RX-RK5 - Sturmey-Archer alignment question

[chuyeu123]

Hello,
I just purchased the RX-RK5 and installed it on my bike. When I have it on the rack it ran smooth but when I tried to pedal the gear hub keep skipping. I've contacted the seller and they say my drop out is vertical so I need to align the yellow mark with the red mark. Not yellow to yellow. However no matter how hard I cannot reach the red mark. I've tried to google search it but cannot find any material related to my problem. Can someone please help me? I'm so excited to try my bike but keep running into problems.

[Brucey]

http://www.sturmey-archer.com/files/catalog/files/85/MANUAL%20-%205%20SPEED%20ROTARY%20HUBS.pdf

[chuyeu123]

Hi Brucey,

Yes, that is the manual I've been following. However, no matter how much I stressed the cable/gear, physically it stopped halfway between the yellow mark and the red mark (as you can see on my photo) . That's why I was wondering if there is another way to adjust this.

[Brucey]

….. no matter how much I stressed the cable/gear, physically it stopped halfway between the yellow mark and the red mark (as you can see on my photo)……......

you shouldn't need to apply much stress on anything to change gear, and it is possible to damage things if you apply excessive force.

Once the gear is run-in shifting should be fairly easy. However although it doesn't say this in the manual (recommending shifting whilst pedalling forwards under no load, and shifting at a standstill), most SA gears shift easiest whilst the hub is in motion, e.g. particular downshifts in some hubs (perhaps not this one) between some gears are eased by backpedalling.

So if you have not attached a chain yet, do so, and it is best to have the bike upside down or in a workstand and to shift whilst the hub is in motion, especially when the hub is new. If you do this is there any difference in behaviour?

cheers

[chuyeu123]

Hi Brucey,

I can align the shifter to the yellow line at 2nd gear. When I adjust the shifter to the yellow line it shifted fine. It go through all 5 gears with ease. When I have it on the rack i can pedal all the gear without skipping. However, when I start put load hence pedaling, the gear skipped even at first gear. So I read the manual and says that because my bike is more of a vertical drop out so I have to adjust the shift to match with the red line but my problem is that the shifter doesn't go to the red line mark. i.e. at 2nd gear the yellow need to line up with the red mark.

I'm sorry I don't know how to explain in any other way.

I'm very thankful for your patience to help me with this

[Brucey]

which mark have you aligned the fulcrum arm with? (step 3.2 in the manual) This defines how the rest of the gear setup progresses. The instructions for gear setting with vertical dropouts are only relevant if you have set the reaction arm to the appropriate position in 3.2.

NB the fulcrum arm can go on the hub seventeen different ways, but it is only designed to be used in three of them.

Also I note that in the photo you don't appear to have used the correct lockwashers on the axle; if so the hub well never work properly and indeed may be damaged the first time it is used; there is a large reaction torque transmitted through the axle and this is only resisted by the lockwashers.

cheers

[chuyeu123]

Hi,

I understand what you are saying. However beside using the washer that come with it I also add my own torque arm which I believe will give it additional strength.

And yes I set the level in the S as the manual suggested.

I understand the manual but I can’t get it to the red mark. As you can see in the photo in second gear I can align the yellow mark but the gear max out halfway between the red mark and the yellow mark. My question is that how can I calibrate your the red mark when the gear doesn’t reach to the red mark.

[chuyeu123]

Additional photos.

The first photo shows it is as far as it can go. I cannot get to the red mark

The second photo to show I know how to calibrate it at 2nd gear to the yellow mark but not the red mark
Thank you

[Brucey]

it says quite clearly in the manual that you should only worry about the red mark if you use the fulcrum arm 'V' position, which you say you have not. So I suppose you should align the yellow marks as indicated for the R and S positions. Your dropouts appear to be angled most closely to 'S' type so I agree that this setting is the most appropriate, provided you intend to route the gear cable along the chainstay.

I am somewhat baffled by your additional torque reaction arm; it has the wrong sized/shaped hole in the centre so I can't see how it could possibly do any good; it simply won't engage usefully with the axle.

I can see that you have used the tabbed lockwashers; however I am not convinced that they will do any good where they are; they are meant to withstand torque in both directions, and if the tabs don't fit in the dropout slot closely, they can't really do this. There may be a more appropriate lockwasher than the standard ones that come with the hub, meant for S,R dropouts which appear to be the ones you have used; for example the lockwashers meant for 'V' type dropouts may be a better fit. [Note of caution; the V-type washers I think are made from something more brittle, so if they are used on dropouts which are not flat, they can crack.]

BTW the free travel in the shift mechanism in the hub is a close match for the cable pull of the shifter. If the shift mechanism always moves with the shifter, the cable setting can't be very far off the correct position.

If the gear is slipping when the settings are correct (yellow marks aligned in gear 2) then this likely means that there is an internal fault in the hub, the cable is draggy for some reason, or perhaps that the cable is being pulled out of adjustment (eg because the axle is turning under load because the lockwashers are not working as they should). It doesn't take many slippages under load before an IGH like this one is likely to be damaged internally.

cheers

[Sid Aluminium]

which mark have you aligned the fulcrum arm with? (step 3.2 in the manual)

And how long is the cable anchorage unit distance? This distance changes with different fulcrum arm alignments. (step 3.9)

[Sid Aluminium]

Fun fact: the factory instruction sheet for the RX-RF5 (C50) hubs - specifically the alignment of the shift fulcrum, the setting of the cable anchor, and the shift alignment sections - has gone through at least three revisions: ©2014, ©2015 and ©2016.

[recycle]

I have the same problem with four hubs that I have bought for customer's all with vertical dropouts. Three where from NL the other from the UK and they were all faulty, the red line will not line up with the yellow line and this was in 2022, two years after the problem first surfaced. they are sold not fit for purpose by the sale of goods act.

[Nearholmer]

I have one of these on one of my bikes, and it is a PITA to get set correctly, and to keep functioning properly, skipping being something it defaults to periodically.

I found an interesting video on YouTube, where a guy describes similar issues (possibly with a slightly different model), traces it all through, and cures it by taking the entire change mechanism out and dunking it in automatic transmission fluid, which provided just the right lubrication to get all the finicky little parts inside moving smoothly. I haven’t had time to try it, but I’m certainly going to.