shimano hub reliability in the kalkhoffs

[Joe]

I suppose a brief pdi will not always pick up a problem with hub gears though the owners have been on to it quick enough. I dont know how many owners of the kalkhoff exist on the forum but i have counted 4 duff hubs now.

apparently there has been a much increased demand for hubs generally maybe this has caused quality issues when production was stepped up to meet the demand?!

It will be interesting to see if the pro connect buyers report better intial reliability from the nexus 8.

 

[flecc]

The Nexus Inter 7 has been a very reliable hub gear for years, and it appears that there's probably a faulty batch. Judging from the reports of failing to change into all gears, it's probably a problem with machining tolerances making the new assembly too tight running. These hubs are often a bit sluggish to change when brand new but change smoothly after a hundred miles or so, but this last batch seem to be a bit worse than that.

The Inter 7 on the Agattu I tested at the beginning of December last, which had done 140 miles when I received it, performed faultlessly, the change as slick as anyone could expect as I reported.

I doubt whether this will affect the Inter 8 on the Pro Connects, as that is a completely different and later hub design. That had some teething problems on the first manufactured batch that appeared at it's introduction but have been past that for some while now.
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[flecc]

P.S.

I've just seen Robin report on his new Agattu and his remark on reluctance to change into 7th, which he fixed with an adjustment tweak at the cable handlebar end.

I suspect that some of these have just been needing a bit of use and adjustment, rather than being faulty. A bit like the SRAM P5 hub which is always very reluctant to find it's bottom gear until it's done a few miles and loosened up.
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[robert44]

My Shimano gear hub operates faultlessly and slickly, unfortunately 6 and 7gears are no higher than 5th. The gear adjustment is correct ie the red adjustment marks are in line, so no solution there.
I am now waiting for a replacement wheel/hub.

 

[flecc]

The changer and cable are operating ok, but the change isn't faultless and slick Robert, since you are only getting 5th in the three higher gear positions. The internal change cam action is spring transmitted, and on your hub there is internal tightness resisting the thrust of the spring. That's why I suggested manufacturing tolerances probably being at the root of the problem.
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[robert44]

Thank you Flecc.
I guess what I was trying to say was that to all appearences the gear change seemed ok, but without any change for the benefit. Like you I concluded that there was a manufactured defect and 50 cycles also agree. I believe mine is not the first hub that they have had to replace.
Thanks again for the explanation.

 

[flecc]

Yes, I think there's been at least a couple more of these with the upper gears not available. We'll have to see if musicbooks' one is the same, as his 7th gear is in question until he's checked out the adjustment.
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[Joe]

all the more frustrating that the nexus 7 is proving unreliable now in such an expensive bike. i wonder how many bikes could be effected by one batch?
and would it be reasonable to expect this to be spotted at pdi stage?

does anybody know if the pro connect nexus 8 is the premium model.the premium model is supposed to have better seals and be slicker in operation than the standard nexus 8.

 

[flecc]

and would it be reasonable to expect this to be spotted at pdi stage?

Only if the bike was ridden some way to get a check at speed. In my experience this sort of hub fault is extremely rare, and they are usually assumed to work ok when new, as that is the norm for Shimano. Their products are usually very consistent.

does anybody know if the pro connect nexus 8 is the premium model.the premium model is supposed to have better seals and be slicker in operation than the standard nexus 8.

I don't know, but given the aiming of the Pro Connect at the top end with all the other components quality types, I think it could be. I wouldn't be surprised if Shimano just "lose" the Standard one now, since the Premium core is also used in the Alfine model. I doubt they'd want to continue with three 8 speed hubs in the range.
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[echowind]

The premium nexus hub gear has a red line around the hub. Until quite recently some naughty bicycle manufacturers have been using the old version. Halfords to their credit used the premium version on their carrera. For the last two years just after Christmas they have reduced the price of the carrera subway8 from over £400 to a bargain £279 and that includes the shimano roller brakes.

 

[musicbooks]

I suppose a brief pdi will not always pick up a problem with hub gears though the owners have been on to it quick enough. I dont know how many owners of the kalkhoff exist on the forum but i have counted 4 duff hubs now.

apparently there has been a much increased demand for hubs generally maybe this has caused quality issues when production was stepped up to meet the demand?!

It will be interesting to see if the pro connect buyers report better intial reliability from the nexus 8.

No problems to report so far on my diamond Agattu
BW
musicbooks

 

[flecc]

If it's ok to start with, it's very unlikely you'll get trouble if the hub is used normally and not abused. As I've remarked on a number of occasions, it's alwasy best to pause pedalling when changing gear on hub gears, ignoring Shimano's advice to the contrary. I'm sure that advice comes from their marketing department more than from their technical side, and it's especially important to ignore it when two power sources are fed simultaneously through the hub, rider and motor.
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[Joe]

An a2b letter reported on use of hubs for all out speed and constant pressure through gear changes leading to 2 hub failures in quick succession. The editor of velovision has also commented on his strong cycling style causing problems with hubs. I think a hub should be valued for its strengths: changing gear when stationary, weather protection, ease of chain care.Rather than looking for the speed and slickness of top derailler systems.