kidshibuya

I am looking to get a better folding bike. I currently have a doppelganger which looks great but is too heavy and it feels like I am fighting a lot of resistance when riding it.

First of all I want it as light as possible and as low maintenance as possible (I live in a small apartment in Japan and literally have nowhere I can work on the bike). So for this reasons I am looking at Dahon Mu framed bikes as they seem to be light and also it seems possible to fit belt drives to them.

My first question is how does belt tightening work on Mu frames? It doesn't look like you can change the position of the rear wheel to make the chain tighter?... Am I being realistic in thinking I can fit a belt drive to a Mu SP9 or Elite?

Second question, my choice is down to the Dahon Mu SP9 and the Mu Elite. Both are a bit fat for my liking, the Mu SLX is only 8.6kg but the much more expensive elite is 9.8kg. However the Mu SLX can't take a belt drive from what I can see. If I buy the Elite I could be scrapping a lot of expensive drivetrain parts so I am thinking the SP9 is the better way to go. However the SP9 frame is a little different, maybe heavier? Anyone know how to see Dahon frame weights? The SP9 weighs a massive 11kg, but I am hoping I can bring that down by eventually replacing the wheels, posts etcs. But if the extra weight is in the frame then i have wasted my money.

Any advice? Would it be possible to get the SP9 down to near SLX weight and also put on a belt drive?

Rick Imby

I'm pretty sure all the MU frames except the frames in their 30 year classics are pretty much the same frame. I would think the old Mu Single would be a great frame to convert to Belt because of the horizontal dropouts---I'm not sure they came with that---but I'm not a Belt drive guy.

With my Mu D10 I just use an old sock to polish her up after a dirty ride. I do it on my front porch. Then a little bit of oil. I don't get why people think the derailleur bikes take so much maintenance. So simple, light and cheap to replace. I am assuming you are going with a 7 or 8 internal hub---lots heavier than 8-10 speed cog and derailleur. Good luck with your adventure. I just lined up some old Rolf wheels for my D10.. I'm going to try to lighten her up a bit. I am much fonder of 406 vs 451 wheels.

kidshibuya

Well I live in a carpeted apartment with no outside areas at all. Its things like cleaning and oiling the drivetrain, how do I do that without getting grease on my carpet and breathing in fumes from cleaning fluid? And even if I could disposing of the fluid is another issue. Belt drive is perfect.

About the hub weight, I was wondering about that. How heavy are they?

Oh also how do you do chain tensioning? Not sure about the D10 but on the other Mu frames it seems you can't adjust the position of the rear wheel at all.

Abu Mahendra

Neither cleaning nor oiling the drivetrain involves spills. If it does, you are using waaaayyyy too much lube or degreaser.

BruceMetras

No vertical dropout bike is a good candidate for a belt drive (unless the frame incorporates an eccentric bottom bracket .. . the SLX wouldn't work due to the rear triangle that is not shared by the MU Elite .. unless you are running a single speed, any IGH multi-speed over 3 speeds will net a significantly heavier weight than a 105 drivetrain.. the MU frameweights aren't going to vary much, the components (like low spoke count wheels) low volume racing tires, and lightweight parts is what drops the weight significantly..

A belt drive is not the panacea for low maintenance.. a cut belt will make for a bad day... dirt in the belt translates into wear at the cogs.. belt drive components are more expensive than chain drive .. trying to find exact replacements for belt drive bits can be a time consuming process..

If you have a drivetrain in mind for a belt drive bike (single chainring - single cog), you would probably be happier with a chain.. on a single/single, the chain doesn't wear as fast as a derailleur drivetrain and can easily be run with a wax type clean lubricant as side plate wear is of little concern..

Advice? I'd prioritize what you want in a folding bike .. how it is going to be ridden .. how often it is going to be folded.. how often it needs to be carried .. what types of road surfaces it will see .. maybe you can get away with low spoke count wheels and racing tires, maybe you need something a little more robust with higher spoke count and larger volume tires .. Japan has lots of cool bikes.. if weight is your highest priority, you can still get a Dahon Presto SL with high volume tires at 8kg

Rick Imby

Nearly all of the cleaning of a bicycle comes from the dirt collected while riding, not the drive train. The fallacy that Belt drives are the cure all for never having to work on or clean your bike is just not true.

An old sock and furniture polish are what I use. Pledge is a big brand in the USA and I have a can of it next to my Triflow lube and sock. For cleaning the chain I usually just pedal it backwards gently while having a couple of paper towels wrapped around the chain to pull off the gunk.

Belt drive bikes are very very hard to get parts for in most bike shops and really are foreign to most bicycle shops.

The rear derailleur both changes gears and tensions the chain in a derailleur style shifting system. That is why you can have vertical dropouts with derailleur systems.

Where a belt drive is an interesting idea is when you are riding in the winter and rain a lot. But in those conditions your bike gets extremely dirty all the time and will need a lot of polishing to make it clean enough to bring into your completely carpeted apt.

Folding bikes that are stored in the front closet are often ridden only in nice weather where they will not pick up much dirt. You will have to get used to polishing your bike if you ride in wet conditions.

Rick Imby

Belt drives also must not have normal rear chainstays. With diamond frames the chain/belt encircles the right chain stay. You must have a way of getting the belt through the chainstay. A chain never comes assembled so you put it through the chainstay and then connect the chain. You cannot break a belt and then reconnect it. This really limits the frames that work with belt drive. It cannot have vertical drop outs and it cannot have normal chainstays.

Rick Imby

If you want a bike with belt drive ---buy the bike that way. Converting is very expensive and time consuming.

Sangetsu

A belt drive doesn't need much maintanence, they have been used on shopping bikes here in Japan since the 80's, and most of these bikes are still running on the original belts.

The man problem is fitment, since the belt cannot be split like a chain, you need a bike which can have the seat and chain stay separated, so you can slide the belt through.

Chain maintanence is not a big issue. I use a Park chain gang cleaner with Simple Green degreaser and a towel. There are no fumes or bad smells, the towel keeps anything from dripping onto the carpet.

kidshibuya

"what you want in a folding bike"
Actually I don't want a folding bike to be honest. I just want a small bike and the only good small bikes I can find are folding. I tolerate folding more than I choose it.

"how it is going to be ridden"
18km per day on and off roads, up gutters and down stairs etc. My current cheap folding bike handles it.

"how often it is going to be folded.. how often it needs to be carried"
Folded; almost never. Carried; daily up and down 5 flights of stairs to and from my apartment.

"Japan has lots of cool bikes"

Hmm I'd say Japan has a lot of bikes. Cool bikes...? Yeah no. Most Japanese people choose the exact same bike in the same color as everyone else. I pass about 400 identical bikes every day.

"Dahon Presto SL"
I don't want smaller than 20". Also I find that bike very ugly.

kidshibuya

So how do you actually clean it? How do you stop the cleaning fluid dripping off the cogs?

Yeah, but there isn't a single good belt driven bike on the market that I have found. I haven't seen one in Japan and on the internet there are a few horrendously ugly and very large bikes. And one stupidly heavy and expense Tern (and also ugly).

Is there such a thing as a 20inch sub 10kg belt drive bike on sale? I know there used to be some Dahons that could be made to fit the bill, but they no longer sell them.

Abu Mahendra

Tyrell CX

kidshibuya

I have just found something super interesting to me:

LIOS Nano Superlite | Carbon Folding Bikes | LIOS Nano

https://www.aliexpress.com/item/JAVA...762828448.html

Are they not the exact same frames? Just one is 5X the price.

I am thinking of buying the Java thing and buying the same belt drive components on the nano as they obviously work.

blakcloud

I think Rick makes a really good point here. I currently commute on a 3 speed IGH hub Brompton. Yes the chain gets dirty but so does the rest of the bike. I still need to clean it, the chain is slightly more work.

You seem to be concerned about getting cleaning fluid on your carpet. First don't clean your bike, belt drive or no belt drive over a carpet, do it outside of your building. Second you don't douse your components so they are dripping. You use a rag with minimal amounts of solvent/cleaning solution and wipe, the same way you would clean your kitchen counter top.

Your project does sound interesting and I am looking forward to seeing what you come up with. Have you thought about a Moulton? At one time they made the TSR-2 with a belt drive.

kidshibuya

I can't clean it outside, you just don't do that in Tokyo. Unless you like getting complaints to your real estate about you. But anyway I could try with a rag, I get what you are saying. I used to tackle it by first trying to drown my bike in degreaser. Now Ill try to wipe it clean first.. I never did because I literally don't have rags nor anything I could use as one. I do have dollar shops near though, bound to have towels there. Sorted.

But I am still gunning for a belt drive bike, just seems like a better solution once installed. And once I have the idea in my mind I won't be happy till I go through with it whatever the outcome.

Now I am deciding between an Dahon Mu base or that Java carbon/lios nano thing. I initially saw the Java bike and liked the idea but I had two concerns. One was the actual quality of the frame and if I would snap and kill me. The other was about things like the seat post, stem and hole for the cranks etc wondering if they are all industry standard and able to accept upgrades. Seeing that the nano bike appears to have a hint of legitimacy should I ease my concerns?

Its also a huge confidence boost that the nano comes with the same belt drive I was planning to put in. But I still can't see how they manage belt tension when the back wheel only appears to be able to move up and down...? was sure Id need a bike frame that allows the back wheel horizontal travel?

Oh and Moulton, I just don't like them visually. Maybe I am out of step with the average consumer but I hate all the old fashioned looking bikes. Not that I particularly like the look of the Java frames I am considering, but if I buy a dull colored one I think I can make it cool via components.

Ah and with your 3 speed, how fast can you go? Are the three speeds all that usable? On my current planet weight folding bike I can keep up with most guys on roadies and I kill them on hills. I still want that speed but Tokyo has some savage hills also.

Freewheel MIN: 14 T × MAX: 28 T
Chain wheel 52T

That is what my current drivetrain is; taken from here:
https://www.doppelganger.jp/product/219/

Rick Imby

They could be nearly the same frame not the exact same frame... The company making the frame is probably the same but the rear dropouts might be different on the Java. Remember you need horizontal dropouts on the frame to adjust tension on the belt drive.

The rear hub width might also be different.

I have never played with a belt drive other than a test drive. I am wondering about the rear cog, is it possible to add a belt drive rear cog to a cassette style or freewheel style hub?

downtube

No this does not exist, and I would not expect anything like it to hit the market in the near term.

Thanks
Yan

leoho5

Actually, there are Gates Carbon Drive cogs for 9-spline Shimano freehubs (and also for freewheels) on the Gates website.

Rick Imby

Thanks @leoho5

I did not realize you could mount to a 9 speed cassette hub.

https://www.gatescarbondrive.com/prod...hub%209-spline

However Gearing will be an issue. It appears the smallest cog to fit the 9 speed cassette is a 20 tooth. With the small wheels and a 20t rear cog I would need a 60 tooth front cog to be even halfway comfortable on a single speed.

slickginger

Weird, because it looks like there is plenty of diameter left to shrink down into. I wonder if it's a limitation of the belt maybe? Like a minimum bend radius?

Abu Mahendra

Wipe the chain down with disposable wet wipes (which have a mild degreaser) after each ride. Two wipes after each ride will keep the drivetrain clean. Five minutes, inside your home, you're finished. No need for reusable cloth towels.

Have you looked into a Tyrell CX?

Diode100

Maybe the OP should be looking for a shaft drive bike rather than a belt drive, that would get round his greasy cleaning at home problems.

kidshibuya

From studying the pictures I can not see any difference at all. See here (hi res pics thanks to bad website optimisation):
https://www.bikerumor.com/wp-content...under-desk.jpg
https://www.bikerumor.com/wp-content...e_rear-end.jpg
https://www.liosfoldingbike.com/files...olded-bike.jpg
https://www.liosfoldingbike.com/files.../bike-text.jpg

The Java:
https://hk1.image4.pushauction.com/0/...147f6a90f6.jpg
https://i.ebayimg.com/images/g/z7UAAO...fz/s-l1600.jpg
https://www.cyclezoneshop.com/Images/...7-IMG_8425.jpg

Looks like the nano and the java are identical, also note they still have the hole for the derailer on the nano, so no custom fixture. Maybe they have a custom belt that 'just fits'?

Um.. Doesn't that wipe all the lube away? And yeah I looked at the Tyrell, not my style unfortunately.

Mind blown, didn't even know they existed. I'll look into them, seems like they might be heavy and limited in options.

kidshibuya

My replies here keep being deleted so I'll jump over my previous discussion (I dropped the idea for various reasons) and move on.

I was all set on the Dahon Mu SLX however I have now realised I can get a Tern Verge X18 (which is cheaper than the x11 and x10 on amazon...? How does that work?) for not much more and I am torn. The X18 is 1.8kg heavier, but seems far better speced. The issue is that I can't see much room for a diet on the X18. I could save maybe 150 grams on the handle bars, maybe another 150 grams on the seatpost. And umm...?

Do you think the better gear on the x18 is worth peddling around another 1.8kg?

tcs

8.6kg. Belt drive. Strida C1.