migrantwing

+1

rhm

Well, aside from the question of why anyone would need such high gears, I'm mostly curious why he chose to go with the 60 tooth ring despite the troubles it caused with the frame. He could have got considerably higher gearing by going with a Capreo hub and Capreo cassette or a three speed hub with cassette.

60_tooth_ring

Cranks were not modified and are either 170 mm or 175 mm whichever came with a Trek cross bike from 1992. I can read when my computer shows me 40 MPH and that's also at or near 90 RPM. You can factor in many more variables, such as being faster on a rainy day due to lower atmospheric pressure and therefore greater tire circumference, but your talking a small percentage of another small percentage.

I've climbed the wall in 2:27 at my best, and nobody's taking that feat away from me.

60_tooth_ring

Because was quoted $550 at the LBS along with the advice the additional chain flex would wear out the chain sooner and introduce clicking/shifting abberations.

habilis

It's worth mentioning that some younger readers with excess testosterone may try to duplicate feats of high-speed descending, with or without pedaling. 40 or 50 mph on a bicycle, on public roads? Not to be encouraged, no matter who you are or what your capabilities. I once hit 110+ on an interstate on a motorcycle - inexcusable, but at least I had a full helmet and leathers. Did it once for science and never again.

cny-bikeman

I would agree that it's unwise to go 50+ mph on a bicycle - not sure what/if I was thinking. I was not even all that young at 25 yrs old, but I don't think I would have had brakes at the end of the hill had I tried to keep below 40 mph.

habilis

Hey, we've all done stuff like this. That's why fewer males than females make it to old age.

Doctor Morbius

I like it.

Chris Chicago

i'm kind of curious what your legs look like

jmb72

The question is not why? But why not? ... you seem pleased with the result - happy days.

Shimagnolo

I think this is him.

noglider 

I love that movie. I saw it twice in the week it came out and bought the DVD the week it came out.

seedsbelize 

Seems the only times I get dropped, on group rides, is going downhill, as I don't have the gears to keep up.

SteelCan

I mentioned Bilenky's in my initial response. Place looks just as I remember from your pic.
A later post questioned the front-end stability and handling of your 90s Trek on winding downhills. Have them take a look and see if they can do anything to firm-up/improve the headset. THAT will provide more speed if that is your goal.

jyl

Just curiosity - on some downhills you know well, compare speed when coasting in an aero tuck vs when pedaling 60x11. It would be interesting to know which is faster at different grades of downhill.

jyl

Oh, hey, I just remembered a component that would have saved you all this trouble - or, you could use it now to get even crazier on the gear ratio.

Sturmey Archer | CS-RF3 Silver

T Stew

Personally my you-know-what goes into pucker mode when I hit 30... especially hitting potholes at speed. But not too many hills around here so I don't spend a lot of time over 30. Though spending more time up there would probably gain me more confidence.

Funny since I was just going the other way with my build. Calculating out gear inches my Tempo in its highest combo 52-13 is 105.1 gear inches and when I put a modern cassette on it with 11t then the same gear inches only needs a 44t chainring! That is good enough for me the only time I even use that gear is downhill. I plan on 44t up front and 11-36 (or custom 11-40) out back.

But I for one think its great to do custom mods especially if it benefits your style, awesome work

dabac

Thing is, (excessive) strength for a cyclist is like Nitrous for a car. It's not sustainable effort.
Big muscles have to be kept oxygenated too.
And if you don't have the cardio to keep your muscles supplied, it's like cranking the bottle open.
Once you've used up what you've got in your system, you're done.

Sure, under some circumstances you do gain a little efficiency by pedalling slower-and-harder.
But physics is physics, and hard to fool. Hoisting yourself up a climb will require the same amount of energy any which way you cut it. And with that, it'll also take the same amount of oxygen.

60_tooth_ring

When I lift a feather off the ground, I'm not burning any more oxygen than if a child does the same thing. As the weight of the object being lifted increases, at some point the muscle fiber is more deeply engaged. I can raise 315 pounds off the ground all day long since it's literally less than 30 pounds more than my body weight. For a slenderly-built cyclist, this is probably not the case.

There is undoubtedly a gear ratio you could pedal all day at some hypothetical cadence that does not leave you sucking wind. What is this max ratio for a cadence of a leisurely 60 RPMs? It's probably different for everybody. I'm saying there are some of us that don't engage deeper muscle fiber at higher gear ratios, and, therefore, the functional oxygen 'consumption' is not as great. I'm simply not exerting myself.

60_tooth_ring

They have custom-built frames hanging from the ceiling covering just about every square inch of the place. The shop floor you have to serpentine around as well. They're doing a tremendous amount of work, and it's only 2 guys from what I can tell.

I highly recommend them.

60_tooth_ring

I'm not sure that can be used with my 7-speed hub.

EDIT: You realize the high gear on that hub will effectively turn my 60-tooth ring into an 80-tooth ring, yielding exactly 200 gear inches, right? I don't think I could push that.

60_tooth_ring

This is what it looks like close up.

60_tooth_ring

Well I was in this commercial back in 2008.

https://m.youtube.com/watch?v=RBZmLzv9NKQ

jyl

You could use the hub's high gear and one of the larger cogs (13T, etc). Saving the 11T for when you get stronger :-)

rhm

Quite right, it can't be used with your existing hub, and it would give you astonishingly high gears.

If you're happy with the system you have now, then this is all academic. But I agree with @jyl that by using an internally geared hub (IGH) you could have saved yourself a lot of derailleur-related aggravation.

So, granting that you've already gone another route, and you won't be needing this suggestion, here's how it would work:

You'd have to replace your rear hub with the IGH. You could use the one jyl mentioned, which takes a cassette, or one of a few others. SRAM makes one that's more or less similar. It is also possible to mount a freewheel on an older Sturmey Archer 3-speed hub, as long as you have an axle long enough. The IGH would have its own shifter; so if you keep the front derailleur and the rear derailleur, you'd have three shifters. Finding room for them all might be a challenge. This kind of gearing is something do-it-yourself guys like to fiddle with. I doubt you'll get a bike shop mechanic interested in doing it for you.

The IGH would essentially give you an overdrive system on top of whatever gearing your bike originally came with, and you'd have a lot of redundant gears. A typical 3x7 derailleur system already has 8 or more redundant gears, and adding the IGH you'll have three times that many.

If you're interested in pursuing this option, I'd suggest you start by playing with Sheldon Brown's Bicycle Gear Calculator.