It had been our intention to switch to a single mass flywheel/clutch on my boy's Fabia 1.6 CR Scout if it had ever needed one done. Unfortunately, with over 100,000 miles (still on the original dual mass jobbie) it succumbed to a multitude of other ailments!
It did focus my mind on the conversion though and there seem to be two main "scare" stories about these conversions. The first is that it alters the dynamics of the crankshaft/flywheel harmonic relationship such that it can cause crankshafts to snap! The second is that it causes gearbox damage due to there being no "cushioning" effect because of the direct drive nature of the solid flywheel.
I've asked around local garages - some of whom I am on very friendly terms with - and they seemed to be all quite in favour and are obviously no strangers to the kit. One said the single mass kits were now his preferred option. I couldn't find even one report of a failure having taken place although it was mentioned that gear "rattle" at tickover speeds was sometimes more noticeable after the conversion kit was fitted. The opinion on this seemed to be that it was more down to the thin watery nature of modern gear oils than anything else. I notice my 2016 3 cylinder Ibiza - which has a solid flywheel as standard fitment and gearbox oil possibly thinner than water - does this as does my neighbour's 3 cylinder Fabia. - sound proofing is so good nowadays that you don't hear it inside the car though.
The last thing I noticed before the Fabia was sold and so I lost the incentive to do any further research, was that at least one manufacturer (might have been Valeo?) was producing driven plates with longer, more resilient, plate springs. I would assume to closer replicate the shock absorbing effect on the gearbox?
Oh, forgot to mention, my local factor says that, taken in total numbers sold, he sells more single mass kits than dual mass although it varies - some months more D/M some months more S/M.
Of course I should say this is all hearsay but from people I trust. So I would be inclined myself to go for a single mass conversion but I would buy a "big name" and probably look for one that had this extra long travel driven plate spring feature.
PS My decision in favour of single mass is greatly influenced by the large number of failures on the transits run in a fleet I have close contacts with.
