Bicycle Mechanics - Schwinn Madison IGH conversion?

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woodenidol
02-07-09, 06:20 PM
This looks to be the best forum for this question.
I use my Madison for commuting only to this point. Its only a 5 mile one way commute, so the single speed has worked out nicely. I have however signed up for Cycle Oregon this year, and have been throwing around the idea of a Nexus type hub, to give me enough gearing to make the Madison work.
I talked to the LBS mechanic, he confirmed what I had feared, that the bikes drop outs are too narrow (120) for the nexus 8 speeds. This is kind of what I expected, but had to ask anyway.
So I thought would ask here, before totally dumping the idea. So is there an internal hub that might work? Would it be robust enough to for some climbs including a short 10% climb and an extended, it appears to be 9 mile, guessing 4-6 %. Would it be so ugly, that I would no longer be able to look upon my bike the same? smile.
My other choice is using my Schwinn Tempo (1987, recently overhauled) or as what is always fun, another bike, possibly building up a Cross Check.
My fitness level will be decent. Im 47 and no longer have a real desire to see just how much I can suffer, so the suggestion of "get in better shape and ride the single" will fall on deaf ears.
Thanks in advance for any help. My tech knowledge is pretty out of date, as I did my last serious riding before I was 30, and only started riding again after the chemo 7 months ago. I know little about the IGH, but have been reading up on the subject to some extent. I have no real world knowledge of them.
rhenning
02-07-09, 06:47 PM
Older Sturmey Archer AW 3 speed hubs are 120 spacing it that helps. Roger
ChiapasFixed
02-07-09, 07:09 PM
there was a thread in the folding bike forum about re-spacing the shimano Alfine 8 spd (next gen. to Nexus) to fit in 120mm or even less, I believe.
maybe do a search there, or look in hubstrippers.com
The Shimano 3-speed and SRAM and Sturmey-Archer 3- and 5-speed hubs will slot right in your 120mm O.L.D. The overall gear range of these wonderful little pieces of kit will probably not be satisfactory for the climbing you have indicated.
You could respace your steel Madison frame's rear (http://www.sheldonbrown.com/frame-spacing.html) without much difficulty. This would allow you to use a wider range Shimano 8-speed hub or a SRAM P7 or iMotion9 hub.
Best recommendation would be respace to 130mm OLD, get an example of the latest Shimano Nexus 8-speed hub, the triple-roller clutch, needle bearing SG-8R36 (http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/SG/EV-SG-8R36-2784_v1_m56577569830646702.pdf) model, and shift with a Jtek bar-end shifter (http://jtekengineering.com/jtek_bar-end_shifter.htm).
HTH,
tcs
Would it be so ugly, that I would no longer be able to look upon my bike the same?
No (http://www.bikecommuters.com/2009/01/30/dynamics-synergy-road-bike-first-look/).
tcs
The Sturmey 8W should work with your narrow dropouts. Do take into account that you'll have to go all the way down to a 30t chainring and 25t sprocket to get usable gearing out of it with 700c wheels.
Otherwise, the Sram 5 speed might be your best option without spreading the dropouts. It is 122mm OLN and has the same gear range as a Nexus 7.
The Shimano 3-speed and SRAM and Sturmey-Archer 3- and 5-speed hubs will slot right in your 120mm O.L.D. The overall gear range of these wonderful little pieces of kit will probably not be satisfactory for the climbing you have indicated.
But for the sufficiently stubborn it is possible to build a quad crank and get 12 decently separated gears out of a 3-speed S-A. It'll give you slightly less than the range of a MTB w/o the granny ring.
The Sturmey 8W should work with your narrow dropouts.
The Sturmey-Archer XRF8 has been a troubled design and I'm reluctant to recommend even one of the later examples. The new, redesigned, much beefier XRF8(W) hub has been expected on the market in "a month or two" for the last 9 months, but I still haven't seen one in the wild - and while I have great hope and good wishes for this hub, I don't think I'd want to be one of the first ones to purchase it.
Do take into account that you'll have to go all the way down to a 30t chainring...
Which, with your Madison, would require the purchase of a different crank.
With a SRAM or Sturmey hub, you'd also have to decide on how you want to adapt the hub's straight-bar twist shifter to your drop bars. There are ways to do this if you decide to go with one of these hubs.
Best,
tcs
But for the sufficiently stubborn it is possible to build a quad crank...
For the full Rube Goldberg (http://globalmoxie.com/bm~pix/rube-goldberg~s600x600.gif), one could combine a two-speed kick-back hub (Sachs or Bendix) with a Schlumpf Speed Drive crank/bottom bracket, yielding four gears of, say, 40, 54, 66 and 90 inches, with just the single chainwheel and sprocket and without any visible shift mechanisms.
Best,
tcs
For the full Rube Goldberg (http://globalmoxie.com/bm~pix/rube-goldberg~s600x600.gif), one could combine a two-speed kick-back hub (Sachs or Bendix) with a Schlumpf Speed Drive crank/bottom bracket, yielding four gears of, say, 40, 54, 66 and 90 inches, with just the single chainwheel and sprocket and without any visible shift mechanisms.
Now that would be rather elegant! Too bad the lack of an actual need and the price of the Schlumpf keeps me from acting on it.
Besides, it'd take some doing to get all the other bits together in something cool looking enough to match such a drivetrain.
Grand Bois
02-08-09, 10:48 AM
I'd get the Shimano Alfine and spend a few minutes cold setting the frame.
fuzz2050
02-08-09, 12:16 PM
I think this calls for a white industries freewheel
http://www.bikeman.com/store/graphics/00000001/Alt-WIND/WIND-FWDOSENO.jpg
How much shifting do you really need anyway?
badmother
02-08-09, 01:00 PM
I'd get the Shimano Alfine and spend a few minutes cold setting the frame.
+1.:thumb:
Afline or Nexus 7 + coldsetting. I`ve put Nexus 7 on four old bikes. They are more reliable than the Nexus 8.
tatfiend
02-08-09, 03:36 PM
I recently fitted a SRAM P5 to a Duracycle track frame. I machined my own version of the Hubbub adapter to use the twist shifter with drop bars. Everything is working well.
The hub is 122mm OLD width while the bike dropouts are about 120mm so I just have to spread the dropouts slightly to fit the wheel in. The bike had an old Sugino crankset so I did need to change the BB to get a perfectly aligned chainline, with the following additional changes. I also moved the chainring to the inside of the spider and machined an old larger chainring, mounted on the outside of the spider, to act as a disc type chain guard.
I am also in the process of accumulating the parts to mount a Alfine 8 speed hub in an old (1973 era) Peugeot PX-10 frame. The prior owner(s) had destroyed any colllector value as it had no original parts on it, someone modified the derailleur hanger with a file, installed cantilever brakes, made a mishmash of the headset, installed a too small seatpost and wiped out the original TA bottom bracket. An interesting project to get it back on the road as a safe IGH bike.
For those interested in IGH hubs and bikes, including conversions, lots of expertise available on the below Yahoo group. New members are always wlcome.
http://groups.yahoo.com/group/Geared_hub_bikes/
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