BMC modified Specialized Crossroads Hybrid 75v lipo 15amp

Hi all,

Been here for a bit reading and learning and decided on Ilia's BMC 600w geared hub. I love to ride my bike but I have 35 mile limit before my butt gives out not to mention I'm beat to shit. I can keep a 15 to 16 mph average but I've seen all the sights I can starting from my house. So I figured if I can do say 20 something mph I could get that much farther and see some new sights. At first I was thinking a Cyclone or R/C set-up but too many bad stories with the Cyclone and R/C was too expensive. I wanted something pretty powerful at the start which led me to the geared hub motor. For power I wanted to use my R/C helicopter lipo batteries. I have 14-6s 5000 batteries. Most are 35C but I have a few 30C which is only 29 to 34 more C than I need. Ilia recommended the 600w over the 1000 watt one because I wanted something that would pull me up a 15% grade all day long and the 600 watt can be run at 75 volts where as the 1000 watt is only up to 60v or something like that. I didn't want have to purchase any other batteries so what ever system I was going to use had work on either 22.2, 44.4 or 66.6 nominal volts. I only have a few long steep grades but being 210 lbs and 6'4" I wanted to make sure I had plenty of get up and go. The bike is a 2008 Specialized Crossroads Hybrid 21 speed with 700 rims. All aluminum frame and the whole bike weighs in at under 28lbs. Since I'm tall I went for the XL and it's like riding a Clydesdale.

So my kit shows up on Monday and the fun begins. I got the kit with the 700 wheel installed and rear cassette so switching things over was fast. I also opted for the torque arm since my bike has an aluminum frame. I taped all the wires to either brake or derailleur cable for a bit of a stealthy look. See the pictures for the install. I custom made a series/parallel cord with all Deans Ultra connectors. It's made up for 3s3p 6s 5000 lipo packs for a 66.6 volt nominal 75.6 volt hot off the charger and a full 15 amps of which 12 amps are available for use sticking to the 80% rule. I got the Cycle Annalist also and programmed it for a max of 15 amps as per Ilia.

So on to the ride. I put in 9 fresh packs and off I go. Good gawd does this thing have some torque. Off the bottom pulls like a train. I ran around pretty much full throttle the whole time with no peddling. I was able to hit 35 mph sitting upright. I rode for about 8 miles and used about 2 amps whether good or bad. Power is nice and smooth. Riding this bike now is like walking down an escalator, you move twice as fast. I can peddle and easily do 35 mph....how cool is that? Tomorrow I'll try to do a nice long ride and see what my range will be. I'm hoping for 35 to 40 miles with major peddling.

Wish me luck....

Tom

Looks like something that might work with my bike .....





did you consider a 9c motor ?

How many gears after the hub motor installed ?

Hi, some advice

Nice setup and yes not surprised with the speed that you are seeing however that's a lot of power to reliably push through a BMC, you are running 66V at 35A, that's over the limit for those motors and controllers. The old school xltye controllers as you are using will work but the switching speed with the high rpms on the halls used to blow controllers frequently.

I have repaired so many of these motors and controllers now just passing a bit of advice along to you as I don't want to see your new ride compromised, the absolute top voltage you should run on these motors is 50V @ 35A any more than that and you are going to seriously affect its reliability its not a question of if but when it breaks.

Also keep hard starts down to a minimum and peddle or make rolling starts where you can, this will save the gears and the one way bearing, watch your motor temps as well excessive hill climbing or long high speed runs will cause the motor to warm, I have seen these get so hot the solder has melted just under the hub cover where the axle wires join.

Thanks for sharing and enjoy your new machine however I would highly recommend you drop the voltage down, I run the exact same set-up but with 12S2P 50V 10AH its the best compromise between power and reliability and it will still push you along at 30MPH which should be enough for anyone especially a newbie! my first bike only did 17mph no peddling and I thought that was magic!!

Cheers for sharing and have fun, stay safe and fit a handle bar mounted stop switch or change the throttle to a Magura, those hall effect throttles are notorious for going south, you can just get a mini moto stop switch off EBay and wire it in to the brake line on the controller, I have put this on all my rides and I am using Magura throttles, you wont stop this thing with your brakes if your throttle fails!

Happy Ebiking!!

Knoxie

jmygann said:

Looks like something that might work with my bike .....

did you consider a 9c motor ?

How many gears after the hub motor installed ?

Click to expand...

They really changed the new ones...looks a lot easier to get on to. Mine is about 40 inches at the seat which makes it tough to throw a leg over.

I didn't want to go direct drive because of the cogging with no power...it will still be a bicycle.

I have all 21 speeds. To note the bike comes with a 14 to 34 which I kinda hated because it was geared so low. The new one from Ilia has 11 to 28 and really suits me much better so I can keep up a decent pace at the higher speeds.

Tom

knoxie said:

Hi, some advice

Nice setup and yes not surprised with the speed that you are seeing however that's a lot of power to reliably push through a BMC, you are running 66V at 35A, that's over the limit for those motors and controllers. The old school xltye controllers as you are using will work but the switching speed with the high rpms on the halls used to blow controllers frequently.

I have repaired so many of these motors and controllers now just passing a bit of advice along to you as I don't want to see your new ride compromised, the absolute top voltage you should run on these motors is 50V @ 35A any more than that and you are going to seriously affect its reliability its not a question of if but when it breaks.

Also keep hard starts down to a minimum and peddle or make rolling starts where you can, this will save the gears and the one way bearing, watch your motor temps as well excessive hill climbing or long high speed runs will cause the motor to warm, I have seen these get so hot the solder has melted just under the hub cover where the axle wires join.

Thanks for sharing and enjoy your new machine however I would highly recommend you drop the voltage down, I run the exact same set-up but with 12S2P 50V 10AH its the best compromise between power and reliability and it will still push you along at 30MPH which should be enough for anyone especially a newbie! my first bike only did 17mph no peddling and I thought that was magic!!

Cheers for sharing and have fun, stay safe and fit a handle bar mounted stop switch or change the throttle to a Magura, those hall effect throttles are notorious for going south, you can just get a mini moto stop switch off EBay and wire it in to the brake line on the controller, I have put this on all my rides and I am using Magura throttles, you wont stop this thing with your brakes if your throttle fails!

Happy Ebiking!!

Knoxie

Click to expand...

Interesting. Ilia recommended going to the 18s pack. I told him I could either do 12s or 18s. I have a cycle annalist which I wrote about in the original post programed at 15 amps. And it does limit the amps. I also have a switch to shut things off. It;s the HML switch in the pictures on the left side. It works but the CA back light gets brighter when I turn the system off with the switch.

Can you point out this throttle you speak of? The thumb throttle I was sent is sticky. Sometimes it doesn't shut off and I have to pull it up with my thumb....not good. I'd like to see the mini moto switch also if it's a direct plug in.

Thanks for the advice....I'll be asking Ilia.

Tom

Hi Knoxie,

I'm just curious to know your range with this Lipo pack because I'm actually building a light bike for pedalling. I like to be able to do about 100 Km in one charge with an Average speed of 30 Km/h in a bicycle path.

Thanks', good day!
Black Arrow

Hi

The 15A current limit will help its the higher voltage thats the problem the high RPM of the rotor causes problems with the old school xlyte controllers they were never designed for that kind of switching speed so they struggle. You would be much better running 12S and upping the current limit to 30A.

The throttle I would use is a Magura see here http://www.4qd.co.uk/accs/pots.html#mag you can get them in the US as well see this link http://endless-sphere.com/forums/viewtopic.php?f=2&t=6145

Stop switch can be wired to the brake inhibit green and yellow wires from memory, see this link for details http://endless-sphere.com/forums/viewtopic.php?f=3&t=4452&p=65926&hilit=+stop+switch#p65926

Hi Black Arrow, the BMC is very efficient compared to the xlyte motors, I can easily do 30 miles on a 10AH pack with peddling it does depend on so many factors, no peddling i can do about half that.

The BMC is a fab motor you just have to be kind to them they wont tolerate the sort of abuse you can throw at the X5, love the X5 as well though as I also have one of those too, i have 3 more BMC motors in other bikes and a modified Kol running my KMX, a stable of amazing bikes all still working as I work them within their limits, great fun just love my e-bikes

Knoxie

Hi Knoxie,

Thanks good to know I'm not really familiar with the BMC motor your motor is the torque version or is the speed version?

I need this ebike to put me back in shape, and 48 Volt with a 25 Ah Lipo's pack is about 75 miles of range wow.

Cool thanks Knoxie for those information's I think it will better fit my needs! good day!
Black Arrow

Hi

It really depends on how you peddle, the BMC is superb IMHO keep them well within their limits they are amazing, this is why I dont understand some folks trying to reinvent the wheel with friction drives and the like I just dont get it combining not very reliable RC motors and controllers with wasteful friction drives when you can already get efficient and powerful systems for less money that wont blow up the first stress that they see bit of a hub motor fan you might be able to tell :lol:

Knoxie

Hi,

I have about the same thinking but I have made allots of ebike before understanding :lol:

I want to keep this ebike in is limit so this kit seems to be the wise choice. I just want to use it for bicycle path and town riding. :wink:

The Black Arrow ebike will became a Dirt bike with 20" rim an motorcycle tire the I will have the best of both words for my needs.

Good day!
Black Arrow

OK, I took a small almost 11 mile ride today to check out the system. Tom gives it two thumbs up!!! I went up and down all the big grades that normally kick my butt and kicked theirs!!! The steepest one is the hill down to the water treatment plant, a 15% ish for about a mile and I peddle about 10mph up it normally but today I ran up it at 25mph...YEA! I feel bionic when riding this thing. I still was able to pump up my legs big time but wasn't "spent" at the end of the ride although it's about a third of my regular peddle route.Tomorrow I'll do a 40 mile trip and see how she fairs. Tonight's ride used almost 3 amps out of a possible 12 which makes me think 40 miles is doable although I might be pushing at the end. One point in my favor is the first 3 miles to the Katy Trail and back have the hills in them, once to the Katy Trail it's all flat so I betcha I can get 45 miles out of it. I thought I was doing 35 mph but I had the CA set wrong. I can get 33 mph siting straight up with no peddling on a full pack flat land no wind. Peddling hard I can get 38mph. I talked to Ilia today on the phone (great guy!) and he assured me that 75 volts and 15 amps will work fine long term so for now I'm going to stick with it. I'll make a new harness sometime soon and see how 50 volts and 35 amps does for me but for now I'm really enjoying the low amp draw. I've bee running high voltage on my R/C stuff for some time because everything runs cooler and amp draw drops tremendously.

Here are some pictures oops I took them in high resolution.....I'll have to re size them....crap!!!

I'll have to describe them. 75.5 volts straight off the charger. 71.8 volts after a 3 amp draw. I used 332 watts which made 22.3 watts per mile. 38.3 max speed and 20.2 average speed (there's a section that's really twisty to get onto the trail about 1 mile and I kinda putted through it.!) on a 30 min 54 sec ride. I charged the batteries and all took anywhere from 950 to 967 mah to charge back to full.

Tom

Knoxie, I'm running my MAC motor with BMC gears at 64v 35A, and I haven't had an issue for 1000km (since I got the BMC gears).


But the MAC at least, is not efficient. I'm lucky to get 18km out of 10Ah - my usage is usually over 27Wh per Km.....but I am doing between 50 and 60kmh



I'm with you on the Friction drives. Bloody stupid idea. One ride down my muddy dirt track on my commute and a friction system would be stuffed. I'm really encouraged by the gradual increase in sophistication and elegance I've seen over the last few years. From DD hubs, to Geared hubs, and now to all the integrated BB drive systems I saw in the Eurobike photos. Friction is a big step backwards.

Great to hear your new ride is ticking all the boxes 8) sounds great would love to see some video from your rides as well.

Hi Mark glad to hear your bike is still running ok and you also got the composite gears which will help, some motors were tougher than others and my BMX was always a lot happier at 72V than some of the other hubs :? anyways maybe the newer motors have improved (there is room for improvement) the newer digital xlyte controllers wont work on the BMC motors though.

Yes I am beginning to think that I missed a meeting with regard to the friction drive thing? i agree that the RC motors direct driven can be amazing however I think friction is a total non starter, I think they have their place on a very small folding bike where fitting a motor or any other drive is impossible (in fact this is the exact type of bike Kepler tests his on) but I dont understand folks on here that already have perfectly good e-bikes that are getting in to it? Kepler himself rides a Bomber with an X5 hubbie on it.

The newer versions of the BMC may be a lot tougher than the old ones, I will keep mine running on 50V for ultimate reliability and 30mph is plenty quick enough for me, if people want to really advance this hobby how about making a hub motor with an internal 3 speed gear that would be real progress, leave the friction drive systems to the past where they belong.

Knoxie

knoxie said:

The newer versions of the BMC may be a lot tougher than the old ones, I will keep mine running on 50V for ultimate reliability and 30mph is plenty quick enough for me, if people want to really advance this hobby how about making a hub motor with an internal 3 speed gear that would be real progress, leave the friction drive systems to the past where they belong.

Knoxie

Click to expand...

Man I hear you on the internal 3 speed. Heck even with a 2 speed would be incredible. On some of the R/C vehicles that got a 2 speed tranny made such great use of the motor torque and power. When I was a kid my parents had a couple townie looking bikes that had the 3 speed planetary rear hubs.....the type with the little chain coming out the axle and the whole set-up was so small. The hubs were not over 3 inches in diameter. We road those bikes for years and they never gave us any troubles so I'd think they were well built.

The gearing is why I originally wanted a Cyclone style kit but without the complexity and with a lot more reliability. The R/C's definitely seem to have the reliability down pat but then the cost becomes a burden. Anyone that makes a reliable multiple speed hub motor will take the market over.

Tom

SRAM have a design for a 2 speed hub motor. I'm sure others are working towards multiple-geared hubs, too.

would love to see that miles 8) I think it would almost be the holy grail IMHO if they could make a 3 speed with say 1 1.5 to 2 KW rated motor and all the associated gears built to take the power I think many folks need never bother to make anything else as you couldnt better it.

To be honest your Bike is for me the absolute top as it encompasses great efficiency with power relative low weight and style, dont tell Randy this he needs no more encouragement! ha ha but yes I think the only thing that would beat your rig is the holy grail, I for one will be selling one of the kids when they arrive :wink:

knoxie said:

I for one will be selling one of the kids when they arrive :wink:

Click to expand...

There's also this possibility:
http://nexxtdrive.com/applications_light_electric_vehicles.php?lang=en
http://nexxtdrive.com/applications_hub_drives.php?lang=en

Well I took a 34 mile trip today and pretty much used the battery up. I never run below 22.2 volts on a 6s pack but today I ran down as low as 65.9 volts at the end of the ride. I used 10.2 amps out of the 12 available which sucks! I was really hoping to use the full 12 amps going with the 80% rule on 15 total amps. I prolly could have run down to 64 volts without hurting the battery but I think I'll just go up one more "P" and make a 20 amp hr pack which should hold voltage better for longer and only add another 5 total pounds. Total miles was 34.3 and watts per mile showed 21.4. I kept an average speed of 22 mph with a few spurts up to 30 and 20 up the big hills. I peddled the whole time. When I make the new harness and add the extra packs I'll do a full out no peddling to see what I can get away with. At the end of my ride I have about 1.5 to 2 miles of steep hills and I had the LVC set at 67 volts. While riding I tried to adjust it and held the right button down to go into set up mode......wrong one! CRAP!!! The above statistics were from the last time I checked which was right before I reset everything. Total miles was from the Cateye bike computer I have on the bike also. I charged the batteries and put back an average of 3400 mah in each pack. Total time was 1 hr 23 mins. Real fun ride flying by all the hot shot bikers. All the hills where so easy it was just silly and there are some steep ones. I took some pictures of the scenery and remembered to set my camera for low resolution.

Enjoy!

Tom

Umm...ahhh...hate to be picky but...

Amps is an instantaneous measure of current.

Amp-Hours (Ah) is a measurement of capacity. 1 Amp for 1 hour is 1Ah.


When you say you used 10A out of 12A, that literally means you were drawing 10A at an instant, and your battery can give a maximum of 12A. That's not what you meant.


You really mean you used 10Ah out of a possible 12Ah. You got it right when you mentioned 3400mah.

But you did KNOW what I meant?!?! Picky definitely comes to mind......

I'll rephrase and say I was only able to draw 10 of the available 12 amps CAPACITY out of my battery pack. As I said before if it isn't enough add some more amp hours! I betcha a 20 amp hour pack should give me enough power to reach boredom. Bring on the boredom.

Tom

Hi Tom

Great to see some pictures from your ride! keep them coming and maybe get some on board video of you shooting past those Lycra dudes although they have a new name according to a report I read recently mamils...middle aged men in lycra! ha ha

Batteries seem fine to me, I did an 18 mile ride yesterday on my pack, I only charge to 4.1V so I loose a bit of capacity still managed to do 18 miles on 5AH, half the pack used saw the resting cell voltage at 3.8V which is about right, I only use the assist on hills and in short bursts, I like to peddle still and so its fine for me.

Have fun!

Knoxie

Tom, nice looking bike! Thanks for sharing.

Your V2S motor is a new 2010 model with V3 clutch that can take a lot more beating then the V2 clutch - here are pics demonstrating differences between the two clutches:


V2S motor in 700C rim has about the same torque and top speed as V3 motor in 26" rim (compared under same input power).

As long as motor and controller stay cool, extra power shouldn't be a problem. I usually recommend 700-800 Watts max for long and steep hill climbs and 1000-1100 Watts on flats for 70-80 degrees weather.

ilia

Alrighty then I went for a ride on just electric power to see how long I could go. Time was limited so I just ran a 75v 10 amp pack or 3s2p 6s 5000 lipos. This thing has tons of bottom end torque. I can punch (thumb throttle!) it and pull up the front wheel and ride a 10 to 15 ft wheelie....yea that's fun. Anyway on a slight down grade I was able to hit 38.8 mph and on a fresh pack as before I was hitting 33.4 mph on a perfect flat run. I have a 35 mph road right to the side of my house that a bit up and down and I just ran up and down the mile long street. I ran my voltage down to 70.9 and could still maintain 35 mph back and forth. Funny thing is as soon as I would go down the first down grade it would up my speed and keep it there till the end of the street. I was bending over and a couple cars didn't expect me going as fast as I was but never cut me off. On the up hill I'd drop to 33 to 34 mph and on the down hill speed up to 36 to 37mph. Plenty fast, quiet and cheap to run. More fun than a motorcycle I can tell you that. Kinda reminds me of the ole Moped saying that they are like fat chic's, fun to ride but you don't want anyone to see you on one. Although I hope I do get seen so I don't get run over. I need to make a video...I will soon. I also decided to go with a cruise control as soon as Ilia gets me one sent out here, I find it hard to keep a steady speed whilst peddling and bouncing around. Plus as I'm day dreaming down the trail I find I either speed up or slow down.... I like a steady pace myself and to conserve energy.

Pics of the performance below,

Tom

To add next I want to do a full suspension 40 to 45 mph bike........just not sure if i want to go R/C or brushless direct drive hub at 100 volts or so.

Recommendations welcome!

Tom

9c 2807 will just touch 40 mph at 20s lipo 84v , and 45 for sure at 24s, 100v hot off the charger. Seems able to go 10 ah without overheating much, but I did just drill some holes for cooling since I'll be racing. Hard to beat that for cheap speed.