My 1984 Record Ace now has a triple with 26/36/46 and a 10 freehub with a 32 on the rear.Old age does not come alone! Campagnolo/Shimano 8-speed cassettes have different spacing , so you can't generally get good indexing using a Campagnolo 8-speed wheel with a Shimano shift system or vice versa. Hold the bicycle with the rear wheel off the ground, and leaning to the left at about a 45 degree angle. An assistant may be helpful for this. Turn the pedals around a couple of times to get the wheel spinning fast, then let it coast (helps to be in high gear for this.) working on freewheel bodies is generally not worth the trouble. The freewheel bearing gets the least wear of any on a bicycle, since it only turns when it is not carrying any load. Some people will ignore my advice and try to service freewheels (or have no choice).

SpeedsIn the 1980s, these two approaches were combined to create 7-speed freewheels, with 5 mm ("Ultra") spacing that would fit the same 126 mm hubs as "standard" 6-speeds. All recent freewheels and threaded hubs, regardless of where made, use ISO threading. The older British and Italian standards use the same thread pitch but a very slightly different thread diameter, and are generally interchangeable. However, for strong riders and on tandems, it is best not to mix and match -- freewheels sometimes do strip the threads of aluminium hubs. A French freewheel may start to thread onto an ISO/British/Italian hub but will soon bind. An ISO/British/Italian freewheel will skim the top of the threads of a French hub and will slip forward if an attempt is made to use it. Do not force a freewheel -- you will ruin the hub. Now you thoroughly clean all the parts of the freewheel mechanism. I (John Allen) use solvent followed by a strong solution of dishwashing detergent and a water rinse. I dry the parts afterward with paper towels to prevent rust. So my question is does this have a good chance of working or might there be problems? What pitfalls do I need to look out for? I made a spreadsheet of the gear ratios and they look very good. There is no large gap in the lowest 2 gear ratios and the middle gears that I mostly use are also very nicely spaced (between 11 and 14% gap). Although "Road" and "Mountain" hubs are no different as far as cassette fitting is concerned, they are different in terms of overall spacing. "Road" hubs generally use 130 mm spacing, while "mountain" hubs are 135 mm.

Standard spaced 6-speeds required increasing the frame spacing to 126 mm, aggravating the problems introduced with the move to 5-speed, but still providing satisfactory service in most cases.

Hyperglide cassettes are commonly sold as a unit There are dozens of different cassette combinations available. Most cassettes are designated by a one- or two-letter code. Dura-Ace 7800 and 7801 10-speed hubs (and Ultegra wheelsets) with the aluminum Freehub body and tall splines accept only Dura-Ace, Ultegra and 105 10-speed cassettes. For example, Shimano doesn't make any true "corncob" (one-tooth-jump) cassettes for time-trialists or flatland riders. In 7 speed, the closest is the J (13/14/15/16/17/19/21). But also, most Uniglide Freehubs can be updated by installing a Hyperglide ratchet body. This is an easy and inexpensive modification (see below.) A freewheel that has been ridden for a long time, especially by a strong rider with low gears, may be quite difficult to remove because the threads are so tight.While rear indexing is the same for all recent shifters/derailers, Shimano fronts use a different amount of cable pull for drop-bar vs flat-bar controls. Freewheel bodies have a larger diameter than the spoking flange of many hubs. Warning: loosen a freewheel before cutting the spokes to replace the rim, otherwise you may not be able to loosen the freewheel or to replace the spokes on the right side of the wheel. The barrel (between the flanges) of many hubs will break if you respoke only the left side and then try to unscrew the freewheel. FH-7850 and FH-7900 Dura-Ace bodies, which have returned to a splined attachment between Freehub body and hub shell, but it is larger than the usual one. It is similar but not interchangeable between these two models. Shimano information on the 7850; 7900.

Shimano wants you to use one of its standard combinations, and offers a wide-enough choice to suit the needs of most cyclists, but you don't have to if you don't want to! From the combination of widening the cog ratios (from 14-28 to 13-34) and widening the front chainrings (from 24,34,42 to 20,34,42), my potential spread of gears will go from 3.5 to about 5.5 which is about 57% wider range. The same procedure works for off-brand Freehubs that have a LH threaded fastener accessed from the LH side of the hub, too. It doesn't work with freehub bodies that screw directly into the hub shell. working on freewheel bodies is generally not worth the trouble. The freewheel gets the least wear of any bearing on a bicycle, since it only turns when it is not carrying a load.

How Many Speeds?

Replacement bodies are not available for these early hubs, which can sometimes be identified by the narrow barrel, without the characteristic bulge on the right end. (The bulge is to accommodate the threading for the hollow bolt used on newer Shimano Freehubs) See the photos below, kindly provided by David Landsberg. Shimano lists Freehub bodies as a separate part, or you could cannibalize a hub. Wheels with damaged rims and good hubs are not hard to find. Long-cage derailers have greater takeup capacity, and work with all types of cassettes. Long-cage derailers are commonly called "mountain" derailers currently, though in the past, this style of derailer was known as a "touring" derailer. (The marketeers retired the use of "touring" as a buzzword in the late '80s when mountain bikes became the hot item.)