTKSp4
For new owners: is this kit powerful enough to shift under full torque?
drewjet
10 kW
This is different than the manual shift hub. The manul shift hub took 2 revolutions at the input in the axle. This one requires 4 revolutions and is driven by a motor. I was doing some more testing yesterday and while pulling 2500 to 3500 watts it had no trouble shifting up, (downshifting in Auto will happen as you slow down so no power is being applied). I had a wattmeter on it and it only showed a peak of about 2 amps. I drove about 3 miles and it only used .o5 AH on a 12 volt pack.
rkosiorek
100 kW
circuit said:
i have not timed it. but it can definitely shift fast enough to keep up with the acceleration you can do with the 7 to 10Kw rated input. the shift is actually imperceptible. if you are accelerating fast enough for the actuator to lag, you'll need a bigger CVT. like maybe one out of a unlimited class racing snowmobile.
rick
drewjet
10 kW
I did some testing today. I now have it set up as automatic and it took playing with the shift points a bit to find something I liked. It really is quite easy to do.
Anyways I tested it out on my electrathon. This is currently set up as follows. 3 wheels, 2 yellowtop lead acid 12v batteries (24v) Etek brushed motor, total all up weight about 375 lbs, top speed about 28 MPH. With the Nuvinci set at a fixed point, geared for a top speed of about 28 MPH, acceleation was as follows, 0 to 10-MPH 5.1 seconds, 0 to 15-7.2 sec, 0 to 20-10.6 sec, 0 to 27-20.5 seconds, at 27 mph I let off the throttle and the CA said I used .493 AH. I redid the same test 3 times to get average of the numbers, they were all very close.
Next I redid the test having the Nuvinci in Auto mode, speeds were 0 to 10 in 2.6 Sec, 0 to 15-4.5 sec, 0 to 20 7.2 sec, and 0 to 27-13.8 sec. And only .425 AH used. Top speed also increased to 30 MPH. But really it could be set faster based on what you program it with, but the amp draw gets too high to be of any use to me.
That's with only about 9 shift points, I think it can be even better optimized, just need some serious track time to really dial it in.
Needless to say I was quite amazed at the difference.
So to those who say electric doesn't need gearing, I think that proves them wrong.
Anyways I tested it out on my electrathon. This is currently set up as follows. 3 wheels, 2 yellowtop lead acid 12v batteries (24v) Etek brushed motor, total all up weight about 375 lbs, top speed about 28 MPH. With the Nuvinci set at a fixed point, geared for a top speed of about 28 MPH, acceleation was as follows, 0 to 10-MPH 5.1 seconds, 0 to 15-7.2 sec, 0 to 20-10.6 sec, 0 to 27-20.5 seconds, at 27 mph I let off the throttle and the CA said I used .493 AH. I redid the same test 3 times to get average of the numbers, they were all very close.
Next I redid the test having the Nuvinci in Auto mode, speeds were 0 to 10 in 2.6 Sec, 0 to 15-4.5 sec, 0 to 20 7.2 sec, and 0 to 27-13.8 sec. And only .425 AH used. Top speed also increased to 30 MPH. But really it could be set faster based on what you program it with, but the amp draw gets too high to be of any use to me.
That's with only about 9 shift points, I think it can be even better optimized, just need some serious track time to really dial it in.
Needless to say I was quite amazed at the difference.
So to those who say electric doesn't need gearing, I think that proves them wrong.
StudEbiker
100 kW
Wow, those are impressive numbers! I am getting very tempted to put the Nuvinci kit behind the Bike E if I can't get the Sachs 3x7 sorted out. So the Nuvinci totally just shifts automatically under power with a smooth acceleration? I would still be running with a jackshaft mid-drive set up though and I'm not sure that's a good way to go with this kit.
As I understand it, you basically tell the Nuvinci what pedal cadence you want to maintain and it shifts for you to keep that cadence right? I'm just wondering if my application is well suited for the Nuvinci or not. The way the setup is right now, the jackshaft is turning a little faster than I would like to keep a cadence with my pedals.
With the Nuvinci, I could just program it to keep the jackshaft turning at a good pace for the cranks and still get the speed I want right, or is there something I'm forgetting??
As I understand it, you basically tell the Nuvinci what pedal cadence you want to maintain and it shifts for you to keep that cadence right? I'm just wondering if my application is well suited for the Nuvinci or not. The way the setup is right now, the jackshaft is turning a little faster than I would like to keep a cadence with my pedals.
With the Nuvinci, I could just program it to keep the jackshaft turning at a good pace for the cranks and still get the speed I want right, or is there something I'm forgetting??
drewjet said:
What are the Wh/mi. values? Isn't that what you're interested in for an electrathon competition?
I suspect that you did less work, but you did it quicker. You could do the same thing without gearing by increasing the power rate. So its true that electrics don't need gearing.
drewjet
10 kW
gogo said:What are the Wh/mi. values? Isn't that what you're interested in for an electrathon competition?
I suspect that you did less work, but you did it quicker. You could do the same thing without gearing by increasing the power rate. So its true that electrics don't need gearing.
The distance I was going was too short for the CA to give Wh/mi, but obviously it was lower with the Nuvinci, since it took less Ah to get to speed. The difference to top speed was about 200 feet less, so I could of backed off the throttle and continued the 200 feet, travel the same distance in less time and less amp hours.
If I stayed with a fixed gear, and simplyed added more power, the Wh/mi would go up even more as it would put the motor into even more of an ineffecint zone.
What I really need is a test track so I could make some closer to race conditions testing.
The only way I could say gearing would not help is if you had so much power that you could power whelie at any speed up to 90% of your top speed. But then you would be nowhere near the top speed capable, and then if you had gearing, it would help you attain a faster top speed.
Chalo
100 TW
StudEbiker said:
Sachs 3x7 is a fine hub, but it is in no way suitable for more-than-human power levels. It has a modest (I think 250 lbs.) weight rating, which is I believe an attempt to moderate torque loads on the gearbox. One of my friends quickly destroyed a few of them by using them as jackshafts for pedicabs, and those weren't even motor-assisted (nor were the riders unusually big and strong).
The Fallbrook NuVinci N171 is the gearhub you want for power assist. It's always in gear, and it can handle far more power than human legs can supply.
Chalo
LI-ghtcycle
10 MW
StudEbiker said:
+1 for using a NuVinci on your mid-drive, sorry the sachs isn't working out for ya, but I can't imagine why you wouldn't try the NuVinci, sounds like a perfect application!
So good to see so many having good results with these hubs! I'm going to seriously consider working one into next month's budget!
Now if I could just be well enough to finish the pedicabs sitting in my driveway .... good thing I have such a patient customer!
StudEbiker
100 kW
Yeah, I guess I'm gonna give it a shot. The only thing I'm concerned about is if the actuator will clear the frame. The Bike E has an odd geometry in the rear, and I'd still really like to be able to pull the trailer too, which was one of the big reasons for doing this build.
Jay64
100 kW
drewjet, or anyone that has the full unit installed, could you post some pics of everything?
This unit sounds very promising, I tried a Sturmy Archer 8 speed internal geared hub on a Rmartin R10 crank drive to get around the skipping issue with the orignal 11 tooth freewheel underhigh load conditions. The sturmy will not shift under any load up or down and is noisy in certain gears. Now that I have upgrade to 48 volts with lyen 12 FET the sturmy skips in gears higher then first(direct) when the watt draw is 700+
rkosiorek
100 kW
circuit said:I got my invoice today... $149 for NuVinci and ... $217 for shipping to EU.And taxes on top of that. $500 total. Not that cheap. :|
$217? damn, i hope your NuVinci is enjoying champagne and caviar on that flight.
Completely off topic, my parents hail from your area, except They called it Wilno and they speak Polish. i visited that area back in 1970 with my parents. they wanted to see what was left of used to be their parents old farms from before WWII. nothing of course.
rick
Jay64
100 kW
drewjet said:
I just got my 20" wheel laced up. The guy said he tried a 4 cross
and it didn't work so he did a 3 cross. The spokes look bent as hell to me going into the nipples.
LI-ghtcycle
10 MW
Jay64 said:drewjet said:
I just got my 20" wheel laced up. The guy said he tried a 4 cross
3 cross for a NuVinci Hub?!!?! That sounds like all kinds of terrible!
Hope it works out for ya, but I can't imagine the nipples are going to last long like that.
Jay64
100 kW
I was kind of concerned looking at it when I took it home, but the bike shop "professionals" told me this was the way to do it, so I took their word on it. I'm not that into bicycles, so I took their word on it. The more I sat here an looked at it, the more concerned I was. Before I went down there, I hadn't read all 16 (at that time) pages of this thread. But after becoming more concerned with how bent they were, I read through the whole thing. And now I have read that guys are doing 1 cross and radial. The problem was that was the only local shop that cut spokes. I didn't know enough about spoke lacing to refuse the workmanship. So what would be the general consensus for getting them relaced, 1 cross or radial? I hope to get this in a pretty powerful bike, so it sounds like 1 cross might be better, or am I backwards on that? Again, I'm not that into bicycles, so I gotta go with your guys' expertise on this. I think I better just have them cut the spokes for me and try and learn how to lace them up myself. I don't think I can do much worse than they did.
edit: P.s. are these nipples still usable if I unlace the wheel and put in new spokes for 1 cross or radial? Or would this bending have cause some damage to them?
The problem was that was the only local shop that cut spokes. I didn't know enough about spoke lacing to refuse the workmanship. So what would be the general consensus for getting them relaced, 1 cross or radial? I hope to get this in a pretty powerful bike, so it sounds like 1 cross might be better, or am I backwards on that? Again, I'm not that into bicycles, so I gotta go with your guys' expertise on this. I think I better just have them cut the spokes for me and try and learn how to lace them up myself. I don't think I can do much worse than they did.edit: P.s. are these nipples still usable if I unlace the wheel and put in new spokes for 1 cross or radial? Or would this bending have cause some damage to them?
drewjet
10 kW
That looks really bad Jay. I think radial is the way to go for a 20".
I don't have a lot of miles on my 20" radial Nuvinci yet, but I have tried to push it pretty hard, and remember it is in a trike so no leaning and so far my radial is holding up fine. Granted I am only pushing about 3500 watts max.
I would take it back and tell them to redo in a radial
I don't have a lot of miles on my 20" radial Nuvinci yet, but I have tried to push it pretty hard, and remember it is in a trike so no leaning and so far my radial is holding up fine. Granted I am only pushing about 3500 watts max.
I would take it back and tell them to redo in a radial
StudEbiker
100 kW
Just a word, if you look in the manual that came with it, and then follow that to the page on the Fallbrook website, it advises to use 1X on wheels smaller than 26". Page 7 & 8 on this page (http://www.fallbrooktech.com/docs/Nuvinci_Technical_Manual.pdf) has the info regarding wheel building. They don't even recommend 3X on 700c wheels. They actually specifically say, never use more than 2X lacing. Hopefully you can get them to redo it.
StudEbiker
100 kW
Jay64 said:
I have to say, I don't enjoy building wheels very much, but if you take your time, it's not too bad and you certainly won't do worse than those yahoos did!
I would think the nipples would be okay as long as they didn't round them off when tightening. If they are even a little rounded though, I would go with new ones. Keeping the nipples square is a skill I haven't quite mastered yet and if it will be your first build you may want to start with the best stuff you can.
rkosiorek
100 kW
1 would recommend the 1X. some cross is better than no cross.
In a 20" wheel (406mm or 16" diameter rim) 3 cross is too much. the spokes are bent right at the weakest part. the spokes are weakest at the thinest part, right where the thread starts. and that is exactly where they are bent. for highest strength nipples should be in line with the spoke.
even 2 cross would be a bit dicey. but 1 cross makes for a nice even wheel. even the NuVinci manual recommends 1X.
Those 3X spokes should be long enough to re-cut and use for 1X.
as for re-using the nipples? You would have to inspect them first and see how mangled they were when they were tensioned. but since you can usually buy 100 plated brass nipples for about $10 i'd say don't bother, just get a new set.
rick
In a 20" wheel (406mm or 16" diameter rim) 3 cross is too much. the spokes are bent right at the weakest part. the spokes are weakest at the thinest part, right where the thread starts. and that is exactly where they are bent. for highest strength nipples should be in line with the spoke.
even 2 cross would be a bit dicey. but 1 cross makes for a nice even wheel. even the NuVinci manual recommends 1X.
Those 3X spokes should be long enough to re-cut and use for 1X.
as for re-using the nipples? You would have to inspect them first and see how mangled they were when they were tensioned. but since you can usually buy 100 plated brass nipples for about $10 i'd say don't bother, just get a new set.
rick
