Bicycle Mechanics - Upgrading a three speed hub ...
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10-11-08, 01:45 PM
OK, so my wife has what I think is called a three speed utility bike. In England we'd probably call it "Junk" :) It's a Sturmey Archer three speed hub probably 20+ years old. Having been doing bike mechanics for over a week now, hooray, I'm considering upgrading the bike to having straight handle bars and derailleur gears. More fool me perhaps! Having looked at the back end there seems to be nothing to hand a derailleur off. I just see a dropout for a hub wheel and bits for a bike rack. Do I have any option in upgrading?
10-11-08, 01:53 PM
If the terrain is flat and the bike is going to be used for utilitarian and recreational riding that 3 speed should serve you really well...if the stock gearing a little high you can increase the size of the rear cog.
If you want a derailer and multiple gears it will need to use a separate hanger.
10-11-08, 02:12 PM
You can get the old style axle clamped retention style hangers. Or there are the low end Shimano derailleurs that come with an arm that fits into the dropout slot rather than screwing into a dedicated hanger. The separate types have a small screw to retain them when the wheel is off but rely on the clamping action of the axle to provide the full retention force. And they look like this.....
Look at the third picture under the topic "Adapter claw".
Depending on the quality level of the bike you may be pouring good money after bad unless you're doing this with existing parts or shopping around for cheap deals in new or used.
Also there's a rather strong following for the old SA 3 speed stuff when used on bikes that are intended for casual riding. You'll also soon find that there's not much support for flat mountain bike style bars for casual riding as well. For many folks the bars put their wrists into the wrong position if you're not bent forward and elbows out in a typical mountain bike racing posture. Again, it all depends on how your wife wants to ride this bike. Casual or leaned forward and aggresively powering it much of the time.
10-11-08, 02:14 PM
ive done single speed and 3speed conversions to multispeed bike with deraillur gears a few times now. you can use a lowlevel deraillur with a built in hanger and install that. you'll need to lengthen the chain if not switch it to a 3/32 narrow chain all together. if you do go to a narrow chain, of course you'll need to get a narrower chainring up front. it can ba done, but probably better to just do what was prev said and look for a larger rear cog for the hub, if you want a lower gear, smaller if you want a higher gear. alot of work to add a little range from a deraillur bike, but it can be done.
id definatly go to a straight bar, but be equipt to change the brake levers too. hope it helps.
OK, so my wife has what I think is called a three speed utility bike. ...I'm considering upgrading the bike to having straight handle bars and derailleur gears. .. Do I have any option in upgrading?
1) buy another wheel with more internal gears. I believe you've got 5, 7, 8 or 14 to choose from.
2) Just buy one of the hubs above and lace it into the existing wheel. This might even be doable w/o having to get new spokes.
3) get a new wheel with external gears, and one of Shimanos low-end derailers that attaches by a bracket that gets clamped under the axle nut. Or do a hub replacement as suggested above.
4) You can buy the same type of bracket as above, but drilled and threaded to accept prettty much any derailer. Harris cyclery carries them, but right now I can't remember its name.
Do note that going to a derailer rear wheel will probably require spreading the rear stays to get the wheel to fit.
10-11-08, 02:27 PM
Try a search here at bike forums using the keywords "northroad pic" or "northroad bars" without the quote marks and see some nicely setup casual riding bikes. I know everyone will point fingers at me and scream "HERETIC ! ! !" but bicycle riding doesn't always have to be about going fast.... :D And it may be a nice option for this particular bike. Save the go fast mods for something worthy of them.
10-11-08, 02:36 PM
The bike is not worth spending any money on as far as converting it to der gears. You can get a second hand der gear bike for much less than what it will cost to convert this one.
And as others have said, an english 3 spd is great around town bike as it is. Gears that are more than adequate for the flats, and a comfortable, upright position that is easy on the arms/wrists. I ride mine every day.
The only real problem with 3 spds is the steel rims make the brakes pretty minimal when dry and almost non-existent when wet.
10-11-08, 02:44 PM
... I didn't realise that rear hangers were available, or that in fact they can come built into a new derailleur? I think this might be the best plan for me. Buying a better/bigger rear hub did come to mind, but in the UK we are "screwed" (a technical term) by tax and import costs etc. That means a new rear hub was much much money. Spreading the rear sounds like a bit of a serious thing, but since it's a project bike now I could give it a try. Realistically by the time I replace the handle bars, probably the headset, new wheels, derailleur. I might just as well change the BB/crank, blast it and get it powder coated pink to finish the job :rolleyes:. Hey! I'll just buy her a new bike, it's almost the holiday season :thumb:. Many thanks for the posting so far, lots of great information. Be assured I am making notes.
10-11-08, 02:54 PM
Good point. It'll be sure to have steel rims. The braking in the wet is as you said non existent. That explains it. Thankfully my wife does not ride the bike downhill in the rain. At least I think that's a good thing? I'll add some kind of expensive non-pad based braking mechnism to the ever increasing cost of upgrading this bike. Looking more like this is an overly expensive exercise by the minute. Next thing you know someones going to start talking about suspension. Front, rear or saddle? :)
10-11-08, 07:50 PM
....steel rims....Thankfully my wife does not ride the bike downhill in the rain. At least I think that's a good thing? ......
That depends on what sort of life insurance you have on her.... :D
Just kidding! ! ! !
You sure won't get any criticism on using this as a project/training bike. As such any reasonable, for you, amount of cash spent on it is fair game. As long as you're going into it with your eyes open and realizing you won't get diddly back for it other than knowledge and perhaps a unique bike to putter around on. Hell, just powder coating it is likely going to cost more than the bike is worth so right there you just blew the budget :D
By the way, Sturmey Archer also makes upscale geared hubs as well as the 3 speed options. And being British you may not be hit so hard on the cost. Something to look at anyway.
A really nice upgrade would be to re-lace the old SA-3 with an aluminium hub and get an alternative front wheel with aluminium hub. It'll make the bike feel like you lost easily 5 times the weight that it really did. And if possible look at switching to a rim that'll let you run a more common size so there's some nice higher performance tires available. Even with 26 inch mountain bike rims there's a lot of really nice fast rolling road slicks available. But you'll need to check that your brake calipers are compatible with the switch in size on the rims.
And whatever you do do NOT forget the wire basket on the front, the white hand grips and pink tassels dangling from the ends. If you're going to make a statement you may as well shout loud enough to make yourselves hoarse.. :D
10-12-08, 04:52 AM
Does your wife actually want a bike with more gears? My wife was the opposite, had more gears and wanted a simpler less confusing more comfortable bike, so I got her one of those old "junk" 3-speeds and she loves it.
10-12-08, 01:34 PM
I think the point of cost vs what's actually needed (three speed good enough?) is a good one. The wife get's on better with three speeds that I do. One point is that she's needing a low step though style. Short of hack/welding the frame I'll probably have to go with buying a mid-cost low step womens style later in the year. Though the idea of pink pimping this frame is starting to really grow on me. :) One big drawback is that the frame takes narrow road style 26" wheel. Even with spreeding the rear stays I'd think fitting a wider wheel's got some issues. I'll have think. My brain's gone into meltdown ... :roflmao:
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