My first entry into the world of E-Bikes

[NRG]

I’ve finally joined the world of E-Biking!

I want to share my experience of how I eventually managed to get here and also post this thread as a cautionary tale to all fellow ‘noobs’ like me currently thinking about but have not taken that first step.

I could have taken the easy route and just simply purchased a commercial bike, I know lots do and in some ways I wish I had….maybe I still will at a later date. Anyhow I found the commercial prices too steep for me as I only wanted a bike for occasional use and couldn’t justify £1200 ~ £1500 or more…if it was for a daily commute to work and something I had to depend on then the decision would have been simple...

So I decided to go DIY and convert my Hybrid Peugeot…I read loads here and on other forums…well , at least I thought I had read loads but I still made some fundamental mistakes. With hindsight I should have purchased a locally sourced kit, the Alien Bike kits being an obvious choice IMHO….in fact their bikes look good too! Hmmm… I digress, I started looking at Ebay and selected a Chinese seller who’s kit seemed to tick all the boxes….IE: 700C wheel, Pedelec, Throttle, Brakes, rear mounted with gears, controller etc etc.

I went for a 24v motor which was my first mistake but my thinking at the time was to use SLA’s and 24v is easy to arrange using them. My next mistake was to not realize that the motor was a direct drive type… Doh! This could mean problems as I need assistance for hill climbing….yes I know *now*!

The kit was duly paid for and shipped only to spend 3 weeks stuck in Chinese customs...I asked for my money back and the seller duly paid after a few email exchanges..The kit then turned up a few days later! So I will pay for the kit as is right and proper but only after I’ve factored in the repairs that I’ve had to go through as you will see below…

The Kit (do you recognize these parts? I do I’ve seen them in other posts and the motor is a Cohnis by the looks of it…it sure is heavy!

I inspected the parts and found my first (minor) problem:

That was easily fixed but this was more of concern:

The sharp edges of the hollow axle where starting to cut into the motor wires, so I needed to round them off with a file.

The 24v charger came with a USA plug and by the looks of it doesn’t meet EU or UK regulations! Best not to leave this unattended when charging as I have no idea how safe it is…

 

[NRG]

I decided to check even further as I now had concerns over the quality, safety and longevity of the parts. Taking the controller apart was an eye opener for me as an Engineer with an electronics background…

Quality it is not, we’ll just have to see how it holds up.

Also the power wiring via an underrated IEC plug and socket was of concern. It made me chuckle to see a 30amp inline fuse hooked up to 6amp wiring! So that had to go and I remade it using 30amp cabling and a new fuse/fuse holder.

I decided to go ahead and see if the wheel would fit, it did to my surprise but only after I cut down the supplied cylinder spacer on the non-gear side…a bit of further faffing and the wheel slotted home. However I now had a few more issues, there were too many washers and spacers on the gear end of the axle and I could not remove them because of the sensor plug attached to the end of the motor wire!

So I had to cut the wires, remover the washers and re-splice the wires back together! The kit came with anti-torque washers and they fitted neatly into the frame dropouts…finally something that went right!

Also the pedelec sensor went on without any issue:

 

[NRG]

Buoyed by the seemingly improvement in fortune I tightened up the axle nuts and found myself looking at a wheel offset to the right by about 5mm! After much head scratching I decided to sleep on it as this was too much. Refreshed I finally realised that the wheel had no dishing…if I could adjust the spokes maybe I could dial enough in to get the wheel sitting in the middle of the frame. It was around this time that I also discovered that the motor was not in the center of the wheel, it was out by 6mm….good grief at this point I very nearly gave up…it was Friday and I retired for a small beer…

…but as I’m stubborn I would not let this beat me so thinking I had nothing to lose I read up a little on truing wheels and dishing and set about the spokes…I don’t know how long it took me…many hours but I finally ended up with a wheel that is not perfect but is at or close to 1mm true vertically and about 0.5mm horizontally! I have no idea what the spoke tensions are and I fully expect to have problems later as they do vary (tapping them indicates they vary a lot, some very tight) but I don’t care just now…

I adjusted the brakes and inflated the tyre and noticed another problem, somehow the beading of the tyre did not seem to sit in the rim:

I took the wheel out and removed the tyre for inspection, I found the tyre seemed to be OK but there was no Rim tape on the wheel. This is not related of course but I don’t know if its general practice to fit tape to all wheels but I didn’t like this so used a role of insulation tape(!) as a substitute…it seemed to do the trick.

It was at this point that I remembered reading about the Marathon Plus tyres on the forum so decided to order a set along with some other accessories: New mudguards, fold away stand, comfy seat, rear light and rack bag from those nice people at SJS.

Whilst waiting for the other bits to arrive I finished putting on the rest of the kit…well just the throttle TBH as I didn’t like the look of the cheap bake levers supplied. A few days later the tyres arrived and I could finally re-assemble and test out the electronics.

I’m using a pair of 10Ah SLA’s as a temporary measure as I plan to go Lipo in the very near future. I like the power to size and weight ratio of Lipo and with my occasional use the limited cycle life should not be an issue….in fact reading the Endless Sphere forum the data sheets for Lipo indicate that with careful monitoring of discharge and charge voltages the life can be extended to 1000 or more….not sure if it’s true but I’ll stick with the recommendation of a max cell voltage of 4.15v and minimum of 3.2v.

Going Lipo will also fit with my plans to change this motor for a more compact geared one running 36v at a later date. Electronics and batteries fit neatly into the padded rack bag:

 

[NRG]

And here is the finished beast:

So how does it ride?

Well, its surprised me greatly…firstly it seems quiet! I’ve read a lot about motor noise on the forum but this motor seems good in this respect, maybe because its rear mounted I don’t notice so much but even turning my head side ways it still seems very quite.

The handling seems fine as well, I don’t notice the motor when riding only when I come to move it around by hand as it does weigh a fair bit. The bike will accelerate from rest in a slow’ish fashion, the low level torque is not super due to the direct drive motor and probably also due to the use of SLA’s currently, the voltage does sag under load….Lipo’s should improve this. Top speed, assisted by top gear peddling at a relaxed cadence is about 17~18mph which is more than enough for me…throttle only it gets to 15mph or a bit less on the flat.

As this is my first E-Bike I don’t have any baseline to compare with regarding hill climbing and speed plus I have no reference for the use of the Pedelec system and throttle.

The pedelec seems to be all or nothing, IE you have to pedal up to the 15mph limit and keep going, not matter what… if you want to go 10mph forget it as the motor quickly overtakes your cadence and there this annoying on assistance, off assistance, on assistance operation. The throttle is better in use, control at low speeds is OK not brilliant but manageable, above 5mph it’s very good. Unassisted you can feel the motor drag so I tend to select a lower gear now than I used to prior to conversion and travel a bit slower but when faced with a hill / incline or head wind just crack open the throttle until the strain on my legs backs off…works very well.

This also seems to extend the distance, not that I can go too far on these SLA’s. For short hills if I approach in the right gear the motor assistance is noticeable and where I would struggle to hit 6~7mph I breeze up them at 12~14mph….that’s not bad given the batteries. However I have yet to tackle a really big’un! And there are some huge ones around here.

Anyhow that’s enough…I’ll come back and update this thread when my Lipo’s arrive and when I decide to chuck this motor away!

--NRG

 

[NRG]

Update: My Lipo batteries have arrived from HongKong. After reading the EndlessSphere forum I went for these 5Ah ones:

I need 24v and felt that 6 cells at 3.7 nominal was not quite enough so I decided to run on the high side and use 7 cells to give 26v nominal. The controller and motor are rated for just over 30v so I'm hoping this will be OK. The pack is made up of 3 pairs of Lipo packs (4 and 3 cell packs in a pair) 6 packs total. Also going for this combo of packs means I can easily reconfigure for 36v with the addition of just one more 3 cell pack. All the cells came in good and I balance charged each individually to get me started.

The reports from ES are these cells don't drift apart that much and are very stable so I'm hoping I can just charge normally for 7 cell voltage (29.4v) and balance charge when necessary which should be an infrequent event.

Low voltage cutoff is critical with Lipo so each of the 6 packs has its own BM6 monitor...unfortunately, one unit keeps alarming as it's miss reading a cell and thinks its at 4.25v when its really at 4.19....

This is how each pair will be configured:

The pairs are stuck together with double sided carpet tape and all 3 taped together with Duck tape:

 

[NRG]

Here's the pack with the BM6 stuck to each battery using double sided foam tape:

This was never going to be a neat solution compared to a 'commercial battery' but I intend to put the pack in a aluminum box to make it neater and offer some case protection. The all up weight is impressive, I think its about the same as just one of the SLA's I have used up 'till now and the size is really compact for such a powerful battery.

It looks a bit of a rats nest like this but when connected up I have 29.2v and 15Ah of power....all that's left is to connect it to the bike and go for a test run...that's if this rain will let up!

 

[Beeping-Sleauty]

well done...

good post NRG, thanks for that.

glad you finally got it all going despite the problems.

excellent photos describing the difficulties, this is very helpful for others considering the DIY route.

the hub looks big, but if it does the job, so what, the finished article looks good

happy mileage,

beeps

 

[flecc]

Direct drive motors are generally very quiet, it's the gears and hub shell resonances of orbitally geared motors that create much of their noise.

Congratulations on the way you've dealt with all the issues arising, I can well imagine your frustration at some points. A rim tape is essential, leaving the spoke holes exposed is bound to lead to problems, but your insulating tape may be sufficiently strong to do the job, though much depends on the tyre pressures.

Once you've ridden the bike for a while to enjoy what you've created, you could return to the truing and spoke tensions since second time is always easier with the experience gained. Should you have a spoke break and need a short spoke replacement, SJS have a range of good quality British made shorter spokes:

Short spokes at SJS
.

 

[NRG]

Thanks Flecc, I think I will go back and check the spokes again and for piece of mind use the correct rim tape.

I've been out on the bike this afternoon to see how it tackles some of the larger hills around here, I have to say I'm impressed given the weedy batteries I'm using. I tackled two 14% hills plus some 10% ones and although there was a fair bit of input from myself on the 14% ones I managed to go up at 10mph...I think with stiffer batteries capable of delivering the required current these will become easier....I did 8.3 miles and the poor SLA's where getting close to the end...10miles max I reckon given this sort of treatment. Great fun though!

 

[Vikki]

Nice pictures and very good work there. I think I'd have been inclined to accept the refund and send it all back. I admire your persistence. Bet you learnt a great deal and that alone would have been worth the experience I suspect.

As to weedy batteries. SLA are far from weedy, only the capacity is weedy. SLA have a very low internal resistance and will provide far more current than the controller would care to handle. Range would be the problem rather than strength. Agree with going lipo though, I have several pounds I would like to shed.... what? Oh, that kind of lipo. Lighter with a higher storage density will see your range increase. I think you going to have loads of fun with your new bike - and you made it yourself Enjoy.

Best regards.

Vikki.

 

[OneWayTraffic]

Well since I'm now the proud owner of a Kona Smoke acquired for $399 NZD new from a NZ bikeshop (it was advertised on trademe-our ebay. I got lucky) I will be going the DIY route myself. Of course I'm going to spend more money and get an ebikes.ca Ezee kit. That should just drop right in and they now offer it with 8.5 Ah LifePO4, 14 Ah Lipoly (maybe cobalt?), and the regular Phylion 9.6Ah LiMn.

The main thing that pushed me to DIY is the ability to choose a bike. And I'm no fan of this move to Aluminium and carbon that everyone is going for. The only advantages that they have over steel is weight as far as I can see. Who really cares about 2kg or so saved off the frame when you're putting 10kg+ of electrics on your bike?

 

[john]

Electronics and batteries fit neatly into the padded rack bag:

Putting the controller in a padded bag may not be such a good idea. You could start to cook it in the summer

 

[NRG]

Good point John! I'll keep that in mind, thanks.

 

[flecc]

I'm no fan of this move to Aluminium and carbon that everyone is going for. The only advantages that they have over steel is weight as far as I can see. Who really cares about 2kg or so saved off the frame when you're putting 10kg+ of electrics on your bike?

I fully agree, I'd rather have a steel frame on any bike and think it's sad that e-bike companies are so obsessed with only using alloy. In practice the weight difference is negligible in most cases and steel gives a far better ride.
.

 

[Alex728]

has some anomaly with metal pricing made aluminium alloy cheaper than steel (presumably forgetting about the costs of all the electric required to produce aluminium?)

I've noticed since about 2003/04 that nearly all mid range bikes (including conventional push bikes) are exclusively alloy frames, yet just over 20 years ago I remember an aluminium mountain bike being a premium priced item..

 

[flecc]

I've noticed since about 2003/04 that nearly all mid range bikes (including conventional push bikes) are exclusively alloy frames, yet just over 20 years ago I remember an aluminium mountain bike being a premium priced item..

One word explains this, fashion.
.

 

[Barnowl]

One word explains this, fashion.
.

And the robots can't handle the narrow steel tubes.

Totally agree onewaytraffic steel is the way to go.

 

[Alex728]

I've also seen aluminium replacing ferrous metals in all manner of objects from larger electrical goods to garden furniture though, and always thought it used to be more expensive?

Even a Dawes Horizon stopped being made as steel framed from the 2004 model...

 

[flecc]

And the robots can't handle the narrow steel tubes.

Generally not applicable to e-bikes though, production scale too small.

Even the very large Derby Cycles who make the Kalkhoffs and other e-bike brands hand weld frames, and the same is true of many, maybe most, in the Orient who supply us, eZee for example all hand fabrication.
.

 

[OneWayTraffic]

And the robots can't handle the narrow steel tubes.

Totally agree onewaytraffic steel is the way to go.

Well my new bike is CroMo. So hopefully that will keep me sorted for as long as I need it to.

But I think I'm hijacking somebody's thread.