« The perfect climbing AND descending set-up for big mountains / mere mortals ? »
Demonstration here of a10/42 Sram XD cassette (same for 11/40 or 11/42) in combination with Ultegra Di2 and 50/33
chainrings (same for 50/34). Wolftooth Roadlink DM fitted to extend the RD-r8050GS medium cage rear derailleur. Rear derailleur spring re-positioned to tighter position (standard setting is the lower of 2 tension options). 34 inner chainring replaced with Specialites TA X110 11v 33 chainring to gain even more gearing advantage. Works perfectly on the road (110,000m climbed so far) and very quiet (noisy in video as filmed in closed room). Shimano chain here but works equally well with gold KMC chain :0). Freehub replaced with an XD/XDR compatible one. XD / XDR hub conversions available for many brands of hub. 2mm standard cassette spacer was required before installing the cassette with my set up. BTW I should have kept one more link in the chain for this video to reduce pressure on the rear derailleur in “big-big”. I have added a link since and everything is even better, with no chain slack at all :0)
NB. Di2 default setting prevents use of 2 smallest rear cogs when in small front chainring, so manual groupsets are more likely to suffer chain slack.. Note also that the cage on the earlier rx-6870 GS is shorter and so 40 might be the biggest cog you can fit, with a generic hanger extender (Roadlink DM only compatible with r8050 models onwards).
50/10 allows pedalling downhill at 40mph / 60 kph (95rpm). 33/42 is “bliss” for 10% plus climbs (6mph/10kph @ 100rpm).
BTW, I am in the top ten for my Strava age category for all climbs local to me : Iseran 1st place), Cormet de Roseland, Col du Petit Saint Bernard (1st also).... It works for me anyway !
I have tried this set up using Osymetric 2020 50/34 chainrings. Unfortunately it was not successful as the chain would drop off the 50 chainring if I selected the 36 or the 42 rear cogs (not that you should !).
Instead of a Sram cassette, you can opt for a 11/42 (or 11/40) Shimano cassette. I have used both of those previously with 50/34 and 50/33 chainsets. The advantage with the Sram 10-42 is that you get better downhill pedalling performance.
P.S. It's a really good idea to check the rear hanger alignment before trying any new set-ups, and also that your Roadlink/hanger extender isn't bent/twisted.. I use a classic hanger alignement tool (rotating bar) but I see Wolftooth have brought out a different type of tool for this that looks interesting..
Негізгі бет Add gears to road bike for climbing: 11-42 cassette (or 10-42 ,11-40), 50/34 chainset / crankset,Di2
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