IRD freewheel Dissection

For discussions about bikes and equipment.
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: IRD freewheel Dissection

Postby Brucey » 5 Nov 2020, 10:42pm

14-16-18-21-24-28-32 is an appealing set of sprockets for touring. I note with interest that there are various options for obtaining a 32T sprocket including

-stripping an older shimano HG megarange freewheel (current ones have a riveted cluster and the large sprocket cannot easily be fitted to another body)

- stripping an even older shimano UG freewheel for a 32T sprocket

- buying an IRD 32T sprocket (£5.99)

- buying a cheap new freewheel mainly for its 32T sprocket.

I note with interest that SJS are selling a cheap 14-32T 7s freewheel at present (£10). However it has 14-16-18-20-22-24-32 ratios. It also uses a Falcon type remover, which (although I don't know for sure) suggests that the sprockets will be made like falcon ones too; these have a shimano HG type spline, but the exact dimensions vary slightly. IIRC it is such that the other bodies will accept falcon sprockets but falcon bodies need a slight modification (or the sprockets do) to fit other sprockets .

Anyway once you have a 32T sprocket most users are unlikely to wear it out, meaning that it can perhaps be re-used in several freewheel rebuilds, based perhaps on a much less expensive freewheel (eg a sun race one). In an ideal world something like a sunrace 14-28 6s freewheel can perhaps be rebuilt as a 7s freewheel and fitted with the 32T sprocket....?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Brucey
Posts: 42167
Joined: 4 Jan 2012, 6:25pm

Re: IRD freewheel Dissection

Postby Brucey » 5 Nov 2020, 11:20pm

funny ratio choices by IRD in 13-32T

5s 13-32T: 13 / 16 / 20 / 24 / 32

6s - 13-32T: 13 / 16 / 20 / 24 / 28 / 32

7s Cyclone - 13-32T: 13 / 15 / 17 / 21 / 24 / 28 / 32

7s classica - 13-32T = 13 / 15 / 18 / 21 / 24 / 28 / 32

17-21-24 is a very odd combination to have in the 7s cyclone....?

Image

in 6s I'd vote for 13-15-17-20-26-32

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

thirdcrank
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Joined: 9 Jan 2007, 2:44pm

Re: IRD freewheel Dissection

Postby thirdcrank » 6 Nov 2020, 7:08am

cycle tramp

Have you a reason to spend good money on sourcing 5 speed freewheels?

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: IRD freewheel Dissection

Postby Brucey » 6 Nov 2020, 7:41am

I don't know if this applies to cycle tramp but there are several possible motivations for using a screw-on freewheel. For example;

1) simplicity/repairability; wherever you go, you will probably be able to find a screw-on freewheel of some kind, whereas with a cassette hub you might end up needing a new wheel in the event of a freewheel mechanism failure; there are so many variations in freehub body design and fitment.

2) running costs; in utility use, especially if you don't need many gear ratios, running screw-on freewheels can work out a fair bit less expensive than running cassettes. Obviously this doesn't necessarily apply if you are buying expensive IRD freewheels

3) Brakes; if you want to use specific hub brakes and derailleur gearing some of these setups are most practical if they are accompanied by a screw-on freewheel rather than a cassette type hub.

4) using vintage equipment. If you want to use your nice vintage Campag record hubs etc then you need a screw-on freewheel.

5) running dishless rear wheels; this effectively means having fewer sprockets than is currently fashionable or making the rear hub ever wider. Since shimano have more or less given up supplying 7s freehub bodies, narrower cassette setups are less easily achieved.

Maybe there are others too.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

tatanab
Posts: 4328
Joined: 8 Feb 2007, 12:37pm

Re: IRD freewheel Dissection

Postby tatanab » 6 Nov 2020, 7:48am

Brucey wrote:4) using vintage equipment. If you want to use your nice vintage Campag record hubs etc then you need a screw-on freewheel.
About 3 years ago I wanted a good quality freewheel to go on a 1956 frame I was renovating. I bought an IRD but did not use it because it would not screw onto my virtually irreplaceable hub (not Campag or any common brand). Shimano and Maillard all screwed on just fine, but the IRD thread was extremely tight and would have been damaging to the hub. I returned it to SJS and got another which was better but still over tight. I sold that one very cheaply at a jumble sale with a warning about being tight. Fortunately I had a Maillard body and some sprockets that I had saved for another project, so use that instead.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: IRD freewheel Dissection

Postby Brucey » 6 Nov 2020, 8:13am

that is interesting about the freewheel threads. Was it a Defiant, Classica or Cyclone model that you had problems with?

I found this photo of a 'cyclone' body which is interesting;

Image

you can see the way the timing spline is done; the 'solid lump' (which is quite unlike other 'modified UG/HG freewheel splines) means that unless there are modifications, only IRD sprockets will fit onto an IRD body. However IRD sprockets will also fit some other bodies (provided the other dimensions of the spline are compatible).

The body above is listed as being appropriate for 5s, 6s, and 7s uses. It isn't clear to me how many of the sprockets fit to the larger spline in each build. However if it is like others it might be three large spline sprockets for 5s, 6s, but it might be different for 7s (where the sprockets are more closely spaced).

It is great to have more choice in freewheels, but if you want something other than a 13T top sprocket, an ITD cyclone won't do.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

tatanab
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Joined: 8 Feb 2007, 12:37pm

Re: IRD freewheel Dissection

Postby tatanab » 6 Nov 2020, 8:40am

Brucey wrote:that is interesting about the freewheel threads. Was it a Defiant, Classica or Cyclone model that you had problems with?
Through the marvels of the internet was able to see past orders. In Feb 2016 I ordered a 6 speed Classica

cycle tramp
Posts: 995
Joined: 5 Aug 2009, 7:22pm

Re: IRD freewheel Dissection

Postby cycle tramp » 6 Nov 2020, 10:18am

thirdcrank wrote:cycle tramp

Have you a reason to spend good money on sourcing 5 speed freewheels?


It's most of what Brucey's already written.. I use a rear drum brake, with a threaded freewheel fitting, which limits me to using freewheels. To build a stronger rear wheel, the existing spacing for a 7 speed freewheel was rejected. This allowed me to move the whole axle and hub to the right allowing for a stronger wheel to be built.
I've stopped being a touring cyclist some time after 2016 - and reverted to being a utility cyclist. Which meant that having gears and brakes which could cope with any and every situation was irrelevant, but having a mechanically simple bike which could avoid being stolen, could work despite some level of neglect, and could be easy to repair became more important. Equally against a back drop where many bike shops are now not carrying the most basic of stock it also made sense that any consumables (freewheels, chains) could be bought and stored in my shed without too much investment.
I had tried hub gears, firstly the nu-Vinci hub and then a SA 3 speed. I was thinking about a shimano 7 or 8 speed hub, but the frame I was using didn't have disk fittings, and the rear drop out shape could foul the brake arm, and having tried a roller brake in the past I wasn't impressed with its performance (and that's me saying this using a 70 mm drum brake). Further more a freewheel is a very simple device, especially when operated by a deraileur controlled by a friction shifter - if it any part stops working it's a 20 minute job to remove and replace it with a nice new part.
Would I change from a five speed if I returned to touring? Depends on the type of touring - if I was by myself and rode for my own pleasure, then probably not. If I toured with a mixed group then I'd possibly change the single chain ring to a double, and if I toured fully loaded, then I'd consider fitting a triple chainset and definitely an out rigger bearing just inside of the freewheel.

thirdcrank
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Re: IRD freewheel Dissection

Postby thirdcrank » 6 Nov 2020, 10:35am

Thanks for that.

For utility purposes, I suppose a lot still depends on terrain. It's pretty hilly round here - flat as a billiard table compared with Cornwall of course - and I found a Nexus 7 + coaster brake ideal, even though 5th was unreliable.

amediasatex
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Joined: 2 Nov 2015, 12:51pm
Location: Sunny Devon! just East of the Moor

Re: IRD freewheel Dissection

Postby amediasatex » 6 Nov 2020, 12:00pm

Cycle Tramp, I have some old NOS (Shimano and Suntour I think...) freewheels in a box in the loft, various 5,6 and 7 speed, I have a feeling at least one of the 5 speed ones is a 14-32, I'll dig it out later if you might be interested?

cycle tramp
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Joined: 5 Aug 2009, 7:22pm

Re: IRD freewheel Dissection

Postby cycle tramp » 6 Nov 2020, 1:07pm

thirdcrank wrote:Thanks for that.

For utility purposes, I suppose a lot still depends on terrain. It's pretty hilly round here - flat as a billiard table compared with Cornwall of course - and I found a Nexus 7 + coaster brake ideal, even though 5th was unreliable.


Sounds like a good rear hub I really like coaster brakes.

Absolutely... I live in the middle of the Somerset levels have have to ride for some 20 to 45 minutes to find a hill of any decent height. Within this flat plateau I've got the towns of Burnham on Sea, Glastonbury, Wells and Cheddar. I don't have to cycle up any major hill to or from my ultility routes and I've got a myriad of lanes to cycle in.

Speaking personally as a utility cyclist and someone who rides for pleasure I'm also completely free of the expectation that i should cycle up any hill I encounter, or pedal down a hill. If you let go of the idea that somehow you are less of a cyclist if you walk up hills, you suddenly become less worried about what gears you have.

If I ever return to group riding, it's going to be a shock because I'm going to lose part of this freedom that this style of cycling affords me- the chance simply to stop and properly enjoy the view, or to listen to a stream, or even to completely stop for half an hour in some sunny meadow, break out a book, or watch the clouds.
Each cycling activity I've ever encountered seems to make you race from the start to the finish line and we've got so used to evaluating cycling technology against this purpose, that we've almost forgotten that the bicycle is just a tool - a happy method by which to escape the confines of our abodes and send us out into the world.

Brucey
Posts: 42167
Joined: 4 Jan 2012, 6:25pm

Re: IRD freewheel Dissection

Postby Brucey » 6 Nov 2020, 10:37pm

tatanab wrote:
Brucey wrote:that is interesting about the freewheel threads. Was it a Defiant, Classica or Cyclone model that you had problems with?
Through the marvels of the internet was able to see past orders. In Feb 2016 I ordered a 6 speed Classica


Q would you have known if you had been sent a Defiant instead? Is there any difference in the appearance in fact?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

mig
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Joined: 19 Oct 2011, 9:39pm

Re: IRD freewheel Dissection

Postby mig » 6 Nov 2020, 10:47pm

cycle tramp wrote:
If I ever return to group riding, it's going to be a shock because I'm going to lose part of this freedom that this style of cycling affords me- the chance simply to stop and properly enjoy the view, or to listen to a stream, or even to completely stop for half an hour in some sunny meadow, break out a book, or watch the clouds.
Each cycling activity I've ever encountered seems to make you race from the start to the finish line and we've got so used to evaluating cycling technology against this purpose, that we've almost forgotten that the bicycle is just a tool - a happy method by which to escape the confines of our abodes and send us out into the world.


great post.

Carlton green
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Joined: 22 Jun 2019, 12:27pm

Re: IRD freewheel Dissection

Postby Carlton green » 7 Nov 2020, 8:32am

cycle tramp wrote:
Speaking personally as a utility cyclist and someone who rides for pleasure I'm also completely free of the expectation that i should cycle up any hill I encounter, or pedal down a hill. If you let go of the idea that somehow you are less of a cyclist if you walk up hills, you suddenly become less worried about what gears you have.

If I ever return to group riding, it's going to be a shock because I'm going to lose part of this freedom that this style of cycling affords me- the chance simply to stop and properly enjoy the view, or to listen to a stream, or even to completely stop for half an hour in some sunny meadow, break out a book, or watch the clouds.

Each cycling activity I've ever encountered seems to make you race from the start to the finish line and we've got so used to evaluating cycling technology against this purpose, that we've almost forgotten that the bicycle is just a tool - a happy method by which to escape the confines of our abodes and send us out into the world.


The above must surely rank amongst the best and most sensible comments to have ever been posted on this forum.

Amongst the best cycling that I’ve ever had has been either by myself or with likeminded people who actually understand that before all else : “the bicycle is just a tool - a happy method by which to escape the confines of our abodes and send us out into the world.”

I would fully concur that once you have freed yourself from expectations with regard to hills and distance and speed then you can, in its use as a transport tool, better enjoy cycling. Unfortunately it’s not an easy idea to get ones head around, goes against a lot of what we have been ‘taught’ and is in opposition to the prevailing culture. Of course there are times when the distance you cover and the time that you do it are important, when cycling is essentially for necessary transport and not really for recreation - we find ways to enjoy cycle commuting but those rides are for business rather than pleasure.

Whilst they are not everybody’s ideal I’m all for the simplest of bikes; at one time I used to ride a wide ratio five speed derailleur geared bike - I covered a lot of miles on that arrangement and it’s a pity that such blocks/gearing are effectively no longer available. Earlier in this year I fitted one of my bikes with a three speed hub gear, my top gear (select your preferred gearing with care) is a little above 60” and I tap along happily on that bike. I freewheel down slopes, spin comfortably along the level, climb the inclines and if necessary walk the last section of the occasional ‘stiffer’ hill. It’s simple, it’s reliable and it works - a very effective part of the bicycle as a tool for the job (“a happy method by which to escape the confines of our abodes and send us out into the world“).

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: IRD freewheel Dissection

Postby Brucey » 7 Nov 2020, 9:21am

the way I look at it, when on two feet you can "go for a stroll" or "go for a run". The only thing common between these two activities is that you are on your own two feet. You can ride a bike in similarly disparate ways.

Mr Pedersen (of bicycle fame) was quite clear about why his bike was like it was; "like walking, but faster" was his objective. Much as they always have done, the particular needs of racing (both on and off road) drive equipment development in particular directions. Needless to say this is at best of limited benefit or even counterproductive in relation to many other cycling activities.

This means that with every new generation of equipment both manufacturers and users alike try and make best use of these designs for other applications which have different priorities altogether. So it is easy enough to lose sight of the fact that you don't need a confection of fancy materials with a million gears and a million and one electronic gizmos attached to it if you just want to "go for a bike ride". Something simpler might do; indeed something simpler might be better.

Speaking as someone who has done very large mileages on various bikes most of which have an unfashionably small numbers of gears etc I guess I have long thought this way.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~