E-BIKES KIT CONVERSIONS

Electrically assisted bikes, trikes, etc. that are legal in the UK
TonyN
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Joined: 18 May 2020, 11:15am

E-BIKES KIT CONVERSIONS

Post by TonyN »

E- Bikes have definitely become acceptable to the cycling fraternity when my hard core MTB magazine has features about them every month.
Ebikes have evolved electronically like cars and have moved out of the realm of DIY repairs. With Ebike prices of £5000 to £7000 for our top make bikes, spares and repairs are correspondingly expensive.
These prices are beyond the range of many people and our Ebike experiences show that much less outlay is possible if you are converting your own bike with a motor kit. This is a relatively simple task for anyone with bike overhaul skills as the kits come with all the colour matched wiring and plug connections so that it is very difficult to assemble incorrectly.
Definately the most difficult task is the mounting of the magnetic power pick-up disk onto the chainwheel axle as the kit manufacurer cannot cover all the different chainwheel axle types available. Most of the kits provide a disk which is in two halves and clips around a square taper axle in the space between the bottom bracket and the LH crank. This was useless to us as our chainwheels are Shimano Hollowtech with no space between the LH crank and the screw-in bearing. So the disks which were supplied with our kits had to have the centre hole band-saw enlarged to clear the bearing shell and are epoxy resin glued to the chainwheel face on the RH side. This is not as insecure as it may appear because the magnetic studs in the disk clamp it firmly to the chainwheel before the glue is applied and our disks have an outer diameter which fits perfectly onto an 22 tooth chainwheel. The pick-up unit comes with a mounting bracket washer which fits onto the screw-in bottom bracket bearing.
Another problem which required minor sorting was that although the front axles in the new motor wheels supplied have standard widths between the forks the slots in the fork ends needed carefully filing out by 1mm to allow the new axle flats to fit into them,
The bonus from all this self-assembly of the Ebike is that any subsequent repairs and replacement of parts are simple and inexpensive.
My wife and I are well into our eighties and some four years ago I electrified her Giant tourer with a front hub motor kit and pannier battery. This was a great success because on the lowest power setting she was able to easily keep up with our club bunch instead of straining for the whole ride. I followed this with a similar conversion on my GT Avalanche hardtail MTB tourer and that year we both completed the NW 500 Scottish route with fully laden pannier bikes using B&B accommodation. This illustrates the reliability of our machinery The biggest problem was avoiding being run off the single track road by endless campervans. Included in this trek were two 60mile hilly days and since then I have managed over 100miles on one charge generally using the lowest power setting with some power boosts on the hills.

Our conversion kits cost about £700 each (£350 for the motor/controller and £350 for the battery). It is possible to buy a complete Ebike for this outlay but quality and reliability would be in doubt.
I still use my converted GT Avalanche but my wife has upgraded to a ladies Specialised MTB with the motor kit from her Giant swapped over. They are very comfortable all-terrain touring bikes which have 700c Front motor wheels with Schwalbe Marathon tyres. The 26ins Rear wheels have normal 9 speed gearing with Schwalbe Black Jack super rolling MTB tyres. Note that the external tyre diameter for both front and rear tyres is almost the same with the front MTB fork mitigating the hardness of the front tyre. This use of different wheel sizes only works with disc brakes, most rim brakes cannot cope with the variation of the rim diameter.
Last year I added another kit to my Specialised full-suspension MTB. The conversion went well but due to the rear suspension shock occupying most of the frame triangle space the battery had to be fastened under the downtube using the water bottle eyelets found under most MTB frames. This mounting method has stood some fairly hard shocks and the security straps also fitted have not been needed.
Although our converted bikes are relatively heavy (around 20 kg ) they are a similar weight to current state-of-the-art very expensive Ebikes with internal downtube batteries and bottom bracket motors. The main difference is that our max charge range is 100 miles compared to a max of about 60 miles given on most reviews for current Ebikes.
Our batteries are the downtube fitting type and are identical for emergency swapability. However In our time with our identical batteries they have never had to be changed around for an emergency. On our Specialised ladies step-through bike there is not room on the downtube for the battery so the largest job in our conversions was to make a double-tiered rear pannier rack with enough room to accommodate a 100mm tall battery between the tiers. To avoid this major DIY construction task low batteries with suitable pannier racks are available off the shelf and in the supplied kits.
Just a footnote about batteries, all the good ones consist of Lithium-Ion cells fastened together in batches (even in electric cars). Generally the weight of a conversion kit battery is in line with it's Amp Hour capacity and governs the maximum distance on one charge..
Our 36 Volt 15Ah batteries are about as heavy as the complete front motor wheel. The bikes use about 1.5amps on No1 (the lowest power) setting and so the simple maths of 15Ah divided by 1.5 gives a time of 10 hours. At 10mph this represents 100miles which roughly coincides with the max distance I have achieved. Note that the power settings rapidly increase the amps for each click and so on setting No5 the power used is over 20 amps. This gives about 0.75 hours of riding !!!
The overall weight (and cost) of the converted bike can be reduced by using a smaller battery but the distance on one charge will be reduced proportionately.
Beware of adverts for Ebike kits of greater motor power than is allowed by law. This has to be a continuously rated maximum of 250 watts for your bike to remain as a pedal cycle on public highways.
The most comforting feature about an Ebike is knowing as you set off on a ride that there is help in the background in case of tiredness, very steep hills or accidents. This is particularly important when tackling baggage-laden day by day follow-on touring where one very tiring day can play havoc with the next.
Obviously we are keen fans of Ebikes in our waning years and wish to state that we have no connection with any manufacturers or suppliers.
Tony Newton
Last edited by TonyN on 12 Jul 2021, 9:35am, edited 5 times in total.
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horizon
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Re: E-BIKES FOR ALL

Post by horizon »

TonyN wrote: 9 Apr 2021, 3:53pm E- Bikes have definitely become acceptable to the cycling fraternity when my hard core MTB magazine has features about them every month.
I wonder if that is because MTB'ing isn't esentially about fitness*, health and travel but about skills and thrills. In that sense it has more in common with downhill skiing than cycling. After all, skiers have been using powered ski lifts to get them to the top of hills for decades.

* That doesn't mean you might not get fit but it isn't the prime motivator.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher
Cyril Haearn
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Re: E-BIKES FOR ALL

Post by Cyril Haearn »

€bikes get people into all sorts of trouble, there was a report of people who hired some in the Alps, they tootled up the hill and had lunch up there. But when they looked at the hill from above it seemed frighteningly steep, they were too scared to cycle down. They walked down an easier way

The €bikes were later recovered by the mountain rescue people, the costs of hundreds of euros were recovered from the miserable hirers. Still, they had more sense than many mtb and €bike riders, better to be 'too careful'
Entertainer, juvenile, curmudgeon, PoB, 30120
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TonyN
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Re: E-BIKES FOR ALL

Post by TonyN »

I think that some commentators have been looking at my headlines only, my article is NOT about the pro & cons of Ebikes but merely a pathway for some, less endowed with money, to enjoy Ebike advantages particularly in advancing years where it is quite possibly the only method of carrying on with their cycling. We write from experience.
Cyril Haearn
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Re: E-BIKES FOR ALL

Post by Cyril Haearn »

I was warning of dangers of €bikes, they increase speed = danger too. What if the €bikers had ridden down and lost control?

I spent a lot of money on retirement to move home to a flat area to reduce the danger of needing an €bike, I accept not being able to cycle so far or so fast

There may be benefits to €bikes for people who otherwise could not cycle, but there are lots of minuses, young fit people who buy them because they can and endanger others. On shared paths where children are gambolling these €bikers whizz along silently at 30 kmh :?
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DaveBeck
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Re: E-BIKES FOR ALL

Post by DaveBeck »

Cyril Haearn wrote: 10 Apr 2021, 9:26am
There may be benefits to €bikes for people who otherwise could not cycle, but there are lots of minuses, young fit people who buy them because they can and endanger others. On shared paths where children are gambolling these €bikers whizz along silently at 30 kmh :?
That is as likely, or more likely with non electric assist bikes, as the legal ebikes in the UK are limited to 15.5mph (24.8kph). A speed which most moderately fit cyclists on a non ebike could exceed on the flat with ease. If you are on a shared use path with people, children, dogs etc, riding at those sort speeds, electric assisted or not, you shouldn't be riding anywhere close to 15.5mph when you pass them.
Cyril Haearn
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Re: E-BIKES FOR ALL

Post by Cyril Haearn »

24.8 kmh is bad enough. Lots of €bike riders upgrade their machines to go faster than allowed. Anything increasing speed increases danger

I have seen some people on €bikes not going fast, I wonder if they even needed to buy the machines. They just have the downsides, cost weight bulk maintenance.

What does the title 'e-bikes for all' signify?
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DaveBeck
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Re: E-BIKES FOR ALL

Post by DaveBeck »

Cyril Haearn wrote: 10 Apr 2021, 10:51am 24.8 kmh is bad enough. Lots of €bike riders upgrade their machines to go faster than allowed.
I think we both agree and hopefully everyone else here, that riding at anywhere near 15.5mph (24.8kph) when passing walkers, horse riders, children or dogs in a confined space like a shared use path maybe isn't the best thing to do.

I do know at least eight people that I regularly cycle with, admittedly al past their 50's, who ride ebikes. Some are road-bike versions, some mountain bike types. None of them have derestricted their bikes. I would be interested to see your source that talks about people derestricting the ebike to exceed the legal limit for the UK.

Dave B
Cyril Haearn
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Re: E-BIKES FOR ALL

Post by Cyril Haearn »

There have been threads on here describing how to illegally modify €bikes. One hopes the moderators have deleted them
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stodd
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Re: E-BIKES FOR ALL

Post by stodd »

DaveBeck wrote: 10 Apr 2021, 11:11am I would be interested to see your source that talks about people derestricting the ebike to exceed the legal limit for the UK.
If you look at the pedalecs site (https://www.pedelecs.co.uk/) you will see lots of examples.
They even have a sub-forum specifically for speed pedalecs (https://www.pedelecs.co.uk/forum/forums ... ussion.43/) (Of course such bikes are not intrinsically illegal, just almost always ridden illegally; on road without plates etc, off road in public places).

That is an excellent site with lots of very technically knowledgeable people, the majority riding legal bikes in legal ways, but with a significant minority that are not.

~~~
Because of different rider profile I'm not sure if the average speed that ebikes are ridden isn't below the average speed for regular bikes. I've never been a speed demon, but I certainly ride my stately step-though Motus slower now than I rode my Claud Butler tourer 30 years ago (and slower than my son rides the same old tourer now). And thinking of the busy local shared bike/pedestrian path, much more of the inconsiderate cycling is on non-e bikes.
Jdsk
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Re: E-BIKES FOR ALL

Post by Jdsk »

Thanks for sharing your thoughts and experiences, Tony.

Jonathan
Oldjohnw
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Re: E-BIKES FOR ALL

Post by Oldjohnw »

Any Ebike can exceed 25kph perfectly legally. Just that when it does exceed that speed it should operate on human power alone. Just the same as any other bike.
John
Red Kite
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Re: E-BIKES FOR ALL

Post by Red Kite »

stodd wrote: 10 Apr 2021, 1:11pm
If you look at the pedalecs site (https://www.pedelecs.co.uk/) you will see lots of examples.
They even have a sub-forum specifically for speed pedalecs (https://www.pedelecs.co.uk/forum/forums ... ussion.43/) (Of course such bikes are not intrinsically illegal, just almost always ridden illegally; on road without plates etc, off road in public places).

That is an excellent site with lots of very technically knowledgeable people, the majority riding legal bikes in legal ways, but with a significant minority that are not.

~~~
Because of different rider profile I'm not sure if the average speed that ebikes are ridden isn't below the average speed for regular bikes. I've never been a speed demon, but I certainly ride my stately step-though Motus slower now than I rode my Claud Butler tourer 30 years ago (and slower than my son rides the same old tourer now). And thinking of the busy local shared bike/pedestrian path, much more of the inconsiderate cycling is on non-e bikes.
People who build and or modify e-bikes are I expect more likely to be forum users, it's a way of getting and exchanging information on how to do it.

I think you are almost certainly right about e-rider profile. Speedsters aside, the people I am aware of with e-bikes tend to be older. I'm not old of course at 67, but I do have a chronic heart condition which restricts me and I have bought an e-bike so that I can cycle reasonable distances at normal bimbling speeds and get up hills. My aim is to enjoy it, which I can't do so easily on an unassisted bike if I am pushing it up gradients or being overtaken by pedestrians. I'm happy at 12-14 mph on the flat, and an assisted bike means I get more exercise, not less. It's a big benefit to me.
Cube Touring Hybrid One e-bike, Brompton P6R with Swytch conversion
peterb
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Re: E-BIKES FOR ALL

Post by peterb »

Cyril Haearn wrote: 10 Apr 2021, 10:51am 24.8 kmh is bad enough. Lots of €bike riders upgrade their machines to go faster than allowed. Anything increasing speed increases danger

I have seen some people on €bikes not going fast, I wonder if they even needed to buy the machines. They just have the downsides, cost weight bulk maintenance.
Damned if you do (more than 15mph), damned if you don't ('some people on €bikes not going fast'). In spite of the numerous posts about this it seems the message hasn't reached everyone yet - as Oldjohnw has stated above, the maximum legal ASSISTED speed is 15.5 mph/ 25 kph. It is up to you and your legs just how fast you go after that. There is NO 'maximum speed allowed', just as there is no maximum for unassisted bikes.
Jdsk
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Re: E-BIKES FOR ALL

Post by Jdsk »

Yes.

Of course if anyone wants to post why they choose not to ride one themselves that's a different matter.

Jonathan
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