Free Hub Sprockets

General cycling advice ( NOT technical ! )
Drake
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Free Hub Sprockets

Postby Drake » 1 Jul 2013, 8:25pm

I'm in the process of helping to finish building a single speed machine . We were going to use a rear wheel with a freewheel screw on hub,but we have since managed to get to s/h unused wheels with a freehub . Although there are plenty of single speed conversion kits on the market,they all seem to favour 16,17 and 18 teeth sprockets .
So the questions e would like help with are.

1. Can we purchase individual sprockets,(not in a kit). preferably 20,21 or 22th . Personally,i would favour 21th .
2. Can we purchase spacers separately .
3. And a lock ring to hold it all together .

Manythanks in advance .

p.s We have been told that the splines on this freehub are Shimano compatible,if that helps .

mig
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Re: Free Hub Sprockets

Postby mig » 1 Jul 2013, 8:58pm


Drake
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Joined: 19 Apr 2012, 9:01am

Re: Free Hub Sprockets

Postby Drake » 2 Jul 2013, 7:29am


Very manythanks for the info . We will give them a try .

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andrew_s
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Re: Free Hub Sprockets

Postby andrew_s » 2 Jul 2013, 2:55pm

Rose sell Shimano sprockets separately (list the cassettes section in cheapest first order).
However many of the larger sprockets come grouped with 2 or 3 sprockets on aluminium spiders, rather than loose, so what you want may not be available.
Velosolo looks the better bet, even if it does cost more.

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Redvee
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Re: Free Hub Sprockets

Postby Redvee » 3 Jul 2013, 12:13am

Shimano cassette sprockets might seem like a good idea but the teeth are shallower than the offerings from Velosolo. I used a cassette sprocket when I built a SS MTB but had to buy a proper sprocket after having the chain unship cause of the ramps and shallow tooth profile.

Brucey
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Re: Free Hub Sprockets

Postby Brucey » 3 Jul 2013, 6:31am

I think that if you are prepared to do a little grinding, you can fit a SA (or other IGH sprocket) to a freehub body.

For a bargain conversion, you can use a bunch of old cassette spacers and a cassette lockring.

Running a 1/8" chain with full rollers (such as a KMC S1, instead of a bushingless design) is very much the best route for a singlespeed.

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

Drake
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Re: Free Hub Sprockets

Postby Drake » 3 Jul 2013, 7:00am

Redvee wrote:Shimano cassette sprockets might seem like a good idea but the teeth are shallower than the offerings from Velosolo. I used a cassette sprocket when I built a SS MTB but had to buy a proper sprocket after having the chain unship cause of the ramps and shallow tooth profile.

Since posting this subject,i've been reading various articles on single speed conversions, particularly on mtb's fitted with Free Hubs . Although quite a few people have successfully used F/H sprockets, the general consensus seems to favour sprockets specifically made for this application .
I've no personal experience of the following,but it does appear that under riding conditions,if the F/H sprocket moves it can cause damage to the hub splines .
Purely by accident i came across this site,"Charlie the Bike Monger" . . (sorry,but i dont know how to create a link). Has anybody tried this supplier?

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Erudin
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Re: Free Hub Sprockets

Postby Erudin » 3 Jul 2013, 7:23am

Bought a KMC Z510 HX Chain and Dicta freewheel for my singlespeed from Charlie The Bikemonger last year, like the website and order was dispatched promptly and well packed.

Edit: Also got some free stickers :)
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Last edited by Erudin on 10 Jul 2013, 1:20pm, edited 1 time in total.

Brucey
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Re: Free Hub Sprockets

Postby Brucey » 3 Jul 2013, 8:17am

Drake wrote: ....I've no personal experience of the following,but it does appear that under riding conditions,if the F/H sprocket moves it can cause damage to the hub splines ....


that is true; the best method of avoiding this is to use metal spacers and to do the lockring up to the full torque spec. Since I have not yet seen the end of a freehub body break through an overtightened lockring, I have always assumed that they will take a fair bit more torque if necessary.

cheers
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Redvee
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Re: Free Hub Sprockets

Postby Redvee » 3 Jul 2013, 10:43am

Brucey wrote:
Drake wrote: ....I've no personal experience of the following,but it does appear that under riding conditions,if the F/H sprocket moves it can cause damage to the hub splines ....


that is true; the best method of avoiding this is to use metal spacers and to do the lockring up to the full torque spec. Since I have not yet seen the end of a freehub body break through an overtightened lockring, I have always assumed that they will take a fair bit more torque if necessary.

cheers


It isn't the side-side movement that causes the damage it is the sprocket 'rotating' on the freehub.

Image

The Velosolo sprockets have a wide footprint where it meets the freehub as do other SS sprockets.

Brucey
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Re: Free Hub Sprockets

Postby Brucey » 3 Jul 2013, 12:38pm

it may not matter how wide the interface is on a cassette hub; if the lockring isn't tight, the sprockets tend to wear into the cassette body; it might be slower if the interface is wider, that is all. Obviously this happens faster if the materials are not hard, also. With the lockring tight enough, the sprocket won't move in the same way in normal use.

BTW the traditional IGH sprocket interface uses what is arguably a better design (for use with a freewheel, anyway, and albeit generating additional radial loads in the assy) in that the harder you pedal, the less likely the sprocket is to move. I think that is why you can get away with a simple spring clip to hold the sprocket on an IGH.

The three lugs on an IGH sprocket must have to work rather hard, but they rarely appear even slightly worn, even when the sprocket teeth have clearly been to hell and back.

The straight splines of a cassette hub interface do not give the same self-tightening characteristic at all.

cheers
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Drake
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Re: Free Hub Sprockets

Postby Drake » 5 Jul 2013, 5:43am

Erudin wrote:Bought a KMC Z510 HX Chain and Dicta freewheel for my singlespeed from Charlie The Bikemonger last year, like the website and order was dispatched promptly and well packed.

Manythanks for the info,(i really must learn how to create a link).
Another question arises concerning a freehub lock ring tool . Are they all the same . . i.e, one size fits all . Our experience centres around freewheel hubs and i think we've got 3 or 4 different removal tools in our tool kit .
Just out of curiosity . . who designed the first freehub . My money is on Shimano,but one of our group thinks it was Campag .

Brucey
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Re: Free Hub Sprockets

Postby Brucey » 5 Jul 2013, 7:33am

an early freehub design was produced by Bayliss-Wiley, over seventy years ago. Other manufacturers produced something similar but no one system ever became very popular.

The first Japanese freehub was the suntour 'unit hub' (~1969).

Shimano resurrected the idea and produced versions for sale in ~1978, using a similar splined sprocket fitting to that in use to this day. A modern freehub will accept a 1978 model cassette sprocket. The first shimano freehubs did not secure the freehub body using a hollow steel bolt, but instead had a rather unsatisfactory extension to the hub body that acted as a large hollow rivet.

Campagnolo did not produce anything similar for about ten years, and when they did, they made the freewheel body ride on the axle, leaving the hub bearings with a narrow spacing and the axle with higher stresses than in the shimano design.

Arguably anyone fitting more than one sprocket to an SA three-speed gear is then using a 'unit freewheel hub' of some kind BTW...

cheers
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Drake
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Re: Free Hub Sprockets

Postby Drake » 5 Jul 2013, 7:20pm

Manythanks Brucey for the info . Just goes to prove that so called new innovations are sometimes a re-working of an old idea .