Folding Bikes - Dynamic Bicycles shaft drive folder

Any comments on this bike?
http://www.dynamicbicycles.com/buy/Bikes.php?prodid=60#
http://www.dynamicbicycles.com/admin/bikes/m161139.jpg

A little pricey if you ask me, but it is temping as I'm struggling to make my Downtube clean for carrying.

The handlepost looks sloping backwards too much; compare to Dahons which have them sloping forwards. I think this one's cockpiot may be cramped.

The shaft drive, although scorned by conventional cyclists, may be not bad for a folder where you're probably not looking for tarmac-burning performance anyway. If I could get my hands on one with suitable fit, I'd be tempted for commuting purposes.

Deep inside my brain, even though I am not racing or anything, there is a call for performance. I would rather deal with chain and lube than deal with a direct shaft drive.

The sad thing is, we could have our cake and eat it too if bike manufacturers put full chaincases on their bikes, or at least made them available as after market accessories. But they don't.

I agree Makeinu, I have no idea why they are not available. I have this bike:

http://www.comparestoreprices.co.uk/images/ca/cannondale-bad-boy-ultra-2006-bike.jpg

and I wanted this chaincase:

http://www.hobidas.com/blog/special03/archives/6Street_blk-thumb.jpg

or even this one:

http://www.cycle-heaven.co.uk/graphics/Cdale%20St.700%20fem.jpg

It's from freaking cannondale, but they don't have it unless I have one of the bikes that carry them, under warranty and have it damaged LOL.

Now, for the Curve, would something like this work for us?

http://www.landrys.com/content/products/Hotrock%2016.jpg

I'm even willing to buy the entire bike and donate it to the Salvation Army just to get a decent chainguard for my cute Curve. Now, IDEALLY, since we have no external gears, this would be the perfect setup:

http://www.cannondale.com/bikes/07/CUSA/large/7SS8_slv.jpg

How can we do that?

How can we do that?
That last one is a Hebie Chainglider (made in Germany). It sits on the chain (no frame mounts). I was considering one for my Downtube VIIIH. There are two models, one for a 38T chainring + 18-22T rear sprocket and one for a 42T chainring + 15-17T rear sprocket.

The problem for us foldaphiles is that these gear combos are meant for big wheeled bikes. The Curve D3 has a default gear ratio 46/13. You can't get anything close to that with the above combinations.

The situation on my Downtube is a little better. The default is 46/23 which could be substituted with 38/19. Unfortunately, the default gearing on the VIIIH is way too high and, since the SA 8-speed uses nonstandard sprockets, I basically have to choose between the Chainglider and lower gearing.

In any case, like I said, the Chainglider is made in Germany, but there are a few shops that've imported them to the UK (www.bikefox.co.uk (http://www.bikefox.co.uk) and www.velorution.biz) (http://www.velorution.biz%29). I suppose those of us in the US could order from one of these shops. On the other hand, the Chainglider is being used on the 2007 Cannondale Street (as the pic you posted illustrates). It's unfortunate to hear that Cannondale won't supply these kinds of spare parts, but perhaps one could talk a Cannondale dealing bike shop into selling it?

Their website now have a pdf in English (http://www.hebie.de/pdf/0350_S_42_E_1_EN.pdf)

Hey 14R, I have a site from Taiwan that sells all these items and then some. I tried buying some 20" mudguards from them but stalled when I could not pay. They wanted a money order which turned out locally here at my country to cost more than the amount itself. I tried convincing them to open a Paypal account but wasn't sure I got through to them. They were perfectly willing to sell to an individual.

I wonder if we could make it happen via people in the forum here? We could try a group buy or something.

I'll post the website when I find it again.

Their name is Sunny Wheel Ind. Co.

http://www.sunnywheel.com.tw/

According to the encyclopedic knowledge of Sheldon Brown, many bikes do not use chain guards because it causes problems with adjusting front derailleurs. Also, in some cases the chain could get wedged between the chainring and the chain guard, and otherwise make it more difficult to fix a dropped chain.

I.e. they aren't common because they aren't that useful. Roll up your pants next time. :D

AFAIK shaft-driven drives are pretty horrendously inefficient. AFAIK Kevlar belted drives are a better option, as they are still greaseless, don't need much maintenance, and don't lose as much performance as a shaft drive.

Has anyone tried the IXI cycle which has a belt drive I think ?
It was briefly available from a very high end lifestyle shop in London, but I never managed to get to see it.

We are considering a chain guard to a bike that does not have any external gears, so chances of chain drops are minimal.

Their name is Sunny Wheel Ind. Co.

http://www.sunnywheel.com.tw/

I'm very impressed with ALL their chainguards, I can only dream how nice some of those would look on a Curve.

Is anybody else here interested on some chainguards or is it just me and makeinu?

I'm very impressed with ALL their chainguards, I can only dream how nice some of those would look on a Curve.

Is anybody else here interested on some chainguards or is it just me and makeinu?

Me too. I have ruined so many pairs of pants, it's crazy. But I couldn't get that website to open all the way up.

By the way, I understand how this came to be discussed under this thread, but digressions of this kind, once forgotten, are hard to find again. Why not start a new one devoted to chainguards?

Speaking of which, Mobiky has a nice chainguard as well.

I was in Velorution (London) on saturday and they have just got in a range of Danish bikes called Biomega, a fair few of which were shaft drive, no folders amoung them that I could see, but some nice clean designs. Price for a very nice minimalist road bike were around 750 pounds.

I have a recumbent that has the chain running through a length of clear vinyl tubing. Seems like you could use a similar idea for a folder, using zip ties and spacers to get it into the right position. Not that pretty, but pretty easy to do...

I build kayaks as another hobby and it wouldn't be that hard to laminate one up from hardwood veneer strips using epoxy with layer of fiberglass on top. A little time consuming since you would need to build a small form to build the laminations on, but you could probably make the first a chainguard in 2-3 hours working time with a couple of days wait time for epoxy curing. The process would be similar to building a cockpit combing on a kayak. See http://www.kayakforum.com/cgi-bin/Building/index.cgi/noframes/ (http://www.kayakforum.com/cgi-bin/Building/index.cgi/noframes/) for info on kayak building and search for threads on carbon fiber combings.

The ugly but easy option would use corroplast (corregated plastic) and duct tape. Build a box that fits around and covers the chain, chainrings, and rear cog. Right now my rear fender on my DT VIIIH is a piece of corroplast from a local political campaign sign cut and wedged under my rack. If nothing else, the price is right.

I was in Velorution (London) on saturday and they have just got in a range of Danish bikes called Biomega, a fair few of which were shaft drive, no folders amoung them that I could see, but some nice clean designs. Price for a very nice minimalist road bike were around 750 pounds.

Check out the Biomega BOston Puma folder - you can find it at - http://www.biomega.dk/biomega.aspx

Description:
"The leading edge Semi-fold Puma bicycle is designed by Skibsted. It is a totally new type of bicycle: lending coolness & rugged factor from BMX/Down Hill bikes such as though tubing, DH handlebar, small wheels and disc brakes. It folds & has folding pedals & it’s a city hybrid: The geometry, treadles tyres, saddle makes it work the best in city environment.

The Down Tube wire is a structural part of the frame – integrating the locking mechanism in the frame subsequently rendering the bicycle non functional if someone breaks the lock to steal the bicycle.

Although the bike has a folding mechanism it isn’t a regular folding bike. It is made for quick & dirty type fold: Entering the elevator, the tube, the office."

Not sure how semi the semi fold is, but I am sure if you REALLY wanted one, Andreas at Velorution coul get one in. Cost quoted on Biomega site is $1158 which prob equates to £s at Velorution. Nice looker but not sure would be top of my shopping list.

Some of Biomega's other bike designs - the MN and the Brooklyn look pretty radical, though non-folding...

Some of Biomega's other bike designs - the MN and the Brooklyn look pretty radical, though non-folding...

There are Biomegas on Ebay.uk at the moment...

The big advantage of a full chainguard is that the chain and sprockets run totally free of grit. You can oil up the chain mightily and it just runs really smoothe and clean. Chains last for ever, and so do sprockets and chainwheels. Puts me in mind of the old motorbikes I used to ride at the end of te 1960s - most of them here had a fully enclosed primary drive chain between the crankshaft sprocket and the clutch that ran in a bath of clean oil, inside a case on the engine. They lasted forever whereas the final drive chain running much more slowly, but outside in the dirt and wet, were trashed in a few thousand miles.

A person with some fabricating skills could probably knock up a chain case out of sheet aluminium and screw it all together.

Here is a link to some prety cheap chain guards for old Raleigh cycles from yesteryear -

http://www.cyclesofyesteryear.com/cycleshop/sparepart.htm#Chainguards

http://www.cyclesofyesteryear.com/images/spares/cg008cg010.jpg

Not bad for £18!!! The joys of dealing with China....

AFAIK shaft-driven drives are pretty horrendously inefficient. AFAIK Kevlar belted drives are a better option, as they are still greaseless, don't need much maintenance, and don't lose as much performance as a shaft drive.
Horrendously inefficient? From what I've read, they're in the 90s for efficiency, somewhere between a clean oiled chain, and a dirty one. On my hybrid, I can't tell the difference. Other factors will dominate in everyday riding.

Horrendously inefficient... Baccia got it right


thor

Hey Thor, don't you have connections with some german distributors? Any chance you could import a few Hebie Chaingliders for us?

Per Dynamicbicycles tests, their shaft drive is 92-94 % efficient without any maintenance. They have cites stating expensive chain systems in perfect alignment are 95-97 % efficient, whereas the averagely maintained average system is 75-85 %.

Do you have any cites or tests?

A little less efficient under certain conditions? Yes. Horrendously? Nope.

94 %
and I have that bridge for sale ....... its really cool
take paypal ..

thor

http://www.sjscycles.com/forum/post.asp?method=Reply&TOPIC_ID=364&FORUM_ID=25

read a little down about the hebie... it looks good but it rubs all over and most likely doesnt fit on our bikes... but I will keep my eyes open

thor

OK, so you do not have any data.

Here is an article about efficiencies. There is no shaft drive test there.

http://www.recumbents.com/links.htm

It's in the 2001 summer edition, hp52.

See also Sheldon Brown's glossary entry for an intro.

I think most people tend to be snobbish about these. I think they might have a place in the market. I would like to testdrive one.

I think most people tend to be snobbish about these. I think they might have a place in the market. I would like to testdrive one.
There's a guy in the commuting forum that has one of the nonfolders. He seems to like it.

Don't see any articles on efficiency on that page, except one about cranks that are intended to increase efficiency. Can you post a direct link? Thanks.

http://www.ihpva.org/HParchive/PDF/hp52-2001.pdf

Thanks JUR for the ihpva pdf ... good reading, and sort of blows open some myths. (Why is it the cycling world is so full of myths ?). I'm fascinated by shaft and belt drives, and from what I've seen shafts are no longer 'horendeously' inefficient, ditto belts.

From my purely subjective view, trying them out, Shafts, like belts loose v little power, so little not really noticed, indeed hub gears can loose more, as can Big ring to granny and other deraillieur combinations. BUT THE snag with shafts especially in a folding bike is their weight - looks like they ADD at least 1 Kg (2.2lbs) , often more EXTRA.

Sheldon Brown mentions something I didn't realise before: The shaft torque is parallel to the longitudinal axis of the bike; frames are not all that stiff in that axis, especially folders.

But still I think these have an application for people who are not after performance riding, ie the casual shopper/short commuter/bike path pootler. I remember well an occasion not so long ago, when someone on the local commuter forum posted pics of his shaft drive bicycle which he was using for commuting. The interesting thing was, he was an experienced rider, and he was not hooted out of town like I sometimes see when these come up for discussion from time to time. Double standards...

One thing I did not see is how easy it is to remove the back wheel. Could be messy?

http://www.sjscycles.com/forum/post.asp?method=Reply&TOPIC_ID=364&FORUM_ID=25

read a little down about the hebie... it looks good but it rubs all over and most likely doesnt fit on our bikes... but I will keep my eyes open

thor
Well, that link leaves some question as to whether the guy who cried about rubbing had it installed properly. Another poster in that thread accused him of using the wrong size chainglider and there are some other nuances which we don't know about. For example, spring clip master links are wider than regular links and, therefore, chains containing such links are out of spec.

As far as fitting your bikes: Granted it doesn't fit any stock configurations, but it should fit many models after swapping the chainwheel and/or cog. You need a frame adapter to use the kick flix accessories, so why not a sprocket swap for the Hebie?

Thanks JUR for the ihpva pdf ... good reading, and sort of blows open some myths. (Why is it the cycling world is so full of myths ?). I'm fascinated by shaft and belt drives, and from what I've seen shafts are no longer 'horendeously' inefficient, ditto belts.

From my purely subjective view, trying them out, Shafts, like belts loose v little power, so little not really noticed, indeed hub gears can loose more, as can Big ring to granny and other deraillieur combinations. BUT THE snag with shafts especially in a folding bike is their weight - looks like they ADD at least 1 Kg (2.2lbs) , often more EXTRA.

The biggest snag from my point of view is the difficulty of swapping overall gear ratios. On a chain driven system that's dead easy. How could you do it on a shaft drive without major problems.

Shaft drive was big in the late 1890s and early 1900s. Here's Major Taylor on one of the shaft drive bicycles he used to set track records:

http://www.ltolman.org/chainless-b2.jpg

Suzuki for many years built two motorcycles models with the same 800cc engine, the heavier, slower chain drive Marauder and lighter, faster shaft drive Intruder.

TCS

Chain drive is used in some automobiles to this day. The 3-wheel rickshaws in Asia use chain drive, and there are only millions of them. I think it is because chain drive needs less precise manufacturing, and this application isn't a high performace one. For every other application I can think of, gears and shafts have displaced chains.

I recently tried my first shaft drive bike, and when I first hopped on, I was quite impressed. I was riding down a slight incline, and clicking through its 7 gears. As I took it up its first and ONLY hill, things all changed, the feeling of relative efficiency was gone, replaced with a terrible feeling of loss. I then tried accelerating while on the flat quickly, again a huge loss. I am a fit rider, who rides a wide variety of bikes, from light and efficient to, well, Raleigh Twenty, but I can't imagine living with shaft drive. Worst still is the fact that many of the would be buyers are in less than athletic shape, meaning their average commute time would go up considerably. I tried the shaft drive hoping to like it, because I am a true cycling nut, interested in all the irregular ideas. Shaft drive, not yet.

All the arguments commonly made against shaft-drive bicycles are poorly-argued nonsense. See thread in rec.bicycles.tech for example.

You must be a human dynamometer to be able to feel the 2-4% relative inefficiency of the shaft-drive on a test ride.

Can the shaft drive be used with a mountian drive?

I recently tried my first shaft drive bike, and when I first hopped on, I was quite impressed. I was riding down a slight incline, and clicking through its 7 gears. As I took it up its first and ONLY hill, things all changed, the feeling of relative efficiency was gone, replaced with a terrible feeling of loss. I then tried accelerating while on the flat quickly, again a huge loss. I am a fit rider, who rides a wide variety of bikes, from light and efficient to, well, Raleigh Twenty, but I can't imagine living with shaft drive. Worst still is the fact that many of the would be buyers are in less than athletic shape, meaning their average commute time would go up considerably. I tried the shaft drive hoping to like it, because I am a true cycling nut, interested in all the irregular ideas. Shaft drive, not yet.

Don't take this as an attack, I'm just curious: are you a masher, or a spinner? If one of the real downfalls of shaft drive is that, when under torque, the drivetrain can shift around and not be in proper place, then it would sound like mashing would lead to loss of efficency. But perhaps spining would avoid that? I agree, one big loss with shaft drive is the loss of the ability to customize overall gearing with the change of a sprocket.

Also: is part of the inefficency that you noticed from the internal hub? Have you ridden other 7spd IH's, and not felt the same loss?

Just seems to me that shaft drive would be perfect for a folder. Maybe not long rides, maybe not for strong riders. Perhaps its time has not yet arrived.

Oh: I keep looking at the Dahon 3spd's, it looks like they used to come with chain guards? And no more? That's sad. I keep looking at them, something to live in the trunk; but again, that whole problem of grease...

The sad thing is, we could have our cake and eat it too if bike manufacturers put full chaincases on their bikes, or at least made them available as after market accessories. But they don't.

Last years Dahon models had partial chaincases on some select bikes but not anymore. Here's why.

The chain case makes a slight racket expecially when riding aggressive. I ride my bikes slowly but can see right away that someone more aggressive would damage the device. I suspect Dahon was getting a significant amount of returns and complaints due to the plastic chaincase.

The problem for us foldaphiles is that these gear combos are meant for big wheeled bikes. The Curve D3 has a default gear ratio 46/13. You can't get anything close to that with the above combinations.


It's a shame that Dahon did not include the Curve with a chainguard. My Dahon Presto and Vitesse 5 speed both have them and today, there isn't a single bike offered by Dahon that has them. A shame.

I want to bring this thread back to the main topic, which is the Dynamic Bicycles shaft drive folding bike (Sidekick 7 (http://www.dynamicbicycles.com/buy/Bikes.php?prodid=60)); it seems like the discussion topic veered off on chain guards for folding bikes and the merits of shaft drives vs. chain drives.

So... does anyone own one of these bikes or has tried one?

I admit I'm intrigued by the idea of a shaft drive on a folding bike--the promise of clean, non-snagged pants and fewer maintenance issues due to protection for weathering seems very promising. I asked Yan at Downtube if he had plans to add a shaft drive to any of his models, but he said no. :-(

4 years later; Dynamic Sidekick 8 is current folding model - is shaft drive technology / popularity making any headway?

http://www.dynamicbicycles.com/pdf/RemoveRearWheel.pdf

looks like removing and replacing the rear wheel is a snap.

I have a Bike Friday,20" wheel, the place where it folds
is between the BB and the hub.

where their Tikit has the whole rear portion including the BB
fold as a unit.. so Hebie chain glider can be used on the tikit.

the biggest clearance is for a 42t chainring.. IGH SA8 Speed ,
or 13t on a shimano or rohloff may work..

Can the shaft drive be used with a mountian drive?

you need a machine shop, maybe the Swiss one that made the Mountain drive
in the first place, can offer suggestions?
http://www.schlumpf.ch/

with a chain drive the cranks turn at a different rate than the chainring,
when the planetary gear is engaged.

OK I've seen more than my fair share of "shaft vs chain" drive threads on several bike forums and message boards. Shaft drives were first introduced back in the 1930s but didn't catch on as chain driven bikes seemed to make more sense due to cost and yes, somewhat better efficiency.

But as with anything, the march of technology never stops, and with better metallurgy, high precision bearings, and very close tolerance machining, shaft drives don't suffer from the drawbacks their predecessors from decades ago, except that they are definitely more expensive than a comparable chain drive.

A good quality shaft drive does approach the mid 90s in efficiency, and keeps it that way no matter what environment they are being operated in unless it gets submerged in water or something. A really good chain drive will lose efficiency really quick just by riding on a dirt surface, or through a puddle and other similar scenarios.

Don't be so quick to blow off this technology. If it's not for you, it's not for you! But calling it "Horrendously inefficient" is, well, horrendously misleading.

Now one thing that I almost forgot to mention is that shaft driven bikes are probably not recommended for "high performance" riding, and most definitely not for racing. A strong rider can generate an awful lot of torque and that could actually cause a torsion on the shaft which can in turn cause slight loss of power.

There is no reason to market a chainless drive bike if it were not for some very real advantages, otherwise they would do just like everyone else, and sell bikes with conventional drives. After all, that would be the "path of least resistance".

Peace
Ed

a Shaft drive bike with really fat ATV tires as a Beach bike would be fun.

Shaft drives were first introduced back in the 1930s...

Actually, 1880s. Shaft drive bikes were quite popular in the USA from ~1895 to WWI.