old's'cool

I wanna see that mounted on a Raleigh Twenty...

poprad

Well now, that about sums it up, doesn't it?

doofer

Let me start by offering that I'm a relative Newbie. I have already made a few upgrades to my bike (in profile), but I really want to add this relatively new offering by SRAM. The GX Eagle groupset. I need to know what parts are needed to get rid of my ES Bottom bracket, what type to replace it with and what all parts I would need to complete this swap.

63rickert

Calculated data. Given a wheel with a rolling diameter of 750mm, a 30x50 gear and approximately limiting uphill pedal speed of 40 rpm, speed is 2.1mph. Why is this preferable to walking? In 30x10 with normal pedal speeds 25mph is possible. Does anyone ride these two wheel monster trucks at that speed?

It's just another monster truck. Something to sell, not anything to use.

Ten sided polygons are not circles. With sufficient attention to sculpting ultimate tooth form the chain will not skip, nothing will make a 10 drive with any efficiency. Shimano totally missed the boat with DuraAce 10. With short pitch chain you could use more teeth. Less load per tooth. Less load on each chain pin. Smoother transmission and reduced drivetrain wear. This has been done before. Chainette as produced by Coventry Chain Company from 1909 to 1939 had a pitch of 8mm. Powered to many victories by Freddy Grubb and Hubert Oppermann. What was possible in metallurgy and metal forming in 1909 is certainly possible now.

obrentharris 

But that's a very slow cadence. For most of us mere mortals the cadence has to go up to 60, 80, or higher when the surface is slippery and the grade is 30% or more.
Brent

bicyclridr4life

I'd like a 14-50 7 speed for my 1989 KHS with a 22/32/44 triple crank.
The KHS is set up for touring, I pull a trailer (repurposed 2 kid hauler) everywhere, so that 22/50 granny might come in handy for my ancient knees when going up hill.
"Why not walk up?" You ask?
I find walking painful thanks to my hips, knees, and back.
If not for my bicycles, I would be in a (((shudder))) wheelchair.

52telecaster

i think its interesting that this can be done but i can't ever imagine needing it myself. but then i dont really mountain bike so i guess i am not the target audience anyway.

ThermionicScott 

Since this thread has been bumped, it's interesting that there is opposition to single-chainring systems in the C&V forum, given that that's how bicycles were until the adoption of multiple chainrings! One could view multiple-chainring setups as an imperfect kludge to the long-present issue of not having enough range on the freewheel, that is being obviated better and better with these new systems.

Single-chainrings setups are much more intuitive to use. I've pondered going to 1x on several of my bikes, but always stopped because I would need to upgrade to cassettes with more cogs than 7 in order to be satisfied with the range and spacing.

HTupolev

If the limiting factor is the rider's torque, off-road it's often practically impossible to pedal that slow, because the rear tire can lose traction on steeps hills if the rider's form becomes choppy. But even on road, if I can only manage 40rpm on a climb, then I'd consider the bike I chose to have been poorly suited to the ride; I don't like merely being able to complete a route, I like being able to do it with good form and performance.

Walking is almost never preferable when it can be avoided. Oftentimes people see cyclists climbing slowly and think "they could walk that fast!" Which would be true, if the cyclist was walking unencumbered on flat ground. Walking a bike up a steep hill is slow and clumsy.

At your assumed wheel size, 25mph would only be about 95rpm. People can usually push higher than that before feeling all that spun out.

Sometimes, at the faster points in a ride or race.

C&V bikes arguably have the most use for multiple chainrings, whether to expand range or divide out intermediate gearing steps.

63rickert

You have and know good form. My hat's off to you. Comment based on what I see people do, not on what's best.

Twenty-five years now since I raced off road. Old bones break too easy. Best placing was 2nd in the hillclimb at Slatyfork. Had a mechanical off the line, fixed it, and struggled up w/o benefit of a pack to race in. Right when the course gets flat for a mile (?) or so an elite rider who had also had some early problem caught me. Grabbed his wheel and motored over rocky trail at 30mph in 48x14. On 700x40 when that was unknown. Passed a hundred riders. All of who just stared. Had I known the course at all, known where the finish line was, or known who was in my division I'd have easily won that day. Since then have not seen any who understand how to spin offroad. Fewer and fewer who spin on the road. And precious few who can grasp that surges of torque break traction. 60 rpm on a limiting climb would be really good. Still only 3mph in 30x50. If you can do that at 80 rpm I wish you many victories.

Uphill running carrying a bike was something we used to practice. On rain and snow days it is a great workout and reduces sloppy day bike maintenance.

ThermionicScott 

They do indeed. Perhaps what I was expecting was more appreciation that 1x has a long history, and that multiple chainrings have never been a 100% satisfactory solution. They can work well enough if you choose the chainrings just right and set up the derailleurs properly, but still...

Narhay

Maybe this will be paired with a larger chainring so one can bike to the mtb park in a higher gear at a reasonable speed but still retain the low gear you had with a smaller chainring.

dddd

With mtb chassis design changing fast these days, there is now a need for even lower gearing, not just for the larger rolling diameter of 29er and PLUS-width tires, but also because of the much greater traction afforded by shorter chainstays and much softer tires.


1x gearing gives the designers more clearance for wider tires using shorter chainstays, so from there the challenge is to provide enough gearing range.

My low-speed balance has improved a lot since I began riding on super-low air pressures, as stalling due to sudden tire grip breakaway is more a thing of the past. This can become very strenuous as the grade steepens, so lower gearing allows the rider to relax and focus on balance and line selection.

This dog is really heavy, it's from WalMart after all, but even with not-so-short chainstays the traction available to the rear tire at 22psi is incredible.






As compared to the bike new with 2.1" tires on narrow rims, LOL (The 57mm 650b fat rims shown above came from a K-mart Mongoose and feature all-steel freewheel hubs, oh so light!).

pcb 

My restomod '83 DiNucci with SRAM 1x11, 11-36 x 40t. I've been shifting front derailleurs, with just about every chainring scheme, since 1972. I have zero complaints with a wide-range, simple, sequential, 1x drivetrain. Maybe about half of my geared bikes are 1x now, and I never get on one and wish it still had a front derailleur.



Here's an '85 Weigle Special Road; bar-con in this pic, now has a brifter:

dddd

Yep, unless you are road racing, today's wide-ratio cassettes are pleasant company along all but perhaps the flattest of rides.


Here in the foothills, I've done entire rides in the big ring using a 13-30t 7s freewheel, with just a bit of extra effort over the last few miles. Oddly enough I broke my generic bb spindle the last time that I did that, but at only 140lbs I can say that it was defective.

Iride01 

The article linked in the OP is two years old. As well is the thread is a year and a half old.

Ya'll do realize that, right?

Not that I don't mind arguing about more speeds and only one chainwheel. But not here.

Salubrious

I was recently on the Tour Divide and my bike (Salsa Cutthroat) was equipped with the SRAM 1:11 with 44 teeth in the rear.

It was painfully obvious that the 32T chainwheel I had in the front was too big. 'Monster' was how it was described when I got to Divide Cycle in Helena. I went to a 28 and it was still too big, but now I didn't have a good high gear either. IMO/IME the 1:11 setup isn't ready for prime time, at least not for wimps like me.

But when I was ascending (pushing my bike) up Poorman's pass (between Lincoln and Helena in Montana and one of the steeper ascents on the TD) I was passed by a person riding the Eagle 1:12 setup, and I watched him ride out of sight up the pass while everyone else was walking. Not only did he stay ahead, he gained on the people pushing. It was one of the more heroic sights I saw on the Divide this year. The Kiwis that passed me on foot said 'walking is likely more efficient' which is probably true, but its not as fast.

Next year I'm back on the Rolhoff- **done** with these stupid dérailleurs!

And if you've not been on the Tour Divide, you totally have to go!! This year a 17 year old kid did the whole thing on an early 90's mtb with no suspension and 26" wheels...

ThermionicScott 

As long as interesting information and new perspectives keep getting added, who cares how long the thread has been running?

OldsCOOL

Thanks for the shout! That’s the class of MTB I ride, a ‘97 Trek 7000 rigid and 26”. Very cool bike.

Congrats on finishing an epic ride!

RobbieTunes

It just seemed odd not to have a front shift option. Rode fine, and was super quiet.

Bikerider007

Great article. Aqua Blue Sport to compete on 3T Strada disc bike with 1x drivetrain in 2018 | Cyclingnews.com