More tweaks to the V

Greg S

Guru
I did a 150k ride this past weekend on the V20c that included a number of 9%-10% climbs of varying lengths. This was the first time I've done a route that included climbs above 8% and this one had several. One thing I noticed was that the gap between the biggest (easiest) cog and the second-biggest was annoyingly large. Big cog was too easy, next biggest was somewhat too hard.

To recap: I built the V20c with an eTap AXS 1x drivetrain, 42 tooth oval chainring and a SRAM 10x50 cassette. The cogs on that cassette are: 10-12-14-16-18-21-24-28-32-36-42-50 so there's an 8 tooth jump between the last two cogs and I found that to be too large to be comfortable. N.B. not saying I couldn't push the 42 tooth cog on those gradients but I knew there were a number of them on the route including some very late in the ride and I wanted to manage my effort.

So what to do?

I have a couple of DF bikes that I'm (sort of) in the process of selling. One has a 1x drivetrain so it's not really a candidate. The other has a Shimano 11 speed group on it with a 2x drivetrain with a 48x32 crankset (165mm crank arms) and an 11x40 cassette. That'd be a decent candidate, I'd still have a fairly wide range of gears and an even easier gear (30x40) for the really steep stuff. The jump between the last two cogs is 5 teeth (35-40) so that'd be an improvement albeit a small one.

In pondering what to do, I realized that I'd prefer to have 12 cogs (or more!) for smaller jumps between all the cogs so how do I solve that problem? I should also mention that the V20c has GrowTac Equal cable actuated disc brakes (which are excellent btw) so switching to hydraulic disc brakes would not only be a PITA but wouldn't buy me a whole lot in terms of braking power/modulation.

So what did I do?

I ordered a Wheeltop EDS TX groupset with cable actuated brakes. This is a full wireless system which will be an easy replacement for the Etap AXS that's on the V20c now. The Wheeltop system can be set for any number of cogs from 3-14(!) so it'd be perfect for my 12 speed setup and the price is certainly reasonable - you can barely get a Shimano or SRAM RD alone for the price of the full Wheeltop group.

I've read positive reviews of the Wheeltop group although apparently the setup app is fairly obtuse (poor Chinese->English translation) but, as with all things internet related, there are better translations on the web so I can more than likely figure it out.

I also happened to have a Prestacycle 12 speed 11x40 cassette. The spacing between cogs on that cassette is: 11-12-13-15-17-19-21-24-28-32-36-40 so only a 4 tooth jump between the top 2 cogs - even better! Plus the jumps between the other cogs are a bit smaller so that's a bonus.

All the stuff has yet to arrive. I needed to order a new T47 BB for the crankset I'm going to install (a Sugino 901-XD) that's inbound from Japan. All the other things (groupset and chain) have shipped.

I'm going to be doing a week long ride next week (well, 5 days) leaving in a couple of days so I won't get a chance to build it up before I go but I'm looking forward to it!

More to come.
 

Henri

scatter brain
[…]-42-50 so there's an 8 tooth jump
The jump between the last two cogs is 5 teeth (35-40) so that'd be an improvement
[…]-36-40 so only a 4 tooth jump
You really shouldn't just compare the tooth count between different size cogs. Call it 19%, 14% and 11%. 8 teeth drom 42 to 50 is the same jump as 4 teeth from 21 to 25 or nearly the same as 2 teeth from 10 to 12.

You've already chosen but for anyone else I'll mention another choice: Halfstep. SRAM Eagle is purely made for 1x and can't take a big jump in the chain rings, even if you only use the small ring with the big cogs and the big ring with the small cogs. But it has a bit of play for suspension. You can get two chainrings with just a small difference for fine adjustments when you would otherwise be cought between cogs. You'd still retain the fast progression through the large tange of the cassette when grades shift quickly.
But going normal 2x from the ground up should be a good way for many people. Especially when setting up the bike at first. (I've enjoyed only 1x on my bikes for a while now. Be it SRAM AXS Eagle or Rohloff Speedhub or Pinion C1.12 or even just the two gears of a Schlumpf High Speed Drive. - Only the 1x8 on the cargo bike is a bit narrow in range and can hardly be changed meaningfully.)
 

Greg S

Guru
You really shouldn't just compare the tooth count between different size cogs. Call it 19%, 14% and 11%. 8 teeth drom 42 to 50 is the same jump as 4 teeth from 21 to 25 or nearly the same as 2 teeth from 10 to 12.
My comparison is valid for my purposes. Feel free to measure however you’d like.
 
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