Help converting 110mm O.L.D. singlespeed to Sturmey Archer 5sp

Lumen

Creative/technical input sought for a new project...

I have a steel frame with 110mm O.L.D. horizontal dropouts and no cable stops. It is currently running singlespeed with riser bars and rim brakes.

I want to convert it to an unbraked geared hub, using a wheel built around a Sturmey Archer S-RF5(W) hub.

That hub comes in a 111mm OLD version, which I assume is close enough to squeeze in.

Here (PDF) are the instructions for fitting the hub. It looks a bit complicated for my simple brain; I know little about hub gears.

I assume the instructions concerning the "fulcrum lever" are only relevant for the braked versions of the hub, so can be ignored.

The frame doesn't have any fitting for gears (e.g. cable stops, BB shell drilling for plastic cable yoke). Is this a problem?

Basically, I'm not sure what the requirements are of a frame for fitting an unbraked hub gear system.

For shifting, I have a choice of grip shifters or thumb shifters. I want the shift action to be as light as possible. Any opinions/experiences?

How can I tell whether my existing rear cog will fit on the hub? Should the hub come with a new cog?

Other complications I have missed?

Beasty

On the shifters question, I have no experience of Sturmy Archer, but generally would have a strong preference for decent thumb shifters over grip shifters. The grip shifters I have used have tended to feel quite tight and requiring a bit of force to shft, whereas thumb shifters tend to be quite smooth in their operation

Holyboy

I LOVE S.A. internal geared hubs are the way forward and S.A. products are much better quality now than they were in the last few years they were made in the U.K. as for fitting the hub it's really easy and that model has a cable stop and cover that come with the hub, all you'll need is a few cable ties or if you want to be fancy steel cable clips for the down tube and chain stay Dia compe still make them, as for shifters both are nice to use so it's just personal preference and of course you can shift gear when stopped which is great at traffic lights!
The sprocket you have won't work on the hub unless it happens to be a coaster brake hub you're using at the moment, which I doubt!!
I'm pretty sure the hubs don't come with one either but they are very cheap to buy, usually from 14tooth up to about 22tooth but other sizes are available if you search, it'll depend on your front chainring size, wheel size and your riding style what size you'll need, if you're unsure a 18 or 19 tooth is the norm for a 46 tooth chainring and a 590-635(26x13/8-27x11/4) wheel, 700c being in the middle of those(622)

Hope I've been some kind of help.

lescol

I don't have a hub gear, but I have vague recollections of fixing my dads Sturmey Archer. If I recall, the cable was sheathed to the cable stop on the chainstay where it was secured by the fulcrum cable clip.


The cable was clamped to the frame at various spots by spring clips, it would run over the top of the BB.

St John Street Cycles are a great source of the necessary bits http://www.sjscycles.co.uk/sturmey-archer-internal-hub-gear-spares-dept426/

Holyboy

Don't get confused, you won't need a fulcrum clip, your hub comes with a kind of built in (all though bolt on) cable stop, but yes SJS cycles are brilliant, my kinda shop:D

Doctor Bob

Lumen wrote: »

For shifting, I have a choice of grip shifters or thumb shifters. I want the shift action to be as light as possible. Any opinions/experiences?

There are strengths and weaknesses for both, but on balance I'd go for thumb shifters.

I had first grip shift, then thumb shift, on my Nexus 8, and I have grip shift on my current Nexus 3-speed. For the 3-speed grip shift is fine as the gears are pretty widely spaced on the shifter, but the 8 speed had a slight tendency not to engage precisely if the shifting wasn't firm, as the gaps on the shifter were smaller (I hope that makes sense- think of three big slices of cake vs 8 smaller slices of cake ).

One advantage of thumb shifters is that you're less likely to end up 'between' gears, i.e. a single firm click bumps you up or down one gear (assuming they're indexed correctly). But that's also a drawback - probably the only one - of thumb shifters- every gear change required a solid click, whereas with grip shifters you can jump multiple gears at a time if required. This can be handy after, say, an emergency stop, if you want to go from 8th to 3rd.

Another advantage of thumb shifters is that your hand can stay solidly on the bars while you change gear, but grip shift requires a slight loosening of your grip on the bars. The difference is marginal, but if you spend any length of time on the bike it might start to count. ("My doctor says I have the wrists of an 80 year old" &c.)

I've never noticed any tightness with grip shifters like Beasty describes.

Having said all that, I've never used modern SA hub gears, only Shimano.

Lumen

Interesting, thanks folks.

The only recent experiences I have of flat bar shifting is Dublin Bikes (3sp, gripshift, easy action if a bit sloppy, Sturmey Archer?) and a SRAM 3.0 7sp gripshift with derailleur, which is accurate but quite tight (maybe a cable kink issue).

I suspect that gripshift works better with hub gears, but I think I'll try thumb shifters for a change - the bit about keeping a firm grip seems appealing for the intended use.

I don't think Shimano or SRAM is an option for the hub due to the narrow dropout width; I don't want to spread the frame as it's very small and I might convert it back to singlespeed for sale at a later stage.

PM sent to Holyboy regarding wheel build

tomasrojo

My Brompton has a very old-fashioned thumb shifter. Can't find a specific image, so this'll have to do.



I like it. I've never tried grip shifters with hub gears, but I didn't really like them with derailleurs.

The only downside is the old-fashioned thumb-shifter gets in the way when you want to turn the bike upside down for maintenance.

I'm pretty sure you aren't interested in this type of thumb shifter (in fact, it may not even be one, strictly speaking), but sure I've posted now.

Lumen

It's done!

Thanks all for the help, particularly Holyboy @ Bee Cycles for the fantastic little wheel build.

In the end I went with a Dahon rim and stainless steel plain guage spokes. I calculated the spoke length using 14mm nipples but ordered 12mm ones, so Holyboy had to find some of those.

The 1mm mismatch in OLD wasn't a problem for getting the wheel into the dropouts, but due to the thickness of the dropouts the axle wasn't long enough to take both "lock washers" so I left one out. I have no idea if this is important.

The hardest part of the install was getting the tyre on the rim, probably due to its narrowness. I've never had to use a metal spatula as a tyre lever before. :eek:

I'm not quite sure how well the shifting works, as the wheel has so little inertia it's difficult to feel the changes on the stand and I'm too big to ride the bike. :pac:

The geared hub has added less than 450g to the weight of the rear wheel, so it doesn't feel particularly unbalanced.

Until someone can disprove the assertion, I'm claiming this as the smallest geared bike in the world. Still, this has probably superceded my travel bike as most dubiously-justifiable-and-arguably-pointless project ever.

To the trails!

Tonyandthewhale

Put it in the images of beauty thread.

doozerie

Too late to be relevant to the discussion at this stage, but another selling point for thumb shifters for me is that you can change gear in a variety of hand positions. I have them on my MTB as I fitted them at a time when grip shifts were relatively new and not entirely reliable when faced with mud/grit. I'm sure the reliability of grip shifts has improved in the intervening years but I'm still a fan of thumb shifters. Mine are positioned so that I can change up or down with a twist of my wrist much like grip shifts (relying on first knuckle to change up, which is easy, base of thumb to change down, which is admittedly more tricky), and I can also change up/down with my thumb when my hands are on the bar ends. Mind you, it's all just a matter of what you are used to, to a certain extent.

Lumen wrote:

I'm too big to ride the bike.

"There is no tiny bike, there is only fear!" as Jens probably said at some stage or other...

quenching

Congrats on a great job Lumen! Now frighten me with the cost :-) I also have a Cnoc 16 that my 5 year old is the perfect size for but finds it a bit slow so I would actually be keen to hear how practical or financially sensible it is to do it (PM if you like and would rather not say publicly how much it cost). How many hours do you reckon it took you? I'm sure its more sensible to buy a larger geared bike but I like the idea of doing this as well.

Lumen

quenching wrote: »

Congrats on a great job Lumen! Now frighten me with the cost :-) I also have a Cnoc 16 that my 5 year old is the perfect size for but finds it a bit slow so I would actually be keen to hear how practical or financially sensible it is to do it (PM if you like and would rather not say publicly how much it cost). How many hours do you reckon it took you? I'm sure its more sensible to buy a larger geared bike but I like the idea of doing this as well.

<sharp intake of breath>

- Rim: £46 shipped
- Spokes: £9 (+shipping, but I was ordering a bunch of stuff from SJS anyway)
- Hub: £126 shipped from oldbiketrader
---
£181 (€204)
+ Wheel build: €30
= €234, ish.

Yes, it's complete madness - it's basically doubled the cost of an already expensive bike, by kids bike standards. Still, it's cheaper than any of mine.

I could have saved some money by using the existing rim, and the result would have been better (the Dahon rim is really too narrow for this application) but that would have meant more delay sourcing a 20h hub, and it was hard enough getting the hub with 28h in the right OLD as it was, although oldbiketrader reckons he has an inside line to Sturmey Archer so it might have been possible. As it is I have a spare SS wheel and unless I find someone else similarly unhinged I'm expecting to sell the original bike on and use the hub for something else (or sell it).

Installation was super-easy, the hub kit came with good instructions. Apparently the wheel build was hard. It would have been easier with 1x lacing, but I couldn't easily source the shorter spokes.

We went for a spin in the Park today and Little Miss Lumen (four next month) was faster than she's been on her CNOC 14.

Hub gears make loads of sense on small kids bikes. Apart from the cost. There are no derailleur clearance issues and the ability to change to any gear at a standstill is a bonus.

As for your requirement, my shortish almost-6 year old just fits a Beinn 20 and he loves it. I'd question the value in doing the same job for a 5 year old unless you have a smaller child lined up to inherit it.

niceonetom

I wish you were my dad.

quenching

Lumen wrote: »

<sharp intake of breath>

- Rim: £46 shipped
- Spokes: £9 (+shipping, but I was ordering a bunch of stuff from SJS anyway)
- Hub: £126 shipped from oldbiketrader
---
£181 (€204)
+ Wheel build: €30
= €234, ish.

Yes, it's complete madness - it's basically doubled the cost of an already expensive bike, by kids bike standards. Still, it's cheaper than any of mine.

I could have saved some money by using the existing rim, and the result would have been better (the Dahon rim is really too narrow for this application) but that would have meant more delay sourcing a 20h hub, and it was hard enough getting the hub with 28h in the right OLD as it was, although oldbiketrader reckons he has an inside line to Sturmey Archer so it might have been possible. As it is I have a spare SS wheel and unless I find someone else similarly unhinged I'm expecting to sell the original bike on and use the hub for something else (or sell it).

Installation was super-easy, the hub kit came with good instructions. Apparently the wheel build was hard. It would have been easier with 1x lacing, but I couldn't easily source the shorter spokes.

We went for a spin in the Park today and Little Miss Lumen (four next month) was faster than she's been on her CNOC 14.

Hub gears make loads of sense on small kids bikes. Apart from the cost. There are no derailleur clearance issues and the ability to change to any gear at a standstill is a bonus.

As for your requirement, my shortish almost-6 year old just fits a Beinn 20 and he loves it. I'd question the value in doing the same job for a 5 year old unless you have a smaller child lined up to inherit it.

Thanks Lumen, madness it may be but still great fun and an interesting project, if hard to justify in my case as you say. I've just received a Beinn 20 Large for my 6 year old and passed the Cnoc 16 down to 5 year old, but I tend to agree that its more sensible to buy him a Benin also when needed next year. My wife is not convinced our 5 year old with Evel Knievel tendencies needs to go any faster anyhow! Its a pity Islabikes don't do a hub geared 20" bike as I can see the gears on the Beinn having a hard life, its difficult to convince a 6 year old to treat them nicely.

BTW, I think you'll find you will fit on the Cnoc 16, I'm 6'1" and 88kg and I manage to ride one, not the most graceful sight I'll admit but possible none the less

Holyboy

It looks awesome, a difficult build but I loved doing it, I still stand by the fact that internals are the way forward, the first gearing option that there was and in my opinion still the best for a lot of purposes, probably most!:D

Hermy

Can you post a pic Lumen?

Lumen

Hermy wrote: »

Can you post a pic Lumen?

Sorry, for some reason all the links died.

click thumbnails to enlarge

Hermy

Looks great Lumen - thanks for posting.