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-   -   Feedback on SA Type W 8 speed IGH (http://www.bikeforums.net/folding-bikes/531327-feedback-sa-type-w-8-speed-igh.html)

konut 04-15-09 10:42 AM

Feedback on SA Type W 8 speed IGH
 
Been soaking up the great posts on the folding forum for the past month. Great info!! I was wondering if anyone has had any experience with the NEW 8 speed hub from Sturmey Archer. The new hub has "Type W" printed on it. The older hub has had a reputation for self destruction over time. The new hub has a wider ratio of 325% vs 305% for the older one. Specs can be found here.
http://www.sturmey-archer.com/pdfs/s...1(2009-03).xls
Click IHS80 at the bottom of the PDF.
Because of the construction of the hub, significantly smaller chainrings can be used. This would benefit clearance issues.

tcs 04-15-09 12:26 PM

I've had one in service for the last three weeks - not long enough for any kind of reliablity/durabilty evaluation.

My aftermarket SA8(W) hub came well packaged, complete with the required shifter and cable, anti-roation washers which can be used for vertical, horizontal or slanted dropouts, acorn nuts, plus a 25T cog (for 1/8" chain). There was a two-page installation and set-up document, but no overhaul instructions, exploded diagram or parts list (and those documents haven't showed up yet on Sturmey's web site, either).

The new SA8(W) is husky compared to the old version, and that hub shell contains much beefier parts, so at least SunRace acknowleged the past problems and there has been an attempt to make the original design they inherited from the old British SA more robust. Time will tell.

(The local shop that built this hub into a 36 spoke, 16"/ISO349mm wheel for me made a hash of the job, but this was in no way any fault of the hub.)

The hub is easy to connect/disconnect without tools and initial shift alignment is easy and tolerant. The hub seems to stay in adjustment well.

Despite sounding like poor technique to me, in the last few years "shifting under pedal pressure" seems to have become the touchstone for modern bike drivetrains. If shifting under pedal pressure is your bag, the SA8(W) will disappoint. While it doesn't like to shift under pressure (just like every multi-gear bike I've owned for the last 40 years), it does shift quickly and quietly if I ease up.

My SA8(W) makes a soft gear-mesh noise in 4th gear (and only 4th gear) but otherwise is smooth through the pedals.

The 325% overall range (and the straight, "no dump" chainline!) is an improvement over the 8 rear-derailleur derived gears that came from BikeFriday on my tikit. The 30%-14%-14%-14%-14%-14%-30% steps work fine for me on my folder (YMMV). I'm geared 39/25, which gives me a 25-81 gear inch range on the tikit.

I'll try to keep the community updated over the next several months as I put more miles on this hub.

Best,
tcs

konut 04-15-09 01:35 PM

Thanks so much for the detailed review!! Excellent! Very encouraging! Looking forward to updates.

rhm 06-03-09 09:55 AM

I have the new X-RF8w hub on my Downtube Mini. Long story, but the short of it is that I took the bike with the older X-RF8 hub (it's got maybe 5500 miles on it from two years of riding) to my LBS for an overhaul, and the head mechanic killed the hub. Ended up charging me $120 labor, plus tax, for which I got a whole new wheel with the new model hub. I believe Sturmey Archer supplied it for free.

At this point my hub has about 75 miles on it, and I like it a lot.

But I gather tcs is having trouble with his.

tcs, want to vent?

tcs 06-03-09 12:18 PM

Not vent, but I'd be happy to share.

Coming home on the bike recently, I shifted into 3rd ratio...and it just wasn't there. Great big neutral. By the time I got home, 4th ratio was the same way.

This is with less than 250 miles on the hub.

I found by pushing the bike backwards ten feet or so, 3rd and 4th gears would hook up and return, but only work until the next shift when they would again be neutrals. I don't think anything is broken, it's just the internal selector doesn't seem to lock into those gears.

I was waiting for Sturmey's response to my issues before I went public, but I emailed them two weeks ago and haven't heard anything yet.

In the meantime, I'm riding the bike with a SRAM iMotion3 hub. If you can get along with just three ratios, this is a great gearset. Not many miles on it yet either, but so far I'd say it's the best three speed hub I've ever used.

tcs

Dahon.Steve 06-03-09 10:30 PM

Quote:

Originally Posted by tcs (Post 9034952)
Not vent, but I'd be happy to share.

Coming home on the bike recently, I shifted into 3rd ratio...and it just wasn't there. Great big neutral. By the time I got home, 4th ratio was the same way.

This is with less than 250 miles on the hub.

I found by pushing the bike backwards ten feet or so, 3rd and 4th gears would hook up and return, but only work until the next shift when they would again be neutrals. I don't think anything is broken, it's just the internal selector doesn't seem to lock into those gears.

I was waiting for Sturmey's response to my issues before I went public, but I emailed them two weeks ago and haven't heard anything yet.

In the meantime, I'm riding the bike with a SRAM iMotion3 hub. If you can get along with just three ratios, this is a great gearset. Not many miles on it yet either, but so far I'd say it's the best three speed hub I've ever used.

tcs

Interesting.

It seems like the only bomb proof Hub Sturmey Archer makes is the 3 speed! I don't know why can't make a solid 8 speed hub? Anyway, Why didn't you go ahead and buy the Nexus 8 Speed Hub? I don't think I've heard anyone complain yet and it seems like a good product.

tcs 06-04-09 06:39 AM

Quote:

Originally Posted by Dahon.Steve (Post 9038601)
Why didn't you go ahead and buy the Nexus 8 Speed Hub?

You mean, other than the Shimano being harder to demount, more expensive and having less advantageous ratios, or are you asking if there's a non-obvious reason?

Best,
tcs

tcs 06-04-09 06:41 AM

Quote:

Originally Posted by Dahon.Steve (Post 9038601)
It seems like the only bomb proof Hub Sturmey Archer makes is the 3 speed!

What are your complaints with their 5-speeds?

tcs

rhm 06-04-09 06:48 AM

Quote:

Originally Posted by Dahon.Steve (Post 9038601)
Interesting.

It seems like the only bomb proof Hub Sturmey Archer makes is the 3 speed! I don't know why can't make a solid 8 speed hub? Anyway, Why didn't you go ahead and buy the Nexus 8 Speed Hub? I don't think I've heard anyone complain yet and it seems like a good product.

I have a Nexus 8 on my touring bike. It is a very nice hub. The gears are not as evenly spaced as the Sturmey Archer 8, though; in particular there's a pretty big step between 5 and 6, that kinda throws off my cadence since that's right where my shifter is most of the time. But enough whining.

The real problem is that Nexus-8 is geared too low for a bike with 16" wheels. I like a range of 28 to 88 gear inches; on my touring bike, that's 19T/38T (cog/chainring). To get there on my folder I'd have to do 16T/66T or something. The 16T is no problem, but a 66T chainring is not readily available. I don't remember exactly why, but Sheldon (peace be upon him) said you can't use smaller than 16T on the nexus.

bromptonS8 06-04-09 09:42 AM

rhm - I am not sure what folder you have, but for one with 16" (349) wheels, a 52/16T combination gives you the range you want (according to Sheldon Brown's internal gear calculator).

tcs - I think there was something on the Brompton Yahoo list about needing to break in the XRF-8(w) hub with the adjustment a bit off of the alignment marks - I imagine you have tried this. Please keep us posted - I have a 16" rim waiting for a hub and I prefer the ratios of the XRF-8 over the Alfine.

itsajustme 06-04-09 09:48 AM

Quote:

Originally Posted by Dahon.Steve (Post 9038601)
It seems like the only bomb proof Hub Sturmey Archer makes is the 3 speed!

I don't necessarily think this is a fair conclusion. tcs's hub probably just needs to be broken in.

Has anyone actually destroyed an old SA8 through riding other than Jur or are the complaints just about poor shifting? Because the shifting on my old SA8 has only gotten better with use.

Joako 06-04-09 10:30 AM

Quote:

Originally Posted by rhm (Post 9039656)
I don't remember exactly why, but Sheldon (peace be upon him) said you can't use smaller than 16T on the nexus.

Because the shifting mechanism is integrated instead of using a clickbox. Therefore you need a dished sprocket. If you use a flat one, then the chain might rub against the hub. The low gears was the main reason I sold my Curve SL. Highest chainring I have seen in 130 BCD was 70T (custom made), and the highest one I found from an online retailer was 60T.

rhm 06-04-09 12:28 PM

Quote:

Originally Posted by itsajustme (Post 9040730)
Has anyone actually destroyed an old SA8 through riding other than Jur or are the complaints just about poor shifting? Because the shifting on my old SA8 has only gotten better with use.

I agree, shifting gets better when the hub is broken in, like after 1000 miles. After that there was a long period when the adjustments were easy and lasted a long time. But as the hub got on towards 5000 miles on it, adjustment got very difficult. I did partial overhauls several times, getting modest improvements each time, but it was a lot of work. The hub was in rough shape, but not destroyed, when I dropped it off at the bike shop in March. Mileage on the hub was about 5300 at that point. So arguably the mechanic destroyed it, and riding did not. The hub is pretty destroyed, too! I thought I'd try to fix it at some point... probably a waste of time, though.

tcs 06-15-09 08:59 AM

Quote:

Originally Posted by itsajustme (Post 9040730)
tcs's hub probably just needs to be broken in.

Not sure how one would break-in a hub with inoperative gears.

Sturmey responded (after three weeks) and said they had some problems with the engagement pawls on the (W) hubs. They have offered to send me a replacement X-RK8(W).

Best,
tcs

rhm 06-15-09 09:13 AM

Quote:

Originally Posted by tcs (Post 9103635)
... They have offered to send me a replacement....

I imagine you accepted that offer?

K6-III 06-15-09 05:34 PM

Please keep us updated on your progress. I'll be ordering an XRD8(w) to test pretty soon and I'll be sure to chime in when its up and running.

Joako 06-15-09 08:10 PM

Where can we get one of this (W) hubs? All the online sellers advertise them without the (W). How is the efficiency of the hub? Is it better than a nexus/alfine apart from the ratio? I am planning on getting an IGH in my Xootr and the SA 8 is the best option due to the ratio I can achieve, but I am hesitant due to its reliability.

K6-III 06-15-09 09:59 PM

The (W) hubs are shipping through www.biketoolsetc.com and any bike shop that can order through United Bicycle Supply. It also seems that the drum-brake variant is already in stock at QBP (XRD8 (w))

ChiapasFixed 06-15-09 10:07 PM

in terms of gear ratios, my 16"-wheeled Seasons Tikit has an 8 speed Alfine hub, with a 53 tooth chainring and a 16 tooth cog, it gives me all the gears I need for city riding and even loaded touring over mountain ranges: 27.5 to 84.3 gear inches. no dramas!

tcs 06-16-09 06:19 AM

Quote:

Originally Posted by Joako (Post 9107688)
How is the efficiency of the hub? Is it better than a Nexus/Alfine apart from the ratio?

AFAIK neither the Sturmey 8 nor any of the many Shimano 8 variants have been empirically tested for efficiency. Because of the way the Sturmey creates its ratios, some have theorized it is relatively efficient, but real world efficiency depends as much on small details of construction as general design. The ten different Nexus/Alfine 8-speed models released by Shimano to-date certainly have different efficiencies.

I'm always amused that cyclists fuss over the efficiency of IGHs but never raise a peep about efficiency in derailleur gear drivetrains (and yes, it can vary quite a bit!)

Best,
tcs

jur 06-16-09 07:57 AM

Quote:

Originally Posted by tcs (Post 9109256)
AFAIK neither the Sturmey 8 nor any of the many Shimano 8 variants have been empirically tested for efficiency. Because of the way the Sturmey creates its ratios, some have theorized it is relatively efficient,....

...while I have theorised that the efficiency depends on the gear you're in, because of the way the ratios are created! :D The 3 planet systems operate in cascade; so efficiency must be the mathematical product of each system in use, ie if each system by itself is roughly 92% (gears 2,3 & 4) the the next set which use 2 systems in cascade (gears 5, 6 & 7) would be 0.92^2=85%, and 8th gear where all 3 systems are cascaded, would be a meagre .92^3=78%! :eek:

ChiapasFixed 06-16-09 07:19 PM

I generally find the Alfine to FEEL more efficient than the Nexus redband. Perhaps this is because it is quieter, smoother, or perhaps it has to do with the fact that the Nexus is spinning 24" wheels while the Alfine runs 16" ones. Or maybe the different geometries of the bikes have to do with it.
In general, I am generally happier with the Alfine, and with the general feeling of the Tikit, generally.
But this is, of course, a generalization...

alhedges 06-16-09 09:52 PM

Quote:

Originally Posted by itsajustme (Post 9040730)

Has anyone actually destroyed an old SA8 through riding other than Jur or are the complaints just about poor shifting? Because the shifting on my old SA8 has only gotten better with use.

I have a friend who destroyed both a Nexus 7 and and Nexus 8 through riding. He is kind of a big guy (~260), which probably had some effect...but aside from that he didn't do anything particularly abusive. Since an 8 speed IGH is the same size, roughly, as a 3 speed IGH, it may be that some parts have to be made too thin to be durable.

Both of these hubs were on (different) trek navigators.

Dahon.Steve 06-16-09 10:24 PM

Quote:

Originally Posted by tcs (Post 9039635)
What are your complaints with their 5-speeds?

tcs

I haven't destroyed my 5 speed yet but it sounds like a coffee can when operational. To be honet, I haven't used that bike much at all.

tcs 06-17-09 06:36 AM

Quote:

Originally Posted by ChiapasFixed (Post 9113986)
I generally find the Alfine to FEEL more efficient than the Nexus redband.

I'm skeptical that nuances of efficiency can be "felt" by a rider.

Take a ride on a derailleur geared bike in a 39/11 ratio, then take the same ride in a 53/15 ratio. It's the same overall gear, but the larger tooth count set is significantly more efficient. Nobody talks about this because nobody can "feel" it.

Mr. Frank Berto dismissed three-speed hubs as "friction boxes" in his book "The Dancing Chain" because they "felt" inefficient. Imagine his surprise when he and Dr. Chester Kyle conducted instrumented efficiency tests ten years later and found that broken-in and and lubricated three-speed hubs are arguably the most efficient multi-gear drivetrain a cyclist can use.

BTW, an Alfine SG-S501 and Nexus SG-8R36 are identical in internal construction.

tcs


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