alanf

Just curious about belt drives. How do they compare with chain?
Efficiency
Weather resistance
Slippage
longevity

Anything else?

Teamprovicycle

Just go read about them or watch videos on yootoob.

Less effcient , less mess , less options
More for easy going city bikes and such .

skookum

belts
less efficient
last longer
much more expensive
more finicky to set up
easier to maintain

I have one of each on similar bikes. The belt performs as advertised, no problems at all, but I don't think there is any real advantage over a chain and a few downsides.

BrocLuno

If I had to ride wet, it would be belts all the way. I had a belt on my Harley 1200c that took all the abuse you dish out and never whimpered once. Almost as good as a shaft drive for low maintenance

Prolly less resistance than a dry dirty chain. Prolly more resistance that a well oiled clean chain ...

fietsbob

Gates belt drive for bicycles , is what you are looking at ? can you be more specific? what combination?

ericzamora

I was just perusing youtube videos earlier today. This guy spec'd a belt drive for his 2-year bike touring trip from Argentina to Alaska. Belt drive mentioned at 4:04
I have no experience with belt drives though a buddy has one on his city commuter hybrid and loves it.

eric/fresno, ca.

General Geoff

Belt drive is the way of the future, IMO. My next bike will probably be a Gates Belt Drive coupled with a Pinion gearbox.

Greater longevity and no need to lubricate or clean/degrease saves far more time and effort than the ~1 watt you lose from efficiency differences vs a chain.

fietsbob

FWIW at my LBS they had a Broken crank cog ring, hanging from a nail for several years..... so know They are not invulnerable .. it took several days for a replacement to arrive,

Special order , with fast shipping charges..

but as the town is being made over for tourism,, abundant hotel rooms, restaurants and brew -Pub-cafes to fill up that waiting time..


A nice ,little , Drinking town with an old Fishing problem ,



When I saw them I thought inside a chain cover would be great ! , mostly to be anonymous,, not a 'steal me' , feature, highlighted..

and since chains in those covers rarely get oil , a drive that never needs it is Ideal ...





....

seamuis

prathmann

The Gates belt clearly has a longevity advantage compared to derailleur chains, but it should really be compared to 1/8" chains used with single speeds or IGHs. In that case I'm not so sure since I've had chains on 3-speeds and the cross-over chain on our tandem last for well over 30,000 miles and only require minimal maintenance - i.e. add some oil every few months and wipe off the excess.

BrocLuno

Any of the K2/ProFlex/Girvin bikes can accommodate a belt w/o modification. Either the aluminum swing arm, CroMo arm, or the carbon one. No hassles. There are other brands with arched swing arms.

On the elastomer suspension bikes, you can use a stiffer poly bushing. On the shock arms, you can put in an Air Shock and pump it up enough and you will never have to worry about pedaling losses from bobbing.

I don't mind a bit of bobbing for the plush ride on my K2, even on the street (Fox Shock). It only happens when I'm up on the pedals climbing steeply, and not much even then. As long as I sit, no issues.

28 lbs all up with plush seat and rear rack, not bad for a trail bike that can run errands too

Not mine, just a snap off the Net:



Many are now getting converted to Gravel Bikes

fietsbob

Belts need to be under a consistent tension, not a variable one, maybe a V belt can handle a spring loaded 3rd pulley ..
Bike Fridays Silk had what looked like a swing arm , but it was rigid and included the BB and a way to tension the belt..

Shimagnolo

Some years back, I picked up a new-old-stock Calfee Luna Pro frame and built it up. When it was arrived, I was surprised to see the seatstays are bolted to the dropouts, with the bolt heads on the inside of the dropout. Now Calfee has been producing these for years, and I'm wondering if there were even belt drives around when they began. I'm thinking they may be doing it for ease of production.

https://calfeedesign.com/luna-classi...53973388671875

Andy Thousand

HerrKaLeun

That sure is a low maintenance setup. However, a system requiring proprietary frames for the pinion and expensive components (belt, pinion) is unlikely to be a widely adopted future unless prices really drop.
For some reason I think the Rohloff has more chance to be more popular. It also could have a belt (or chain), but will work with regular frames. But again, at the cost it has it won't be widely adopted.

General Geoff

You're right about the Pinion being fated to the high-end adventure/commuter bike market exclusively due to cost. But the belt drive combined with IGHs, I think, has a much brighter future in the sub-$1k bicycle market. Priority makes nothing but belt drive bikes, and they've been selling their models very well since they started up a few years ago.

Archwhorides 

I've run a Gates belt on my 8 speed Alfine IGH commuter for three years. My commute is an 18 mile round trip and I average 4 days a week on the cycle. I have also used the bike for some casual 25-30 mile road rides.

Downsides:

• IGH/belt a bit less efficient and a bit heavier (maybe 1 1/2 lbs) than comparable conventional drive. With this margin, I would say the engine is a much bigger factor for acceleration and speed, so this issue of weight/drag doesn't matter at all to me.
• Needs to be properly tensioned. The OEM eccentric bottom bracket on my cycle was crap and had to be replaced after two years with a quality part (however not all belt drives use this same tensioning method). The tension has been fine since.
• Bit more work to change a flat.

Upsides:

• Addictively quiet and smooth in any condition
• Virtually maintenance free once set up, even when riding every day in the worst weather (this is very important for me, as I hate having to clean/lube a chain)

A month ago I pulled the trigger on a new pinion/belt commuter that I have fitted out for winter riding with studded tires. It rides smooth and trouble-free in any road condition, so I'm a happy camper all around. The pinion gearbox is a bit heavier still but the bike runs great and changing flats is as simple as a single speed.

Based on my experience I wouldn't hesitate to recommend the belt drive with IGH or Pinion.

BrocLuno

If you modded a ProFlex with the elastomer rear "strut" it would not change length much. It could be your tensioning system.

Harleys have been running belt drives for years with 3 inches of suspension travel at least. Belts can handle some slack, just not as much as chains with a spring loaded derailleur ... And you can add an idler roller with a spring to keep the tension constant, if you want to.

I was just offering a rear end example that did not require cutting the rear triangle ... I'll bet there are a lot of older MTB designs where the seat stays or upper suspension "rods" are moveable/removable, making them easy candidates for a belt conversion. Limit the travel and you are good to go

An ingenious person could prolly calc the belt length so that as the rear triangle came into alignment, it would induce correct tension ... And maybe adding a simple roller in the right place would keep the tension as the swing arm moved a bit for better ride ...

JonathanGennick 

My first exposure to belt drive was a Kawasaki that I bought in 1987. Fantastic experience w/that motorcycle, and it was an easy leap for me to accept belts on bicycles.

Belt drive is wonderful in winter. I do nothing in winter except to let my bikes drip dry inside. No lubing, no rusting of the chain, no crud in the (internal) gears.

The OP asked about slippage, and no one's commented yet on that. The belt does need to be "in the zone" with respect to tension. Too loose and you get slippage under load, and too tight leads to friction and noise. Hoping I don't get crucified for admitting this in a public forum, but I just "wing it" when adjusting my belt tension. There are tension gauges, and a phone app works pretty well, but I have good experience going by feel.

Belt drive is wonderful for people who just want to ride and enjoy a few miles now and then without having to fuss a lot with cleanup and lubing of chains. My daughter is a perfect example. She's not a bike enthusiast. She just likes to ride to work and back -- year round, including in winter! --and for enjoyment on sunny days. A low maintenance bike that needs no oiling and cleaning is perfect for that application and is easy to store inside her apartment, because no worries over grease on the carpet.

fietsbob

FWIW at my LBS they had a Broken crank cog ring, hanging from a nail for several years..... so know They are not invulnerable .. it took several days for a replacement to arrive,

Special order , with fast shipping charges..

but as the town is being made over for tourism,, abundant hotel rooms, restaurants and brew -Pub-cafes to fill up that waiting time..

AlmostTrick

This makes perfect sense to me. Anyone with a good mechanical aptitude should be able to set the tension to the sweet spot with little fuss, I figure.

ksryder

Belt drive + IGH is a fairly common setup on the Tour Divide rigs. Seems like belt drive ticks a lot of boxes for commuters and ultra distance bikepackers. Somewhat odd venn diagram there.

Darth Lefty 

Kedosto

flatlander_48