I-Like-To-Bike

Never heard of anyone having that alleged problem. Have you run into it anywhere?

CliffordK

It may have been something I read about the S3X hub a while ago. But, haven't started using that hub myself, and not necessarily the hub of choice for City Bikes.

I just bought a bike with the Sachs/SRAM Dual Drive hub a few days ago. Former rental, of unknown age, but not heavily used. It is built with 8s SRAM components, so somewhere around 20 years old I would guess. Anyway, it does shift into the the high gear which seems to work, but gives a pop every crank revolution or so in that gear. First and Second seems to work fine. Trimming doesn't seem to affect it.

I'll pull the hub apart shortly, and hopefully get some idea of what is going on. But... those hubs can eventually have issues.

CliffordK

It sounds like the problem with the Chinese Dockless Bike Share.

https://www.bikeforums.net/northeast/...l#post19779226
https://www.bikeforums.net/general-cy...graveyard.html

With the Chinese system, one gets a flat tire, one just dumps the bike and grabs another one. And the broken bikes pile up.



The electronic tagging of faulty bikes sounds like a good system, and hopefully is effective.

I-Like-To-Bike

Doesn't sound like a "basic IGH hub" nor an IGH with a skipping or worn gear selector problem.

CliffordK

It is an IGH hub problem.

And, the guts seemed pretty "basic" the last time I had one open. The only difference is that it also has a cassette option.

I have ridden it more since my first post, and with experimenting with trimming, I have realized that it probably isn't the gear selector, but rather something else internal that has worn.

The question still remains whether the CVT now being used on some City Bikes is to make the the bikes easier to ride (thus encouraging more riders), or it is being used due to easier maintenance.

There is a long history of Sturmey Archer 3 speed hubs, and presumably they are relatively reliable. However, I have seen reports of the 5, 7, and 8 speed hubs having more failures.

I can't think of when I've limited my self to just 3 gears. I suppose once I get the Dual Drive fixed, I could give it a try, just finding my favorite sprocket with the cassette, then using the IGH only for a ride. But, my choice might not be the same as everyone else. So, a 3-speed city-bike would likely be a turn-off for me. So... 8 speed vs CVT?

Assuming a Nuvinci is more expensive than an Alfine, then the choice of one or the other has to come down to:

• Better Advertising/More Rentals
• Cheaper Capital Costs
• Cheaper Maintenance.
• Owner's goal to incorporate new technology?
• Manufacturers Rebates?
• Something Else?

RichSPK

I like shifting in my car. I might not miss doing the shifting on my bike. It's an intriguing thought. Does anyone know anything about scheduled maintenance on the Nuvinci CVT system?

noglider 

Citi Bike bikes with 3-speed hubs have a twist shifter. If I rest my hand gently on the shifter, it can cause gear skipping and clunking. It's much too sensitive. This could cause wear in the hub, I imagine. But I blame the shifter more than anything. We know how durable those SA 3-speeds are.

But if the NuVinci is even durabler (to coin a word) than the 3-speed, then even better, because I really like the experience. They must cost a lot more, though. And these rear hubs also have drum brakes. The front hubs of these bikes have dynamos and drum brakes.

ascherer 

Oh, I like 'em. I've just been on my own bike a lot lately. If I spot one in a dock I'll go for that over the other models.

JonathanGennick 

You're in Manhattan, aren't you? If you like the NuVinci, maybe try and get down to 174 Hudson one day and check out what Priority Bicycles has going on. They have a commuter model with NuVinci in the back, and now a dynamo hub and light in the front.

I will have to look for one of the new Citibike models next time I'm visiting my company's home office. Last time I rented one of the three-speed models and took it all the way the Hudson River Pathway. Started somewhere near Battery Park Ballfields, and ended up past 120th. I forget precisely where I quit. Fun ride. Great way to end a work day. Rode the whole way in my suit and good shoes, with my laptop bag bungee'd to the front basket-like-thing. Next trip I am hoping to circumnavigate the island.

noglider 

Next time you're here, give me a call, and maybe we can ride together. The river-edge paths are great in all boroughs.

Thanks for the tip on Priority. That's only a mile from where I live. I tend to prefer drop bars and derailleurs for myself, but I love townie bikes for everyone else. The reason is that I tend to ride longer distances. For short trips, I use Citi Bike.

ascherer 

Manhattan Meetup!

JonathanGennick 

I would love that!

ascherer 

Cool, look forward to it.

tubesocksFred

I've rode the Citibikes w/Nuvinci hubs since early this year. I've encounter a few issues with them.

I feel that the shifter slips ever so slightly while riding. On my commute down the hudson river greenway, I usually ride resting my lower arm on the handlebar just inside the grip area, so I usually leave it in at the highest gear. With the Nuvinci shifter, I sometimes go check the gear and sure enough, it has downshifted ever so slightly. Changing that gear ever so slight is also a little hard, due to the plastic giving a bit before the friction gives away or the 2 cables were not tensioned correctly. They should have had some micro ratchet shifter so I know when I am actually changing gears.

I've also had one instance where the highest gearing seemed too low, thus I was spinning like crazy, but not getting anywhere. On startup from a standstill, the gearing might feel OK, but as my cadence picks up, it doesn't translate to speed. I suspect that there must have been a lack of traction fluid, which is needed for CVT to transfer power from one surface to the other. That was one slow ride back.

Other situations were the gearing felt lower (me and my friend both encountered such situation) compared to the IGH hubbed bikes. Maybe the cables weren't adjusted so that the CVT is geared at its highest ratio.

wilfried

Count me in for a meetup he when it happens.

tcs

Hmm. NuVinci's standard shifter for the N360 & N380 is the C8, but they also offer a C8s shifter, advertised as "extra slip-resistant".

tcs

And that's cool; something for everybody, don't ya' know. That said, 3-speed gearing on bikes has been around continuously since the 1890s so it must work for somebodies.

I-Like-To-Bike

Yeah but who wants 3 speeds or more when a one speed with no coasting capability is so cool?

Staypuft1652

I know, right?

noglider 

I'm not a fixed gear zealot. It's been months since I rode my fixie, but I enjoy it from time to time.

Staypuft1652

Does anyone know off-hand if there is any way to aquire a 3 speed 20 inch wheel? Preferably with an SA hub? My son in law wants to make a 3 speed bmx. I found a Shimano hub option, but I am leary to recommend him that. I also don't know about spacing, but assume it is doable.

noglider 

Yes, 20-inch 3-speed wheels are available.

Staypuft1652

Thank you.