Bilenky Cycle Works was able to complete the dérailleur conversion project to get my 60 tooth chainring to work. It required a complete disassembly of the bottom bracket, installation of custom spacers to position the crankshaft slightly more to the right (Tandems East made the first attempt at this, but it required additional finesse that was not apparent at first glance), and customizing the dérailleur a bit.

Shifting now is smooth as glass.

Took it out for a test run today. Hit 42 MPH but no faster. I will have to start training more this fall to make better use of the new gears.

My congratulations to Bilenky Cycle Works!

Nice! Forum member [MENTION=170179]Homeyba[/MENTION] has used rings in that range on his long-distance bikes.

Sweet! We need a larger gear but I had not even fathomed a 60

I don't think so......

Well my old 110 mm ring was a 56. Until I make a quad dérailleur I have no use for it.

42 mph! Wow!

Was on a downhill, of course. But I don't need much more than 90 RPMs to hold that speed.

So what's the point? I can coast down hills faster than that at 0 RPM.

Auto Reply: This bikeforums.net user has elected to ignore you. Your replies made in response to this user will not be seen until they choose to disable this feature.

but seriously, what's the point?

For all those hills that you hate to spin out on? Bragging rights? Speed trials? Got a deal on knee replacement and can't wait?

I'd think it would be more challenging if you switched it fore and aft. An 11/60 must be a bear to ride.

Maybe this is a good time for a lesson on The Internet. Feel free to waste as much time you like on pointless endeavors. But once you go bragging about it online, expect questions.

IIRC, OP has a previous thread where he explains his extraordinary leg strength and inability to pedal at higher cadence.

I've learned that some people just like to pedal downhill to get another few mph. Makes no sense to me if you have to go uphill at all, because it wastes so much energy, but luckily I get to choose how I ride. I only intercede in the "higher gear to go faster" threads to keep the misinformation at a minimum so as to prevent it from infecting others. The OP obviously has a very, very unique situation, one unlikely to apply to more than a tiny slice of the cycling population. If one's goal is to spin slower, rather than to go faster, the solution chosen is the correct one.

My personal speed record is 55 mph on I-15 through Cajon Pass in CA - coasting.

I've had a 56/11 ratio since 1993. Knees still fine. Age 49 still doing squats with 585. Just can't maintain 110-120 RPMs even in a low gear for long. I get out of breath.

But I can ride, seated, uphill, in a 48/28 without too much strain. I have leg strength. I don't have the cardio I did in days gone by.

I know what I can and cannot do, and this bike was built for me.

I don't need "bragging rights" -- The things I have done that will be carved onto my gravestone are well known by those who care. I doubt the bike setup qualifies to displace anything.

The purpose of the post was to thank the individual who made it happen, despite all of the nay-sayers and pissants.

I will continue to work on my electronic quad FD project, more for fun than anything else. And when that is completed, I'll post pictures of my 60-56-48-28 x 11-13-15-18-21-24-28 version of the bike.

Again, for no other reason than to show that...

The human will,
That force unseen,
The offspring of a deathless soul,
Can hew away to any goal,
Though walls of granite intervene.

oh no, not that... was Leonard Zinn mentioned? And a need for unusually long crank arms?

Forgive me, if I seem to scoff. I, too, once thought i just needed bigger gears to go fast.

Sheesh! When I wear out the 53T on my summer roadbike, I plan to replace it with a 50T because the 53/11 is so tall it is barely usable to me. My touring/winter bike has a 48/11 top gear which is only a little lower than I would like.

I don't see what the big deal was. Little wheel flodder bikes have 56 to 60T cranks.
My Sturmey Archer 5 spd has done 44.63 twice and 45.8 mph. I used 120 GI Rohloff on my bloated tour bike on most downhills and the uphill right after after. As long as I'm still going 22 mph or so i'm still in high gear.

But if you biked up the Manyunk Wall in Philadelphia every week for 15 years you might have different needs.

https://en.m.wikipedia.org/wiki/Manayunk_Wall

The 60-tooth ring was a little to wide. The ring was touching the frame. The bottom bracket needed disassembly to insert spacers to move the crankshaft to the right slightly, etc etc, and this also added complexity which needed to be addressed.

Is Bilenky the shop/builder on the north side of Philadelphia? I've heard some really good things about them. Doesn't surprise me they could make it work. Glad you found the right people!

It's not far north, which is what most people think of when saying "North Philly." It's just north of where Roosevelt Boulevard splits off of the Schuykill expressway. The next traffic light north of Mascher street is Front street, where I turned left. Then you pass a high school, and the next light is Fischer street, make another left. Make a right onto second street, and it dead ends up a small hill. Train tracks are right behind it.

"Why ..."

Just drop it fellas.

I've used cranks as long as 205mm. Gear inches are a red herring on bicycles because they don't take into account crank length or effective tire circumference when inflated. One of the least known Sheldon Brown contributions was introducing Gain Ratios:

Gain Ratios--A New Way to Designate Bicycle Gears

I've got to say, without knowing what crank length the OP is running, the project and the thread seem like a vanity pursuit, without more information. There is a HUGE difference between being able to push big boy rings on the flats and rollers versus wanting a big ring to pedal downhill. I think that's why this post/thread is getting the reaction it more or less deserves.

I read the Gain Ratios pice by Sheldon and even ran the numbers, but didn't want to listen to the truth when I was putting together my touring bike. It has normal touring gearing but with proportional sized 205mm cranks I can spin it out pretty easily even on 630 rims. Anyone who has ever ridden a tandem for any mileage understands the conundrum of simultaneously trying to get gearing high enough that you don't spin it out, and low enough that you can actually turn the cranks when climbing. You need both spectrums.

I think I'm with most others when reading this thread I walk away believing the OP…doesn't. Even if he's using 215mm cranks if he has normal (not tall) leg length I'm not buying the need to pursue a 60T chain wheel just to claim you're coasting faster while going downhill. Heck I've blown through 45mph on descents on the Wisconsin Dairyland Dare route (10,000ft of climbing but ALSO 10,000 of descending ) and did so with the tandem drag brake fully engaged and while white knuckling the brake levers. I can't see wanting to add that much weight to a bike just to claim I can coast down hills faster.

If that is what the OP wants, leave him be.