From: "Nickolas E. Hein" Date: Tue, 6 Oct 92 13:43:44 PDT Subject: Re: hub gear information? For information on currently available hubs see the Cyclo-Pedia HPV catalog. In fact, why don't I just copy the description since I have it handy. - Beginning of Quote - STURMEY ARCHER GEARED HUBS Lately there has been a movemnet (started by the Counterpoint Tandem) toward smaller (20 in) wheels on recumbents. When done right, this results in a compact, well balanced, good handling machine. However owners of the machines are running out of gear at the top end (56t front CW, 13t rear cog 20" wheel= 86 gear inches in high gear). It is costly to change to cranksets which will accept 62 and 64t chainwheels (when they do this they have problems with the front deraileurs). One option that some are looking to are the geared hubs. These are not without their problems- they will not accept freewheels, internal gear ratios are fixed, heavy etc. They also have some benefits: gear changes can be made while standing still, not affected by weather, and most importantly higher gears can be obtained. Look at the chart below for a bike using a double crankset of 42 & 56 teeth, 14t cog on hub and the 5 gear in hub with a 20 in wheel: 42/14 56/14 Low 40 53 33% gear reduction 2nd 48 64 25% " 3rd 60 80 Hub locked up 4th 76 101 33% overdrive 5th 90 120 50% " (Cogs for Sturmey Archer Hubs are available in sizes from 13 to 22 teeth) It is possible to mount more than one cog on a Sturmey Archer hub and we have in stock a limited number of 3-cog conversion kits (16-19-23t cogs) designed for use with a Sturmey archer hub and a deraileur. We have in stock 3-speed hubs with built-in drum brake. Please call if you have questions about installing a Sturmey Archer Geared hub (with or without internal brake) on your bike. Installation is usually very easy. We also carry a large selection of repair and replacement parts. We can also build any of the SA hubs into your rim or ours. Give us a call at 1-517-263-5803 to discuss your gearing. - End of Quote - On the homebuilt I ride there is an intermediate freewheel on a jackshaft so I only use a single cog on the back wheel anyway. This is nice from the maintenance standpoint since you don't have a deraileur there to get mud thrown at it from the rear wheel. There are other drive systems in development. The closest one to production ("We'll have it in stores for you to try any day now") is the Terry Continuously Variable transmission. This reportedly gives infinite adjustment between ratios from 1 to 4.5 and works with two cables and can spin on to conventional freewheel threads. If it really works it could be the best thing to happen to bike transmissions in 100 years. It offers the potential of reducing the time and thought re- quired to shift when your attention might be better used to look for traffic in addition to permitting more efficient use of the motor. They have a brochure which you can get by calling. (I don't have the number here). If anyone has seen or used this product please post here. From: Ben.Brown@IUS4.IUS.CS.CMU.EDU Date: Wed, 7 Oct 92 11:50:11 EDT Subject: Re: hub gear information? I've used the S-A 5-speed hub with internal brake on a 20" front wheel of my tricycle (modified Brike). With a 12 or 13 tooth sprocket, it gives a good speed range, as the gearing goes from 2/3 to 3/2. But I've had problems with shifting. The unit uses a single, cam-action shifter to operate the 2 cables (one into each side of the hub); this is very convenient, but it doesn't work reliably. It seems the shifter is not adequate to overcome the heavy spring forces and friction to operate the cables. I was able to make the thing work tolerably well by using small pulleys to reduce friction where the shift chains make the 90-degree turn into the hub, and by putting helper springs to overcome some of the spring tension. Has anyone had experence with these hubs? Thanks, Ben (hbb@cs.cmu.edu, Carnegie Mellon U., Pittsburgh) From: pardo@cs.washington.edu Date: Wed, 07 Oct 92 16:50:17 -0700 Subject: Re: hub gear information? There are two internal-gear 5-speed hubs that I know of, the Sturmey-Archer with a hand-operated drum brake and the Sachs-Huret with a coaster brake. The traditional S-A 5-speed shifter uses two trigger shifters. It's a bit more complicated to shift than with the modern one-lever design, but I think it's easier to get adjusted and it has lower friction. I got trigger shifters from my local bike store (Bikesmith, here in Seattle). I've used older versions of the current Sturmey-Archer model on folding bikes and the shifting just generally seemed finicky. Even when the dual trigger shifters were used. I've heard some claim that the shifting is better on large-wheel bikes because things are turning slowly. I don't know if that's true or not. I'm curious if anybody else has tried dual trigger shifters on a recent (say, less than 2 years old by the shell date) S-A 5-speed with hub brake. I currently own a 5-speed Sachs-Huret unit. It came with a single-lever control that I've replaced with two trigger shifters. I've guessed at the cable travel distances and the unit hasn't failed yet, but (a) incorrect cable travel can ruin an internal-gear hub and (b) there are some clunking noises I don't like and don't recall hearing from other (S-A Bendix and Shimano) hub gear units. For those of you considering the Sachs, consider that they're hard to come by and the literature that comes with themclaims they are both permanently lubricated (not quite, but something to that effect), and to take them to a qualified dealer for lubrication. At the time I got mine (about 2 years ago) the importer said there were only a dozen or so units in the country and there *were* no `qualified' service centers. In short, don't try this at home, but if you do, you didn't hear about it from me :-) ;-D on ( Gearhead says ``Speed? I'll take 5!'' ) Pardo