Hello.
I bought the MK1 last week, after a long serch time.
In the first round i had a accident and i broke the crankset. 
Where can I buy a new?
Can I adapt a new one from other model?
Help please!
Thank’s
Go to a BMX-shop: the crankset is from a BMX-bike…
Hello.
It´s the plastic black circle that recives the belt. Is broken.
Thank’s
Check on ebay-UK for spares: sometimes there are Mk1 parts for sale.
Alternatively: buy the complete crankset from Mk2-Mk3.3 - that could fit.
Alternatively: I´ve got a MK3-beltdrive and might sell - but need photographs of your crankset (or the broken part) in order to judge if it fits…
In UK Velorusion / Bike Republic stock remaining Mk1 strida spares (Not all parts are available … but I think most of the plastic parts are).
velorution.com/
bikerepublicstore.co.uk/
Otherwise as previously mentioned: Ebay UK.
OR … as the Mk2 is same 100Teeth (but grey) that would fit.
And with some ‘adaption’ (to either axle ie converting from BMX style bearings to normal BB )
or adapting front freewheel to match a Mk5 100T Front pulley (or using whats left of Mk1 front pulley as an adapter to a Mk5 f pulley).
Finally … how broken is the Mk1 F pulley ? … cracks can be fixed, and the flange rim is not necessary for drive … maybe it can be repaired (if a bit ugly 
)
Tom_T