Threaded type rear hub gears

gordone6

Finding my (electric) wheels
Jun 4, 2009
6
0
Hi,
I have a Powacycle Salisbury that has a 6 speed Shimano old fashioned threaded rear hub gears as opposed to the newer cassette type gears.
I recently did the C2C and Reivers route which had some steep inclines and god downhill sections, although the bike was great I found I could have done with a greater range of gears higher and lower for the ups and downs, is there a way to give me a lower gear for hill climbing (Hartside- Pennines) and a higher gear for the downhills? Ss I was limited to around 20mph with the electric assist off as my legs would not turn any faster on the flat and downhill and up the steep inclines me and the electric assist needed a lower gear.
Gordon
 

Straylight

Esteemed Pedelecer
Jan 31, 2009
650
2
I to have been looking for a bit more top end gearage, after a lot of trawling, the best solution was to order myself a bigger front chainring. It should be arriving soon and is a 53tooth as apposed to the original 48. My wisper came with a shimano megarange screw-on freewheel gear set, and I have never found myself using 1st, so I don't think the hill climbing will be comprimised by the bigger front cog.

It seems that the smallest sprocket available for the rear gearset, in the screw-on variety is a 13tooth model made by suntour, and as this would be such a small incremental change from my megarange's 14 tooth, I didn't see the point. Sad, but shimano did at one time make a version of the megarange freewheel that went down to 11tooth, but no longer.

I did look into wether it was possible to convert a threaded hub to be able to take a cassette, as there are far more possibilities with this type of gear, but didn't find an obvious path to do so. Hence have opted for the larger chainring.

I found this page very useful for seeing the effects of changes to my gear set up:Sheldon Brown's Bicycle Gear Calculator

BTW, when searching the net for information, use terms such as "freewheel" & "screw on", but not "hub" as this will lead you down the wrong path altogether :) You might well find that the "shimano megarange" is what you're looking for, don't know if they do a six speed version though, so it might involve a new gear shifter in order to use it.
 
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Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
Gordon,

That sounds like a "freewheel" instead of a cassette gear cluster. What range is it at the moment?

A popular version of the 6 speed is 14-28 Teeth. I think the biggest range you will find easily available is 13-34 T.

Nick
 

Mussels

Esteemed Pedelecer
Jun 17, 2008
3,207
8
Crowborough
There's always an answer if you have enough money but that will probably be quite a lot of money.
If the range is too high or low then you can change the chainring but that won't increase the range. You might get a slight improvement in gear range by changing the freewheel but that might require a new rear derailer, new chainring or even frame modifications.
 

frank9755

Esteemed Pedelecer
May 19, 2007
1,228
2
London
Yes to more lower gears; not (easily) any more to higher gears.

Not the first time that this has come up as the Powacycle gear range could do with an extra gear at either end.

You can replace the rear freewheel (which i recall is a 14-28) with a 14-32 megarange. One of those would add a good climbing gear. You'd need to change the rear mech too, but that is not too hard.

Shimano used to make 13-32 and even 11-32, but they stopped doing them last year. They would have been even better as they would have added an extra gear or two at the top end. Alternatively you would need to try to add a larger chainring. A standard chainring would mess up your pedelec sensor so it would most likely involve bolting it to the existing one, and would lose some of your low gears.

Your best bet is to see if you can find an 11- or 13-32 freewheel on ebay or elsewhere. I did see one a few weeks ago in the for sale section of the CTC forum - but may be gone now. NB If you find a 7-speed one with the gears you need, I would snap it up. You would need to change your shifter but that is not hard.

PS - crossed with three other answers!
 
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Danny-K

Esteemed Pedelecer
Aug 25, 2008
281
0
South West
6 SPEED SHIMANO CADET MEGARANGE FREEWHEEL 13-34

They're still available brand new (just checked) from Edinburgh Cycles. In fact they've gone down in price! Last year I paid £9.95 - this year they're about 20p less. I did post on here at the time they were available - I called in at one of their branches but they're big in online ordering if there isn't one nearby (I was visiting relatives at the time so it all went together like two-birds-one-stone thing).

Theirs is the Shimano Cadet Megarange 13t (Only a one tooth increment increase for speed) to a massive 34t hill climbing gear. How about that then?

Here's the link to the web page - in stock as I post this = Shimano Cadet Freewheel (£9.74)




P.S. At the time of my purchase I had a lot of trouble finding these freewheels. Chatting to the lad at the counter, he checked on his computer and said they had another 30 or so coming in that week, there was no problem in getting them and that they'd heard that due to demand from 'some quarters' Shimano had restarted production of them - I said the 'some quarters' were us: e-bikers! I told the lad at the time it might pay them to place one of those side ads on this forum.
 
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Tiberius

Esteemed Pedelecer
Nov 9, 2007
919
1
Somerset
Thanks Danny,

That sounds like the one I got (not near the workshop right now so can't check).

If you are starting from the likely 14-28 T, then a 13-34 T will give 7.7% increase in the top gear and a 21% decrease in the bottom gear.

You will probably have to put three extra links in the chain to cope with the bottom gear and then hope the derailleur mechanism has enough movement to take up the slack in top gear.

Nick
 

Danny-K

Esteemed Pedelecer
Aug 25, 2008
281
0
South West
...You will probably have to put three extra links in the chain to cope with the bottom gear and then hope the derailleur mechanism has enough movement to take up the slack in top gear.

Nick
The derailleur fitted to the Salisbury is not up to the job for this range. In fact I found it a very poor mechanism as it stands regardless - the worst I've ever experienced. As mentioned above select a wide-range derailleur.
 
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flecc

Member
Oct 25, 2006
52,763
30,349
Virtually all hub motor e-bikes use multi-sprocket freewheels Gordon, they cannot be designed to use a cassette. The reason is that a cassette cannot accept the larger diameter spindle necessary on hub motors which have the electrical cables running through the spindle.

The cheap 6 speed 13 - 34 tooth Megarange from Shimano is the one I use on both my e-bikes and it's quite long lasting.
.
 
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gordone6

Finding my (electric) wheels
Jun 4, 2009
6
0
13-34

Hi all,
Thanks for the replies and info, going to give a 13-34T a try, have looked on the internet for a 11-34T but with no luck, if they did exist they seem to be now extinct.
Gordon
 

frank9755

Esteemed Pedelecer
May 19, 2007
1,228
2
London
Well done to Danny for finding a supplier of those 13T ones. It is only 1 tooth but it will give you that higher gear that the Powacycle is crying out for, as well as the climbing gear (that it is also crying out for!)

If I were you, given they are pretty cheap, I would buy a spare, just in case theyre not around in a year or two when you might want another one!

I have an 11-34 7 speed one on my hybrid / kit bike and combined with the triple chainring, it does give an amazing gear range but, as you say, they seem to be no more.