Dynamic “Crosstown 7” Shaft-Drive Bicycle

The other day, I got a package in the mail from Dynamic Bicycles. Hmm…what is it?

Look what came in the mail!

The good folks at Dynamic offered their “Crosstown 7” commuter bike to us for testing. In many respects, it is like so many other commuter-oriented bicycles on the market — aluminum frame, mounting points for fenders and rear rack, upright riding position. Where this bike differs, however, is how power gets from the pedals to the rear hub. This bike uses a very clever and deceptively simple shaft-drive. Yeah, that’s right — no greasy chain, no chainrings to chew up your pants. In fact, Dynamic takes things a step further by mounting the shaft-drive to a Shimano Nexus Inter-7 internal hub. So, no derailleurs either!

Here’s how the bike looks once removed from the packaging and assembled (a process that takes all of 10 minutes):
The assembled bike -- do you notice what's missing from this picture?

Here’s some of the specs, straight from the manufacturer’s website:

    7005 Aluminum Frame, butted for light weight
    Aluminum front fork
    Alex DA-16 High Profile Alloy Rims (28-38C tires)
    Kenda EuroTour Tires, 700x35C, 50-85psi
    Dynamic Street Shaft Drive
    Shimano Nexus Inter-7 Gearing, All-internal (17-gear range)
    Shimano Nexus 7-speed Twist Grip Shift
    Tektro Quartz alloy brakes; front disc brake optional
    Tektro 2-finger Alloy brake levers
    Base price: $679.00

Shaft-driven bicycles have been around for over 100 years, but most were plagued by problems with complexity and durability. Not so for this bike — Dynamic’s shaft-drive assembly, manufactured for them by Sussex, appears in every way to be rugged, well-sealed from the elements and elegantly simple, both inside and out. Here is a picture of the shaft-drive as mounted on the bicycle:
The shaft drive assembly, mounted to a Nexus internal hub.

Over the next two or three weeks, I will be riding this bicycle exclusively both for my work commute and for my recreational rides. Stay tuned for a full-length review. In the meantime, check out Dynamic’s excellent “FAQ” page. Also, check out their supercool Java-based animation of the shaft drive assembly in action!


  1. Moe June 28, 2007 9:57 pm 

    I’ll be looking forward to your review, I have always being curious about shaft-driven bikes.

  2. Ghost Rider June 29, 2007 3:34 am 

    I’m looking forward to spending a lot of riding time with this bike…especially since I am very skeptical about “alternative” drivetrains (belts and shafts).

    Based on the one 6.5 mile ride I took it on last night, I can say that the bike is virtually silent, both under power and while shifting…this baby’s got “stealth mode” written all over it!

  3. RL Policar June 29, 2007 4:40 am 

    Does it drag? I’m not sure how to ask the question, but do you feel the shaft dragging…is it free wheel…ah nevermind, I’ve got nothing.

  4. Eric June 29, 2007 4:53 am 

    As usual, I am most concerned with how this climbs hills. I usually attack my hills standing and I am a big guy. So my question really is: Does (Shaftdrive + Big Guy) + (aggressive climbing * steep hills) = Broken Shaftdrive… ?

  5. Ghost Rider June 29, 2007 5:06 am 

    I will attempt to answer both RL’s and Eric’s questions in the subsequent review…for now, though, I noticed no drag on my maiden voyage — the system feels very smooth and efficient. I’ve got no way to quantify the friction difference between a chained bike and this shaft drive, so all I’ll be able to give is my perception of smoothness.

    Eric, I only weigh 140 lbs. soaking wet, and there aren’t a lot of hills around Tampa…it’s pretty flat. Still, there are some neighborhood “high spots” I will grind up, just for you. Remember, though, that this shaft and the bevel gears are made of hardened chromoly…pretty tough stuff.

  6. RL Policar June 29, 2007 5:51 am 

    Can you see if you can take it on any sweet jumps and get three feet of air?

  7. Rob June 29, 2007 7:28 am 

    FYI that’s not javascript, it’s Java.

  8. Logan June 29, 2007 7:32 am 

    How much does it weigh?

  9. Ghost Rider June 29, 2007 7:42 am 

    Rob, thanks for the correction.

    Logan, you’ll just have to wait for the review! Ha ha! Let’s just say that this bike weighs less than a pound more than a comparably-equipped bike with chainrings, derailleurs and a chain. That’s pretty impressive!

    Sweet jumps? No problem! Just “fix me a dang quesadilla, Napoleon!”

  10. RL Policar June 29, 2007 7:45 am 


    Consider getting a $5 fishing scale to weigh the thing.

  11. Ghost Rider June 29, 2007 9:16 am 

    It’s a good idea — I already have a Chatillon fishing scale (the Rolex of fishing scales) from a previous job. I’ll press it into service for the review.

  12. Ben C. June 29, 2007 12:21 pm 

    Now that is a bike I would really enjoy commuting with. Can I ride it next…pleeeeeaaaassseeee???

  13. RL Policar June 29, 2007 12:54 pm 

    Sure Ben go for it, but you’ll have to catch a flight to Tampa,FL to try it out.

  14. Ghost Rider June 29, 2007 2:04 pm 

    Sure, come on down — I’ll introduce you to commuting in 85% humidity and temperatures in the mid-90s…you’ll LOVE IT!

  15. Doug July 10, 2007 7:32 am 

    I’ve also been interested in shaft driven bikes for commuting, especially in the Northeast where we have months of salt laden slush that eats up bike equipment.

    I stopped into L.L. Bean’s in Freeport, Maine (I live nearby) and asked the mechanics about the Dynamic Bikes. They sold them last year for a few months and dropped them because of lack of customer interest in commuting bikes. Since Bean’s has a good repair and return policy, I figured they would have seen many returns if the bikes had mechanical problems. So far, they haven’t seen any come back for mechanical problems, so I take that as a moderate endorsement.

    Thanks for a good website, and keep up the good work on the needs of commuting cyclists.

  16. Duncan July 12, 2007 8:12 am 

    Thanks for the user info on the Dynamic Crosstown – I’m looking into buying that bike. I’m a year-round Vermont commuter, and I would love to ditch the chain. There were a couple of times this winter when the chain was literally “frozen” with rust and grime. I’m guessing that is way more inefficient than a clean shaft drive!

    I have a very hilly 6-mile commute. I’m concerned that the 7-speed does not offer enough of a “granny gear” to deal with a couple of the steep hills. I wonder if you can mix/match components – I would like to get the 8-speed on the Crosstown model.

    Any Dynamic bike owners with winter and/or hill climbing experiences?

  17. Ghost Rider July 12, 2007 10:41 am 

    The Crosstown comes in an 8-speed model, and with a choice of two different shaft drive ratios…may or may not be enough “oomph” to get you up those hills!

  18. Stefan November 25, 2007 5:29 pm 

    Review of the Dynamic Tempo Cross.

    I’ve had this bike since March ’07 and I regret the purchase.

    Although there are bonuses to the shaft drive (mainly, for me, the ease in avoiding grease), the major drawback is that your local bike shop cannot service the drive train, or the internal hub (at least no one I can find San Francisco is willing to).

    Major problems:
    1) broken frame where downtube connects to enlarged bottom bracket, after 2 months riding. Frame replaced by Dynamic free of charge (but of course I had to move all parts over).
    2) multiple problems with nexus 8 hub and hardware – grinding gears, bevel slipping off, and finally first four gears of hub not engaging at all. After many hours of tickering (again, bike mechanics have not been willing to go there), hub with rear wheel replaced by Dynamic no charge. This seemed to be both a hub problem (not Dynamic’s fault) but also a rear bevel gear problem (which is Dynamic’s purview).
    3) OEM rear wheel breaks multiple spokes. I’m a big guy (230lb) and often commute with panniers. I broke 10 spokes over a few months and finally was told by my local mechanic that the OEM rim (I believe it was the Alex DA-16 High Profile Alloy rim) – was not up to the strain. I finally had a new wheel built on the Nexus hub – and since then no problems with broken spokes. Mechanic tells me another customer with a Dynamic bike also had to have a new wheel built because of the same problem.

    You’ll note that the company has been excellent all along by phone (not email) – they sent both the new frame and the new hub after I emailed pictures of the broken frame and spent some time on the phone with their mechanic about the hub.

    Minor problems:
    1) grinding. This comes and goes, and seems to be mostly at the rear bevel. During community the rattle in the pedals and the noise is usually not too distracting. But outside the City I’ve had other cyclists stare at my bike trying to figure out why it’s making so much noise – especially while climbing.
    2) Screeching. This comes from the front gear case, mostly when climbing. I use the grease gun from Dynamic as directed, and it helps somewhat, but the screeching often returns before the scheduled time to re-apply grease, and it’s LOUD, and I can really feel the resistance.
    3) The OEM rack was too small for most panniers – had to replace.
    4) Changing a flat is significantly harder on the rear wheel than on a chain drive bike. The main reason for this is that getting the rear bevel and shaft drive back into alignment so they mesh, and so the wheel is centered so that the brake alignment is accurate, can take 1 to 10 minutes or more – sometimes a lot more if you’re in low light, and have to snap all the little parts that make up the rear of the drive train back into the precise place.

    1) Saves me lots of time during the day: I ride for work around San Francisco and must wear dress pants. I get on and off the bike 6-12 times a day or more and don’t have to worry about strapping and unstrapping my pantleg.
    2) The unusual rear wheel setup is a theft deterrent: I routinely lock my bike on the street in the most bike-theft-prone areas of San Francisco and have had no problems with theft. Yet.

    I’ve spent too many unnecessary hours on maintenance that I couldn’t pay someone to do if I wanted to (because they can’t or won’t work on the drive shaft or internal hub) to recommend this bike, despite the excellent customer service from Dynamic.

  19. Brian Allen September 4, 2008 10:38 pm 

    I purchased one of these out of a Popular Mechanics magazine about 8 years ago. The bike only lasted about 5 months until most of the teeth stripped off both of the bevel gears. A bevel gear drive ( think automotive differentials ) requires precise alighnment at all time, esp when under a load or they will destroy themselves. This just isn’t going to happen in a bicycle, it’s just too flexible, and in order for it to be rigid enough it would also be excessively heavy. I rode about 25 miles, 6 days a week, I weigh 190, and it didn’t last long. If your into non-strenuous peddling on flat terrain and use it just occasionally…..maybe. Regular usage….nope.

  20. vaccinefiend November 8, 2008 7:19 pm 

    I owned a Dynamic Bicycles shaft drive bicycle. The Sussex shaft drive was not built to specifications that could handle the torque generated when pedaling uphill, or pedaling hard on level ground. The result was that the shaft drive was not maintenance free–in fact, it broke. I replaced it with a new shaft drive sent by Dynamic Bicycles. The new one began to break and I was told by their Production Manager that I was exceeding the specifications of the shaft drive. I received a verbal agreement from him to refund the purchase price of the bicycle. Dynamic Bicycles even took care of the return shipping for the bicycle.

    Once they received it, however, the president of Dynamic Bicycles told me that I had owned the bicycle longer than 30 days, so the satisfaction guarantee no longer applied. I was given the option of having my bicycle returned to me with a tightened bolt and new grease, which would supposedly fix the problem, or receiving a refund minus the cost of shipping and a 15% restocking fee. Despite phone conversations, emails and then a complaint process with the Better Business Bureau In Eastern Massachusetts, Maine, Rhode Island and Vermont (http://boston.bbb.org/WWWRoot/SitePage.aspx?site=27&id=b9531757-8bff-425c-83ce-ef5cf233e6a5), the president of the company would not uphold a verbal agreement stated twice and acknowledged by email. Because I do not live in Massachusetts, the state where Dynamic Bicycles is located, it made no sense for me to pursue a mediation or claim in small claims court, which would have required my presence. I will never do business with Dynamic Bicycles again, nor would I recommend doing business with Dynamic Bicycles. I am also weary of bicycles sold with shaft drives built by Sussex.

  21. Patrick Perugini November 21, 2008 6:48 am 

    I am offended at Vaccinefiend’s misleading and shameless posting above. So let’s set the record straight. This customer owned his Dynamic Bicycle for nearly a year. He called us and claimed that his shaft drive was broken and asked for a refund. Even though his bicycle was 9 months beyond the normal return period, we offered a refund in good faith that it was actually broken. When the bicycle was returned to us, it did not have the problem he claimed — the shaft drive was perfectly fine. His bike only needed some adjustments and it was as good as new. When we called him to tell him his bike did not have the problem he thought and that it was running great, we thought he would be pleased. He wasn’t. We did the service at no charge and even offered to ship the bicycle back to him at our expense. He refused. At Dynamic Bicycles, we have a great reputation for our excellent customer service. But even we have to draw the line when we think we are being taken advantage of. This customer clearly was trying to take advantage of us. He thought he could claim to have a problem and send a bike back after riding it extensively for nearly a year and get a full refund. This is incredulous. Yet despite his attitude, we still gave him a generous refund – his entire initial purchase price less 15% plus shipping – quite a deal for using the bike for nearly an entire year. Then he goes onto blogs and posts his drama for the world to see. We regret that this customer had difficulty with his bike, but we stand behind our bikes and our efforts to serve him. He clearly had no interest in resolving the problem with his bike. He just wanted a free ride.

    If you have questions about Dynamic’s bikes, ask us. We take great pride in our bikes and stand behind them with great customer service.

    We have many thousands of very happy customers. Just read some of the reviews and customer comments on our web site. However, if one of our customers is not fully satisfied with their bike, we do whatever we can to resolve their issue. Our technology, like all technologies, improves all the time. We are happy to upgrade our customers (usually at no charge) to our latest components. All they need to do is ask. We would even be happy to try and help the person above named Brian who bought his bike 8 years ago (which isn’t even Dynamic’s bike).

    Patrick Perugini, President
    Dynamic Bicycles, Inc.

  22. Andrea McDaniel May 23, 2010 7:02 am 

    Nice! Just wanted to respond. I thoroughly loved your post. Keep up the great work. 😉

  23. Hedwig Esterline July 23, 2010 7:00 am 

    You’ll want alternative fishing gear for different angling circumstances. The best purpose because of this is usually that it helps you catch more fish. When the wrong fishing gear are being put into use, bites are going to be a lot more hard to detect, and therefore fewer fish would be caught

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