E-mail reply from strida.co.uk

I have written an e-mail to strida.co.uk suggesting some improvements on the design of the futher generations of Strida, e.g. add an internal-gear hub on it, make the tubes/posts extendable just like the Sinclair A-bike to make it more compact when it is folded.
Here is their reply:

dear amuro

thank you for your email enquiry and interest in Strida.

strida was designed to be a zero-maintenance, ultra-light, “a to b” bike. for flat terrain, you can ride the bike indefinitely - on steep hills the range is limited, though one owner rode the strida the length of new zealand.

because the bike is so light, it doesn’t take much energy to pedal and the gear inches have been optimized through both application of theory and extensive test riding. interestingly, we learned after finalizing gear ratio that the one spec’d was the same one on all the british postal service single-speed mail-delivery bikes. - 56 gear inches.

in short the terrain found in such cities as new york, and london is suited for the strida.

we recommend taking a look at the evaluation provided by journalist tim pestridge, who experimented with replacing his 24 speed bike with a strida for his daily 11 mile daily commute. see pestridge.com/strida3.html

when evaluating whether you’ll need gears or not ask yourself what sparked your question and where would you anticipate using bike?
for most city commuters gears are far from essential.

p.s. following is more chatty response offered by mark sanders, inventor of the strida, to a customer inquiry in 2005 on the subject:

“Yes I have made several prototypes of geared versions, 2 speed & 3 speed, these were also retro-fittable … but no plans for production … most people prefer the simpler, lighter, fuss-free single-speed strida… which has a lowish 56” gear. I found the only real benefit to the geared versions was faster decents, hill climbing was only marginally better, with a lower gear."

“Try a Strida as it is - single speed suits its uncluttered, clean and minimalist design philosophy… Strida IS fast in its natural urban habitat ! For example in London its as fast as all but the lycra boys, its also about overall journey time and ease of use … which includes near instant folding (5-7sec), and convenience when folded (just wheel along - no carrying and no bruised shins).
Strida.co.uk has a 60-day money back trial - so If you find you can’t live with it, chop it in for a conventional folder of which there are plenty to choose from - all very similar, ‘F’ frames.”

we thank you for all your comments and confirm that they have been forwarded over to management. we do appreciate feedback.

if you need any further information regarding this matter, please do not hesitate to contact us.

kind regards

debbie - strida customer services

They make a fair point, but would at least like to try a ‘heavier’ geared version of a Strida - to decide for myself. It may well be I then prefer the simpler single speed, but at least get to try - I wonder if Strida UK would loan out one of these mark sanders prototypes ?

Photos of a prototype lightweight geared Strida 2 on Mark’s web album:
picasaweb.google.co.uk/MAS.DPL/S … 5302027810
picasaweb.google.co.uk/MAS.DPL/S … 8813672882
picasaweb.google.co.uk/MAS.DPL/S … 5815587410

Interesting. I’m trying to puzzle it out. It looks like it will give two speeds the ratio depending on the number of teeth on the ring gear which isn’t shown and must be built into the right hand cover. I don’t think I quite have its workings sussed out, but it looks as if the low gear will be provided by driving the ring gear and having pawls push the dogs around under the rim of the large pulley. High gear will be achieved when the sun gear is locked to the main unit containing the planet gears. The pawls on the ring gear (not shown) will allow the ring gear to free wheel over the dogs when the system is set in high gear, because the ring gear will always be rotating more slowly than the front pulley - I think… It’s a puzzler.

I’m not sure how they would lock the sun wheel to the planet cage to get the high gear.

I’d much rather it was made out of aluminium and steel though. Of course this being a prototype, there are all kinds of reasons why it is plastic at the moment. Nicely lubed up, steel sun and planet with the planet gears on hard steel pins set in an aluminium pulley, that thing would last for years.

I hope they develop this and sell it, but I hope it won’t be all plastic. I love the way the Schlumpf drive is made. Look at the quality of this →

Here’s another type of epicyclic cranks set by SRAM →

There is an excellent video of the SRAM’s Truvative Hammerschmidt here →

It isn’t cheap though.