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ravingbikefiend
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Discussion Starter · #1 ·
I had a goal of building a single speed to use for commuting and somewhere along the way the SS project morphed into a 3 speed project... the fact I had a spare 3 speed SA AW hub and wheel sitting in the shop and had bought a Raleigh Criterium 12 speed had some effect on the "morphage".

So what started as an experiment to see how well an SA hub would perform if it was dropped into a lighter road bike has now become a serious project that will end in me having quite a decent high speed commuter / road bike.

Fitting the hub into the Criterium frame was simple and it took two spacers to make for a really nice fit. Removing the deraileurs was simple and I figure that when I do the weight math I'll be ahead as the SA hub and (soon to be replaced) steel wheel was lighter than all the parts I removed (which includes the old wheel).

One issue that arose was the fact that the old SA rear cog only accepts three speed chain so I hunted down an Shimano 18 tooth cog that swapped straight into the hub assembly and now I am running normal chain.

I spent quite a few miles working out the optimal gearing and settled on running a 16 tooth Shimano cog in the rear with the 40 up front. For those unfamiliar with the gearing on an SA AW hub this gives me gear ratios of 49, 65, and 87 gear inches or a 1:1.9 , 1: 2.5, and a 1:3.63 ratios. This is the same ratios as the stock gearing on a 3 speed which is normally a 48/20 setup although a stock 3 speed cruiser is a 40 pound (plus) bike.

I called the LBS this afternoon to get a quote on the cost to build a new (no dish) wheel around the SA hub and a relatively bombproof Mavic, double walled, eyeletted wheel will run me $120.00 Cdn. The labour is only going to be $ 40.00 while the rest of the cost is for the parts and I can buy a decent front wheel off the shelf for well under 60.00.

The new wheels will cost more than what I have spent on the bike so far and with some slick tires the bike I have nicknamed the "Critter" should really haul my skinny ass around at some good speed. I rode it all day with the new gearing and cruised along pretty easily at 22- 25mph and with a little more kick was hitting 30 mph with my pamiers attached and lightly packed with stuff.

And because we all like pictures...


The hub dates to 1979 but the stainless wheel nut/chain guide assembly dates to 1951.


I have had many folks think the bike was a singlespeed and found that many had never heard of a Sturmey Archer hub. The cranks and chainring are a Shimano 600 and I fabricated the chain guard from a 52 tooth Shimano 600 chainring that had seeen better days.


I was thinking of painting her a copper / orange and wrapping the bars in basic black...
 

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Cool..

I've been considering doing the same thing with a on-one ill pompino frame that i currently have set up as a SS roadie. i have a SA hub from a bike some one abandoned in my front yeard but would have to get it laced into a 36H rim.

How did you determine that a 40T chainring up front and the SAs lowest gear would result in a 1:1 low gear? I'd really want that gear around here. Right now im usiong a 42-17 and its OK ..
 

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ravingbikefiend
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Discussion Starter · #4 ·
I hooked up with one of our local MTBR's tonight (Ribaldmanikin) and and when I rolled in I saw I had logged 40km on the Critter... it was all good and the bike ran out wonderfully. It seems pretty ideal for those light to light sprints one does when they're commuting and it's nice to come screaming up to a stop without having to shift down for the next takeoff since you can shift the SA hub at any speed or no speed.

Ribald was riding his vintage Kuwahara Club Sport which is an incredibly beautiful and droolworthy bike and we were running out at 30-40 kmh for most of the ride, hitting 55- 60 kmh on the downhill runs, and making some hard climbs where I really had to stand up on the pedals.

The SA hubs don't downshift under load very well and this should be avoided... you have to stop pedalling and downshift and with some practice this can be done quickly enough as to not lose much momentum. Upshifting is smooth as butter and the transition from a 120 rpm cadence in 2nd to a 100 rpm cadence in 3rd is very smooth. (120 rpm in 3rd yields a speed of 49 kmh).

The 40 / 16 combo gives me a low gear ratio of 1 to 1:9 or 50 gear inches which is pretty steep for the long climbs (but doable) and I was thinking that installing a double cog in the rear might be a cool option for the future. Having a double cog in the back would make the bike a 6 speed and having a slightly bigger 2nd rear cog would be really good when the ride involved epic climbs or for riding on the multi use trails. Mind you... riding this bike up and down hills as it is will get me in even better shape and I expect my hill climbing will improve.

I don't think that vintage rear wheel has ever seen 60kmh (36 mph) but it ran out beautifully and was very smooth... the performance and ride was good enough that I might keep it on for a while since the vintage steel rims are of excellent quality and nothing like modern steel rims (which are crap). The 1 3/8 tires add a little plushness to the ride as they suck up the bumps quite nicely and they're also designed to handle uppaved surfaces so would handle the multi use trails quite well methinks.

The biggest issue with vintage steel rims is the braking one can get but with the right brake pads this issue can be solved. I fitted some v brake pads in the rear thinking the increased contact area would help but they can still get better... I'm thinking that Koolstops or other MEC brakes (which I really like) might improve the stopping power due to their softer rubber compounds. Keeping the wheels really clean and free of any oil buildup (from the chain and hub) is really important to maximize braking.


jrm
- your 42/17 combo yields 64 gear inches if you are running a 26 inch wheel so that is the equivalent of the 40/16 setup and my 2nd gear (which is direct drive).

Sheldon Brown has an online calculator to determine gear ratios on all sorts of gear hubs and you can simply go there and plug in your specs and get a good range of results from gear inches, speeds at various rpms, gain ratios, etc.

I guess now it's time to start tearing the Critter apart so I can deal with the esthetic issues like stripping and re-painting, doing the bar wraps and replacing the white shifter cable with a black one.

I figure she'll end up looking as good as she runs.
 

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ravingbikefiend
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Discussion Starter · #5 ·
PS - The bike really needs a Brooks saddle to keep with the vintage theme.
 

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ravingbikefiend
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2,322 Posts
Discussion Starter · #6 ·
I stopped by one of the LBS's today to pick up tyres for the Superbe and found they were clearing out a bunch of new in the box parts at ridiculous prices... I picked up a complete Dia Compe brake and lever set (remarkably light btw) replete with cables, housings, and brake pads for $10.00 Cdn.

Now the Critter can stop on a dime and give change.

The Critter's old 600 series brakes got moved to my vintage Grande Prix as although the stockWeinman's offered grat stopping power, they're bulky and don't have a quick release.

I'm gonna have to go back and pick up a few more sets of the Dia Compes so I can upgrade the Superbe's brakes as well.
 

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ravingbikefiend
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Discussion Starter · #7 ·
Update;

I reinstalled the original bars which were way lighter than the one's I was using and reconfigured the brake position and control setup by placing the shift box on the upper right hand side so I could shift faster and more naturally when I'm riding in a hands up position.

I also added the coaster bars to the DiaCompes (they weigh almost nothing) so I could brake from a hands up position and although they don't have the leverage to bring the bike to a screaming stop they do work good when you're waiting on hills or just need to slow down a little without dropping your hands.

I also did a little experimentation in gearing by installing a Shimano three speed hub into an old Sekine 10 speed I picked up the other day...

By leaving the front double ring and deraileur in place I have a smooth running triple with a dual range (6 speed)... the original chain and deraileur are still in place as I needed a tensioner and wanted to be able to swap the original wheel back in if I didn't like the setup.

I think the dual range on the 3 speed hub experiment was a winner as the bike ran out far smoother than it does with the five speed hub and has a wider gearing range where the lower bottom end really helps on hills. This bike weighs a ton and I liken it to driving an old farm truck with a high / low range.

I expect that the Critter will be getting a double ring, front deraileur, and tensioner installed in the near future as this means I can even look at having more gear range... by increasing the top ring to a 44 (this would give me 104 gear inches) and with a second smaller ring (perhaps a 36) I'd have a low end of about 42 gear inches for those times one might want a little more spin on long hills...

Cheers!
 

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ravingbikefiend
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Discussion Starter · #8 ·
I expect to be painting the Critter this week as she's been road tested to the Nth degree and has even surpassed my expectations for performance in a commuter... quite a few people have made pretty positive comments on the unusual build and one person has even asked me if I could build them a similar ride.

I'm not sure if I'll go with the dual route as I really like the clean look of the driveline and can get more than enough speed out of the old girl just as she is... running down our relatively flat bike highway the other night (in calm conditions) I was hitting and holding her at 45-50 kmh (30 mph) for some good stretches.

I don't expect the new wheels to add much to the top speed due to my gearing limitations but they should help most by lightening the bike a good deal... this will have a positive impact on how well she climbs and further increase my efficiency over longer distances.

I am even considering taking her on a century ride later this summer as this is the distance between my home and my brothers and I am overdue to go and visit him.

Being able to do it on a triple would make for an epic ride methinks.
 

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ravingbikefiend
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Discussion Starter · #9 ·
I took the Critter down the multi use trails tonight so that we could get a good seat to watch the Canada Day fireworks... I think a few people thought it was odd to see a road bike on the trails but aside from being stalled by masses of pedestrians and having to walk up some really short steep sections, the bike handled the trails just fine.

This is where some extra low gearing would come in handy.

I was looking at Sheldon Brown's site a while back and saw that there is a double rear cog assembly available to convert a 3 speed into a 6 speed and since I have a few spare parts, decided to see if I could fit two independent rear cogs on to the hub without forking out $60.00.

I discovered that when you remove the spacers on the hub (there's two of them) there is exactly enough room for two rear cogs on an SA hub and the driveline remains pretty much arrow straight..

I am now running a 16 and 18 tooth cog with the old 600 deraileur serving switching duties and it's pretty cool... there's no gearing overlap and the Critter now has a range of 43, 49, 58, 65, 77, and 87 gear inches. The shifting between the rear cogs is as smooth as butter.

I am gonna have to postpone the painting so that I can take her back to the MUTs and see how the new gearing works on those harder climbs.

Methinks I am having too much fun with this project and really hope the info is helpful to anyone thinking of making a similar "Frankenbike".
 

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ravingbikefiend
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Discussion Starter · #10 ·
I was never very good at keeping a diary...

The Critter got some flat bars (better for commutes and trails) and is presently sporting some Scott Lite Flites (210g) that I picked up although I'm not sure they'll stay as they might be better suited to an SS cross bike project I have in the works.

The drive went back to being a triple as the 6 speed setup was too cluttered looking for my tastes.

I even found some hybrid tires in a 26 by 1 3/8 which is really nice combination for commuting and trail riding and they still run out at good speed.





With winter here I can finally look at taking everything apart and re-painting the old girl so she's got some pretty new colours for spring.
 

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Sixty Fiver said:
Methinks I am having too much fun with this project and really hope the info is helpful to anyone thinking of making a similar "Frankenbike".
Actually, yes, it has. I've toyed with the idea of doing something like what you've got. Something simple, yet effective. I don't have the money for something like a Rohloff, but finding a Sturmey Archer hub surely is going to be less expensive. As much as I love fellow member Vern Verndog's ride, the Rohloff is just too much money for me.

How strong are the SA hubs (internals)? Any recommendations as to what to look for or avoid?

Not sure if i'd ever get around to it, but at least a "heads up" would be appreciated.
 

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ravingbikefiend
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Discussion Starter · #12 ·
I want an SA 8 speed hub too

The SA hub won't do what a Rohloff will as it is designed for cruising and commuting and will not withstand big hits / drops and wasn't designed for road racing.

They were designed to very reliable, low maintainence, very efficient, and weatherproof... perfect for an all weather commuter or cruiser.

Some really important operational notes:

They don't shift up or down under high load but do upshift very smoothly under moderate load / accelleration.... you can also shift when the bike is stationary which is a nice feature for a commuter.

Standing in high (3rd) gear and hammering things on climbs or sprints must be avoided as this type of extreme load can make the hub skip or even disengage and cause the hub to freewheel which can be catastrophic.

The SA hub is designed for a 110 mm dropout so most modern mb and road frames won't accomodate them which means part of the building project requires finding an old 10-12 speed road bike to use as a base.

Sheldon Brown probably has the most complete info on SA hubs.
 

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Sixty Fiver said:
The SA hub won't do what a Rohloff will as it is designed for cruising and commuting and will not withstand big hits / drops and wasn't designed for road racing.

They were designed to very reliable, low maintainence, very efficient, and weatherproof... perfect for an all weather commuter or cruiser.

Some really important operational notes:

They don't shift up or down under high load but do upshift very smoothly under moderate load / accelleration.... you can also shift when the bike is stationary which is a nice feature for a commuter.

Standing in high (3rd) gear and hammering things on climbs or sprints must be avoided as this type of extreme load can make the hub skip or even disengage and cause the hub to freewheel which can be catastrophic.

The SA hub is designed for a 110 mm dropout so most modern mb and road frames won't accomodate them which means part of the building project requires finding an old 10-12 speed road bike to use as a base.

Sheldon Brown probably has the most complete info on SA hubs.
Damn, glad I asked first!

Thanks for the heads-up. :thumbsup:
 

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ravingbikefiend
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Discussion Starter · #15 ·
I love this bike...

A little update:

The Critter has now seen more than 2800 km of riding since she was built and hasn't caused me a moment of trouble but has been about as dependable a ride as I have ever owned... it's interesting to see how the bike has evolved and devolved since I started the project.

We went out for coffee this eveing and stopped by the store for provisions (20 kilos worth) and since I had the camera I snapped a pic of the old girl with her shiny fenders.



The fenders are really proving their worth since it's been wet and rainy of late and the tubes have been filled with some Victor tire sealant to make sure small punctures don't stop me on my commute. The classic IRC roadster tires seem very puncure resistant on their own due to their heavy centre tread depth and offer a great balance of ride and road speed / handling but a little insurance is always a good thing.
 
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