Hub gear ideas

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fatboy
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Hub gear ideas

Post by fatboy »

I commute 15 miles a day in all weathers on my trusty tourer however I get through chains etc at quite a rate. So I am pondering whether a retro fit hub gear would be better. Trouble is I am a cheapskate (£1000 on a Rohloff, I don't think so, also di2 Alfine isn't my thing either) And I want a big gear range. So my idea is a Nexus or Alfine 8 with a rear mech as a chain tensioner and a double chainring up front (shifting by downtube shifter) to get low gears.

So am I barking mad, spot on or otherwise? Or are there other hubs to consider?

Thoughts please.

Cheers Chris
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
Elizabethsdad
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Re: Hub gear ideas

Post by Elizabethsdad »

I can highly recommend the Alfine 8. I have found it's range to be wide enough but if was going to extend it I'd fit a Schlumpf drive.
Trikeyohreilly
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Re: Hub gear ideas

Post by Trikeyohreilly »

I see your thinking but arent you only loseing a cassette that way?

With double chain rings you might only be able to use a narrow chain which would be just as likley to wear. If thats true you have just added weight but not made it any tougher.

The nexus I had wasn't too bad a range but yes more is nearly always welcome.
fatboy
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Re: Hub gear ideas

Post by fatboy »

eddiewalkling wrote:I see your thinking but arent you only loseing a cassette that way?

With double chain rings you might only be able to use a narrow chain which would be just as likley to wear. If thats true you have just added weight but not made it any tougher.


Hmmmm I see this needs more thought!
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NUKe
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Re: Hub gear ideas

Post by NUKe »

piggy backing on this anybody any clever options for elgantly fitting hub gears into frame withvrtical d drop outs. I 've been thinking of doing similar to my Dahon espresso. But want an elegant solution so I can use a chain guard (I dont need the double upfront)
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townbikemark
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Re: Hub gear ideas

Post by townbikemark »

fatboy wrote:I commute 15 miles a day in all weathers on my trusty tourer however I get through chains etc at quite a rate. So I am pondering whether a retro fit hub gear would be better. Trouble is I am a cheapskate (£1000 on a Rohloff, I don't think so, also di2 Alfine isn't my thing either) And I want a big gear range. So my idea is a Nexus or Alfine 8 with a rear mech as a chain tensioner and a double chainring up front (shifting by downtube shifter) to get low gears.

So am I barking mad, spot on or otherwise? Or are there other hubs to consider?

Thoughts please.

Cheers Chris


Consensus (Brixton Cycles & Kinetics) seems to be that the Nexus can be delicate (get the Red Band version) and the Alfine is more robust. Woulda thought the range to be adequate as it sounds like you're a seasoned cyclist commuting 15 miles daily.
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xcalibur
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Re: Hub gear ideas

Post by xcalibur »

I have never missed gear range on my Nexus 7 and Sram i-motion 8, and they lasted for years with out much fuzz, but I should have had them serviced and regreased more often. The new ones are suppose to be even better (alfine and sram G8). I got into trouble with the Nexus 7, water, salty roads and it rusted. I had to replace the etire internal assembly at one point, but it was still considerably less costly than replacing deraileur chain, cassette and drive. The 8 speed bike is still alive at the family summer cottage. Some of these hubs are not that watertight, the end capsule leave an opening of up to 1-2 mm, (some have caps which close more tightly). Yearly cleaning and regreasing are probably a must on commuter bikes. I think the most watertight hubs would be Alfine, they are oiled not greased. I don't know how to tackle the vertical dropout problem other than using a different frame, but I found this page. With a small chain tensioner, there still should be room for a chain guard. I don't recommend rim brakes with hub gears, it's so annoying when you have to replace rims. There are disk and coaster brake options for most hub gears I think, even drum brakes on Sturmey Acher.

There are loads of clever chain tensioners available that might work for vertical dropout frames.

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Last edited by xcalibur on 18 Oct 2013, 10:05pm, edited 2 times in total.
Elizabethsdad
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Re: Hub gear ideas

Post by Elizabethsdad »

NUKe wrote:piggy backing on this anybody any clever options for elgantly fitting hub gears into frame withvrtical d drop outs. I 've been thinking of doing similar to my Dahon espresso. But want an elegant solution so I can use a chain guard (I dont need the double upfront)

With Shinano IHG units you get different non-turn washers depending on your drop out. For a verticle drop out it is blue on the drive side and green on the non-drive side. Horizontal drop outs are yellow NTWs I think.
fatboy
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Re: Hub gear ideas

Post by fatboy »

townbikemark wrote:
Consensus (Brixton Cycles & Kinetics) seems to be that the Nexus can be delicate (get the Red Band version) and the Alfine is more robust. Woulda thought the range to be adequate as it sounds like you're a seasoned cyclist commuting 15 miles daily.


The desire for a bigger range is for when I take the tourer touring. My ideas for the double up front came from the description of Chris Bell's Dahon using an arrangement like I describe. I think I am concluding that the answer might be an N+1 hub gear bike :D
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CREPELLO
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Re: Hub gear ideas

Post by CREPELLO »

I spoke with a local today who's fitted his 531 tourer with a SA 4 speed hub and a triple chainset up front. It seemed a pretty useful set up from his description.

It may be a compromise in certain respects, but it's cheap to build and pretty damn robust, using a wide spaced chainset suitable for a wider 5/6 speed chain and a friction front shifter. And of course the rear wheel will be dishless.
fatboy
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Re: Hub gear ideas

Post by fatboy »

WaterLab Rat wrote:I can highly recommend the Alfine 8. I have found it's range to be wide enough but if was going to extend it I'd fit a Schlumpf drive.


At nearly £500 this breaks my skinflint requirement!

My basic idea is to have a perfect chainline for the higher range and less good for the baleout front cog. Not elegant but surely should be less stressful on chains than dodangler set Ups!

What is the basic maintenance regime of an Alfine hub?
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RickH
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Re: Hub gear ideas

Post by RickH »

The double chainrings & Alfine 8 combination has performed well on my Circe Tandem (to be pedantic it is actually a triple but uses the inner for the timing chain). That uses a rear mech style, 2 jockey wheel tensioner to keep the chain in order.

My only minor niggle is that I would prefer a bigger difference between the chainrings (currently 52/39) to widen the gear range, but I do live in a particularly hilly spot - regularly riding it solo down & then back up a short stretch that gains/loses 250ft in 1/2 mile if I've been to take the grandchildren out. :D

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Brucey
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Re: Hub gear ideas

Post by Brucey »

fatboy wrote:
townbikemark wrote:
Consensus (Brixton Cycles & Kinetics) seems to be that the Nexus can be delicate (get the Red Band version) and the Alfine is more robust. Woulda thought the range to be adequate as it sounds like you're a seasoned cyclist commuting 15 miles daily.


The desire for a bigger range is for when I take the tourer touring. My ideas for the double up front came from the description of Chris Bell's Dahon using an arrangement like I describe. I think I am concluding that the answer might be an N+1 hub gear bike :D


Shiimano make an Alfine tensioner (two actually) for exactly the arrangement proposed by the OP

Image

Re the robustness of the Alfine vs Nexus 8s gears; there are three main issues;

1) clutches and pawls; later hubs have more of the (quieter, more reliable) roller clutches. The earlier ones occasionally give trouble and spare pawls are not available. Slippage (because of bad adjustment or a sticky cable/cassette joint) overloads pawls and can damage them.

2) Planet pinions; later versions (red band/alfine) use roller bearings which wear less (if the lubrication is bad, which it usually is..) and have less friction, too. You should get five or ten years out of the plain bearing ones if you keep them well lubricated.

3) gear selection pawls; these are in the axle assy and are essentially identical between Alfine and Nexus models, so no real difference there. In any case the trick its to keep the gear well adjusted and the cassette joint free of sticky crud. Bad adjustment/cable problems lie behind most problems with 1) and 3), I reckon.

The OP's idea is far from daft or anything, all the parts are readily available.

However I would question the need for a really wide gear range on most commutes; there might well be an easier way.

For utility bikes, older SA hubs have much to recommend them. I am loathe to say this in some ways, but many of the newer designs are not as robust or well made.

cheers
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fatboy
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Re: Hub gear ideas

Post by fatboy »

Brucey wrote:Re the robustness of the Alfine vs Nexus 8s gears; there are three main issues;

1) clutches and pawls; later hubs have more of the (quieter, more reliable) roller clutches. The earlier ones occasionally give trouble and spare pawls are not available. Slippage (because of bad adjustment or a sticky cable/cassette joint) overloads pawls and can damage them.

2) Planet pinions; later versions (red band/alfine) use roller bearings which wear less (if the lubrication is bad, which it usually is..) and have less friction, too. You should get five or ten years out of the plain bearing ones if you keep them well lubricated.

3) gear selection pawls; these are in the axle assy and are essentially identical between Alfine and Nexus models, so no real difference there. In any case the trick its to keep the gear well adjusted and the cassette joint free of sticky crud. Bad adjustment/cable problems lie behind most problems with 1) and 3), I reckon.



Sor are late Nexus red band and alfine similar in terms of reliability generally? What is a recommended servicing regime for these things. Is it a take apart once a year and lube in some special way?

Brucey wrote:The OP's idea is far from daft or anything, all the parts are readily available.

However I would question the need for a really wide gear range on most commutes.

cheers


This is a tourer that I still want to be able to go touring on and when we go touring we do silly things like ride up Great Dunn Fell, Honister Pass and Rosedale Chimney Band. So hence the need for low gears (I go down to 20" on the current set-up). However I don't often use the low gears. I don't really want to get another bike as the tourer has nice things like a hub dynamo and is a comfy as an old arm-chair (and as frayed around the edges!).

I am coming to the conclusion that unless I had a hub-gear specific bike (so no chain tensioner etc), or something as bombproof (I know they aren't 100% reliable, nothing is) as a Rohloff, the reduction in maintenance may be limited with the added risk of the stuff being hidden away if it all goes bad! I think that I'll stick to the current arrangement but consider something hub gear when the next cycle to work window opens up.
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Brucey
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Re: Hub gear ideas

Post by Brucey »

there isn't a very great difference between late red band and alfine hubs internally. Alfine allows you a disc brake option and has a different RH seal I think.

Once or twice a year hub relubrication/maintenance is a good idea. First time round there may be some running-in debris, so there is something to be said for cleaning the internals properly. After that I'd regard further cleaning as optional. If you use the right lubricant simply adding more of it at services is generally sufficient, hence drilling the hub for a lube port is a good idea. This way the hub never runs low on lubricant, either; however the consequence is that the surplus lube may emerge from the hub in use. Generally the surplus comes out on the right side and just adds to the mess made by chain lube etc. However if it comes out on the left it will play merry hell with a disc brake, of course.

I'm using a special semi-fluid grease in a red band Nexus at present and the gear runs very well in it; as smooth as running in oil, but quieter and with less leakage when standing.

I don't think the added maintenance of a single pulley in a tensioner is the end of the world; the one depicted earlier is for vertical dropouts BTW, the other alfine one has two pulleys and is meant for a double or triple front ring.

When correctly cared for, a good IGH can last for many years. I would say that it is possible to ride a good IGH-equipped bike several thousand miles on a single chain, and during that entire time to spend less than five minutes maintaining the transmission despite all-weather use. Of this the single most time-consuming effort is moving the rear wheel to retension a slightly worn chain, usually about once every 1000 miles. I'm considering a tensioner on the next revision simply to avoid this operation; I think a single pulley tensioner (with a large pulley) will sit out of the way above the chain, under the chainstay where it won't get too dirty (unlike a derailleur which dangles more in the crud), and will run smoothly .

cheers
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