My 20″ Dahon Vector X27h preceded my Bromptons & was an easy choice for a folder when most of my bike-time was spent on a carbon frame race bike. It has a great road-bike feel & the specs make it one of the best performance folders you could ever want (well, until it’s superseded via the usual later-model upgrade-cycle?). Funny about the 20″ moniker though; the wheel size is 18″ on all the Dahons (& Terns) that I’ve seen.

To say, “what lets it down…” may give the wrong impression; it’s a great bike – it’s just that Bromptons are so good & show it up in the fold & engineering departments. However, being a performance bike it probably lacks some of the versatility that a good folder needs. My Vector has also had a number of upgrades (sometimes just to “correct” the engineering?) & our lives together have been a learning experience (often frustrating but better for the learning?). The one aspect of the spec that is pretty unique is also the item that is (almost) the “Achilles Heel” – the 27-speed transmission, with 3-speed hub gears & 9-speed rear derailleur. Once sorted & aware of the quirks; no problems?

Without any great detail, here’s some notes about what’s gone on –

Fitted MKS removable pedals – none supplied (just like a big performance bike?)

Added mudguards – for my comfort

Added side-stand – so convenient

Changed saddle – race-type Kore System saddle swapped to more comfortable saddle “that I just happened to have laying around” (but first needed an adapter to convert Kore System to standard rail system)

Swapped to Kojak tyres – great ride on Sydney roads after the rock-like Durano tyres?

Installed front derailleur – not for derailing the chain (bike only has single chain ring); just for holding the bloody chain in place (a flaw in short chain-stay bikes having multi-speed rear derailleurs which force the chain to extreme angles?)

SRAM dual-drive rear hub – similar ratios to Brompton standard 3-speed; hub changer gearbox with actuator rod & push/pull connection to Tiagra shifter not ideal (too much friction? inadequate cable retention at shifter?); initially very finicky in maintaining adjustment but learnt that axle gearbox needs to be squeaky-clean & well lubed?; rear wheel refitting requires precise gearbox handling to avoid reassembly issues? (acquired skill?)