gwhy

Oset is the OEM, and the mecatecno is a copy of oset, Im not sure about the GG ( I cant remember what they look like ) But either way Oset electric bikes have been on the market for around 7 years ( Longer than any other Manufacture of electric mini trial bikes)

I have a compete 250cc sherco engine/carb and was wondering how much do engines go for on the secondhand market ( Im wondering if its worth hanging onto ) , the engine is in good condition but haven't been fired up for around 18 months ( the wife is beginning to nag me about getting out of the spare bedroom ) .

its a good place to have the motor believe it or not by being in front of the back wheel it helps with cooling ,its a sealed motor and there should not be anything in the motor that shouldn't be in there. If stuff got into the motor this will put undue stress on the motor ( maybe the bearings are totally shot ? )

These batterys may just about be ok for the stock 12.5 as the controller will be limited to around 15A and the performance SHOULD NOT taper off like the SLA but it really depends if the manufacture is being absolute with the specs, ( many battery manufactures will slightly big up the spec of there battery's) . the EathX ETX12A looks like it will be more suitable as the spec says that it has a cold crank current of 120A which will be fine for the stock osets and they also say they are 12ah , so a extra bit of run time over the stock battery. you will need 3 of these battery's to make up the voltage to run the 36v bikes. Any oset running 36v will be fine running 3 of these battery's as regards the controllers. To get the run time your after you need to be looking at using the EathX ETX18's ( any of the 3 types will do ) this will give you approx what you are after, or better still go for the 24ah ( but watch that the physical sizes will still fit into the bikes ). Lipos do still taper off ( maybe only 4-5v) but nowhere near as bad as sla but lipo do get to a point and the voltage will drop like a stone but if the battery has a bms then the bms should turn the battery off to prevent over discharge. those EathX batterys do look like a very good turnkey solution as replacement battery's for the osets for people that dont want to go down the soft pack lipos.

if its getting 4-4.5hrs of run time then the battery/16" can not be a great performer , expample: if you have a 500w motor and running at 36v then the controller needs to be limitied to around 20A ( this is acutally more like 700W ) so riding up hill only give you 0.5 hour with a 10ah battery but I normally look at a round trip so as much up hill as down hill so this will be more like 1hr riding , these batterys will start to sag like a Bast**d at and above 20A which will bring the voltage down as little as maybe 26v ( depends on internal resistance ) so this will then become 26v @ 20A this then only makes 520W ( a loss of nearly 200W! ) these batterys will only be anygood for upto around 20A max, I dont think you will even get 3 hours runtime if every thing is working correctly the absolute max run time will be around 1.5hours if the controller is limited to 20A and your running @ 36v . Its more than likely the the bms is limiting the current to only 8A and that is why its reported such a long run time but 8A@36v is only 288W personally I would not wast my money on these battery's for this application

looks good and looks like it rides ok . Hope it holds up well.

I dont think this battery will be very good for this application as it can only deliver 20A max , built in BMS can seem a very good option but from my experience BMS can be more of a pain and end up causing more problems with your battery than its worth. BMS starts to become usefully on a much bigger battery i.e 100-200v but personally for anything smaller than 50v then forget it, its easier/safer just to manage the battery yourself.

those batterys do look a tad unhappy, I cant think of any single thing that could cause this when you have had different setups. If the charger is giving out exactly 41v ( this is one thing to check ) a fully charged sla is around 13.6v so 3X13.6 is 40.8v that means you will end up with a 0.2v trickle/topup charge when the battery is fully charged , the thing is most sla chargers are not smart and have just a fixed set output voltage then as the voltage of the battery increases with charge this in turn will reduce the charge current. The problem with charging sla's in series ( or any battery ) with a non-smart charger ( a fixed output voltage ) is that if a battery becomes tired, cells within the battery can become short ( instead of a 12v battery it now becomes a 10 or 8 or 6v battery ) and it could be this that is causing your problem, you will no longer have a 0.2v trickle/topup charge it could be more like 3 or 4 v which will not do any of the batterys anygood , once a battery is fully charged the excess charge current is got rid of in heat from the battery. Definatly get your self a cut off timer or invest in a smarter charger.

Converting a gas bike to electric is very easy to do and so much cheaper than buying a off the shelf e-bike ( I know I have done a few ) having said that oset at the moment have the edge for good value and reasonable tech. for a entry level adult e-motorcycle ( or very powerfull kids e-motorcycle ) conversion you are looking at around £500 ( for the electric stuff and basic battery ) + a doner bike ( if you do it yourself ). I just wish manufactures will stop messing about with old out dated tech or at least charge a fair price for a high tech product. There is no need to have a clutch on a e-bike despite what people think but a nice addition is to have something so you can fine tune the power delivery and I spose you could call in a clutch if you want.

it could be sooner than 5 years if the prices were a bit cheaper.

by paralleling the battery you combine the mAh so frogger has 16000mAh ( 16Ah ) you will only have 8Ah , the Ah rating is how much charge the battery can store ( so a 16Ah will last twice as long as a 8Ah ) but the 16Ah will take twice as long to charge ( if using the same charger ). 2x 5s1p in series will give you around 40V hot off the charger and should be fine to run the 36v motor ( it will be a little faster top speed ) like you have said , the most stright forward way for the 36v would be 2 x $18 50W chargers from HK , these can only charge at 2.8A for the 5s so you will be looking at around a 2.5 hour charge time for each 5s 8Ah battery from each charger. I try and stick with 5000mAh batterys and parallel them up as these are more common and a bit cheaper to replace should one battery go wrong ( as different Ah rating can not be mixed safely )

First off : you do not have to balance the battery everytime you re-charge ( but worth checking the balance of the cells before every re-charge ) the chargers have this facilitly , or buy a standalone battery medic ( which is a better bet as the checking can be done very quickly )..only balance them when needed. I would advise to re-charge the battery after everyride even if it was 1 or 2 miles ( this will help the battery stay healthier for longer. I would also advise to remove the battery from the charger once they are charged ( as electronics can just go wrong without warning ). I would also advise to remove the battery from the bike for re-charging as batterys can catch fire and you would not want your bike to get burned, also DO NOT charge overnight in the house just in case they catch fire, best charge them in a shed or garage or better still in a fire safe area. ALL battery can catch fire but lipos if not looked after do so quite spectacularly. The lights on the throttle will not be accurate enough if you convert to lipo, so you would need either a off the shelf lipo alarm or a volt meter/watt meter connected to the bike when you are riding so it can be seen this will then be your fuel gauge. you will need 2X6c1p 5000ma for a 24v 10AH battery I can remember what most peeps are using for the 36v ( maybe some one will chip in ) You can charge everything ( dependant of your configuration for the 36v battery ) with 1 charger, but this will be a pain and will also take ages to charge, so the very minimum you will need 2 chargers and that will make it more user friendly but the more chargers you get the better/faster you can get everything charged back up. I not 100% sure, but I dont think you can take them on a plane. The batterys are bought from Hobbyking in china along with everything else that you will need.

The pot just limits the top speed. I know that oset have a new controller coming out soon that you will be able to limit the max power and the max speed.

I think the GG will make a very good conversion as you say, as a bike, its all good and well tested, hub motors are a very easy conversion but as you have pointed out they are very heavy and yes they are more for the top speed and not torque so this would be one of the main problems with using a hub, the lack of torque can be got around by getting a hub that will do a speed of around 35/40mph in a 26" bicycle wheel @48v if this was then laced into a 20" wheel this will bring the speed down and increase the torque @48v , 600W will make it a bit under powered with a larger wheel if you are comparing it to the oset. It would be very difficult to find the balance between torque and speed with a hub motor unless you can get a hub motor that is custom wound for a top speed of around 25mph that produces boat loads torque in the 20" wheel @ 48v or 60V. To have a bike of this size you will be looking for around 1kw sustained with maybe 2kw peak as a minimum for a small rider. On another negative side to hub motors is how reliable it would be in a trials environment. Geared hub motors generate more torque than a DD hub but again in a trials environment a geared hub will not tolerate to much abuse before the gears strip in the hub, the gears can be replaced with metal gears which will resolve this issue but this will also add even more weight. These are some points that would need considered carefully before selecting a hub motor to use on a trials bike.

All seems good to me, Just a couple of things that could save a bit of money, look for a PSU locally as the weight on the bigger psu's tend to be heavy and expensive to post ( not so much the 60W one above but if buying a 200W+ psu ), its worth sticking with the 5000mA battery's these workout cheaper and are more common, should one 5800mA pack go down it would have to be replaced with the identical capacity other makes may not provide this capacity. The chargers tend to be expensive ( at the moment ) for anything above 6 cells so think about configuring packs using only up to 6 cell battery's the cost of the chargers are so much cheaper i.e $15 for a 150W or $75 for a 400W, a 400W charger will charge/balance a 10Ah 6 cell battery in around 40-60mins ( as long as you have the psu to power it ). And thinking forward if/when oset start using 48v and 70v the 6 cells battery's will be forward compatible as 22.2v blocks.

yes, its a adaptor for the calliper mount 160mm to 180mm , if you still wanted to use the 160mm rotors you just then the mount the adaptor other way when fitting, but using the bigger rotors will give much better braking.

They normally come with a adaptor ( well mine did ), so yes they will fit :-)

You should never leave the alarms connected to the battery's when not in use , what charger are you using ?

that really all depends on your chargers, you could get a couple a 12v car battery's to connect your chargers too, you could prob get 2 recharges into 10Ah 24v battery's from a 40ah car battery, deep cycle leisure battery would be better suited. A 1.5kva genny will only put out about 8A so this would do the job but like i say it depends on your chargers.

I have just been looking at the spare's on the oset website and it looks like the band brake is a screw fitting or ( hopefully a bolt on ) onto a standard hub so a wheel should be very easy to add a rotor to.

I assuming you have these battery's in series so this means that when they all connected this will be equivalent of a 9 cell pack so you will have to disconnect them to charge them as a 3 cell battery you could parallel them all together for charging then you would charge all 3 packs at the same time as 1x 3 cell pack , I not aware of a 9cell charger that is designed for lipo. Yes you could charge them through the balance taps but this will take for ever as you would have to keep the charge current down to no more than 1A due to the thickness of the balance wires. I would recomend buying a additional 2 HK 6cell chargers ( I think they are around $18 each) then at least this will make the whole charging process much faster.

LiFePo4 are not that good for sustained high current i.e not much good for bigger e-bikes ( from my experience ) may be ok for a standard oset tho, I know a few people that use A123 batterys for there e-bikes but for decent capacity/voltage and discharge current they tend to end up very expensive,big and quite heavy, the advantage of the A123 cells is that the the time recycle count tends to be much higher than that of lipo but A123 cells still need as much care as lipo to get the most out of them. edit: Im not sure if this is of any interest to you but I know that zero motorcycles ( there new 2012 line up ) claims a top speed of 80mph and a running distance of 114miles per charge ( which is very impressive ( but it could be hype) ) and I also know that they have developed a new battery for the 2012 models , at the moment the new battery chemistry that they are using ( if it is new ) have not been publish by zero yet.

If the rear dropouts are 135mm apart then that is standard size so you will need to look for a disk hub with that spacing , the one you linked to will not be long enough to fit in the dropouts (116mm ) , I know DMR do one that will do the job http://www.ebay.co.u...b#ht_2232wt_802 you can get also get them in 36 hole but both types are becoming rare with the larger standard screw thread which is what you will need ( would it be possible to mod the band brake on your existing hub to accept a disk? ) , you will also have to have a calliper mount welded to the swingarm . Standard brake posts spacing for the front is 80mm give or take 5mm so a hyro rim brake will be a direct replacement but I think the rear will need some major mods ( maybe worth taking the band brake cover off and looking to see if it is a standard bike hub with a band brake attachment could be either screwed on or bolted on through a disk rotor mount) , I know The larger wheel osets ( with a rear disk )use the DMR hubs so you could ask oset just for a hub maybe . Edit: I just looked at your pictures again, you may also have a problem with the hole count on the rim so you would have to replace the rim as well if you wanted to try a standard hub ( 32 or 36 hole ) and for such a small rim Im not sure you can get them with higher hole counts.

If you post up a picture of the rear wheel hub of the 12.5 I could tell you if it will be ok or not, you can get some nice hydro disk brakes with adjustable pull levers, not sure if there will be enough adjustment for tiny hands tho but well worth looking into I'm also sure that careful selection of levers on a set of hydro brakes will also help ( like a 1, 2 or 3 finger pull )

I may have a very cheap/easy/adjustable solution to the snatcy hall throttle problem, I just need to get out on the bike and test it, unless anyone else wants to. it involves soldering a trim pot into the 0v of the throttle . This is not my solution, I found it on another forum but just may fix the problem. use a 10 turn 1k trimmer pot in series with the ground wire going to the throttle. cut the black wire and connected the ends to the resistor. Be sure to put the wheel off the ground when you first turn on the controller as the motor might start running. With the controller on, you adjust the trimmer pot until the motor starts to move, then back off until it just stops. It's a good idea to back it off a tiny bit more just so variations in temperature don't cause the motor to start creeping at stop.