Motobecane DS Fantom, BMC 600W torque and now Lipo build

[Thud]

OHH crap. Thats a bummer Kin,

Sounds like you been piling the miles on this year....I am jelous & starting to work on doing the same myself with a hard tail giant..

Nasty spot for the frame break also, that gusset is right in the way & that juncture is pretty important for the link anchoring from a quick glance. welding would be a disater for the tempering & the seat stay looks really thin in the photos.

Luckily, You have the skills to splice on a Carbon fiber member/seat tube in that space & prolly make it stronger & lighter at the same time.
T

[kfong]

Hi Todd, I was hoping to do over 2000 in trail miles, double last year’s number. I just will have to use my utility bike for the trails now, but that setup has only 6 ahrs of A123’s. I will be converting it over to Konions to get 12ahrs. Still this is half what I’m use to and will only satisfy me temporarily, limiting my distance goals as well.

I’m tempted epoxy the seat post into the broken frame. This would be a bit drastic since I would be counting on the seatpost to hold up. That was what I thought would end up breaking next. Any repair still won’t address the real problem of having a seat post mounted battery. I might have to settle for just the 12ahrs in the frame. The impacts from my jumps just over stresses any seat post design. This was a known problem, and I pretty much tried to work with it, obviously unsuccessful. I really have to think about building a custom ebike frame with all the batteries needed installed in the triangle, but that will be a winter project.

[kfong]

Woohoo!, bike is back together with a new frame. I didn't do any trail riding while waiting for the replacement. Just would not of been the same. Need to play catch up now, behind in my trail miles. This has left me with the need to have a second backup that is trail worthy. Will have to do something about that this winter. Not sure what to do to prevent the new frame from breaking the same as the previous one. My only plan currently is to get a longer seat post and add shims to take up any space. If it breaks again, I will permanently attach it. The real solution is not to use the rear rack, unfortunately I can't give up on the distances provided by the extra batteries. I did 25 miles today for the shake down, need to adjust the rear derailed. Other than that the rest of the bike came back together fairly well.

[oatnet]

This has left me with the need to have a second backup that is trail worthy. Will have to do something about that this winter.

Suddenly your hipowercycles impulse buy - the spare BMC V2T - finds application. Smart shopping!

-JD

[kfong]

Yeah, just need to find me a good FS DH bike now with enough room for batteries in the frame or a frame with triple forks and mount an extra pack like how you did with your setup Oatnet. Either way it has to beat out my current setup for me to be happy. The motor so far has taken all my trail riding abuse and I am quite content with it compared to what is available. The leaves me wanting a better bike with even higher end components. Full air shocks with good amount of travel, 9 speed since I actually use them like the current setup. Minimum 24ahrs. Really, pretty much the same bike but with longer travel and suspension and no rear rack! I thought I had all bases covered for this season only to still sit around waiting for the bike to be repaired. I see now I need two good reliable trail bikes since trail riding does put it's toll on the bike. Had a couple of crashes yesterday. Shins and arms are bruised, bike is still good to go. Heading out to try Holden today. Supose to be as good as Highland State as far as technical riding goes.

Update:
Got back from Holden yesterday. Nice trails, but east loop was a bit overgrown. West loop had some cool technical sections and a drop off which nearly had me endoed. Lots of challenging log piles and split logs to ride on. I covered 21 miles. It was getting too dark to continue. I also had issues with the rear shock, looks like its loosing pressure. I will have to rebuild the seals most likely, but just won a better version on ebay. Rock shox SID. With the motor and batteries in the back, the rear shock has been taking a lot of abuse. I tried to upgrade to a Fox shock, but couldn’t find any good deals on them that fits my bike. Hopefully the SID will do.

I’ve been giving thoughts on the backup build. Tempted to build a carbon frame from scratch, but still cheaper to buy a DH bike and convert it. Who knows, if the frame brakes again. I will have all the components to mount to a carbon frame this winter. Either way two reliable trail bikes are planned for next seasons riding.

[kfong]

It's been a while since I've updated this thread. I finally have a working rear shock installed. It's an old Fox vanilla. I'll have to see if I like it in the trails. I got frustrated with the air shocks due to bad seals and higher maintenance. Even the new bike I picked up, I was focused on not having air chambers as the main function. When they give out, you are stuck with a limp bike. Springs are much less maintenance, but the performance might not be there with lower end stuff, so do your research.

The bike has been down since the last time I posted. I’ve been busy with other projects as well plus there was a waiting game on the new shocks. I purchase the Sid, only to find it failing on the first ride. These are new, but old stock. Do not buy them; the seals will go bad on you. Mine literally crumbled. I then ordered new seals, but could not get delivery due to the damn post office not finding my address twice. This was frustrating, so I went and bought new seals for the original rock shock, only to find the new seals also leaked. This put me off of Rock Shocks for good. Such crap. I should have spent all that money on a good Fox shock in the first place. Lesson learned.

I finally get to ride the bike today, since the weather finally cleared. It’s been raining all week. Hopefully, the vanilla’s will work out, or back hunting for an upgrade. At least I can ride now. Post of it alongside my new bike. viewtopic.php?f=6&t=32963

[kfong]

The ride results from the past two days of riding. The first day I was a bit disappointed with the spring fox shocks. This was their low end stuff so I wasn't expecting too much. There isn't any rebound adjustment, so the rear had a lot of pogoing. The second day I installed the rear pack. I actually picked up a new rack, due to the bend in the current one right at the base of the added support. Since the old rack was still functional, I thought I would experiment on it. I ended up filling the tubing part way with epoxy and carbon fiber. It seems to have added enough strength, and I will be using it for now. I will repeat this for the new seatpost rack. I know I should be dropping the idea of using the seatpost rack by now, but I need the ride distances, and have a lot of miles to make up for. I'm also counting on the frame not breaking this time around. The good news is the rear rack is actually providing enough damping or weight, making the cheap shock effective. I'm happy enough to leave it as is and focus on getting as much trail riding in before winter.

[kfong]

This definitely has been the year for break downs. I’ve been slowly loosing capacity on my packs and suspected it to be the packs in the triangle. I should have looked into this sooner, but thought it might be battery wear at first. It wasn’t until I noticed a significant drop of 3 amp hours that I really took concern. Initially, I thought it was wear since it was so gradual. I had recently built a 600 watt battery load to test my smart switch and batteries. This came very handy when testing the full capacity of my packs since riding varied too much due to my pedal effort. Sure enough the triangle pack was only 6 ahr while the rear pack was 9ahrs. I should have been on top of this, but was fooled when my packs were charging to 41 volts each time.

I removed the pack and discovered a bad spot weld had come loose from the vibrations. This caused a capacity imbalance which lead to a slow imbalance in packs capacity creating a short in a bank of cells of zero volts. Had this been Lipo’s, I would have been in trouble, since I did not provide taps to monitor the situation. All it ended up doing is over charging my other cells. I will need to rebuild this pack and retest the good cells to sort out the bad ones. Damn, it didn’t occur to me that a loose tab connection was happening at the time. I have never tested the packs since install. These Konions have been super reliable and to me proven safe for trail riding. For now I left the packs off the bike and it also gave me the opportunity to try my Lipo 12S2P pack that I made as a rear pack for my Cyclone build.

I do like the BMC at 48 volts, top speed was around 24mph, but the increase in torque was a nice addition when trail riding. This will be the setup I plan to install in the DH bike. I verified that it fits nicely in the triangle, but will have to come up with extra precautions on that build since the Lipos will be permanently installed in the frame like I did with the Konions on this bike. I think I have a solution that I feel comfortable with, just need to get some boards produced, but more on how I go about it on that thread.

Anyways, riding yesterday on just rear packs, I notice a slow decrease in rear brake performance until I had hardly any rear braking at all. Great, another rear brake replacement. This seemed a bit too soon for brake replacement. Quit my ride early, but I did ride out the Lipo pack which gave me a big grin. Today after replacement, still no rear brake? It turns out I have a cut on the hydraulic lines after I took a closer inspection. This was either due to the suspension cutting into it or gradual wear. Will be glad to have the second trail bike online next year so I don’t have to sit out these break downs. Definitely behind in my total trail miles this year. For those who are trail riding, check your equipment and batteries often!

[kfong]

Now that the bike is down, I've had a chance to inspect it a bit more. I usually do a bolt session, checking to see if there are any loose bolts. I normally haven't been checking the spokes on my hub motor because it's been good for two seasons now. Yesterday I had to tighten everyone of them, it could be from the increase in voltage when I ran the lipo pack or they have been slowly getting loose all year. It was so bad that I thought I had a broken spoke. I'll be checking my spokes more often now. The damage could of been very costly, they were all very loose. The linkages for my rear shock have too much play, I need to look into that. Still waiting on my brake parts

[kfong]

Now that the riding season is pretty much over. It's time to overhaul the bike. The 9 speed DPN freewheel has been getting too wobbly for proper shifting. It lasted 3 seasons. Unfortuanaly DPN seems to be the only company making them with 11 tooth. As much as I hate the quality, i really don't want to do without the 11 tooth sprocket. I picked up an DPN epoch, this seemed a little better. Will only know after use. Getting the old free wheel off became a major project. I tried everything I could think of. Heat, penitrating oil, hammer, ect. Finally the only thing that worked was to take the plate off, mount it to a block of wood with wood screws and then to a large vise. I had to take a large ratchet wrench with a long pipe attached to remove it. I thought I would try to clean the bearing while it was apart. Be careful when removing. I damaged the seal spring when doing this. They use a rubber gasket with a veriy thin coil sping to provide tension. I ended up bending this coil spring. It is hidden behind the rubber gasket, but popped out. I was able to put it all back, but now I'm not sure how long it will keep a proper seal. Best to leave the bearing area alone until replacement is needed.

I will be switching over to lipo's. I really like the BMC at 12S. I just ordered another 1420i charger on sale at eBay for $130. I might even go to higher voltages on the DH build.

Rear brake is repaired, but for some reason it won't spring back after use. I wonder if the brake cylinder is damaged.

[kfong]

Trying to see if the lipo's recently purchased can be used on this build. With the Konions, the smaller footprint allowed me to be more creative in packing in the packs. I can see I'm going to have a very tight fit with lipo's. I really don't like how 2 of them are going to be on an angle with no support. I'll have to come up with some way to secure them.

Here is my plan to keep the packs safe during charge. Since most lipo fires actually happen during the charge process. I've come to the conclusion that bulk charging such big packs is too risky. The only way I will know if there is a problem is to have the Hyperion charger watch for any issues. I wont be able to visually check them each time after a ride and I can't assume that all connections are still good. With the balance taps, it will provide a safety net. Things can still go wrong such as a loose or open tap from one of the packs. Since you have a bunch in parallel, it might even go unoticed. They should still show up as a weak bank of cells, that the charger will detect.

I had some boards made to allow me to connect all the taps with one cable. I made some spare as well, and will be selling them for $10 each. The plugs can be purchased from digikey. You will need 2 boards. One goes to the Hyperion charger while the other goes to the bike. A standard female to female 25 pin serial cable will connect the boards together. I will show more details on how I go about it when I get further on my battery build. It was the only solution I felt I could count on during the charge process.

The silkscreen on the board shows connectors being soldered, but it's really for connector orientation. The spacing is too close for connectors to fit side by side. It's not really practical since packs are not going to all line up and the balance taps will be too short. The idea is to solder ribbon cable of the correct length and have on the ends plugs to connect to the packs. If you only run 2 packs in parallel, then you can solder connectors on the board that are staggard to fit. The simplicity of this setup is you can have any combination of packs up to 21S and 4 parrallel banks. Hyperions can go to 14S, but with 2 of them networked together you can go to 28S. I did not see a need to go that high and just maxed it out for the DB 25 pin connector.

I probably should of spaced the connectors to allow you to solder in the plugs, but I needed the board as small as possible and prefer soldering wires and less interconnects as possible, so this was really setup for my needs.

[neptronix]

I've seen some pics of broken seat racks and broken posts here. I knew seat post racks were bad news, esp. when you get over 10 pounds. I can feel my seat post flexing when i hit bumps with only 12lb on my rear topeak rack.
The higher the rack is extended above the collar of the bike frame, the worse the problem is.

Thedarlington sent me a link to this recently, and i thought it was pretty brilliant.. maybe it would work well:

http://www.instructables.com/id/Bike-rack-for-full-suspension-mountain-bike/

[kfong]

Greenmachine has been using that setup for a while now and there are a few companies that offer a similiar setup. I didn't like the idea of adding more swing weight to the rear. It's bad enough having the static weight back there. I'm hoping to put enough battery in the triangle and with the lipo rear pack now at 8lbs 8oz vs Konion 10lbs 4oz. It's a little better, but not by much. It is possible to put all the batteries in the triangle, but that would make the area too wide and will interfere with pedaling. I'm currently stuck with this setup since I'm not willing to loose out on the range. My new trail bike won't have these issues. I will be putting the batteries in the triangle as well as on the a custom front rack.

[kfong]

I've been testing these blue lipo's. With a cutoff of 3.5 volts per cell they are only providing 1.6ahrs quite a bit short of the 2.65. These must be older gen packs. I would not buy them again or recommend them. With the Turnigy I get the full amp hrs at the same cutoff. These were cheap $15 each, so I didn't loose out too much.

[neptronix]

were those blue lipos from hobbypartz?

[kfong]

Yep.

were those blue lipos from hobbypartz?

[kfong]

I did some more battery testing. Apparently you need to cycle these packs a few times to wake them up. The battery load I built earlier works out well, but I really needed to automate the testing of so many packs. I need to cycle each pack 3 times. I read about regen charging that the ichargers are capable of, and since I had started a 12volt A123 automotive car jumper pack. This quickly became my choice for the regen battery. It’s a 4S3P pack. You loose a little over an amp from the regen losses, but with 6ahr pack I can easily do 3 cycles and then quickly top off the A123 with a 20amp setting on my Hyperion charger. The cool thing is I’m able to discharge at the max rating of the iCharger. This is close to 7 amps of discharge, but I’m only charging these packs at 1C rate, they are probably 1st gen cells. I just hope they last a couple seasons. The latest readings from one pack were 2.472ahrs. Charged to 4.2V and discharged to 3.5V. This is still short of 2.650, but is acceptable since I don’t plan to push it past the knee. With Turnigy’s you get the full amp hours with the same setting and they don’t require this cycling. For the cost I’m willing to accept a slight performance loss.

I really like the smaller pack sizes; this allows me to really pack in the cells. My new configuration is 12S6P giving me 14.82ahrs if the pack above is representative of the rest. In any case, I am committed to using these packs for the Motobecane and ordered 3 more to get the 12 packs needed for the 12S6P setup. I will know more once all the packs have been cycled. With so many packs, it’s going to take a few days. Here is a picture of the regen charging setup, in the background there is a ceramic pot that the lipo battery is actually put in during this testing just incase something goes wrong.

regen charging.jpg (105.91 KiB) Viewed 997 times

Here is a picture of the layout on my bike. The width is slightly wider than the Konions. I was not able to fit this much capacity with the 5ahr packs. They are just too bulky. I plan to build new covers, but this time I will be using kevlar/nomex layer for fire protection and will do what I can to secure the packs from moving. Charge taps will be integrated as well with the pcb board I made. It will be difficult to visually check the pacts so I need to do all I can to minimize any fires. With this much capacity I can do away with the rear pack, but most likely use it as well since I now can ride to my trails without my car and still have plenty of run time to to get back. 1.19KWhrs

Lipo configuration in bike.jpg (117.79 KiB) Viewed 997 times

[kfong]

The battery testing has been going good.

Here are the results so far. Charging 4.2v and discharging to 3.5v. I'm only doing 2 cycles now unless the numbers fall way short. Waiting for my other 3 packs as well. Looks like I can reliably get 2.4 ahrs from these packs. So it will be 14.4 ahs in the frame. The test load is about 7 amps. They get slightly warm to the touch, but should be cool when parallel by 6. I'll try to work on the mounting this weekend. Pretty excited about the larger capacity and voltage, but not so much at the idea of all those lipo's grouped together. At least they are all laying flat and will be well supported. I didn't not like the ideas of having any of them at odd angles so the new arraignment works out really well. The bottom pacs are going to see a lot of compressed weight from the packs on top. I plan to separate each layer with a fiberglass sheet to spread the load. This will also help isolate the packs during a fire. I doubt it would prevent it, but it will direct the fire to the sides where I will have some vent holes. I'll try to burn some test samples as well to see how effective a kevlar cover can be against such a fire.

2420
2472
2468
2492
2486
2449
2503
2478
2462

Now waiting for 3 more lipos, but very happy with results. Will know by next fall if these packs hold up to any useful cycle life. For the price, it seems to be a good value. If I can get a couple of seasons out of them it will be worth it.
2466
2470
2462

Results are in and they look good.

[shock]

Build is looking good so far!

I'm debating on ordering more of these packs myself. For the cost, seems to be a pretty good solution.

Do you plan to parallel charge the LiPo array? i.e. keep the balance connectors connected?

[kfong]

I made a PCB board that will allow me to connect all the batteries together so I can connect the balance leads as one big 12S pack. The balance connector is a DB25 pin connector. I will be using 2 boards one mounted permanently on the bike and the other will be used by the Hyperion charger. All I need to connect them together is a standard female to female DB25 cable. I will be posting pictures of the setup when I get to that stage. I have extra boards for sale as well. $10 each for the bare pcb board. You can see pictures of it on the previous page. You can pretty much do any combination of cells with this setup.

Some more info on the boards.
viewtopic.php?f=14&t=38913

Build is looking good so far!

I'm debating on ordering more of these packs myself. For the cost, seems to be a pretty good solution.

Do you plan to parallel charge the LiPo array? i.e. keep the balance connectors connected?

[shock]

What voltage are you running, 48v?

Are you going to separate the serial connection for charging?

Trying to figure these things out on my build.

[kfong]

I'm going 12S, so that's 48v. I will only need two connectors when I'm done. So it's just plug and play. The DB25 pin balance connector and an Anderson charge connector. My Hyperion does up to 14S, so it makes it easy to charge large cell counts. It manages all the balancing and safety issues. I recommend this charger for ebike use. I won't trust bulk charging lipos and the only other charger 3010b let me down. It burned up during use, bad design flaw plus it only goes to 10S. If you have two Hyperions 1420i, they can be networked to do up to 28S. I picked up a second one during the eBay sale.

What voltage are you running, 48v?

Are you going to separate the serial connection for charging?

Trying to figure these things out on my build.

[mvly]

12s is not quite 48V (44.4V Nominal, 50.4V hot off the charger) I would say 14s is true 48V since "48V LiFeP04" is really 16s which is 51.2V nominal.

I have mine at 14s (10s + 4s) So 2 icharger 1010B+ will do fine.

[maxwell92036]

Fascinating read. This is similar to what I want to do with a mountain bike. I have been mountain biking for years and have seen many aluminum frames break near the seatpost clamp. I do not believe this is a result of your rack since many riders weigh more than you and your rack and battery pack combined. Motobecane, Gary Fisher and many other non motorized bikes break at this same location. They use aluminum on Full suspension bikes to keep the weight down and the stiffness up, but aluminum will break eventually under these stresses.
Spoke tension and wheel true should be checked at least monthly. It only takes seconds to do, but by the time they get loose and start breaking then it is too late and you need to relace the whole wheel.
I don't know how many miles you have on your bike but it looks like you ride it a lot and ride it hard.
You might want to check out MTBR.com since they have a good review section on bikes and accessories. I would think a Thomson seatpost would not bust on you. Here is an interesting read on racks and weight distribution: http://www.adventurecycling.org/feature ... primer.cfm
There are many racks that work with full suspension bikes such as this one: http://www.oldmanmountain.com/

[kfong]

I did some material burning with a small torch. Kevlar burns easily, Nomex must be some other type of aramid fiber. When I looked at its properties it does fail at 700 degs. The fiberglass cloth did not catch on fire as much but I was easily able to burn holes in it. A thin sheet of aluminum worked out better. A g10 fiberglass plated would not be very effective as well since the epoxy gave it fuel to burn. So there goes my plans of a fire resistant shell. Looks like a fire blanket over my bike while charging is a better solution. You end up with a loss of a bike but better than a garage. A metal enclosure looks to be the most effective way currently if you plan to house your battery and charge your battery on your bike. Having to charge the packs away from your bike and everything else is the safest and best approach.

For this build I will either have to figure out a quick release so I can remove the batteries from the frame or stick with a fire blanket approach.

I'm now curious as why a lipo sack works so well. Is is a matter of not allowing enough oxygen to get a pack going in the first place? If that is the case then I might still be able to count on a composite shell to do it's job. The lipo sack looks to me like it's made of only fiberglass cloth and some fire resistant outer material similar to duct tape? Does anyone have a clue of the actual materials used?