makeinu

Any comments on this bike?
https://www.dynamicbicycles.com/buy/Bikes.php?prodid=60#


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

jur

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.

14R 

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.

makeinu

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.

14R 

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



and I wanted this chaincase:



or even this one:



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?



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:



How can we do that?

makeinu

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 and www.velorution.biz). 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?

14R 

Their website now have a pdf in English

jur

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.

jur

Their name is Sunny Wheel Ind. Co.

https://www.sunnywheel.com.tw/

Bacciagalupe

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.

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.

Diode100

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.

14R 

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

14R 

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?

rhm

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.

Diode100

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.

Pine Cone

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 https://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.

matt52

Check out the Biomega BOston Puma folder - you can find it at - https://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...

Fear&Trembling

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

EvilV

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 -

https://www.cyclesofyesteryear.com/cy...tm#Chainguards



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

Nexus7

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.

brakemeister

Horrendously inefficient... Baccia got it right


thor

makeinu

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

Nexus7

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.

brakemeister

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

thor

brakemeister

https://www.sjscycles.com/forum/post....64&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