Cycling UK Forum

gxaustin wrote:I think Shimano brought in free hubs in 1987?.....

about a decade before that, in fact. It did take a while for them to become popular though.

I'll link to the relevant shimano catalogue if I get the chance.

http://www.retrobike.co.uk/gallery2/d/78852-1/Shimano+1978.pdf

Dura-Ace EX in 1978 had freehubs; not sure if they were the first for shimano or not.

cheers

I have a 17" wheel with a 28-hole 6-speed Dura-Ace freehub from 1981. 120mm spacing, and, rarer than hen's teeth back then, it takes an 11t sprocket. Nice.

about a decade before that, in fact. It did take a while for them to become popular though.

I have a 17" wheel with a 28-hole 6-speed Dura-Ace freehub from 1981.

Goodness - I wonder why they took so long to catch on?

I got my incorrect information by going back through old catalogues

1938 Bayliss Wiley unit hub, freewheel hub, using screw on cogs.


https://utahrandonneur.wordpress.com/20 ... -unit-hub/

gxaustin wrote:...Goodness - I wonder why they took so long to catch on?...

because shimano wasn't then the big player it is now and there was a perceived risk that it might be another 'here today gone tomorrow' technology, (like the Bayliss WIley decades before) whereas screw on freewheels looked like a safer bet; there was a vast choice available from several different manufacturers, including shimano, who continued to support freewheels in their quality kit because they knew not everyone would buy a cassette hub.

Even when Dura Ace 7400 came out many (most?) riders in the UK who bought the groupset opted for the freewheel + threaded hub option in the first couple of years. The full potential for 7s freewheels to be the straw that broke the camel's back (well, the camel's axle anyway) only became apparent later, and by that time shimano clearly were not going to pack it in with freehubs anytime soon.

I had my first shimano freehub in about 1987 on a MTB, and it worked pretty well. In about 1988 I 'jumped ship' on the road bike from campag hubs with suntour freewheels to shimano ultegra freehubs.

cheers

I had my first shimano freehub in about 1987 on a MTB,

I think I jumped to the wrong conclusion about the date because the freehubs may have just appeared in the main catalogue as distinct from the supplementary catalogue, that was posted above

I certainly prefer them, having wrestled with a recalcitrant Regina freewheel with those silly little nicks to locate the removal tool.

1980 catalogue here

http://www.velo-pages.com/main.php?g2_itemId=6945

freehubs and all

cheers

Shimano's early freehubs did not have the hollow bolt holding the freehub body in place. It was a close fit onto shallow splines on the hub and was prone to becoming detached.

Let's see if that's any better.

Mike Sales wrote:Shimano's early freehubs did not have the hollow bolt holding the freehub body in place. It was a close fit onto shallow splines on the hub and was prone to becoming detached.

in the less expensive models eg the 105 models at one point, and FH-6251 etc that was certainly the case.

https://si.shimano.com/api/publish/storage/pdf/en/ev/FH-6251_6261/EV-FH-6251_6261-0328G.pdf

However the FH-7250 model (the oldest I have seen, from 1978) the system is much like the later Dura-Ace, where the freehub body screws directly into the hubshell

https://si.shimano.com/api/publish/storage/pdf/en/ev/FH-7250_7260/EV-FH-7250_7260-0335D.pdf

The hollow bolt arrived with FH-1050 and FH-6208 in road stuff, and earlier than that in MTB stuff perhaps.

cheers

The trick with freewheels was to tighten the locknut really hard against the cone. If you were lucky, putting the spacer(s) into hard compression prevented the axle from bending.

7400 was a very pretty groupset, and quite long-lived in production. I still use the cranks and BB.

rogerzilla wrote:The trick with freewheels was to tighten the locknut really hard against the cone. If you were lucky, putting the spacer(s) into hard compression prevented the axle from bending....

This makes no sense; the axle flexes and breaks beyond the cone, so messing about with the locknuts etc makes no difference, not to this anyway.

cheers

Brucey wrote:

rogerzilla wrote:The trick with freewheels was to tighten the locknut really hard against the cone. If you were lucky, putting the spacer(s) into hard compression prevented the axle from bending....

This makes no sense; the axle flexes and breaks beyond the cone, so messing about with the locknuts etc makes no difference, not to this anyway.

cheers

The axle always bends between the cone and the dropout. If there is a rigid metal sleeve around the axle between these two points, it reinforces the axle substantially. If the locknut isn't tight against the cone, the spacers can move and the reinforcement is ineffective.

A rookie error when reassembling a hub is to fit the spacers loose, on top of the locknut rather than under it. Besides falling off when you take the wheel out, they then do nothing to strengthen the axle and it will probably bend soon.

rogerzilla wrote:The axle always bends between the cone and the dropout....

no, it doesn't. Look again.

I have bent and broken about a dozen axles personally and in addition I have seen literally hundreds of others. The damage is invariably just to the left of the RH cone, even if the spacer/locknut are not especially strong ones. Unless something highly unusual has happened the RH end of the axle is still straight when the repair is undertaken.

BITD it was common practice not to bother tightening the spacer assembly to the right of the RH locknut more than finger tight. The logic was that this allowed the freewheel to be removed more easily (many removers required removal of this spacer) and it otherwise made no difference whatsoever; once the wheel was secured in the frame, the clamping loads (from QR or track nut, it made little difference) should pass through the spacers etc and be reacted against the RH cone. Even when the dropouts are vertical and the clamping load isn't necessarily that high, the stresses are still highest to the left of the RH cone.

The idea that whatever preload you might apply to a cheesy locknut (e.g. in soft steel ~3mm thickness) might contribute significantly to the preload in the axle is not reasonable. Nor is the idea that it might achieve anything useful anyway. Lastly, the axle is unlikely to want to bend there anyway; the highest service stresses are always elsewhere.

If you are considering hubs with shouldered axles and cartridge bearings things might be different, but in cup and cone hubs what you describe bears little relation to reality.

cheers

Had you not been so insistent Brucey, I'd have sided with Rogerzilla. I too have seen more bent axles than I care to number but I think you are correct for three reasons.

Firstly, I've never had any trouble removing the cones from said bent axles; if the axle had been bent beyond the cone this would have been nigh on impossible.

Secondly, the inner cone edge is the obvious pivot point. If I think of a the races and bearings without the axle in place, this assembly is a very effective longitudinal (is that the right word?) pivot

Thirdly, said bent axles almost always damage the cone races, if the bend were beyond the cone, the races would be less affected

As they say, you learn something every day