hightekbikes.com motor kit review. Electric bike kit.

[carlerik]

Two things so I'll break up into two posts: First some info on the "700c" tire/wheel, then some CA data for two rides.

Summary: the HighTek "700c" rim is for a 29-er tire, min. 1.9in width (48mm)
So this weekend I was all geared up for a test run with my new WattsUp meter, still using crimped 14AWG wires on my SLAs. Pumped up the tire a bit to 60psi and as I left the driveway "KA-POW!!!", the tire tube blew, ears ringing. The tire was rated to 80psi so I knew what had happened: neither my 700c tube nor my 700x47c tire were correct for this rim- the tube had pushed the tire bead off the rim and split along the circumference where it bulged out (about 4inch split).

So here's the deal if you get a "700c" rim for the Aotema motor (probably goes for WE and other kits): the rim is for "29er" size tire, which is essentially a very fat 700c diameter. These are meant for a 29-er MTB, not a hybrid or road bike with 700c wheels. The rim is in fact the same diameter as a 700c wheel road bike (622mm), but the rim width requires a minimum of 50mm tire or more. These tires are usually sold as "29x1.9" (= 622-48 ISO) or "29x2.1" (= 622-53 ISO) etc. see http://www.sheldonbrown.com/tire_sizing.html These tires are meant to balloon over the rim, with the bead still resting firmly inside the rim edge. With a "700c" tire the tube puts more pressure against the bead and rim wall, so if the tire is too thin for the rim it will pop off.

I got a "Kenda Small Block-8" 29in x 2.1 (about $45) which fits nice and tight now when inflated, but it will slip right off when mounting/dismounting. Not like my old 26" Raleigh roadster tires which needed a crowbar! This has created other problems for me: I had to take the front fender off and the tire brushes the cable of my front centerpull brake, so I threw a bolt in the fender hole to hold the cable out of the way for the time being. So now do I want to buy long reach brakes as well?

$75 and two tires later I think the best solution for me will be to rebuild the wheel on a smaller rim and use the 47c or smaller tire, which is what I wanted. The bike looks weird with the monster 29er on the front and the 622-38c on the back. Maybe I should buy a new bike?

 

[carlerik]

Here's some WattsUp data from my last two rides. Mileage was adjusted about 3% as my cycle computer was not calibrated for a monster 29-er tire (622-53) but the route mileage was known so I could adjust afterward.

First ride= fast and hard throttle up hills, mixture of peddling/ no peddling
2nd ride= part of my morning commute. Peddling , some long 6-10% hills, but slower and I tried to draw < 10-12amps most of the time.
Using 48v Powersonic 10.5Ah SLAs

Ride 1
8.8 miles in 22 min, avg 24mph
4.867 Ah
224.5 Wh
23.6 Ap 43.19 Vm 1094.6 Wp
=25.5 Wh/mile ; .553 Ah/mile

Start Voltage ~52.4 (1 day rest after full charge) ; End Voltage 48.82

Ride 2
7.6 miles in 24.25 min, avg 18.8mph
3.097 Ah
147.4 Wh
24.18 Ap 44.26 Vm 1105.5 Wp
= 19.4 Wh/mile ; .408 Ah/mile

Start Voltage 54.34 (right off float charge) ; End Voltage 49.84

Note I did pull a little over 24A on the second ride, about 1amp more than reported earlier in this thread. Could be my still shaky crimped batt connections and 14AWG wire (I haven't connected my Andersons yet) or the fact that I started on a higher voltage off the charger.

A note on the groaning sound under load/hills: I noticed this doesn't always occur under high amp draw/steep hills. Sometimes the groan happens with only 5 amps drawing, but usually it starts under a hard hill with higher amp draw. It seems like a heavy work load (high amps + hill) will get the groan going, but it will continue or come right back a little even at lower current (~5A). I think this could be a harmonic ringing that continues as the motor pulsates and the metal resonates with this at a certain frequency. Anyway, the groan is definitely a clue that you're working the motor harder but you're not necessarily drawing high current the whole time you hear it.

I kept to around 10-12A for most of the hills (peddling) and still heard it on occasion.

Carl

 

[Christobel931]

My motor makes the same noise if I try to start from a dead stop, or when I'm on a steep climb and the motor start to slow and work hard.

I think its normal, just some vibration that is amplified by the spokes and wheel.

 

[Russell]

Two things so I'll break up into two posts: First some info on the "700c" tire/wheel, then some CA data for two rides.

Summary: the HighTek "700c" rim is for a 29-er tire, min. 1.9in width (48mm)
So this weekend I was all geared up for a test run with my new WattsUp meter, still using crimped 14AWG wires on my SLAs. Pumped up the tire a bit to 60psi and as I left the driveway "KA-POW!!!", the tire tube blew, ears ringing. The tire was rated to 80psi so I knew what had happened: neither my 700c tube nor my 700x47c tire were correct for this rim- the tube had pushed the tire bead off the rim and split along the circumference where it bulged out (about 4inch split).

So here's the deal if you get a "700c" rim for the Aotema motor (probably goes for WE and other kits): the rim is for "29er" size tire, which is essentially a very fat 700c diameter. These are meant for a 29-er MTB, not a hybrid or road bike with 700c wheels. The rim is in fact the same diameter as a 700c wheel road bike (622mm), but the rim width requires a minimum of 50mm tire or more. These tires are usually sold as "29x1.9" (= 622-48 ISO) or "29x2.1" (= 622-53 ISO) etc. see http://www.sheldonbrown.com/tire_sizing.html These tires are meant to balloon over the rim, with the bead still resting firmly inside the rim edge. With a "700c" tire the tube puts more pressure against the bead and rim wall, so if the tire is too thin for the rim it will pop off.

I got a "Kenda Small Block-8" 29in x 2.1 (about $45) which fits nice and tight now when inflated, but it will slip right off when mounting/dismounting. Not like my old 26" Raleigh roadster tires which needed a crowbar! This has created other problems for me: I had to take the front fender off and the tire brushes the cable of my front centerpull brake, so I threw a bolt in the fender hole to hold the cable out of the way for the time being. So now do I want to buy long reach brakes as well?

$75 and two tires later I think the best solution for me will be to rebuild the wheel on a smaller rim and use the 47c or smaller tire, which is what I wanted. The bike looks weird with the monster 29er on the front and the 622-38c on the back. Maybe I should buy a new bike?

What is the INTERNAL width of the rim? The internal rim width is what determines the tire width range that safely can be mounted on the rim.

See here for more info: http://www.schwalbetires.com/tech_info/tire_dimensions#rim

The rim that came on my Nine Continent front wheel has an internal width of 19mm which according to the Schwalbe site can accommodate a 28mm to 50mm wide tire. I currently have a 700x35C tire mounted to the rim. I don't think I've seen a rim which requires a MINIMUM 50mm wide tire but maybe somewhere there is one. There's also the chance that you didn't have the tire properly mounted in the first place so that's why it blew off.



-R

 

[carlerik]

I don't think I've seen a rim which requires a MINIMUM 50mm wide tire but maybe somewhere there is one. There's also the chance that you didn't have the tire properly mounted in the first place so that's why it blew off.
-R

Yeah well here's one! The rim is 24.5mm internal width. Confirmed by 2 bike shops that said "man, that's a fat rim!"

 

[Russell]

Yeah well here's one! The rim is 24.5mm internal width. Confirmed by 2 bike shops that said "man, that's a fat rim!"

Yeah that IS too wide. I just laced my Bafang into a 700C Sun Rhyno Lite and it's pretty wide (22mm internal/27.5mm external) but the bike its on now uses 700x47 tires and I plan to upsize when they wear out.

One reason I didn't go for the kit from HighTekBikes was the rim, which is single-wall, but I didn't know it was THAT wide to boot (Schwalbe site says 44mm tire would be minimum). I'm ending up re-lacing the 9C motor that I recently purchased into another rim anyway but not because of quality concerns, rather it's to match the front to back. The rim I'll be using is the Sun CR18 I had the Bafang laced to before the Rhyno Lite. The CR18 is the perfect size rim (17.5mm internal width) for hybrid bikes with tires around 35mm wide.

-R

 

[HTB_Terry]

That is good info and news to me. Having never used a bike with 700C wheels, I was not aware they all use thin tires. I am going to find a more suitable rim for the 700C and just charge extra. I'm also going to offer an option for a better rim on the 26". If the existing rim is the same diameter, you can always toss the included rim and mount the motor in the existing one from the bike. That way they will be matched. If a customer wants me to mount the motor in their rim, I can do that also.

 

[Russell]

That is good info and news to me. Having never used a bike with 700C wheels, I was not aware they all use thin tires. I am going to find a more suitable rim for the 700C and just charge extra. I'm also going to offer an option for a better rim on the 26". If the existing rim is the same diameter, you can always toss the included rim and mount the motor in the existing one from the bike. That way they will be matched. If a customer wants me to mount the motor in their rim, I can do that also.

Well I wouldn't say all 700C bikes use "thin" tires but most bikes with 700C wheels which people would most likely think about converting are probably hybrid or comfort bikes with perhaps 35-40mm wide tires. If you pick a rim with an internal width around 19mm you cover almost the full range of possible tires from 28-50mm wide (according to Schwalbe) with the ability to use up to 60mm if the pressure is kept lower.

Custom wheel building would be a great option to provide prospective customers since it's not nearly as easy as it might sound to lace a motor into a rim, to do it right you need key dimensions for the motor and the rim to get the proper spoke length, and you need some experience with truing a wheel. For this reason it's not something a newbie might even consider and definitely not as simple as you make it sound.


-R

 

[dogman dan]

That's true, your local bike shop may even not be able to do it right for a motor wheel. It would be great to be able to send Terry a rim and get it back with a proper lacing on the motor for a reasonable charge.

FYI, just about 1400 miles on the motor now, including some nonstop rides of up to 50 miles. The longer rides were done slow to get the range, so heat was no problem then. In 15 mile full throttle rides at 95F so far, the internal temp of the motor is reaching equilibrium at around 160F or slightly above. Even though my thermometer stops reading at 160, I can tell by how quick it cools off when I stop that it is not much above that. Hub cover temps have never been above 112F, so it is looking to me like my 15 mile ride will not be a problem on even the hottest days. These 15 mile rides include about 1000 feet of uphill and 200 feet of downhill along the way. On flat ground, longer rides at full throtte may be possible.

The one thing I have learned about the motor heat since I put a thermometer inside it is that hills can heat up a motor good in any weather. Some riding I did while spectating at the Tour of the Gila showed that. I'd say if you are climbing more than 1500 feet in one hour, you should be checking to see how hot the hub covers are. If the hub covers read above 140, you should be in the area of 190F inside, so that would be a good time to let the thing cool if not sooner. In other words, a half hour at a time continuously climbing 7% hills is going to get the motor pretty warm. That would be say, 3 or 4 miles of steep climbing. At the race, it was about 50F, and I climbed 4 miles of 4% topped off by a mile of 7% and the motor got nice and hot by the top, reaching 160F inside. Surrounded by spectators that pedaled it, I had some real respect for them.

 

[carlerik]

[quote="Russell"][quote="HTB_Terry"] If the existing rim is the same diameter, you can always toss the included rim and mount the motor in the existing one from the bike. That way they will be matched. If a customer wants me to mount the motor in their rim, I can do that also.[/quote]

Well I wouldn't say all 700C bikes use "thin" tires but most bikes with 700C wheels which people would most likely think about converting are probably hybrid or comfort bikes with perhaps 35-40mm wide tires....

Custom wheel building would be a great option to provide prospective customers since it's not nearly as easy as it might sound to lace a motor into a rim, to do it right you need key dimensions for the motor and the rim to get the proper spoke length, and you need some experience with truing a wheel. For this reason it's not something a newbie might even consider and definitely not as simple as you make it sound.
-R[/quote]

Agreed. I've taken back my fatso 29er tire and exchanged for a Mavic A319 rim (19mm), which was labeled to handle 35-50c tires. I'm having the shop lace the wheel for me since I haven't done it before and don't want to screw it up. This is the second time I've had wheels rebuilt and the pricing is pretty standard-
$35-50 labor, +$1 per spoke + the rim cost ($30-60 for a decent one). My rim was $55 so the cost will be $105-141 depending on whether they can salvage the spokes (labor is $50 at this shop, ouch). Rims can differ concerning the eyelet position, double/single wall etc, so there is no guarantee that the old spokes can be used. Most shops just cut the old ones because they won't build a wheel they can't guarantee.[ATTACH type="full" alt="DSCN1859.JPG"]22580._xfImport[/ATTACH][ATTACH type="full" alt="DSCN1860.JPG"]22581._xfImport[/ATTACH]Please ignore my battery/controller setup for the time being--I'll be adding a bracket to hold the controller between the heavy duty rack and the seat. I'll have the new rim back in a few days and will post photos of my final setup in the appropriate thread.
-Carl

 

[dogman dan]

I've been riding the fusin motor lately so this thread was inactive for awhile. I still intend to do some extreme heat testing, but mother nature is not cooperating. We got a good rain in late May, and with some humidity around we are not getting above 100 yet this year. Most years, by now we are getting 105 and in some years 112 by June 10th. Sill no 100's in the 7 day forcast.

Continuing the ride across New Mexico this weekend, I put about 90 miles on the aotema bike. One day went through the mountains between Edgewood, and Santa Fe. That was a 60 mile day and since the weather was quite cool in the morning, temperatures on the motor was not a problem. The ride included some big hills though, mostly at about 5% maximum. Some stretches of less than a mile of 7% The route dropped about a thousand feet, then climbed a thou, dropped a thou, and climbed it back again. Also a good bump about midway of about 500 vertical So about 3000 vertical down and 3000 vertical back up to Santa Fe. I knew I chose the right direction of travel when I came to a sign indicating I was about to descend a 15% grade! Steepest paved road I know of in New Mexico for sure. There was about 3/4 of a mile of it before it eased off to 7% or so. Map my ride showed it as 7%, but I guess I need to look at the steeper parts in a finer scale for the mountains in the future!

The bike was loaded with 30 pounds of batteries, and more water and tools than usual. I didn't actually weigh it, but I am thinking I was pretty close to a 100 pound bike. The extra 30 pounds of stuff didn't seem to slow me down too much, but I did climb hills a bit slower than on the commute to work. Still, I climbed several stretches of steep mountain grades with no problems. Only one hill made me really pedal hard, but that was because I upshifted too soon thinking I was at the top, and wasn't.

One of the fun features of this day was riding through Madrid NM on a sunday. Madrid is the location where they filmed the movie Wild Hogs, the motorcycle comedy about the middle age wimps with harleys meeting real New Mexico bikers. Anyway, on a sunday the road was full of large motorcycles headed for a beer at the bar in Madrid, and along I come on my wild piglet. For sure the smallest motorbike in town.

The other fun thing, lots of roadies on the streets around Albuquerque and Santa Fe. Very nice to be breezing along the bike trail on the river in albq, watching all the sweat on the pedalers as they went by the opposite direction. On the ride to Santa Fe, I got passed by some very tough looking roadies on the flats. I was riding a steady pace of about 13 mph to make the batteries last 60 miles so they blew by me. About 3 miles later, climbing a mountain pass, I breeze by them at my steady 13 mph to thier astonishment. I did slow down long enough to show them the motor, and explain that I was a cheater. They still tried to not get passed though, but no way could they maintain 13 mph up 7% grade and soon they were waaaaay behind me. No way can you compare what I was doing to what they are capable of, but still, I felt real good knowing I would make it all the way to Santa Fe easily.

 

[RTLSHIP]

how do you recharge your batteries when you are between towns?

 

[dogman dan]

At 12-13 mph, I can get more than 40 miles out of the 36v 20 ah ping, and on this trip I got 18 miles out of the 48v 8 ah nicad pack so between the two a 60 mile day was no problem except for the saddle sore. I could have made it to Madrid, and then charged there while drinking in the bar with all the wild hogs.

I find riding so slow just fine out on the road. On the daily grind to work, I just want it over with asap and ride full throttle. Out here though, there are some places with 70 miles between anything at all and places like that I have to drive out there in the car, and then ride the route as far as possible out, and then return to the car. I'm doing this as a way to see my state more intimately, by bicycle. So I don't mind cheating some. Sections I ride both ways, I consider as credit towards not riding a few spots that are not scenic, or get awkward in other ways. I'm skipping about 10 miles of riding through albuquerque, from the mountains down to the river for instance. To dangerously urban and I don't feel like finding the safe route.

 

[RTLSHIP]

I recently got a flat tire (on My BD 36 rear) and I'm in the process of upgrading my 2009 Aotema and BD 36 tires with self-sealing inner tubes.
Do you use self-sealing tubes with slime etc? they can help with thorns and slivers of glass etc. I guess a small pump will still be needed.

 

[dogman dan]

In the land of thorny desert plants, I use about twice as much slime as they recomend, and use only the thicker, chunkier stuff for truck tires. The slime in prefilled bike tires is thin and doesn't have the hole plugging chunks. Sometimes my wheel really hops for the first half mile till the slime spreads out better.

 

[RTLSHIP]

this was my first ebike flat ever. The BD36 rear tires have almost 2500 miles. These kenda tires are puncture resistant but not puncture proof. Of course, the greater the tire wear, the thinner the tire becomes. In my experience, the rear tire wears faster and obviously has to hold more weight/friction. In S Florida, flats aren't a big problem. Most of my flats happen on the sidewalks.

 

[dogman dan]

Finally got a warmish day of 95F, and I can say that this motor can definitely go 15 miles nonstop in that temp without overheating. It got hot, about 170f at the windings, but never did get much hotter. It sort of peaked at 150, and then got another 20 F climbing the steep hill. The real torture test I had planned is not happening, totays weather is supposed to be spotty rain, and 85F . No 110F weather is likely with humidity present.

 

[dogman dan]

Today it got to 100F for the first time this summer, so I took the aotema out for a heat test. Starting at 100F, the ambient temp, gave me 60 degrees to play with before the motor gets to the point I don't like to exceed, 160F.

Riding on nearly flat ground, on a circuit 5 miles uphill, and 5 miles down, I hit 160F at 9.5 miles. I was riding full throttle, and pedaling to about 2 mph faster than the 36v max speed of 23 mph. So with the pedaling, a pretty low amp rate, certainly not over 15 amps. The temps rose fairly quick for the first 5 miles, and then slowed some, as the differential between the motor temp and ambient temp increased. I have noticed this before, that the motor will reach equilibrium where the motor temp is about 80-100 F above the ambient. This is fine when it's 80F out, and the motor reaches 160F max. But if it's 110 F out there, then your motor is heading for 200F, which I think can damage it, usually by melting the magnet epoxy.

So the ride limit I used last summer, after melting a brushed hub, seems pretty right on for the aotema too, about 10 miles max, of pretty flat , full throttle riding in 100 F weather. Earlier testing on cooler days has shown though, that slowing down just a little bit has dramatic effects on motor heating. With less watts going in, the motor will hit equilibrium at a lower temp, allowing unlimited riding without getting much past 160-170F.

So far, the motor shows no signs of damage from riding at 160F-170F. So if it gets to 95F, slow down to 19-20 mph, and if it is 100, slow down to 15-16 and your motor should last forever.

Hills are another story, to be tested another day. I suspect that in 100 F, If I run up and down my one mile long 6% hill, I'll overheat in three laps. Usually just one trip up it adds 20F to the motor temp. So a three mile long steep hill will overheat the motor in hot weather.

 

[RTLSHIP]

You can feel the difference. The BD36 gets much hotter than the Aotema. I suspect the problem is magnified at 48v.

 

[dogman dan]

Oh yeah, the brushed hubs are not for my climate. I remember seeing 140F measured on the cover, riding downhill on a chilly morning once on a bd 36.

Today I did the full 15 miles, up a thousand feet of hill, ride home in 100 F. The motor got hot fast, despite two stops on the way. Just before the hill, I came out of a store and the hub was at 145F, and was overheated by a mile later at the top. However, it never did get much hotter than 158F. The last five relatively flat miles to home climb 200 feet, and the temp just hovered there, sometimes reading high temp, and then later showing 158, back and forth. At the hilltop I slowed down to helf the hub cool, but at 100, I just couldn't stand it. Without the 25 mph breeze it was just too hot. I had some tailwind, so riding slow was like no wind. I said wtf, and just started riding fast again, and felt better. I guess the hub did too, since it didn't seem to exceed 158 by much.

The highest temp I measured on the hub cover, actually on the axle, was 116, when the hub inside read 156. So the hub was running 40F hotter. In cooler weather, it would usually be closer to 30F hotter, so one thing to know if you are just monitoring the external temps, is that the difference gets bigger in hotter weather.

So consider 120 on the axle outside to be a max safe temp in hot weather, if you want to ride with the hub under 170 F.

This is all done with the stock controller, unmodified, at 36v lifepo4.

The good news is, as long as you aren't climbing a steep hill, the hub seems to want to stay right around 160F and not go much higher. 8) Even in 100F weather. I'm beginning to suspect that with this kit, riding on relatively flat ground, you can ride in about as much heat as your body can stand without melting the motor. Hills of course, can kill just about any motor if they are long enough. But 1000 feet of vertical seems doable even in 100F with this motor kit.

 

[RTLSHIP]

Does the bike run slower with that kind of heat?I've read (and seem to experience) that the BD36 hub gets hot and will not go as fast as possible. Also, I started using 48 v on the BD36 and one of the brush-springs got jammed. I replaced old brushes w/new. Maybe it was just a coincidence that the spring jammed. It could have been jammed before the 48v.
It took a while for the uneven brush contact to become no contact. 1 brush was half an inch leftover. The other one had 1/3 leftover but worn at an angle. 2300 miles.
The Brushless gets warm in ordinary hot humid weather, whereas the bd36 hub gets so hot you have to quickly remove fingers f/ hub. This is at 48v

 

[dogman dan]

Yes, when the motor overheats, it will run slower. I can feel this effect with both brushed and brushless motors. Before I wized up, I used this to tell when I was getting too hot. Now I use a remote thermometer, and stop before it gets so hot. I can begin to notice this slowing down somewhere around 150F inside the hub. I bet the brushed hub I melted was gettting to 200F everyday, for the 400 miles it lasted. You couda cooked a burrito on it.

Today on the ride home, again in 100F, I tried a watercooling method. I have tried pouring water over the hub, but found it not so much better than just waiting. Today I draped a hankerchief over the hub and poured water over it. Since the cotton held the water in contact, it cooled the hub much faster. 10 minuites of this, and the hub cooled 30 degrees. Then I was able to start the big hill cooler, and ride home full throttle from the top. Again, the motor seemed to get to around 160-170 and stop getting hotter once I was back on flat ground at the hilltop. It would be interesting to keep going another 10 miles, but in 100F, Uggh.

 

[RTLSHIP]

It takes about 30 or 40 minutes for my bd36 hub to cool down. This is inside home w/ air conditioning. Hub feels room temp in 40 minutes.
You are going a little conservative with brushless because of last years experience. I don't blame you. There's a difference between riding hard and torture testing. What you did last year probably goes beyond factory/engineering tests.

 

[dnmun]

dogman, why not make a band of soft cotton, like an old sock cut into a long strip which would soak up and hold the water around the hub.

if you leave it in place it will insulate a little, but you could put velcro on it so you could remove it for the winter when you don't need extra cooling, or just tie it in a knot, and then in the summer just keep adding water to the sock/cotton band to keep it wet and see how hot your motor gets then. then you could add just a little water at a time while running.

i think the brushes add a ton of heating, more than the brushless, because the sparking of the brushes adds heat.

 

[dogman dan]

Yeah, since the day I smoked a motor in 30 minuites in 60 degree F weather, I got a lot more conservative. That one was the 24v heinsmann, overvolted to 36v, and overamped from 20 to 35. It gave me an eye opener to how fast it can go bad when you have no monitoring of temperature. It may well be that the brushed motors can handle 200F inside, but they do start to run slow when really hot so that's bound to be hammering your battery, controller can't be loving it either, so coservative seems sensible. I got my max temp from the EV Global 24v motor, which had a 70c temp switch inside. Good enough for a german engineer is good enough for this guy with german ancestors.

I did try the sock trick at the start of the summer. I cut a long tube sock into a strip, and wrapped it on the hub, tying it in place to iteslf. It cooled good while stationary, but as soon as you rode, It would sling the water off and dry itself. Then it would insulate, and I was leery of insulating exactly where the magnets are epoxied on the motor. But while stopped, any old rag helps with the cooling over just pouring water on. The ideal thing would be one of those personal, portable misters. You could mount the mister on the fork on the no wires side, and then put the tank in a waterbottle holder. For me, I think the wet rag and a short stop will do me, I just need to start up that hill cooler so I don't overheat till I'm on flat ground again. The best solution is the one I used at the end of last summer, parking a car at the bottom of the hill, and driving with the bike on a rack the last 6 miles.