Many many years ago, when I was a young engineering student, my housemates and I used to consume large amounts of unsweetened grapefruit juice from litre cans sold in Safeways. Then when these cans seemed to disappear from the shelves we decided to enquire upon the reason. It was odd that the sweetened version was still available. On the shop manager's office door was a notice inviting customers to pop in if they had a problem. Strangely after all these years I can still remember his name -Bill Fennessey (I may have spelt it wrong, but I have my doubts as to whether he reads this blog). Anyhow we decided to take up the matter with Bill and knocked on his door. Bill was very welcoming and asked us how he could help. We told him of our concern about the juice's disappearance. "Ah well boys" said Bill, "Right now there's a world shortage of unsweetened grapefruit juice, we can only get the sweetened stuff." We declined to offer the obvious solution.
You may well remember those days in the early 70s when we had all sorts of 'world shortages'. Sugar was one I can remember - perhaps they'd used it all up sweetening grapefruit juice. Anyhow I digress.
You may have read recently that there is a world shortage of e-bikes. The people in the far east can't make them fast enough to meet the demand. It's all these lockdowns wots done it. The people at Halfords are tearing their hair out at lost sales opportunities apparently. Lots of people are turning instead to converting their existing push bikes using e-bike conversion kits, and now there is a world shortage of kits. I know this because we recently decided to electrocute (that may not be the correct word) our rather nice old Dawes road bikes. Living half way up a hill in a surprisingly up and down town, we were getting out of puff in our old age. Lots of little companies advertise kits on the web, but not many have any in stock and a number of customer reviews complained about late delivery and unanswered calls to the suppliers. I was getting wary of going ahead. In the end we found a supplier which makes the stuff here in the UK and that does answer emails and phone calls and can supply at short notice. So now our bikes have shiny little motors pushing the back wheel round while we pedal. Bliss.
The law on these things is interesting. To be legal in the UK, the motor has to use no more than 250 watts (that's a third of a horsepower by my reckoning), it may only assist you while you pedal, and it may not assist you at all once you exceed 15.5 mph (25 kph).
Having used ours for a few weeks, I thought I might pass on our riding experience to anyone thinking about electrifying their boat bikes. In short, I'm not sure it's a good idea. Not because the motors aren't any good - they are a huge help, but . . .
On nice smooth towpaths like the ones CRT have been laying in urban areas in recent years, you will a) almost certainly find yourself going too fast and b) hardly need it anyway as towpaths by and large don't have hills except on longer lock flights.
On lumpy rural towpaths I fancy the pedal assist mechanism might be a problem. The bike motor responds to a sensor on the pedal crank and responds to the rate of pedalling.If you are not pedalling with a reasonably smooth regular action the motor will respond a bit erratically. You might get a choppy ride. On roads and cycle paths it's absolutely fine but I have my doubts about rough ground. (although I admit I haven't tried it).
So if like many people you are thinking of going the e-bike route, make sure you do your homework and if you get a chance to try one on lumpy ground first, do that.
Conversion kits start at about £500. If you already have a decent conventional bike it will get you a better job than a cheap ready built e-bike. Ready made e-bikes start from about £650 (not good quality) and on up into four figures.
There are basically four types of kit.
a) a new front wheel with a hub motor - quite easy to fit as long as your wheels and front forks are in the range of standard sizes
b) a new back wheel with a hub motor - more complicated to fit because of the gears
c) a centre motor which drives the pedal crank directly (they look quite bulky, but I'm told they are powerful). Probably not so easy to fit.
d) A friction motor which sits against the rear wheel tyre and pushes the tyre round. A bit like a caravan mover if you ever seen those. Very small and neat and fits almost any bike. Easy to fit.
Virtually all the kits use the same pedal sensor which is easy to fit, and they all come with a rechargeable lithium battery and some sort of control circuitry usually built in to the battery holder. According to the size of battery, expect to get something between 12 and 25 miles range depending on hills etc.
For a number of reasons including supplier availability and ease of fitting to our old standard bikes we opted for d) a product called Revos from Revolutionworks.com. Look 'em up on the web. They make 'em in Bristol and I can vouch for their great customer care. Friction drives are not optimal in my opinion but they best suited us and well, they work! Now we zip around the cycle paths around town and face hills without fear. The added weight is minimal, so we can still lift the bikes onto our car roof rack quite easily.
A popular front wheel drive kit that gets good press in Swytch bike. They accept orders in batches every few weeks then they build the front wheels to order so you can't have one tomorrow.
Other kits are (supposedly) available. The web is full of 'em.