Electrifying my Dahon Mu Uno

[99t4]

...alloy frame and forks...

If by alloy you mean aluminum alloy, then yes install TAs, if for nothing else than for keeping the wheel attached in case of dropout spread, cracking, axle nut loosening, or other damage. Loss of the front wheel is hard on the body.

 

[LewTwo]

... but the Swytch front wheel motor is a relatively pipsqueak 250W, should I still play safe and fit a Torque Arm (or arms)? ...

ABSOLUTELY !
An once of prevention always beats a week in hospital.

 

[tonythebrit]

Thanks guys for the advice - I'll certainly be following it! The TA's from Hammer are widely available here in UK. Bearing in mind the power of the Swytchbike motor, will I really need the 5mm ones, or will the 3mm be strong enough? I presume it's best to fit one on both sides, and OK to utilise the fender eyelets for mounting them.

 

[tonythebrit]

Update - I've ordered the Swytchbike kit, so there will be a bit of a wait now. In the meantime, there are a few things I can set up on the bike, and still be able to ride it "unpowered". I already have a magnet ring, so I can epoxy this to the crank on the chainring side, then fit the KT-D12R sensor and run the cable invisibly along the base of the frame member to the front end. That way I'll be absolutely ready to install the other components (new front wheel, Brompton Block & battery, torque arm), whenever they eventually arrive. Watch this space!

 

[tonythebrit]

At last! At long last!! My Mu Uno is almost ready for the road. I had no big problems fitting the Swytchbike kit, and the company were most helpful with any queries I raised, and always replied very promptly. Now all that's needed is a little bit of fine tuning, tidying up cables etc. Not that I'm in any tearing hurry - I have to go into hospital within the next couple of months for a pretty serious operation, so I can take plenty of time to finish the project. But I can hardly wait to get my lil' ol' Mu Uno on the road. I was too optimistic with my earlier estimation of the final weight though - it comes out at exactly 30 pounds - pretty good by any standard I'd say!

 

[tonythebrit]

Here's an update on the situation with my Mu Uno. My medical situation hasn't changed, so I'm still unable to carry out the long-awaited road test. But what I have been able to do, though, is activate the Warranty on my Swytchbike kit. This involved completing a form online, and emailing them photos of the various components (PAS assembly, motor wheel etc.) that I had installed. In reply, they informed me that the Warranty had been activated, backdated to the date the kit was delivered to me (1 March 2023). But then, almost Immediately I modified the kit in a way that will probably completely invalidate the Warranty!
About this time last year I had been thinking about a set-up whereby l'd mount the PAS on the drive side, as opposed to the "official" non-drive side. It had been in the back of my mind ever since then, so I was determined to try it out.
First, I epoxyed the magnet ring to the inside of the crank on the drive side, making sure it was central and parrallel to the plane of the chainwheel. Of course, I had removed the crank from the bike to do this. Next, I discarded the supplied PAS sensor (presumably a KT-D12L), and replaced it with a KT-D12R, and wired this in, obviously making sure there was a gap of no more than 3mm from the magnets. Then, having connected in the battery, on the display in "Settings", I selected "PAS direction", and "Backwards". Lifting the front wheel clear of the ground, I turned the pedals, and, what do you know, it worked - contrary to what Swytchbike had told me when I first suggested it to them a year ago! Anyway, I just had to tell Swytchbike, and I'm now waiting for them to tell me that my Warranty is now invalid. But, what the heck, it looks neat, the PAS is much less vulnerable to accidental damage, and moreover, IT WORKS!!

 

[tonythebrit]

At lasr, at last!! My health has improved to the point that The Boss (i.e. my wife) has given me clearance to take a test ride. This is planned to happen on my birthday (I won't say which one) on November 2nd. I've not done much else to the bike since I last posted, except fit a set of battery lights - this is considered very wise in U.K. these days - to make myself more visible on our busy roads. I can't wait to get out on the road - it's been a long time!

 

[UtahPete]

After having a new rear wheel built for the Dahon, when I tried to fit a tyre & tube on it (first, the original Schwalbe Marathon Racer, and then a Schwalbe Kojak I'd bought recently), neither tyre would fit and they just seemed to be far too small. It was then I realised my dumb mistake - the original rim had been a 406, both tyres were 406, and the replacement rim I'd bought and had fitted was, yes you guessed it, a 451. Dohhh!! I suppose I could have kept the wheel like that, but I found that the choice of tyres for 20" 451 rims is very limited. So I decided to overcome the problem by having the wheel rebuilt with a new 406 rim. When I get it back, hopefully sometime next week, I'll post a new pic of the bike.

What's a 451 and a 406?

 

[amberwolf]

Those are the mm diameters (bead seat diameter (BSD)) of two versions of 20" rims.

An interesting page on tire sizing and history

Tire Sizing Systems

Several different systems of size markings for bicycle tires are in existence. The modern ISO system is not as familiar as it should be, this article explains it.

www.sheldonbrown.com