Converting a derailleur to internal gear hub

Question

I use my bike for commuting and trips around the countryside (about 400-500km per trip). I'm tired of changing the chain and gears (when I overdrive the chain's lifetime - my bad, I know) as often as I do. Soon I would need to replace the chain, front gears, cassette and a broken rear axel, so I thought maybe it would be the right time to invest in an internal hub coupled with a rear chain tensioner?

I'm planning on increasing the range of the trips to about 1k-2k and a mechanic told me I would need to change the chain in about every 500km (I weigh 100kg + the bags and quite heavy-footed). I'm hoping the internal hub would prolong the chain's lifetime and, as it uses a singe gear, the maintenance will be cheaper. If the 7 or 8-speed hub is sufficient, I would also convert the crankset to a single gear. I have Trek 7100 and the dropout spacing should be 135mm. It has V-brakes.

My questions are:

• do you guys think this would solve my problems with lifetime and be feasible in the long run?
• if so, then which hub would you recommend?
• would a 3-speed internal hub be sufficient coupled with a 3-speed crankset?

Best regards, Max

Answer 1

Yes - you can use an IGH with multiple chainrings, but there must be an effective way to take up the slack, which means a chain tensioner. But should you?

A Shimano Alfine 11 has 11 gears and a range of ~400%. The Rolhoff has a range of 500% over 14 gears. So changing chainring will give even more range - question is whether its in a useful part of the gearing.

I ran the alfine11 on a triple chainset, and I never ever needed the grannie gear, not even going up the steepest hills. I did use the middle occasionally, but it was very hard to change when doing sub-5 km/h speeds. In the end I just stayed in the big chainring on the 15% grade.

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Tube changes are totally possible with an IGH - depending on how its controlled you may have a power cable to unplug, an inner cable to unhook, or maybe nothing if it has an internal battery and Di2 wireless control.

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I ran an IGH in some short dropouts fine - they come with antirotation washers that sit into the dropout. Upshot you require dropouts to be long enough for the axle and about the same again for the washer's tab. Ideally the dropout would be parallel, mine was "pacman mouthed" and that caused problems if it weren't tightened enough. So I added a 15mm spanner to the kit and all was well.

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Most shimano IGH need an oil change yearly or every 5000 km. Rohloff is a little longer from memory. So there is still maint to be done, but its a cleaner system overall than a derailleur.

Do note that most IGH leak oil a little, specially when parked. So consider what's underneath.

Shifting while stopped is a neat party trick of the IGH, something the derailleur can't do, and very handy if you fast-stop at a red light with no chance to change gear.

You might consider waxxing your chain instead of oiling it. There's some equipment needed, and its a messy process, but the chain remains much cleaner over time.

For touring, a 3 speed IGH will lack the range. Most of them are plus-minus 33% and that's a large jump in gearing. You're looking at 7/8 gears in a Nexus, or 11 gears in an Alfine, or 14 gears in the Rolhoff Speedhub.

Finally, any IGH will require a rear wheel rebuild. They're all wider than any normal hub, so you will need spokes of appropriate length. Its not impossible, but its not simple either.

I think your next ride, wipe down the chain every day after arriving at camp, and give it some chain lube daily. That alone will help you. Give the chain a deep clean about a week before you set out.

Answer 2

do you guys think this would solve my problems with lifetime and be feasible in the long run?

I think you have a major chain cleanliness problem. Most likely from oiling a chain that doesn't require new oil, or letting a chain run completely dry with major squeaking. There's a good middle ground in oiling: oil only a chain that barely starts to be noisy and clean it before oiling, and remove excess oil after oiling. That, or you buy only the cheapest chains made from the worst possible steel. Decent chains ought to last far more than that, 3000 - 4000 km. I weigh 110 kg and my derailleur chain has been fine for last 3000 km despite the fact that it's an e-bike and rumor says e-bikes wear chains much faster than non-e-bikes.

Also do note that in internal gear hubs, you need to adjust the chain tension several times in its lifetime, so maintenance needs are not really reduced. This requires horizontal dropouts. With vertical dropouts, internal gear hub might not be feasible or at least requires a separate chain tensioner (thus causing the problem of derailleur systems where a new chain can skip over a worn sprocket) or an eccentric bottom bracket.

Do note it's a major chore to repair a rear puncture in internal gear hub systems and your fingers will be stained in chain oil if attempting such a repair.

Also, if you let a chain wear to a condition worse than is typical for derailleur systems, you probably need to change both front and rear sprockets on an internal gear hub system. Also don't forget that internal gear hubs might need services such as oiling.

if so, then which hub would you recommend?

One that comes with a frame included -- a hub that is attached to a complete bike. The reasoning being that 99% of derailleur systems today have vertical dropouts, and internal gear hubs are not really feasible on such frames.

would a 3-speed internal hub be sufficient coupled with a 3-speed crankset?

This needs a chain tensioner, thus bringing back some of the problems of derailleur systems. Usually internal gear hubs are chosen for the ability to not have a chain tensioner, thus allowing only 1-speed cranksets.