Sturmey-Archer SRF5(W) hub shifting options. HMN420 versus fulcrum arm HSJ905
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Sturmey-Archer SRF5(W) hub shifting options. HMN420 versus fulcrum arm HSJ905
Looking at the SA 2012/13 calendar I see (pg. 15 HFIS5.PHSV) a fitting kit which seems to use a simple guide-nut (HMN420) in place of the whole gear-selector-guide (HSA650) and fulcrum (HSJ905) arm used in the other fitting kit (HFIS5.YSSS).
Am I right about that? You can just dump that long fulcrum arm (HSJ905) and replace the indicator chain (HSA585) with the appropriate one and the gear-selector-guide with the short guide nut (HMN420)? Please, please, someone, tell me you've done this and it worked like a dream? If so, how is the function of the barrel adjuster used? Does it screw into the hole in the HMN420?
Speaking of said indicator chain, the specification of HSA717 (mark purple) on pg.15 seems at odds with the table on p.56 which says that the indicator type must be Navy-blue (HSA712 ) when used with the short guide nut (HMN420). Does anyone know which bit of the catalogue is correct?
Am I right about that? You can just dump that long fulcrum arm (HSJ905) and replace the indicator chain (HSA585) with the appropriate one and the gear-selector-guide with the short guide nut (HMN420)? Please, please, someone, tell me you've done this and it worked like a dream? If so, how is the function of the barrel adjuster used? Does it screw into the hole in the HMN420?
Speaking of said indicator chain, the specification of HSA717 (mark purple) on pg.15 seems at odds with the table on p.56 which says that the indicator type must be Navy-blue (HSA712 ) when used with the short guide nut (HMN420). Does anyone know which bit of the catalogue is correct?
Last edited by Jcoudonc; 04-15-12 at 03:00 PM. Reason: added SA catalog link
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You should be able to do it, but you'll need the fulcrum clip which goes around your chainstay (or seatstay) and acts as a housing stop. You don't need a barrel adjuster, you do all the adjustment with the threaded cable attachment on the end of the indicator.
As for the indicator, I can't be sure, but I assume that the type of indicator you need isn't affected by the fitting kit used, as the fitting kit doesn't affect how the indicator attaches to the hub internals, and how much of it protrudes from the axle in each gear. My X-RD5 came with the fitting kit you describe (plastic pulley, fucrum arm on the axle, standard nut) and also a long guide nut, I assume it's possible to use either.
As for the indicator, I can't be sure, but I assume that the type of indicator you need isn't affected by the fitting kit used, as the fitting kit doesn't affect how the indicator attaches to the hub internals, and how much of it protrudes from the axle in each gear. My X-RD5 came with the fitting kit you describe (plastic pulley, fucrum arm on the axle, standard nut) and also a long guide nut, I assume it's possible to use either.
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As for the indicator, I can't be sure, but I assume that the type of indicator you need isn't affected by the fitting kit used, as the fitting kit doesn't affect how the indicator attaches to the hub internals, and how much of it protrudes from the axle in each gear. My X-RD5 came with the fitting kit you describe (plastic pulley, fucrum arm on the axle, standard nut) and also a long guide nut, I assume it's possible to use either.
To complicate matters further there appear to be Brompton-specific kits available at SJScycles with some interesting parts not mentioned in the S-A catalogue.
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The fulcrum lever or arm is not required. You can use a guide nut with no problem as long as you have some kind of cable stop mounted somewhere, either on the seatstay, chainstay, or downtube if you're routing the cable under the bottom bracket. I just finished doing that on a build with a 5 speed SA, and it works like a charm.
Had to use the short guide nut on that particular build to avoid crank interference with the cable, but that was just because of the frame geometry.
You don't need the barrel adjuster, there is enough adjustment available on the threaded end of the indicator, so if you are using a guide nut, don't bother with the fulcrum arm.
Had to use the short guide nut on that particular build to avoid crank interference with the cable, but that was just because of the frame geometry.
You don't need the barrel adjuster, there is enough adjustment available on the threaded end of the indicator, so if you are using a guide nut, don't bother with the fulcrum arm.
Last edited by Dan Burkhart; 04-15-12 at 06:38 PM.
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I called them a few weeks ago to find out when they are getting more, and they couldn't tell me. I'll be grabbing a couple as soon as they come available again.
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Looking at the catalogue that I linked to in the previous post, is there a part number that you'd associate with that "fulcrum clip"?
The catalogue specifically says that with the HMN420 "short guide nut" you have to use a different indicator.
To complicate matters further there appear to be Brompton-specific kits available at SJScycles with some interesting parts not mentioned in the S-A catalogue.
The catalogue specifically says that with the HMN420 "short guide nut" you have to use a different indicator.
To complicate matters further there appear to be Brompton-specific kits available at SJScycles with some interesting parts not mentioned in the S-A catalogue.
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Excellent. It's great to get such a detailed answer from someone with experience. My faith in the internets is renewed! I'll post again in a couple of weeks after I've ordered and installed the HMN420 short guide nut.
I notice from your avatar that you're in Ontario. I'm in Québec and have been ordering from the good folks at BikeToolsETC (super service b.t.w.), have you found a more local Canadian store?
I notice from your avatar that you're in Ontario. I'm in Québec and have been ordering from the good folks at BikeToolsETC (super service b.t.w.), have you found a more local Canadian store?
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Excellent. It's great to get such a detailed answer from someone with experience. My faith in the internets is renewed! I'll post again in a couple of weeks after I've ordered and installed the HMN420 short guide nut.
I notice from your avatar that you're in Ontario. I'm in Québec and have been ordering from the good folks at BikeToolsETC (super service b.t.w.), have you found a more local Canadian store?
I notice from your avatar that you're in Ontario. I'm in Québec and have been ordering from the good folks at BikeToolsETC (super service b.t.w.), have you found a more local Canadian store?
Once again, it is possible you will need a shorter indicator, and if that's the case, you will need to disregard the instructions that tell you to align the coloured mark with the end of the axle in second gear, and just adjust it so it's slack in 5th and just a teensey bit short of fully taut in 1st.
I should mention that I've had complete success adjusting the older versions of the 5 speed this way, but have yet to try it on a wide range model.
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Great. That's what I thought: the big, beefy fulcrum arm just acts as a housing stop. It surprisingly heavily constructed. Thank you very much.
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I only buy from retailers when I have to. I have a bike business, so I get most of my parts from wholesalers. Not that it's much cheaper than some of the on line retailers mind you.
Once again, it is possible you will need a shorter indicator, and if that's the case, you will need to disregard the instructions that tell you to align the coloured mark with the end of the axle in second gear, and just adjust it so it's slack in 5th and just a teensey bit short of fully taut in 1st.
Once again, it is possible you will need a shorter indicator, and if that's the case, you will need to disregard the instructions that tell you to align the coloured mark with the end of the axle in second gear, and just adjust it so it's slack in 5th and just a teensey bit short of fully taut in 1st.
I can see how you might need a shorter indicator chain with the short guide nut as opposed to the long one or the pulley, because the short nut takes up less of the chain and there's a chance that the end of the indicator chain will hit the end of the barrel adjuster before the hub engages first gear properly, but if you're using a chainstay fulcrum clip, that isn't an issue because you can move the fulcrum further up the stay if that happens.
I must be missing something in this, anyone know what it is?
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I'd have thought that the length of the indicator spindle has nothing to do with the nut used, seeing as the distance it needs to be pulled out of the axle to engage each gear is the same regardless of how it's pulled out.
I can see how you might need a shorter indicator chain with the short guide nut as opposed to the long one or the pulley, because the short nut takes up less of the chain and there's a chance that the end of the indicator chain will hit the end of the barrel adjuster before the hub engages first gear properly, but if you're using a chainstay fulcrum clip, that isn't an issue because you can move the fulcrum further up the stay if that happens.
I must be missing something in this, anyone know what it is?
I can see how you might need a shorter indicator chain with the short guide nut as opposed to the long one or the pulley, because the short nut takes up less of the chain and there's a chance that the end of the indicator chain will hit the end of the barrel adjuster before the hub engages first gear properly, but if you're using a chainstay fulcrum clip, that isn't an issue because you can move the fulcrum further up the stay if that happens.
I must be missing something in this, anyone know what it is?
When this doesn't happen, the solution is either a longer nut or a shorter indicator rod.
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Here's another cable routing option that eliminates the need for a housing stop on the chain stay. I routed a housing from the shifter to a downtube cable stop, and then bare cable though the guide under the bottom bracket to the indicator. Works well, but the cable runs quite close to the crank arm, so it might not work in every application.
When using stay mounted stops, my preference is to run the cable along the top tube and mount the cable stop on the seat stay.
This photo was taken from the thread in C&V detailing this build. I'm expecting the owner of the bike to bring it by today, so I'll take some more close up photos.
When using stay mounted stops, my preference is to run the cable along the top tube and mount the cable stop on the seat stay.
This photo was taken from the thread in C&V detailing this build. I'm expecting the owner of the bike to bring it by today, so I'll take some more close up photos.
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It's quite simple. If the indicator rod is too long for the short nut, it will pull out too far . The chain has to reach far enough into the guide nut for there still to be outward pull at the outer end of it's travel.
When this doesn't happen, the solution is either a longer nut or a shorter indicator rod.
When this doesn't happen, the solution is either a longer nut or a shorter indicator rod.
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As promised, here's some close up pics of the under the BB cable routing.
As seen here, the crank just barely clears the cable, but if it clears, a millimeter is as good as a mile.
Cable routing to the downtube stop.
After close inspection, I found the indicator was coming out far enough that getting first gear was a bit problematic, so I put a thin lock nut behind the guide nut. I'm going to look about a shorter indicator for him though so we can eliminate the extra nut.
As seen here, the crank just barely clears the cable, but if it clears, a millimeter is as good as a mile.
Cable routing to the downtube stop.
After close inspection, I found the indicator was coming out far enough that getting first gear was a bit problematic, so I put a thin lock nut behind the guide nut. I'm going to look about a shorter indicator for him though so we can eliminate the extra nut.
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As seen here, the crank just barely clears the cable, but if it clears,
a millimeter is as good as a mile.
a millimeter is as good as a mile.
of the BB spindle that much longer would, perhaps, help..
And shift the pedal outboard.
I see plucking that cable with your heel as you pedal could be an issue..
[unless pedaling pigeon toed ]
The roller at the top of the seat tube and housing stop on the front of the top tube
worked well for years on all those AW3s.. eliminated that interference point.
running the cable down the seat-stay.
Last edited by fietsbob; 04-18-12 at 05:05 PM.
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Ah, this could be useful for me.
I tried using an AW three speed nut with the SRF5. Friction was increased but it seemed to work OK, then after about a month I started getting problems shifting to the 5th gear. I realized that the indicator had gotten very slightly bent as the nut wasn't a perfect fit and was exerting a lateral force on the indicator spindle thingy particularly when in first gear. So having gotten slightly bent it was no longer sliding back in for 5th.
I tried using an AW three speed nut with the SRF5. Friction was increased but it seemed to work OK, then after about a month I started getting problems shifting to the 5th gear. I realized that the indicator had gotten very slightly bent as the nut wasn't a perfect fit and was exerting a lateral force on the indicator spindle thingy particularly when in first gear. So having gotten slightly bent it was no longer sliding back in for 5th.
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well .. shifting the chainring onto the inside face of the crank arm and the right side
of the BB spindle that much longer would, perhaps, help..
And shift the pedal outboard.
I see plucking that cable with your heel as you pedal could be an issue..
[unless pedaling pigeon toed ]
The roller at the top of the seat tube and housing stop on the front of the top tube
worked well for years on all those AW3s.. eliminated that interference point.
running the cable down the seat-stay.
of the BB spindle that much longer would, perhaps, help..
And shift the pedal outboard.
I see plucking that cable with your heel as you pedal could be an issue..
[unless pedaling pigeon toed ]
The roller at the top of the seat tube and housing stop on the front of the top tube
worked well for years on all those AW3s.. eliminated that interference point.
running the cable down the seat-stay.
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From what I've been able to ascertain, the new W version 5 speed uses the Mark Yellow indicator with the long guide nut and the fulcrum lever with roller, and Mark Blue with the short guide nut.
All of the old version 5 speeds I've handled used the Mark Blue indicator, including this one. Near as I can figure out, the only 5 speed indicator that's shorter is the Mark green.
3 speed indicators are not interchangeable with the 5 speed as the rods are too thick to enter the hole.
All of the old version 5 speeds I've handled used the Mark Blue indicator, including this one. Near as I can figure out, the only 5 speed indicator that's shorter is the Mark green.
3 speed indicators are not interchangeable with the 5 speed as the rods are too thick to enter the hole.