Now, I’m no great shakes but have done the DR 200 all four times it’s been held and have an entry for next year too.
On year 1 I rode my cannondale Super X with 33mm Challenge Almanzo tyres and a 36 single ring up front with an 11-42 cassette. I was battered and with poor fitness that year it took me almost 12 hours to complete.
The next couple of years I rode my mountain bike with Schwalbe Big One tyres. Probably had a 34 tooth 1x settup with 10-42 cassette and it was so much more comfortable and I didn’t run out of gears.
Last year I went full franken-bike: Cannondale Fsi with drop bars and a microscopic chainring. Got me round in under 10 hours at long last.
Not sure what I’m going to do this year but I just got a new cross bike and I’ll be hard pushed not to use that…
I guess it’s difficult to answer the question about gearing without knowing how strong you are although I would go as low as you can. After 3500m of climbing you’ll want something to winch you up the hills. They aren’t steep but there are alot of them. Also, last year it was a block headwind for about 60km…
Get the biggest tyres you can fit in the bike - you don’t need any grip but you do need comfort.
Double-wrap your bar tape. You won’t regret that.
The couse has changed ofer the years and is a bit mellower than it was at the start and there have been promises of taking out more of the roughest sections this year.