Thirty Years with a Sturmey Gear.

[hubgearfreak]

[quote="breakwellmz"How much of it is weight,and how much is it efficiency?[/quote]

i converted my '50s RRA from AW to a single speed. it was a brief experiment and i soon went back to 3 gears, but this time an AM. i can't tell if there's a difference in efficiency, but having a gear c. 10" up and down from direct drive is invaluable on gradients and headwinds.

the only nexus bikes i'v tried have been awful, but then i suspect they'd be awful bikes whatever the transmission.

the only way to really know for yourself is to try an SA hub in both your bikes. my experience is that an AW will improve both considerably.

[breakwellmz]

Hi.

Interesting.

IF i had a more scientific mind i could get my head around the EFFECT of all the variables-weight,rolling resistance,transmission efficiency,gradient,wheelbase(?)etc

However,i doubt that an AW is THAT much more efficient than a NEXUS 7,that 3 wide ratios would make life easier that 7 evenly spaced ones.

Cheers.

[hubgearfreak]

i doubt that an AW is THAT much more efficient than a NEXUS 7

if 'doubt' is good enough, that's fine.

[Brucey]

Living in Bath there are no shortage of climbs!

`Lightweight`is 80s Raleigh 531 roadbike on 25mm Bontrager Racelights.Weight 18 pounds.Single 63"gear.
Wheelbase is 70cm less than `heavyweight`

How much of it is weight,and how much is it efficiency?

Cheers.

the tyres and wheels will make big difference to the 'feel' of the bike especially when climbing out of the saddle; if wider tyres are not pumped up very hard then they will distort and be less efficient when you are pedalling very hard indeed. The raleigh will be as about responsive and efficient as you wil find anywhere (it bears comparison with a bike I used to hillclimb on), so almost anything else will feel heavier and 'worse'.

I used to visit Bath on the weekend and a few times I took my fixed gear bike, just because it had mudguards that I had rigged to come off easily so it went in the car without trouble. I found it 'challenging' on fixed even when I was roaring fit. I think it would kill me these days. I don't know which was worse actually, riding up climbs like the one running North towards Chippenham, or coming back down again, doing about 150rpm for mile after mile.

I'd suggest trying a hub gear in your Raleigh as an experiment; you might like it. You can get a fixed hub gear which may be of interest, but there is some rather than none in the way of backlash, so trackstands are not like fixed gear trackstands.

It is always interesting to ride out of the saddle in the bottom gear on a hub gear; the SA 3 & 5 hubs typically have little in the way of 'wind-up' but others with more extensive gear trains often feel a little mushy in the lower gears. I'm not sure this mushyness itself causes inefficiency, but it is a sign of a more complex multi-stage gear train that might be less efficient.

cheers

[Brucey]

Sheldon Brown's entry on SA makes interesting reading:

...Back in the day, sometimes a batch of internal parts would be just a bit out of tolerance, maybe a bit too small, or a bit too large, whatever. The production people would take a sample to the engineering department, where a grey-haired engineer would check it out and often say "Well, it is a bit out of spec, but not really enough to cause failure, so let's let it go."
SunRace didn't have those engineers who had grown up with Sturmey-Archer in their blood, so when they found a batch of out-of-spec parts, they would say "That's out of spec! Melt it down, and make new ones, and do it right this time!"
In any case, the quality of Taiwanese production from SunRace/Sturmey-Archer so far has been excellent, generally better than the quality of later English production.....

Rules, it has been said, are 'for the obedience of fools and the guidance of wise men'. What is described there above is a concession; an engineering-based decision, for which you need a suitably wise man. Decisions of this sort are made all the time in engineering, in very many industries, some of which would surprise you.

A lot of businesses these days go out of their way to avoid having to have 'wise men' on their staff. They are -according to people with MBAs and other such fluff- often 'difficult to manage' etc. and when businesses are 'streamlined' or 'rationalised' or any one of the hundred other euphemisms that they use, the wise men are often the first to go. Obedient fools are so much more easy to manage; they will try their best to make sure that whatever they make meets the dwg, even if the dwg is wrong...

I don't know what SR/SA do for wise men these days. I do wonder at their decision to retain the -from my experience- more troublesome version of the recent five speed hub architecture, with the apparently breakable and slippage-prone sliding key for sun pinion locking.

I don't know if it is just coincidence or not, but I have seen several warped SA hub brakes with aluminium shells recently, and they have been SA stuff from Taiwan, not UK made. Most other SR/SA stuff has looked OK to me, but quality wise, I'm not taking anything for granted. Sheldon's pre-emptive 'racism' strike at any doubters is a cheap shot BTW.

cheers

[breakwellmz]

i doubt that an AW is THAT much more efficient than a NEXUS 7

if 'doubt' is good enough, that's fine.

Hi.

I REALLY don`t know what that`s meant to mean

[breakwellmz]

Living in Bath there are no shortage of climbs!

`Lightweight`is 80s Raleigh 531 roadbike on 25mm Bontrager Racelights.Weight 18 pounds.Single 63"gear.
Wheelbase is 70cm less than `heavyweight`

How much of it is weight,and how much is it efficiency?

Cheers.

the tyres and wheels will make big difference to the 'feel' of the bike especially when climbing out of the saddle; if wider tyres are not pumped up very hard then they will distort and be less efficient when you are pedalling very hard indeed. The raleigh will be as about responsive and efficient as you wil find anywhere (it bears comparison with a bike I used to hillclimb on), so almost anything else will feel heavier and 'worse'.

I used to visit Bath on the weekend and a few times I took my fixed gear bike, just because it had mudguards that I had rigged to come off easily so it went in the car without trouble. I found it 'challenging' on fixed even when I was roaring fit. I think it would kill me these days. I don't know which was worse actually, riding up climbs like the one running North towards Chippenham, or coming back down again, doing about 150rpm for mile after mile.

I'd suggest trying a hub gear in your Raleigh as an experiment; you might like it. You can get a fixed hub gear which may be of interest, but there is some rather than none in the way of backlash, so trackstands are not like fixed gear trackstands.

It is always interesting to ride out of the saddle in the bottom gear on a hub gear; the SA 3 & 5 hubs typically have little in the way of 'wind-up' but others with more extensive gear trains often feel a little mushy in the lower gears. I'm not sure this mushyness itself causes inefficiency, but it is a sign of a more complex multi-stage gear train that might be less efficient.

cheers

Morning Brucey.

I suppose i need to have the variables QUANTIFIED,or am i being too scientific?(Pedantic?)
For example,what effect does a 70mm difference in wheelbase make,a 10 pound weight difference etc?

Mushyness? Wind-up? Not sure about those either?

Your last comment SUGGESTS the Nexus is less efficient than the SA5,i think?

I won`t be going down the fixed gear route.Been there,done that.In fact my longest day ride was on fixed-135 miles.A few years ago now!

Cheers mate.

[Brucey]

I don't know for sure that the Nexus is any less efficient than the (say) SA5 but I suspect it for the reasons I have said.

As for the rest of it; maybe the final comment in my most recent post in the chainstay thread pertains...?

I guess you have to try stuff out and see what works for you when all is said and done; I can relate my observations in as objective a fashion as I can manage, but when all is said and done, they are still just my observations; yours may differ!

cheers

[ambodach]

Russcoles mentioned immersing a neglected hub in oil for a while. The advice I was given by a local handyman was to fill the hub as far as possible with WD40 and rotate the wheel every day for a week or so then empty the WD40 out and replace with oil. I have so far resurrected 2 hubs this way.The suggestion was that previous owners had been using 3 in 1 oil which leaves a deposit when the volatile component evaporates. This forms a sticky gunge which the WD40 dissolves and thus frees up the whole thing again.

[tyred]

Never use 3 in 1 in an SA hub.

[Brucey]

Never use 3 in 1 in an SA hub.

I think it might be OK -or at least better than nothing- if you don't stop adding it on a regular basis; wherever it dries it can form a gunge. If it leaks out of the hub and dries on the outside it helps to stop the hub from going rusty. If it dries inside the hub it is a disaster.

I don't think 3 in 1 is the best lubricant for a hub gear even if it doesn't dry out/turn to gunge; proper gear oil has all kinds of additives in it which make it a better lubricant under intense pressures etc. My SA5 has run on EP90 gear oil for years, but now I'm experimenting with other lubricants.

cheers

[breakwellmz]

Me

"`Lightweight`is 80s Raleigh 531 roadbike on 25mm Bontrager Racelights.Weight 18 pounds.Single 63"gear.
Wheelbase is 70cm less than `heavyweight`"
How much of it is weight,and how much is it efficiency?

Brucey

"The raleigh will be as about responsive and efficient as you wil find anywhere (it bears comparison with a bike I used to hillclimb on), so almost anything else will feel heavier and 'worse'."


I went out on the rebuilt lightweight for the first time `properly`yesterday on a mainly undulating 40 mile ride,with a few hills thrown in.

WOW!

I`d forgotten how lovely it is to ride!

Actually,it`s better than i remembered,due to the serviced hubs,new bottom bracket,improved brakes etc.Despite that skinny looking 1" top tube.

I DO want some gears on it though,to `broaden it`s range,so to speak.

However,i am going to `cop out`and do it the cheap and easy way,by putting a 13 to 28 seven speed cassette on the rear(Which i already have,along with a rear mech and control)with a 40 tooth front chainwheel.

Sorry Brucey!


That`s IF i can get on with a`derail-her` after such a long break!

Note to self-Remember to keep pedalling when changing gear AND that i can`t change gear when stationary!

Cheers.

[robc02]

I've got one of the later 5 speeds - the type with a LH togglechain rather than a bellcrank. I can vouch for the fact that they can slip in bottom gear! Mine did so but, admittedly, on steep climbs and with very low gearing - 3rd gear, direct drive, is 32x17. Changing the axle/sun gear/spring assembly for an updated type has, so far, solved the problem but I agree with Brucey's comments about the shortcomings of the design compared to the bellcrank method.

My "normal" gear is 4th - around 63inches and 5th about 76inches. This arose as a result of the need for me to get a low enough (or so I thought!) bottom gear for Lon Las Cymru last summer, but it has turned out to be quite good, giving 4th and 5th as fairly close gears for gently undulating roads. Of course, this arrangement forgoes a gear for fast downhills.

Here's the bike as set up for Lon Las Cymru:


Tourer1 by SturmeyRob, on Flickr

[breakwellmz]

Hi.

I like the look of that!

I clicked on it as i usually do to take a closer look,and was refused

63" is what i have been used to on my single speed.

I`ve not seen an SA5 with anything but a toggle chain control.

Cheers.

[Brucey]

I've got one of the later 5 speeds - the type with a LH togglechain rather than a bellcrank.

That looks rather nice, a far better exemplar than my scruffy heap!

Maybe I'm not seeing all the pictures, but what shifters are you using BTW?

cheers