stevelo333

As a kid I went everywhere on my bike and loved it - the cycling and the bike, even though it was a very basic six-geared road bike, with added cowhorns and knobblies, but then moved to London for uni and found buses and tubes so handy I got out of the habit of riding. After uni and no idea what I wanted to do, I bought a small motorbike, and loved that too, and then needing work I became a motorbike courier, and went through a few bikes - a couple of accidents, one was stolen, then cash problems forced me to get a cheap bike to keep me working and as it ground to a halt 50 yards from my front door having spent most of the weekend fettling it for the week ahead, I decided enough was enough and started looking for office work. Then a friend dropped by, who I'd met at one of the courier companies - he'd loved 'Guzzies, so I was surprised to see him on a push bike. He'd swapped petrol for leg power, and though the money was less, so were his costs and he was getting fit again into the bargain, and he persuaded me to give it a go, too. I'll get to the point - I did that for a few years, and after deciding I'd had a good run with no serious injuries I decided to get an office job, cycling in to the west end but arriving sweaty - after being a cycle courier, it's nigh impossible not go really go for it and as I progressed up the greasy pole the sweaty cyclist look didn't really fit and so stopped that and then gradually got out of the habit of riding at all. Then, some 20 years later, having moved to Cornwall, got out of the rat race (though still working) and wishing I hadn't just dumped my Scott, I saw the Gtech ad on telly. I was 56, still smoking 15 a day (I'm trying the patches at the moment), hadn't done any exercise for 20 years, plus a heart attack (complete recovery) and thought that if I'm going to get back into cycling given those factors, I'd go electric. I did no research, but found a refurbished Gtech on eBay, and haven't looked back. I then bought a Chinese rear hub wheel motor and popped it on a Specialzed mtb (and if the Bosch mid-motors are really so much better than hub motors, they must be amazing!). The Gtech was okay, except for the drag as soon as you go over 15.5mph, but I forced myself to do it and got quite fit quite quickly - and that led me to get a pushbike and now I use whatever happens to take my fancy. I still can't walk up long hills without getting puffed, but I can cycle on pedal power alone for miles - muscle memory, I guess. My stable has grown - I've got six bikes, 3 pedal powered, three electric, and it's my all-consuming hobby, both in the shed changing bits for the sake of it as much as anything, and riding whenever commitments and weather (10 years working outside - I've done my bit in the rain!) allow. Anyone that dismisses ebikes as cheating is missing the point. They're enormous fun, and can lead to increased fitness, mobility and are simply fascinating too. Strength to all of us!

Thanks Lakester, I'll do that!

Thanks again, extremely informative, and right on the money. I've run it a lot with no apparent issues at the time, but as you say, the battery indicator on the 36v throttle always said full - but then when I connected it to the 48v throttle, it immediately said it was empty. So I've been lucky - I may have damaged the battery a bit, but not too badly it seems after the range I got from it today - not great, but comparable or better, proportionally, than the 5.6Ah Gtech battery, and I ran it at full throttle for at least 6 miles, probably more. I had thought I could rely on the BMS to take care of any issues. It's a learning curve, and I'll be asking questions here before doing anything else potentially rash.

I'm in Nth Cornwall but regularly drive to Redruth for work and leisure, and would love to hit the trails down that way - the Camel Trail is beautiful, but I could do with a change and more challenging terrain (not too challenging!)...

Today I took my modified Gtech (removed controller and battery, replaced them with a 48v battery and controller to power the original Bafang 250w motor) on it's first outing, and was very impressed with it's 25 mile range, given the punishment I gave it, until another member suggested it might not be all that great after all (hi vfr, and thanks again for the reply). I'd previously used this 48v battery to power another 250w hub motor through a 36v controller. I can be a bit rash at times, and was half expecting it to burn out or worse, so only gradually increased throttle time and distance, and was constantly checking the heat of both it and the battery until over time I felt reasonably sure it could take it, and feel it may even be entirely designed to take the output from a 48v battery (hard to tell given a) my state of ignorance and b) from the sparse info with and on Chinese controllers from eBay). Neither even got what you could call warm, let alone hot. Today's jaunt made both the battery and the 48v controller lukewarm to the touch. So my first question is - was I imagining things, or can it be expected that some controllers are designed to take higher voltages, or perhaps can detect voltages and respond accordingly by limiting the input voltage regardless of source? Which leads to my second question - if I wasn't imagining things, and the 36v controller I was using was only drawing 36v (I know - I know nothing!) and thus was indeed perfectly safe to use in that way, and yet the performance (speed, on the flat and up the hills near me) was exactly the same (or as far as I can tell), does that mean I'd get greater range from using the 36v controller in the same set up as I'm now using the 48v controller? Please have patience with me! I started visiting this forum to learn about these things, and I certainly have, though the biggest thing i have learned is that there's even more to learn than I ever imagined!

I have another question, but I'll post it on the battery thread, which I've just found. It will be equally dim, but we all have to start somewhere

Thanks vfr400, that's saved me some bother! It's a 10Ah battery, made of 18650 cells of unknown origin, bought when I knew even less than I know now, which is not a lot, though I'm keen to learn! I was quite impressed at first, but then I was comparing it to the original Gtech battery. More research needed!

Hi I have a question about batteries, which I will get to, if you will forgive what may appear to be digressions, for the very knowledgeable people here - your insights will be greatly appreciated. I have posted here already, re: dissatisfaction with my Gtech Sport, in a "reply" to a chat about swapping wires to bypass the controller settings (on said Gtech). I'd already planned to remove the controller and battery in favour of one of each I'd already bought as part of a hub motor kit - and today I took it out for its first spin, having done just that. I'm very happy with what I think is a massive all round improvement. Stats according to a cheap wireless speedo... Top speed throttle only: 21mph; pedalling too: 22.5mph (my feet could go no faster). Distance on one charge: 27m (roughly a quarter of which was done on full throttle, the rest pedalling and throttle to maintain 15-16mph, all on the flat, apart from a couple of small hills, with a strong-ish headwind in places). Average speed: 14mph The battery is 48v, 13s5p, which I bought to power a 1000w hub motor (which was used once and abandoned because I felt like a hooligan riding it through the streets of my small town- it's in a dry place waiting for me to sell it), and the controller, unsurprisingly, is 48v too - and both of them are now powering the 250w Bafang on the Gtech Sport. So, at last, my question(s): I think I read on this site that two smaller capacity batteries of e.g. 5Ah would give a greater combined range than one 10Ah. Is this true? Does the range I managed today sound pretty good for the battery (or is it just impossible to say, with so little to go on)? I like the idea of multiple batteries. A bit of a pain to swap them over mid-trip, perhaps, but not too much, and the option of taking just one on short trips, or three for long ones, etc., appeals. Your thoughts and opinions sought. Thanks in advance.

Removing the bottom bracket... I haven't bothered yet to check closely, bit the "screwy bits" that hold it in place (sorry - "a senior moment"!) seem to resemble those on Hollowtech BBs - so I'd be very interested to hear if they are the same, or if not, how they can be removed. The resistance to un-powered use on my gtech is, very roughly speaking, 90% motor and 10% BB - and if I decide finally to keep only the motor, then i'd like to change the BB too.

Sorry if this is the wrong thread but I can't find the thread with a picture of the insides of the gtech controller now, but it showed what I have seen in mine - a white cable with a plug resembling an external hard drive plug on the end - could this be for programming the controller? And if so, could it be the answer to our problems with hills? No matter what I do - full leg power or "dry pedalling" - I'm defeated by long steep hills - I reach a point where there is insufficient power for me and I have to get off and push (I live in Cornwall - hilly in parts, which is why at 58yo I decided to go electric) on hills that I can still make on my 1990's Marin mtb (with a lot of effort). Kind of defeating the purpose...

"I'd chuck the entire electrical system except the motor, and fit a normal controller.." This is exactly what I plan to do - 48v as suggested, new controller, etc. I think this will make an OK bike into a real good 'un

I've used a non-Gtech battery on my esport.. 1\ I put the Gtech battery in place, and made sure it was switched to full power, then switched it off and removed it. 2\ Then simply attached a different battery to the larger pair of terminals on the controller (having checked which was which by looking at the base of the Gtech battery which has + and minus symbols) with female spade connectors. The bike runs exactly as it is meant to run. Absolutely no difference. So I think the two smaller terminals merely tell the controller which setting to use - full or eco. The upshot - use any 36v battery and it will be fine. Incidentally, I used three 12v power tool batteries wired in series to make my own 36v 2Ah battery, as a back up to the Gtech battery, the range of which had dropped from 20 miles at full power (on a flat trail on a non-windy day) to about 12 miles (from pathetic to even more pathetic). A 2Ah battery is small and light, so not a bother to carry or fix to the bike alongside the original. But I'm considering better, permanent solutions.

I'm prepared to be that brave Gtech (esport) owner - could you be a little more precise about which wires to splice? There are 3 wires running from the sensor to the controller - red, black and green - I've cut them (and added bullet connectors so they can all easily be reconnected) and tried every possible combination, I think... But could easily be wrong. I think the Gtech bikes are a great concept - very simple and low maintenance - but they didn't get it quite right (mainly the internal resistance in the motor - I have a 250w motor that I've put on a Specialized mtb - MUCH less resistance!).