weshigh

My brother handed me down his 1980something Bridgestone Sirius bike. I'm thinking of converting it to an IGH+fenders+wider tires to compliment my derailleur+narrow tired bike. It was thinking of getting the Shimano Nexus 8 but my frame is only 120mm spacing. The bike shop that was taking a look at it said the SA X-RF8(W) would be able to fit.

Does anyone have any experience with this hub for commuting? I'll be using this around my neighborhood and also sometimes for my 30mile RT commute to work.

1st gear on the X-RF8(W) is direct drive, and while I don't have any huge hills I'm not the strongest climber, would you be worried about that gearing? Seems like a lot of people use this hub for smaller non-700c wheels.

Any advice would be helpful.

tcs

Couple thousand miles on my XRK8(W); sweet hub. Suggest the companion S-A FCS80 crank.

mconlonx

Gear it down as low as you need. It will look a tad strange, with a chainring not too much bigger than the cog on the hub...

People on the folding bike forum, who typically run 20" wheels or smaller, love this gearing. Not the best solution on full size bikes, but only available solution for narrower dropout spacing.

Airburst

I'm fairly sure Sturmey-Archer say there's a limit to how low you can gear any of their hubs without risking damage from putting too much torque on the mechanism. Gearing the hub lower than their limit will probably invalidate the warranty on it, as well.

Scheherezade 

Anyone have more info on this? I really wanted to lower the ratio below 2:1 on my new SA hub, and there is nothing in my technical manual about limitations.

weshigh

I heard this regarding all the other hubs but can find no solid info on it. Looks like tcs has it geared pretty low with seemingly little problem?

fietsbob

Lesser gear count SA put the direct 1:1 in the middle,
so the reduction gear is in the hub
chainring /cog look not so curious ..

actually the inverse of the overdrive gear. 3/4 & 4/3, for AW3.
Recent S3X is the middle and 2 low gears of the 5 speed.

torque limits are recommended on the low side, not on the higher end,
sticking a huge chainring on and trying to go fast against the wind on the flats,
is just not that hard on the internals, though it may fatigue you.


I have an AW3 hub in my Brompton, folding bike, I got a Schlumpf Mountain
drive 2 speed planetary gear crankset, a 2.5 reduction gear..
a 50t chainring acts like a 20t in low, as the crankarms
turn faster than the chainring then,
and the lowest gear in the hub becomes 4th,
3rd is high gear in the hub, low range in the crank.

A Rohloff hub in a similar manner, uses its 7 speed planetaria
twice, 7 is high in low range, 8 is low in direct gear/high range,
#11 is the 1:1 gear of the chainring/cog/wheel diameter.

so they limit to 2,4 , a 16/38 in a 26" wheel is an excellent gear range
for normal hilly riding ..

Though, in a tandem they use a 16/42 as the minimum.

tcs

As stated, I'm using the Sturmey-Archer FCS80 crank with its 30T chainring which is meant by the company to be used with the XR*8(W) hub. With the 25T cog, this gives me 31-100 gear inches. Sturmey's official company 8-speed IGH show bike @ Interbike 2009 had an XRD8(W) hub, 700C wheels and their fancier FCSX4 crank.

mikeybikes

Sturmey Archer offers the FCS80 crank with a 30T chainring specifically for their S80(W) hubs with a 25T cog. I'm running a XRD8(W) with 26" wheels, 32T chainring and the 25T cog. It's just about right with the gearing.

weshigh

Thanks for that info. Glad to hear! I'll be going down to my LBS later today to discuss.

I see you are using the jtek bar end shifter. Is that working well for you? besides the price it looks great and I'd like to go with that over the twist shifter.

tcs

The Jtek barend is the cat's pyjamas.

I like my S-A XRD8(W), but if that old Sirius is a steel frame (and I think it is), then resetting the OLD to fit a Shimano Nexus SG-8R36 wouldn't be that big of a deal.

tjspiel

I was also thinking that cold setting the frame might be preferred if you'd rather use a Nexus or Alfine. I've done it do a couple of bikes. It's not that hard.

Oh and I have the Jtek shifter as well. I like it and it's made in the U.S.

weshigh

Thanks for the info. I can't seem to make up my mind. Since the Sirius doesn't have a small enough front crank set to work with the Sturmey Archer right now its getting to the point of too expensive to make that conversion happen. Dangerously close to new bike prices by the time its all said and done.So for the time being I think I am going to upgrade my daily commuter to the a Nexus or Alphine IGH, and then migrate the parts I am replacing off my daily commuter down to the Sirius(spare bike). This way the bike I ride daily gets all the new fancy parts and the Sirius gets a modern drive train. I need to rebuild the rear wheel on my commuter anyway as I'm getting too many broken spokes.(3 in 3-4months) I realized that I under bought for the amount of riding i'm doing so its time to upgrade some of those parts!

Think I will still be going with the Jtek though.

tcs

The Shimano 8 is a great hub, but don't do a conversion based around it to save money. A quick price check indicates (in general, depending on where you buy them) an XRF8(W) + FCS80 is still a little less $$ than an SG-8R36 and a fair bit less than an SG-S501. The Sturmey hub also comes with a (twist) shifter, not included with the Shimanos, but if you want to use the Jtek with a drop bar that's moot.

Mr IGH

I'm fed up with SA stuff, the front dyno/drums are good but the IGHs leave much to be desired. I replaced my SA 5 speed drum with a Nexus 8R35/roller brake, night and day. Much better shifting, much better braking. I'm giving up on the SA IGH line until they address the poor shifting issue and develop a seal for the drum cavity that works.

BTW, the Nexus 8 can use the Alfine 8 trigger shifter too.

KrisPistofferson

That SA seems pretty cool, do us a favor and post a review if you end up going with that.