Confused! Performance Ebike newbie advice please

[Daveintheuk]

Hi all,

My first post, but undoubtedly not my last!

Firstly, everything I know so far about Ebikes I’ve pretty much got from this forum. The level on expertise and knowledge on here is incredible.

I need a bit of help and you guys always seem to give great answers!

I bit about my E bike needs;

Ok, I live in the UK and with fuel prices hitting £1.30 a litre (or $12.00 a gallon) its time to get alternative transport for the work run.

The run to work is a round trip of 10 miles on smooth tarmac with plenty of long straights and some long but gentle(ish) gradients. I can charge up at work but I’d rather make the round trip with out charging if possible.

I’m after speed and would like to hit and sustain up to and/or over 40mph (I’m quite aware of the law and the safety regarding these speeds and really don’t want to start a safety/law debate)

You just can’t get these powerful hub motors and controllers in the UK so I will be importing everything from ebikes.ca and because I’m importing I want to get it right first time and avoid disappointment.

This is where you guys come in! I have an idea of want I want along with a few questions and just want to be sure I can get the range & speed I’m after.

Ok here’s what I’m thinking;

1) I have a bike already – and have a budget of around $2000ish (can dip into the kids college funds if need be!)

2) A Crystalyte 5 Series rear Hub – But which one? Was going to get the high speed one but after reading various posts about torque/speed I’m unsure!

3) A 72V 48A controller and the cycle analyst.

4) Batteries – It all gets blurry for me here, I might be getting these from the UK, I’m not scared of making my own but I need all the advise I can get here as this will probably be the bulk of my budget.

Was thinking about connecting two 36V 12Ah LiFePO4 together? (Like the ones of ebikes.ca) Would this work? Would I need two chargers? Will this give me my range/speed? Would two 48V batteries be better? What sort of discharge rate do I need? I just don’t know! Help!

Or is it more feasible to make my own – if so what specs should I be making it to and what kind of chargers should I be looking at?

The bike I will/may be using is decent but has a aluminium frame (and forks) so I will be rear mounting the motor – is this ok? Or should I get a steel bike? Do I need to use torque bars if I’m mounting the motor on the rear?

Is there anything I’m missing or need? (Aside form common sense & good looks)

Well, I’m done; (yey) and I look forward to reading your responses! Once I’m clear on everything I need I’ll be parting with my hard earned money and posting the results!

Cheers!
:wink:

 

[Link]

*stretches*

Nrgh, haven't replied directly to a n00b post in a while. Here goes.

The run to work is a round trip of 10 miles on smooth tarmac with plenty of long straights and some long but gentle(ish) gradients. I can charge up at work but I’d rather make the round trip with out charging if possible.

Hmm, 20 miles trip at 40mph...

Doable, but you're going to need a lot of battery to do it. I'd bet on around 1kWhrs worth; at a relatively low efficiency (I'm guessing around 40Whrs/mi), that should be enough and a little more.

I’m after speed and would like to hit and sustain up to and/or over 40mph

Kay. I hope you have a good helmet, though. :wink:

1) I have a bike already – and have a budget of around $2000ish (can dip into the kids college funds if need be!)

Good budget. Should be around what you need.

2) A Crystalyte 5 Series rear Hub – But which one? Was going to get the high speed one but after reading various posts about torque/speed I’m unsure!

3) A 72V 48A controller and the cycle analyst.

4) Batteries – It all gets blurry for me here, I might be getting these from the UK, I’m not scared of making my own but I need all the advise I can get here as this will probably be the bulk of my budget.

A 5305 would be best, but you need a lot of voltage to get it up to 40mph. 96V or more. A 5304 will do the job on 72V, but at the cost of a little efficiency. It may be negligible, however.

20Ah of Ping could pull it off (and you'd have plenty of spare range, too), but his situation is sketchy until after the Olympics, I guess. Though I've heard he's found a different courier...? Someone else care to chime in on this?

Otherwise, you've got too much choice for me to really say what you should go with. A123s if you've got patience and money, or perhaps Milwaukees, Headways, LiFeBatts, there's another eBay seller that apparently makes custom packs, ebikes.ca's packs...You get the idea. Shop around and see what will do what you need for the best price. :wink:

Was thinking about connecting two 36V 12Ah LiFePO4 together? (Like the ones of ebikes.ca) Would this work? Would I need two chargers? Will this give me my range/speed? Would two 48V batteries be better? What sort of discharge rate do I need? I just don’t know! Help!

72V/12Ah would be a bit marginal for a round trip, IMO, but they should be able to make the one-way trip without issue. The ebikes packs would work, but they are a little expensive. And I don't know if their BMS can handle putting two packs in series. You'd have to ask. A 96V/12Ah (two 48V) pack would work with a 5305 and give you enough range for the round trip.

Or is it more feasible to make my own – if so what specs should I be making it to and what kind of chargers should I be looking at?

Like I said, shop around and see what works. Building your own pack is time consuming, but is a cheaper way to do it. Suitable chargers can be had from numerous sources, including ebikes.ca. BMSs are harder to come by. Ping I know sells them, but you'll need to modify them a little to be able to handle series packs. I don't know the status on the one GG and Bob are working on.

The bike I will/may be using is decent but has a aluminium frame (and forks) so I will be rear mounting the motor – is this ok? Or should I get a steel bike? Do I need to use torque bars if I’m mounting the motor on the rear?

Aluminum is fine. Most here have aluminum frames. It's the drops you need to worry about. But, with the amount of power you plan on running, you're going to be using torque arms no matter what your drops are made of. As long as you have somewhere to put the batteries, the frame should be fine.

I'm assuming this is not a road/racing style bike frame, however. Ditch it if it is; they aren't at all suitable for electrification.

Is there anything I’m missing or need?

No, I think you have the main bits worked out. But it's the details that are going to test your mettle. :wink:

 

[deecanio]

Hi Dave,
Welcome to the Forum
yep those are the questions for sure, i asked the same about 2 years ago when i first found the forum!
I can help on a couple of fronts but you need the more knowledgeable guys to help you out with battery choice.
So far sounds good - controller 72v48a and CA from ebikes.ca is a sound choice of kit and supplier.
as far as motor goes i think again you are right to go for the x5 for your use, i would say X5304?? but others will help here who run x5's.
Batteries is always the most difficult choice, in my experience i would say think long and hard before investing here.
A123/lifepo4 are the best imo but think about how you plan to mount them before you buy, i initially bought 2 36v packs but have now moved on to A123's custom built pack to fit my bike.
I think ally frame is fine especially in rear mount, dont forget to support the dropouts with some good torque arms!!
Post up a pic of the bike you intend to use too and have a think about what gearing setup you want to use too.


Cheers


D

 

[Mark_A_W]

A constant 40mph? That's 64kph in real measurements...I hope you wear a motorcycle helmet and leathers..

It's one thing to peak at this speed on occasion, going downhill, but going that fast all the time.....you'll get car doored...they just won't see you coming.


You said you didn't want to start a debate, but fark me, you'll kill yourself.

I'd be aiming to top out at 50kph or so. That's dangerous enough, cars just don't see you even at this speed - they all think you are doing 20kph.

 

[Daveintheuk]

Thanks for the quick response guys. Fantastic!

So it seems I’m good to go with regards to my motor and controller choice and I do need a torque arm for my rear wheel. Glad that’s cleared up.

Deecanio – you say about gearing setup; I take it you mean for pedalling? I’m not planning on doing to much of that. Will probably use pedal power to start up only and to rescue me in the event of a flat battery.

Also just to clarify, my total trip distance to work and back is 10 mile. I’m looking for a total range of 12 – 15 miles ideally @ 40mph (ish)

This battery lark is what’s getting me. Looking in the battery topics here only seems to confuse me further, hence, more questions;

Is there a ‘off the shelf’ (with charger) option for my needs?

For my speed and range can someone point in the right direction of what I need?

72v or 96v? (volts = speed, is this correct?)

What ‘C’ rating do I need? (This is the amps drain speed, right?)

Will 12AH be enough? (I believe ‘AH’ to be range?)

Which battery should I go for, So much choice – which is best? Looking at the pings but I’m thinking there’s an issue with the amps (C rating) I’ll be drawing from it?

Is (dare I say it) SLA an option? :?

I’m also happy to build my own but would need a picture guide for sure!

Will I be able to charge this beast with one charger?

Sorry about all the questions…. And Link, your answers where fantastic but I’m still scratching my head on this one. The battery saga is really niggling me. I’m on a steep learning curve and want to understand what I’m doing fully rather than ordering $1000 of the wrong battery!

Mark, I appreciate your concerns, and I will of course be wearing a helmet. I’m after speed… I’ve hit 40+ before on downhill mountain runs in Wales a few years back so I know how fast this is on a bicycle. Also I live in Milton Keynes and we have really wide smooth tarmac cycle lanes with no cars… so I won’t be playing with traffic. My commute will also be at times where there’s no-one around. So its perfect for high speed and it satisfies my desires at the same time.

So, I’m done, again! Thanks again on your input… fantastic.

I just need to get my head around this battery business! Anyone care to educate me further?

 

[TylerDurden]

Ja what they said...

plus, going 30mph instead of 40 will require 50% less battery.

 

[TylerDurden]

Re batts:

A Ping battery is a great value, no complaints from users AFAIK.

Building a pack from cells is a chore, but fine if you are experienced with elec.

Steer clear from LiCo, AKA li-poly... unless you are a veteran R/C enthusiast.

 

[Daveintheuk]

hmmm, Thanks guys. Handy chart that.

Ok, so looking at the ping batteries I've read elsewhere that the BMS shuts this battery down at 32 amps? Which I’m guessing will be a little light for my needs.

Surly the controller I’m intent on getting will constantly be making the BMS kick in?

If I hook 2 ping batteries 48v 20ah to make 96v the ampere rating remains the same? Is this correct? Or does it double?

This is where I get confused – I could quite easily spend a small fortune of two ping batteries – get great voltage and range BUT the BMS on this battery will be constantly cutting in when I’m pulling 32 amps or more… Since the controller can handle 50 amps I’m guessing this configuration will be inadequate?

Or am I talking pants?

Cheers – Keep it coming.

 

[John in CR]

Ping recommends NOT to put his packs in series. It seems to make sense that the BMS may not like having the higher voltage running through it. I have 2 of his 36v packs that I run in parallel, which has cleared up my current limitation issue. Of course Ping also recommends not putting them in parallel either, which I can't make sense of. Maybe one electronics gurus can offer some guidance. If the BMS can be easily modified for series connections then I'm game as the test case.

Also, Ping's shipping is pretty pricey until after the olympics, and he also mentioned some new packs coming soon that will permit higher current draw along with possibility of parallel and series combinations. It may very well be worth waiting.

John

 

[stew007]

I more or less agree with Tyler on the Lipo's, They can burst into flames if they are mistreated. But with some basic knowledge on how to initially programme the lipo charger i.e follow the instructions, and how to set the LVC on the Cycle analyst they are pretty safe, Newbies are getting into electric rc flight all over the world without many accidents, chargers are now very safe, just type lipo into ebay and see the market is awash with these. the good points are the best energy density out there, long life, quick charges, small size, lightweight and not that expensive.

I built this outdoor charging station so I could charge them up unattended in safety so I can have total peace of mind, the three batts in the pics are 22.2v 10ah packs giving 66.6v 10ah total at only 3.6kg in total and can give 100 amps continuous, the packs are only 60mm x 60mm x 160mm each so fit neatly into the lower frame for good balance.

These come ready made http://www.maxamps.com/Lipo-10000-222-Pack.htm and this charger can charge 2x packs at once in around an hour http://www.maxamps.com/EOS0610i-DUO.htm powered by this Power supply http://cgi.ebay.co.uk/400W-24V-16-7A-Switching-Power-Supply_W0QQitemZ310058417791QQcmdZViewItem?_trksid=p3286.m20.l1116 also another great place for Lipos's all these places deliver to the UK. http://home.comcast.net/~truerc/custom/custompack.htm

Tens of thousands of Newbies all across the globe in the RC arena are managing to use these packs safely, so I think even a few elec bike nuts should have little problems too. But they do present some risk if the user is careless.

 

[docnjoj]

Stew007:
That seems to be a well thought out assessment! I have a few little Lipo packs for small electric planes, and have always been impressed with their performance! The equipment U show is a really large investment compared to current LifePo4s. In my case the weight difference means little, but the cost means alot! Thanks.
otherDoc

 

[deecanio]

Hi, yes i was talking about the pedal gearing - you will need to remember that if you do break down an ebike is heavy to pedal home also dont discount having the option to pedal - i have gone from power only to half and half meaning i dont have to lug around masses of batteries, even a gentle pedal will help out with range so don't dismiss it out of hand?
batteries? mmmmmm, if only someone inthe uk had some cheap lipo's for sale so you could test :lol:
i would say order you CA,throttle,Motor,controller - i think everyone agrees with the choices you've made on these so far - it will give you more time to figure out what you want to do for batteries and once you have physical kit you will be able to see how you plan to mount etc? - put up a picture of your bike and tell us how you plan to put all the parts on it.
I say this gingerly but if i was starting from new again i would have A123/life custom made pack - i dont have the nouse to build it myself but i know a man who does


cheers


D

 

[fechter]

Ping recommends NOT to put his packs in series. It seems to make sense that the BMS may not like having the higher voltage running through it. I have 2 of his 36v packs that I run in parallel, which has cleared up my current limitation issue. Of course Ping also recommends not putting them in parallel either, which I can't make sense of. Maybe one electronics gurus can offer some guidance. If the BMS can be easily modified for series connections then I'm game as the test case.

Also, Ping's shipping is pretty pricey until after the olympics, and he also mentioned some new packs coming soon that will permit higher current draw along with possibility of parallel and series combinations. It may very well be worth waiting.

John

Check out the last post in this thread:
http://endless-sphere.com/forums/viewtopic.php?f=16&t=1312&p=70490#p70490

I don't see any reason you can't run packs in series if you use the diodes.

Putting packs in parallel would be OK too as long as one pack does not discharge into the other. Another job for diodes, but as long as both packs keep the same state of charge, diodes may not be needed for parallel connection. If one pack was fully charged, and one was fully discharged, there could be excessive current when you connect them together.

 

[John in CR]

Check out the last post in this thread:
http://endless-sphere.com/forums/viewtopic.php?f=16&t=1312&p=70490#p70490

I don't see any reason you can't run packs in series if you use the diodes.

Putting packs in parallel would be OK too as long as one pack does not discharge into the other. Another job for diodes, but as long as both packs keep the same state of charge, diodes may not be needed for parallel connection. If one pack was fully charged, and one was fully discharged, there could be excessive current when you connect them together.

Fechter,
Thank you for that. I just happen to have the right diodes. I guess this is a case where I can't look at electricity with a water visualization (current=flow volume and voltage=pressure), because when I do, it looks like current will leak around from the bottom pack and through the diode on the top pack to result in some kind of strange parallel and series wiring combination. This is exactly the kind of thing where electricity and I don't see eye to eye, so I didn't take the time to learn it.
John

 

[Daveintheuk]

Wow, Thanks for the input guys, just fantastic.

Stew007 very very interesting & great links but would it give me my range?
And you just connect the – and + wires from the 3 packs together and straight into the controller with no problems? Obviously I have heaps to learn about batteries but although warned about lipo’s this sounds like a good idea. The outdoor charging station is doable for me to.

Deecanio – I haven’t dismissed out the pedal factor and I will be using pedal power to get me going and of course for when I break down. I think I’m going to go ahead and order the 5304, controller and assist computer from CA.

I will get some pictures at some point over the weekend and post them up with my plans, I’m after a neat look! :wink:

I want to take my time over this and get it right first time – I’m a nightmare for doing a project then realising I want it bigger and better and starting from scratch again!

In the mean time I need to learn a lot more about battery technology (the more I learn the more complicated it all seems to get) and I need to get my head around all the options and what’s best so keep the ideas and recommendations coming please – it’s really helpful.

But I guess whatever technology I use I’m looking at these figures as an output;

72 – 96 volts
As high AH as possible for my range
A technology what can handle a high amp drain (40-80amps)

Does this sound right? Is there other figures I should be looking at?

Questions, Questions, Questions - I’ve checked out some of the battery building projects on here and it looks complex – I’d rather buy a readymade pack to be honest and avoid all the complications – buying two pings and wiring them together seems like an easy option and at the moment is top of my list (I need to be sure this can handle the high amps drain though)– but I see that’s already sparked a debate!


Also – straying from my battery dilemma – rear torque bar, I’m told I need one but where do I get it from – if it’s something I need to make myself how do I do it?

Well, thanks so much for the input so far – keep it coming – I’m learning loads but still need more help on choosing the right battery for me.

No doubt I’ll wake from my sleep tonight in a cold sweat screaming “LIPO’S” and “PING”! :lol: Honestly, This Ebike thing has taken over my mind recently. Can’t wait to get cracking!

 

[tno]

If you see a used wavecrest X bike/motor for sale, it might be a good choice too.
I'm running one with a 14cell 20ah Ping battery. with that battery, it will accelerate to 33mph in stock form.
it needs at least a 14cell Lifepo4 battery to have good climbing power.
To go over 40mph, the controller needs to be modded with IRF4110 mosfets and panasonic 63v capacitors.
A 15cell Lifepo4 battery with this setup and setting the controller max amps at 60 will give you a top speed around 45mph.
The advantage of this setup is that it seems more reliable to me.
I have an X5 that keeps breaking spokes and it's hard to keep it true.
I ended up removing the rear brake because I got tired of truing the wheel.
With the wavecrest, the wheel stays true and the power and speed is similar to the X5.
The controller is inside the wheel so that's one less thing to mount.
It has quick release axle bolts so is much easier to change a flat tire.
It has a round axle so there's no worries about breaking the dropouts.
The only problem is that you or a friend has to be able to modify the controller for 40mph and you have to find it used.
you can go up to 100v if you can squeeze some 100v capacitors in there and change the volt regulator.
The X5 is easier to find though and if you get it, just make sure the wheel is built well. Maybe that will make it lower maintenance than my X5.

 

[stew007]

Stew007 very very interesting & great links but would it give me my range?
And you just connect the – and + wires from the 3 packs together and straight into the controller with no problems? Obviously I have heaps to learn about batteries but although warned about lipo’s this sounds like a good idea. The outdoor charging station is doable for me to.

Well, on 66.6v my Crystalate 408 can do around 33-35 mph which is pretty fast for a bicycle! but keeping her at around 20-25mph I can get 25 miles per charge easy, and the roads around here are hills and tight corners everywhere. If you want more power, I'd say go for 4 packs, 88.8v or 77.7v, the top end 50a controller from ebikes and a crystalate 5304, but check with them that 88.8v will be ok. Or you could go for 3x 22.2v packs and 1 x 11.1v pack to give a less brutal 77.7v but you would have to switch settings on the charger when you charge the 11.1v pack which takes 2 seconds.

You can choose the connector type on the maxamps site, I have my packs fitted with Femail deans ultra connectors, good for 100 amps.

You will need to make a connector harness for connecting the packs up in series (+-+-+-+-) i.e to get 88.8v, 77.7v or 66.6v. For 88.8v/77.7v for this you will need 5x male deans connectors, and 1 x femail, (one of those male deans is for soldering onto the speed controller to replace the connector it comes with) You will need to be able to solder, and have a 70+ watt solder iron, flux etc, some 6mm heatshrink, and some flexible 12awg such as wire http://www.maxamps.com/products.php?cat=70 http://www.maxamps.com/Deans-Male-2PK.htm http://www.maxamps.com/Deans-Female-4Pack.htm This is a series harness for 2x packs

The hyperion gear, Deans, Wire, Heatshrink etc you can buy in the UK from http://robotbirds.com/catalog/

But I will say, If you have never soldered chunky wires before then this might not be for you, it can be a bit tricky soldering deans connectors, they need to be held lightly in a vice/self grips while you solder them. amazing what you can find on youtube http://youtube.com/watch?v=CT18mxfGRjo http://youtube.com/watch?v=xZU9rtACdZY&feature=related http://youtube.com/watch?v=XYhmzY5wQAA

One more thing, your low voltage cut off must be set no lower than 3.3v per cell, so if you have an 88.8v pack which is a 24 cell pack, you LVC will need to be set at 79v, of a 77.7v 21 cell pack it must be set to 69v.
3.3v per cell is considered a good cut off point, 3v per cell is considered minimum but you might shorten the life of your cells slightly. And you want to mount your packs so they dont rattle around, and protected from sharp edges, this is the battery box made from 3mm plywood

 

[deecanio]

Hi Dave,


yes this crazy hobby will dominate your mind :lol:
expect to sleep very very lightly for a few weeks because your brain will be doing calculations for your bike at a mind blowing rate - this isn't always a bad thing though as occasionally you will wake up remembering some that actually work!!! the days work after 3 hours real sleep is quite hard but you can always get throught it by planning some more instead of concentrating on your job
Right back to it!!! post up the pic as soon as you can - once we can see what type of bike you want it will be much easier to point out flaws or suggest things you haven't considered yet.

IMHO the batteries are always the worst problem, more specifically mounting them,it's not easy (impossible?) to buy two premade blocks and make them look good on the bike, possibly with the exception of choppers.
If you want to build once (this will neve happen btw ), think hard about your battery choice and know that you DO have all the choices you see on the forum - i can't build packs either but Jozzer can and he's uk based, price is no where near as scary as you might think!!! ( by the way not trying to sell you anything here i'm just saying don't think it's not doable) - personally with batts i have come full cycle from like you wanting two big blocks that work to wanting a pack that actually fits my frame so i had to go the custom route, best thing is i can now pick the shape and the size of the pack to suit my needs more accurately.

Anyway enough of my rambling crack on son!! get the x5304,72v50a xlyte controller,ca,throttle etc - i'd be surprised if there is there anyone that disagrees with these?????? and then put up some pics of the bike and if you can draw in/describe well where you plan to mount your kit, batts included.




Cheers


D

 

[Miles]

Technobots is a good UK source for electrical stuff & materials.

 

[dogman dan]

Just my opinion, but if you want to go 40 mph you really need to start with a frame and wheels that are made for that kind of use, day in and day out. You describe the performance of a motorcycle or scooter conversion, and need to double your budget to do that, or settle for 30 mph or less. Above 30 on a bike is pretty sketchy. I just broke both collarbones in a wreck at less than 10 mph. A ping 48v 20 ah battery on a good hub motor will do that in your budget easy, but 40 mph sustained for 20 miles. Not for cheap.

 

[monster]

hello and welcome to the forum. tis good to see more fellow brits using high power ebikes.

the 12-15 miles range is easy to do. however 40mph continuous is pushing Ebike limits a bit. the problems you will face are numerous but not impossible. they will be:

braking, over heating, battery placement and charging.

you may have hit 40mph for a split second while going down a mountain but you may be underestimating the requirements for riding 40mph continuously on the flat. my commute is 22miles (round trip) and i ride at 25mph continuous. i have the X503 and 1kwh battery. i have hit 50mph (peak) and i can ride 40mph anytime if i want, but don't because it will drain my battery and endanger my life.

i would suggest at least 1kwh of battery, get a motor with a rear disc brake mount, use big thick wires for current carrying and place as many batteries in the triangle as possible.

 

[stew007]

Stew007 very very interesting & great links but would it give me my range?
And you just connect the – and + wires from the 3 packs together and straight into the controller with no problems? Obviously I have heaps to learn about batteries but although warned about lipo’s this sounds like a good idea. The outdoor charging station is doable for me to.

Yeah, just hook them up in series and your in business a 21cell 10ah pack will easy shift you 10-20 miles, no probs at all thats a serious amount of energy you will have stored, you could start off with 66.6v and see how it goes, and if you want more speed/range, just add another pack

 

[Daveintheuk]

Cheers people, just superb. And hi to the other UK guy Woooooo!

Ok, I’m kinda swinging towards going with the lipo’s now. Although the charging & setting up seems a bit complicated I’m sure it’s something I can learn. It seems this can offer what I need in terms of power and range and my moneys on the lipo’s.

Do you guys agree?


Now, there are obviously concerns about hitting 40mph and your points are being taken seriously. :|

From a safety point of view – yes, it’s dangerous, but I like that. If I wanted to go 20mph I wouldn’t be strapping a motor to it in the first place. I like speed and a sniff of danger and it’s this which makes the Ebike build exciting for me.

From a Mechanical point of view – this is important to me, I don’t want my frame to fail at 40mph. I’ll be checking welds etc regularly and will strive to maintain the bike to very high standard and I’ll also be fitting top end tyres and brakes for sure. If I need to spend more to make this happen then so be it.

There seems to be lots of other Performance Ebikers out there hitting 40mph... I appreciate your concerns guys, truly, I do. But it’s doable with lots of others out there doing it and although I’m a newbie, naive I am not.



Anyhows, rant aside and back to business. I have two bikes and would love to hear your thoughts on which one to go for –

Personally I would like to go with the duel suspension bike; rear mount the motor, batteries preferably on a rear post mounted rack (if it can take the weight 15kg max) or in a wearable backpack. Controller etc mounted either under the rack or seat.

The other rigid framed bike would have the same setup but with the batteries mounted on a strong pannier rack.

Both bikes are aluminium with aluminium front forks as well with 26” wheels. and the chosen project bike would have upgraded tyres and brakes fitted.

There is a third option – if you guys think that both bikes are unsuitable for this project I would look at buying another specifically for this build.

So what do you think?

And any other thoughts for the batteries? Do the lipo’s sound like a winner

And any input on where I get the torque bar from? Does it come with the motor

Keep your thoughts coming! Cheers.

 

[Link]

So what do you think?

And any other thoughts for the batteries? Do the lipo’s sound like a winner

And any input on where I get the torque bar from? Does it come with the motor

I was leaning toward the full suspension, too. Bumps aren't fun at 40mph. Upsides and downsides to the seatpost and backpack. The backpack is kind of a pain (I used to use one), but the seatpost rack will make the thing very rear heavy, and it may even try to wheelie on you (I could do this with my Golden Motor and 20lbs of LiFe on a seatpost rack). Though I haven't had any problems with it otherwise.

If you can find them cheap, the lipos should be fine. I don't like them for their cycle life (and I got a screaming deal on some LiFe), but if they work for you, go for it. They're light and small.

I'd put in a post in the Buying/Searching forum. There's a few here who could help you out.

 

[knoxie]

Hello

Just my two pennys worth, I am in the UK and have and still own the following, a USPD kit, 4 x BMC Puma, an X5304 Xlyte, 8 x 42V Lithium polymer batteries, 2 x 24V 14Ah NIMH Packs, all of these coupled to 7 different e-bikes! I have a lot of experience of all of these setups!

40mph on any bike is a tough call, to hold those kind of speeds in anything other than perfect conditions is tough on batteries and very dangerous, esp if you intend to do this on the cycle paths of MK! I know MK very well indeed and I dont recommend it, stick to 30mph tops! you will get so much more bang for your buck if you aim at this speed.

My 5304 does 30mph at 48V on old NIMH cells, I can do 30 miles with moderate peddling on old NIMH cells like that! my advice would be to go with either a ping pack or get Jozzer in the UK to make you up a headway pack, I may even go in to the battery business if somebody in the UK does not do it before me!! the situation is crazy at the moment IMHO.

48V 10AH will do your commute, you will have to of course charge at work though ( is this a problem ) at 30mph you will get a lot of looks from folks if you want to hit 40 you will need 3 times more in the way of battery power to make your commute and you will be noticed doing it!! believe me 30mph is fast enough on an e-bike!!

We have all had a huge amount of experience on this forum with speed and the kits that are available please listen to what folks advise!! you are more than welcome to come and try any of my rigs! my X5 will be running 72V 35A of lithium shortly! will make 40MPH but I wont be pushing it to that!!

New batteries are coming on-line now that will make our commute so cheap and doable in the very near future, at the moment 40mph is a bit of a tough one! knock it down to 30 and you are on the ball.

You may have seen some of my videos on youtube? check them out and see if 30mph is not quick enough for you, PM me with any questions and good luck!

Knoxie