Dahon Mariner D8 Conversion Build

gpt

Finding my (electric) wheels
Jan 29, 2023
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I plan on keeping this thread now as the master build thread - hopefully with a lot of input and helpful to others in the future

So ive settled on what bike I wanted. The main reason for this was going for a folding bike that I can keep in doors, I like the utility of being able to travel easy with the bike, and it seems really well received by those who have had one - plus 20" wheels & price. I didn't go for a pre built bike as I wanted the freedom to put the strongest possible motor on the bike (within legal limits). Bike use will be primarily commuting (6mile max daily all year in UK weather) but with occasional leisure (again not far)

I will add this will all be new to me - So those replying, assume my complete lack of knowledge

Current Situation (Will update as I go) - I need to get both the bike and the conversion kit (on a cycle to work scheme - I have checked, both are possible). These are the Dahon Mariner D8 & a BBS01ET. I have heard from colleague the process of applying for the voucher to receiving it can take up to 4 weeks. So in the mean time I need to line everything up, make additional required purchases, and get myself ready to go as much as possible so Im not wasting time when I eventually get the bike

Yesterday while doing my research I found this very handy thread - https://www.pedelecs.co.uk/forum/threads/after-market-bbsxx-crank-drive-gear.32691/page-4#post-585293

If the items in the thread are still relevant I will make my start here - other information obviously greatly received

So, due to my complete inexperience - does anyone see any problem with the planned conversion (before I start the cycle to work scheme order).
Any issue with the folding bike and the potential strength of the torque on the motor?
Any possible issue with the fitting of the kit on the bike? I did try to go Halfords yesterday morning as they sell them but dont keep them in stock to look at
Any other motors/kit worth considering that would be more recommended? I want the bike to be as effortless as possible - So i think i will be quite happy with the cadence system

Hopefully this will be a nice little project.

A pre thank you to anyone that wants to get involved on this little journey
 
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Woosh

Trade Member
May 19, 2012
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wooshbikes.co.uk
D8veh did have a similar folding bike that he brought to my shop some years back, I remember it well.
fitting of a BBS kit is straightforward.
He had a 10AH down tube battery that he installed to the main beam. I don't recommend this because the mid fold protrudes and will make the job difficult. I would suggest a saddle bag battery. It's a lot more straightforward to fit.
You will have to hide the excess of the trunk cable somewhere. You can use a small bag behind the seat tube for this.
One thing though, if you don't have suspension fork, go for the basic 36V BBS01. The extra torque may be too much for a rigid fork.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
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Some have difficulty mounting the battery to the rear rack, which I prefer because doing so retains my Dahon Helios P8's easy folding ability: I went with a quick pallet wood plank bodge: drilled holes through, secured the plank and the battery mount on with hex bolts and locknuts, using galvanised steel joining plates I had lying around. I've since replaced those with one long aluminium flat bar. My original plan was to use aluminium instead, but thanks to the magic of toxic chemicals, heat and compresssion, the pallet wood is light, strong and quite rot proof. I bought rectangular 6mm walled aluminium box section to replace it a few months ago (100g heavier), will get around to it.
 
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guerney

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I used this webbing for cables - the advantage is that you can tighten zipties without pinching the cables; causing internal breaks:



I used this over nearly all of the connectors:


...plus this:

 
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guerney

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Bonzo Banana

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Sep 29, 2019
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Wouldn't the Carrera Intercity Disc be a better folding bike to electrify. It has better all weather mechanical disc brakes is likely stronger than the Dahon (which focuses more on being lightweight) and is considerably better value. Most Dahon bikes are made by other factories, many of them have been made by fuji-ta who have also made many of the Halford's bikes including the current Transit model.

The other issue is Dahon often use their own proprietary parts which can be difficult to source after a few years and can mean the bike has to be scrapped. The Halfords bikes tend to use more generic components related to the frame and stem and are easier to source.

I'm not saying Dahon are as bad as Tern when it comes to weak frames and frame recalls but Tern and Dahon were started by members of the same family. Tern pushed the low weight performance site of folding bikes a bit more admittedly but still a typical Dahon would not match the strength of many other folding bikes. If you are going to electrify a bike its not a bad idea to think about the strength of the bike and is it overbuilt enough to handle a motor.

For a folding bike I personally think a front hub motor and steel forks is the best option with the controller and battery if possible mounted on the handlebars like a Swytch setup. I'm not recommending Swytch just that style of setup.
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
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Ordering Dahon spares from Europe-based websites is frustrating - they never state sizes, upload detailed photos, specify compatability... If this shop ever closes down, I'd struggle. They have stock nobody else has anywhere.



Parts section:



They sell custom builds, and won't sell some items unless part of a custom build:



...there's always AliExpress and a huge worldwide Dahon user base, for third party manufacturers to serve. So I'm hopeful there will be years of spare parts for my bike, at least for the remaining lifespan of my aluminium frame. When it fails, I'll probably get a Mariner... but only if @gpt 's conversion goes well. ;)
 

guerney

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Sep 7, 2021
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Halfrauds doesn't state tyre width, but those look like 1.5"




...which I found to be a harsh ride... but the Helios rims wouldn't accommodate 1.75" or 2.125", so I had to buy Tern wheels. Wider rims are also available on AliExpress.



You'd have to measure the Mariner's rims, to see what's possible to fit. Perhaps roads were smoother when they made the Helios P8, and Dahon is now making wider rims as worldwide economic conditions deteriorate.
 
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guerney

Esteemed Pedelecer
Sep 7, 2021
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Actually this looks great for a BBS01B conversion - good price, Dahon parts, and those rims may be wide enough for 1.75"+



Just don't mention you want it for conversion.
 
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gpt

Finding my (electric) wheels
Jan 29, 2023
16
4
Wouldn't the Carrera Intercity Disc be a better folding bike to electrify. It has better all weather mechanical disc brakes is likely stronger than the Dahon (which focuses more on being lightweight) and is considerably better value. Most Dahon bikes are made by other factories, many of them have been made by fuji-ta who have also made many of the Halford's bikes including the current Transit model.

The other issue is Dahon often use their own proprietary parts which can be difficult to source after a few years and can mean the bike has to be scrapped. The Halfords bikes tend to use more generic components related to the frame and stem and are easier to source.

I'm not saying Dahon are as bad as Tern when it comes to weak frames and frame recalls but Tern and Dahon were started by members of the same family. Tern pushed the low weight performance site of folding bikes a bit more admittedly but still a typical Dahon would not match the strength of many other folding bikes. If you are going to electrify a bike its not a bad idea to think about the strength of the bike and is it overbuilt enough to handle a motor.

For a folding bike I personally think a front hub motor and steel forks is the best option with the controller and battery if possible mounted on the handlebars like a Swytch setup. I'm not recommending Swytch just that style of setup.
Its not a bad shout! - I found the following review


Unfortunately I cant find much else on it. Youtube doesnt show up much else and for the disk 9 (easily confused when looking around at the normal carrera intercity). The disc brakes would be a welcome addition if I was electrifying the bike - that would be the main convincing point. The price isnt really a factor for me, Id have a brompton if i thought it was better. I just found too many examples of flex in parts and people having problem with bromptons for some reason. For the best folding experience - go brompton - for anything where the priority is elsewhere, other folders seemed better (and cheaper!)

The dahon just has more of a global reputation which is why I settled on it. Im still happy to hear other opinions though.
 
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guerney

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I'd prefer disc brakes, but sadly retrofitting isn't possible on my bike. Mind you, when wheels are true, it's V-brakes work very well. I've just ordered new pads, I'm really getting through them with trailer hauling.
 

gpt

Finding my (electric) wheels
Jan 29, 2023
16
4

I'd prefer disc brakes, but sadly retrofitting isn't possible on my bike. Mind you, when wheels are true, it's V-brakes work very well. I've just ordered new pads, I'm really getting through them with trailer hauling.
Just came across this which I hadnt spotted before whilst looking at ways to potentially upgrade the mariner. Just not seeing much in the way of UK retailers and the cycle to work scheme is also a priority
 

guerney

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Sep 7, 2021
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Just came across this which I hadnt spotted before whilst looking at ways to potentially upgrade the mariner. Just not seeing much in the way of UK retailers and the cycle to work scheme is also a priority
I had a good search.... it's a pity that Dahon don't seem to be overly keen on selling to the UK. The absence of mudguards and rear rack: dealbreakers, for me at least.
 

esuark

Pedelecer
Jul 23, 2019
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Its not a bad shout! - I found the following review


Unfortunately I cant find much else on it. Youtube doesnt show up much else and for the disk 9 (easily confused when looking around at the normal carrera intercity). The disc brakes would be a welcome addition if I was electrifying the bike - that would be the main convincing point. The price isnt really a factor for me, Id have a brompton if i thought it was better. I just found too many examples of flex in parts and people having problem with bromptons for some reason. For the best folding experience - go brompton - for anything where the priority is elsewhere, other folders seemed better (and cheaper!)

The dahon just has more of a global reputation which is why I settled on it. Im still happy to hear other opinions though.

found this review on halfords site today

Great spec, no replacement tyres available
a month ago
Fantastic spec for the price but pity help you when you need new tyres. Nothing fits, seriously. Local store ordered in 20 inch x1. 35 Schwalbe Marathon (listed as compatible) ... too big for the rim. Halfords don't stock anything that fits, I suspect rim is not an accurate size, currently high and dry without bike and no obvious solution.
 
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guerney

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found this review on halfords site today

Great spec, no replacement tyres available
a month ago
Fantastic spec for the price but pity help you when you need new tyres. Nothing fits, seriously. Local store ordered in 20 inch x1. 35 Schwalbe Marathon (listed as compatible) ... too big for the rim. Halfords don't stock anything that fits, I suspect rim is not an accurate size, currently high and dry without bike and no obvious solution.
If it's a standard spoke count, rims could be replaced... it'd be a bit of a job working out spoke lengths and building the wheels.
 

guerney

Esteemed Pedelecer
Sep 7, 2021
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I'd deffo get the gear sensor, if I was converting that Dahon Mariner - doesn't seem to suit some bikes and/or riders here on this forum, but it makes gear shifts a no-brainer on my Dahon Helios P8... except up steep hills in the rain, when the timing of the gear change isn't quite long enough, by a smidge, or about a shake of a lamb's tail. There's no setting in firmware for gear change timing adjustment.
 
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gpt

Finding my (electric) wheels
Jan 29, 2023
16
4
Well - Back with an update :D

C2W applications finally all approved last Wednesday evening.

Went to order the dahon mariner and i noticed a review stating some shimano parts had been replaced with custom own brand pieces. This was evident in some pictures but not others. I raised a query with Halfords to find that such parts had infact been removed. Which was enough to pee me off and put me off the bike. In the past month we had also looked at building a porch area at my house where I now feel I could keep a full size bike. So i broadened my horizons a little and for a similar price point which what looks like a much more quality offering - I selected this


Im really quite looking forward to it - that black and orange is sleek and sexy!


On top of this im just finalising the order with Woosh for the 48v bbs01et kit. Unfortunately ive now got some things coming up thats going to stop me jumping straight onto the project for about an extra week but im starting to look forward to it!
 

AntonyC

Pedelecer
Apr 5, 2022
249
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Surrey
48v bbs01ET, 1x10 drivetrain, primarily commuting 6 mile max... we need to know more about how this camel got here ;-) How steep are the hills and what will your usual all-up weight be? Will you need to count on the bike "daily all year" or will high maintenance be part of the fun?
 

AntonyC

Pedelecer
Apr 5, 2022
249
118
Surrey
Actually with such a short commute perhaps reliability needn't dictate everything. I'm interested to see how it works out.