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Bafang BF1808H66200-1 36V 250W Rear Hub

Has your bike lost it’s Oomph, does it now feel like it does 0.0mph extra to your effort?

Do you know how your hub looks on the inside? You can’t tell what lurking in there from the outside…

Has your bike sat for a long time? Has somebody said it’s your battery but you don’t want to believe them?

Does it still make a noise like it want to move but doesn’t? This is your biggest clue maybe, how does it sound?

Did it stop working with no clues or did it give up whilst riding?
The later means you may have damaged something, the former is an indicator of this issue maybe, you see grease ages, it gets old and sticky and parts eventually stop moving, if they do so for long enough then you’ll end up with no drive if your clutch seizes open, or perhaps it’ll jam on and not release, you may hear the motor whir whilst you spin the wheel by hand if it’s still engaged.

The Customer phrased this as

“it just doesn’t do anything on full power, all the lights are on, but there’s no discernible difference between settings anymore, it just stopped working one day, maybe it hadn’t been used for a couple of months. The batteries charged and all the lights come on, but it’s useless on a hill!”

This had me stumped for a bit, but I had a hunch, the strange thing was I’d have assumed and tested further for electrical errors and faults except for the fact the hub made noises like it was still doing something… Just zero discernable torque added with pedal assist at it’s highest level, you could feel a little boost on the flat, but on a hill you’d get zero benefit.

So, what to check first, is it switched on, well yes of course, full battery indicator, all visibly operational, no damaged connectors or wires and some form of response from everything except the power output of the Hub in Assisted Drive modes.

So the strip down begins, the battery removed and voltage checked at 42V so that’s well charged, and looks like it’s not suffering, but I’ve not load tested it or worked out any internal resistance yet, I would almost instinctively think of this to be an issue, it seems odd that the battery level doesn’t drop on the indicator in use. We know therefore the charger also is good. The bike had been left standing in the shop whilst they tried and failed to fault find the issue, so a dud cell could be suspected, but that’s not it.

Hub internals removed, time for inspection…

The wheel has been rebuilt and installed with the axle cutout facing downwards which isn’t ideal, so I go to great lengths to check the continuity of the leads from the 9-pin Juliet Plug to the circuit board solder joints, which appear good, I’m more hesitant of the multimeter I’m using giving false negatives, but it doesn’t appear to be damaged. I’ve full disassembled the hub now and also have the planetary gears visible, these are in good shape although looking a little dry the grease is old and grey but it’s not the issue, it does point towards the age of the hub.

The gears are stuck on the axle shaft and I use a 3-arm puller to remove them along with the clutch, and loose the small woodruff key as I do (easily found, but watch out for it) the twirling and inspecting probably shifted it loose, so be careful as the clutch may float but still need persuading off the axle it gives enough space for it to fall out. Had I realised sooner I might have caught this quicker, but the clutch was off, at this point I’m still running blind, it didn’t function like a clutch should an I just span it and span it, one way then the other, nice and freely it span, little to no real resistance. I secretly knew this was a bit off, but as things were still covered in crap old grease and every part of this hub spins around itself rather freely it wasn’t as obvious to me until I caught a video of someone hacking one apart and I thought all of a sudden about that old grease again.

The sticky old grease in the clutch rollers was holding them back? Maybe, but that leaves one of two options of which either could end in failure, but worth a shot. It’s not an available spare, none of the internals strictly are, it’s sealed and riveted shut in production.
After some moderate cleaning and a blunt tickle it hadn’t got much better but had changed a bit, it got put down and I came back to it and low and behold it jammed on and wouldn’t release, once it released under much load, the was game on!
The second option would involve cutting it open, grinding off the rivets and possibly just riveting it back up afterwards, but I don’t favour the gear shafts staying put for too long, it may become an option next time.

Lot’s of GT85 and a little bit of “engine oil” later, it moves and lives, albeit sporadically operational, it does catch and release, not every time but it’s viable almost, when it grabs though it’d strip the gears so not good enough.
Next come out the big persuader and the flying anvil, oscillating almost syncopated blows on opposing sides whilst giving it a small degree of rotation slowly and then going back to working it round slowly, like checking a bearing for smoothness, or a freehub for engagement.

All of this working it free was done in the vice whilst it was mounted on an old 9mm axle using the cone nuts to centre it with a good clamping force. Using a bar between the planet gear pegs to free it up when stuck again success was judged in the torque required to release it again.

Did it work…

The hub was reassembled with new bearings in the disc / non-drive side and in the planet gears too and low and behold worked as desired first time back on the bike. Sounds good as new, or as good as it’s going to for a hub that’s probably done a good few miles now… Whilst everything looked in almost tip top condition once cleaned up to service it’s not got any noticeable wear except the bearing all feeling like they’d like to have failed a while ago.

Servicing is an important part of keeping your eBike running and we can help you do that, get in touch if you’d like to find out more.

Bike Summary

Bike: Halfords Carrera Crosscity E Folding Bike 250W

Hub Motor: Bafang BF1808H66200-1
Hub Motor Circuit Board:
Planetary Clutch Model: BF180704YA
26T-40T Reduction / 12mm Axle / 9.2mm x 72mm Case x 34mm Total depth / 3x 7.9mm x 20mm Planetary Gear Shafts running twin 688Z Bearings on 17.8mm of shaft.
Bearings (not including Cassette Body freewheel): 6001-2RS for Disc-side x1, 688zz x6 for Planetary Gears

Battery: Reention Rapier IR-III
Li-Ion 36v / 8.7AH / 313.2Wh


Spare Parts available through Halfords, although supply may be currently limited the products you may need are available as;

Spare Battery Product Code: 321489 – £300
Spare Speed Controller: Model Year Variants possible; 321885 Battery Controller Unit – £50
Torque Sensor: 299468 – £15
Spare Wheel: 321406 – £150
Handlebar control: 299500 – £25

The Batteries are also offered by a third party on ebay based out of Bristol with a 10.5Ah Upgrade for £359 link here

Fitted to a Carrera Crosscity E Folding Bicycle, it’s built into a 20″ Rear Wheel, powered by a Reention Battery which is honestly worth getting upgraded if it’s the problem unless you really want to avoid the small weight penalty for the gained range.

Some useful videos on similar hubs

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Cycling, Exercise & CORONAVIRUS COVID-19

  • If you can run you can ride, balance isn’t your problem… & Loo Roll isn’t the answer
  • Fear is a really powerful motivator, are you that sick already?

If you’re thinking of getting a bike for any reason, now is a great time to accelerate that decision and reap some healthy & financial rewards as the weather improves or local transport closes down

In 2015, dementia overtook heart disease and stroke as the UK’s biggest cause of death. This graph shows the percentage of all UK deaths from the top four leading causes in 2017. These were dementia, heart disease, stroke and lung cancer.

It won’t be much surprise to you that compared to other ailments and things that might kill you, we’ve faced worse, and there are still bigger issues to consider going forward through this crisis, as a nation are we fit enough to survive, I’m not intending on spending it all sat down that’s for sure.

A new study from Imperial College London found the death rate from heart disease fell dramatically between 2005 and 2015, from 80 deaths per 100,000 people to 46 per 100,000.

Experts said fewer people smoking had fuelled the drop but warned that obesity, Type 2 diabetes and high blood pressure kept the death rates too high.

Heart disease still caused double the deaths from lung cancer (the second biggest killer) in 2015 and 18 times the number of deaths caused by road traffic accidents.

– Press Association

Whilst Self Isolation may be vital for the coming weeks, it’s not for everybody, and won’t be forever, but in the short term it will prove successful if people take the time to consider their actions wisely. If your plan is to eat yourself into a food coma with netflix for a companion for 14 days it’s not going to make you any less mortal than surviving a game of cluedo, however if you get your heart racing against a competitor in a game it’s actually proven to help boost your bodies systems and prove to be a great distraction from time for a while at least,but too much of a good thing can also be bad; so don’t forget to get up and stretch, eat sleep etc… Try a little socialising with those folks called your family, even if it is just a video or phone call.

CYCLING: The Tour de Yorkshire, scheduled to take place between 30 April and 3 May, is postponed with no new date yet announced.

Feeling a little lonely I posted this the other day encouraging people not to forget about the power of hugging, and we’re not all in the at risk groups but to some of us this isn’t appropriate for now, but there are going to be loads of people feeling strained over this and we spend so much of our time trying to distance ourselves that we may forget this is only a brief period. But if tensions are running high and you’re all couped up for a long period you’d be surprised what a hug can fix, you don’t have sneeze all over them though to pass it on so use some judgement and be considerate.

Please use your time and body wisely for the next few weeks it's crucial to keep a bit of distance, consider keeping a diary of anybody you can name as being close to you in the last few weeks before now if you can, you never know who it may help in the future. 

Getting back to the point of all this, it’s a great time to consider giving up a few unhealthy habits, dusting off that exercise bike or treadmill you put away 2 weeks into the New Years Resolution and work off those snacks you’ve already depleted (from what it turns out was meant for week two rations… Am I right?) Let’s face it the gym is out of the question for now, and if you’re stuck inside so is actually cycling for your average person.
Take a look around the world at what’s happening right now, if you’ve not been glued to it already, it’s quite simply amazing to see how fast nature can recover from humans malpractice in our own environments, theirs too mind you!

There’s a story gone viral about the canals in a certain Venetian setting, created for self amusement in India, and I hate to drop the spoiler alerts but it’s fake news, debunked, there are no Dolphins there, and the swans live there anyway, the fish are now visible but the water’s by no means clear…

National Geographic, Fake animal news abounds on social media as coronavirus upends life

There’s exciting things on the horizon don’t forget, we all have things we wanted to do, but plans change, develop further and change again and we do it all the time year on year keeping the machine running, until you guessed it!

This will and already is the year for Electricity, cars bikes and even now scooters and the likes so if you’re scared of putting in too much effort (good if you’ve been told not to over exert yourself by a physician), fancy a little luxury or new technology there will be something to get you interested, if you’re in certain zones around the world there are grants and loans to convert you to e-bikes for both business and personal reasons, there are more benefits than than I could squeeze into a thesis or dissertation and there are enough people who’ve already done that…

If 2020 is anything it’s been long predicted to be then we are in for some change!

If you’ve been paying attention to the state of the planet none of this should surprise you, XR gave shot across the bow of the commercial world, and TESLA going from strength to strength, some things will change, we can now ride small electric scooters in certain parts of the UK and with cities around the world shutting down for the longest sustained periods in modern history urban people have seen pollution drop considerably in certain locales, if we can sustain this change alone the air quality will improve many peoples chances of surviving this and many other viruses to come (and believe me there will be more and more if we don’t)…

People are by and large it seems trying to adopt a work from home or more localised approach to solving this problem, and it’s going to have many benefits for some, for others I can safely assume you don’t get out for much in the way of exercise and your commute was never of the active sort to raise that heart rate at all, well some of the younger generations didn’t have your youthful pursuits of yesteryear and have already grown fat and in active with more years of screen time in their youth than some of these middle aged types have in their working lives, so you have to wonder where is your health heading?

With the youngest victim being only 21 in Spain and 45 in the UK for the Coronavirus and the larger at risk group being not too far ahead of that, there could be a lot of children growing up without parents and grandparents sooner than expected so this change of habits could really last a lifetime if we take the time of consideration before we start to spring from our nests, which could by a short stretch take us well into the summer as schools start closing for unknown periods and exams, and most reasons to leave the house get cancelled…

The lists of cancellations now stretching further and further ahead the events industry is being obliterated taking many sports out of play and I’m hoping at a long shot maybe that this might actually promote more active participations in activities linked to all these events you love to watch… It’s going to take a while to master it for sure but it’s the taking part that really counts in heart beats not points or prize cups but tangible improvements with less pollution could be easy to achieve with a bit more cycling in our lives.

Why start cycling now?

The health benefits of getting out are hardly understated, by the time you’ve realised it’ll already be the summer, and then what are you going to do with all that sun and no cheap flights… This is a great activity for the family to enjoy, it could probably cost less to buy some bikes rather than pay for a summer holiday that might be spent at school anyway at this rate…

If you have a bike, it’ll probably work given a little wash and some air in the tyres, a drop of oil on the chain, etc etc if that sounds like to much trouble you could always get in touch with your local bike shop and see what they can do to help you or take a little time to learn how to fix it yourself.
Your local bike shop may even offer collections or delivery for your repairs at this time to help keep movement outside the house to a minimum, if they don’t please suggest it to them…

Fixing what you’ve got already can be a great way to get back into something with little outlay, a second hand bike with a bit spent on it can be upgraded and given a new lease of life. It’s won’t cost the earth, it’s an investment in it and in your future health too. Simple Services often range from a simple check over to full replacements of parts like the complete drive train and will make your bike feel like new.

Consider selling your old bike now, it’ll help someone in need, apart from the famous n+1 paradox your average person doesn’t really need or want to keep the old bike they’ve grown out of and probably won’t return to using it but someone else out there will still love it for years to come possibly getting a great deal more from it than you did.
If your confining yourself to the house, it might be a good time to start sorting out things like that pile covering everything in the garage, the shed you can’t get in, maybe with Spring here your garden’s overgrown the bike storage, it’s time for clean anyway whilst your going around disinfecting indoors (is anyone?) take the time to if you’re not, stop worrying about somebody else’s sh!t unless your sewers blocked with it that is (don’t flush those wipes & kitchen roll etc)…

If you’re thinking of getting a bike for any reason, now is a great time to accelerate that decision and reap some healthy & financial rewards as the weather improves or local transport closes down (I wonder which happens first, TFL is already reducing services) . They have more payoffs than I can be bothered to get into right now and if you’re not convinced already just even a little bit more not even for your kids sake (if they don’t have one, they’re gonna want one if they’re kept off school for the next 12 weeks and you’re stuck in a bed!)

Kids bikes are actually getting a whole load better, the more ergonomically designed ones cost a bit more but they pay off in miles of enjoyment you’d never have thought possible on a basic model you maybe grew up with.

Adults bikes are more amazing than ever the more you spend the more you get certainly applies to the quality of metals and workmanship available these days.
If you’re lucky enough to qualify for a discount like cycle to work or the cargo bikes loan in Scotland it’d be worth taking the option.

I’m going to write a post about what I think is reasonable to spend on a new bike, it will vary, there are scales of difference but for a guide your average MTB or Road Cyclist may ascribe to the following rule of x=20% of salary or +£100 p/year of age, x=n+1, but for commuting or simple exercise this isn’t necessarily a good formula for those on a pushed budget or space constraint.

Other Stuff

So what on the way then? Here’s a few things to keep you excited for 2020 there’s enough gloom for most to survive with for a while…