Yes you are right on the shifting speed. I did noticed that on that mega range ratio the shifting was not as fast as how it should be. This actually sparked a thought on me to switch to 2X11 11-30 setup instead. I race marathon XC mostly and having 2X11 may work better for me.ooo wrote: ↑Mon Jan 15, 2018 2:43 amSafer approach is to build heavy bike and work with parts 1 by 1 with test riding between changes - but this is very slow
Your approach is reverse, much faster, probably make sense to wear extra protection for testing period.
If we forget about safety, other downside is that some problems can have a consequences (other problems) and it may be hard to figure out what happened first
I have some concerns was about shifting quality - ultegra shifts slow on mtb cassette, i would not go more than 11-32
and while your bike have testing period, may be you don't need high top speed? you can use 32x11-32 or lower combo
about modification - I am worried about stem. it may be ok for road use with suspension for, but not for offroad use,
in some places suspension fork and air in wheel will be not enough to save it from failing...
As for the gearing ratio, I did the maths based on Sheldon Brown calculator and based on repeated tests on several chainring size and cogs, combined with the factor of crankarm length that I use, here's how it looked like:
* at the top end, with 165mm cranks I have found that I can pedal to racing speed with 32t chainring and 11t cogs. If Strava were to be trusted my personal record was a sustained 35kph average speed over 46kmh of non stop endurance ride on tarmac with MTB - and that done within 1.30 hour. I have developed my riding style to spin more and grind less - so I will suck big time at sprints but the type of races I participated does not depend on bursts of speed. What worries me the most is my climbing ratio. At full strength I can still pedal uphill on steep terrain with 1.6 or even 1.7 ratio. But on long and tiring race, having a 1.5, 1.4 or even 1.3 will help a lot to minimize fatigue