Belt Drive Bicycles – Trek Soho

Trek Soho with belt drive

Trek Soho with belt drive

Ever wonder why bicycles never jumped on the belt drive idea? If they're strong enough for a Harley or a Buell, they should work on a bicycle. Trek thought so, too, and they've introduced the Trek Soho.

Gates Technology, same company that makes the belts for Harley Davidson, makes the belt for the bike. The Soho comes with an 8 speed transmission inside the rear hub, no derailleur involved. No more greasy fingers when getting the chain back on the gears, no more cleaning a dirty, gritty chain, looks like a pretty neat technology transfer.

UPDATE: The first comment points out, belt drive bikes aren't really new, but previous bikes were single speed, you choose the sprocket you want and mount it on the bike. The Trek has an 8 speed hub which makes it (I think) the first belt drive multi speed bicycle. (Disclaimer: I'm NOT a bicycle expert!)

Link: Trek via Popular Science

Trek Soho with belt drive

Trek Soho with belt drive

Comments

  1. kneeslider says

    CAK, I believe those are single speed, aren’t they? I’m not really up on my bicycles so I’m not sure but I think that’s the difference with the Trek, 8 speeds.

  2. Phoebe says

    Trek is a major manufacturer. A company that hand-builds bikes using this is one thing, but it’s kind of a big deal when a mass-producer begins using a technology that wasn’t mainstream previously. It’s pretty brave of them; it might not catch on, after all.

  3. CAK says

    Spot makes a 3 speed internal geared belt driven, so not quite the 8 that TREK has, but they have been doing belts for years. But you are right, their main claim to fame is the SS belt drive bikes – and they are beautiful, more or less custom jobs.

  4. jp says

    Now there’s an idea whose time has come. Derailleurs are clever engineering solutions but are a royal nuisance, particularly if the bike sees any shock loads. I’m sure I’m not the only person to wipe out after landing a jump because the chain went where it had no business.

    I’d buy a downhill bike with a belt and 8spd in a heartbeat.

  5. says

    Nice idea, not new, of course, but most likely not as efficient as a chain in good condition – just like on motorcycles. So if you treat your bicycle like most people to, the belt would work just fine. There are a few shaft drive bicycles out there too, but on a bicycle transmission efficiency may be more crucial than on a motorcycle.

  6. Don says

    I would think the reason chain drive is preferred on multi-speed bicycles is because it allows easier gear customization. The internal 8-speed of the Trek, though a great idea, is pretty much fixed. You’re stuck with those 8 speeds. Gears on sprocket clusters and chainrings, however, can be replaced with an assortment of sizes to fit the needs of the rider. I know most folks buy it once and never mess with it, but by design it’s there to be toyed with, if they need it.

    Plus, I don’t see belt drive giving the 20 or 22 gears that chain drive now offers with dual chainrings on the front, or 24 to 30 gears with a triple crank. Chains are just more versatile… at least for now.

    Bottom line, for performance minded riders, chains are the only way to go. For a commuter looking for simplicity with less mess, it looks like belts do offer a good option.

  7. JC says

    “I’d buy a downhill bike with a belt and 8spd in a heartbeat.”

    DH is the last place this will be, mud and dirt and belts don’t work well together. The long travel usually dictates a chain tensioner regardless of drive train, so if you have that might was well have a derailer, and then you might as well have a chain.

  8. todd says

    Then there was always the problem of getting the belt out of your frame without having a less than optimal bolted frame. All the diehards will complain that the belt is too wide and less aerodynamic.

    -todd

  9. OMMAG says

    I think it’s a great idea.

    For the kind of bicycling I do … just an evening ride to the park and a couple of times around as long as the weather is nice. Maybe a quick spin to the convenience store.

    My hard riding days are OVER … only thing is .. Do I need it?

    Still its a good looking bicycle.

  10. kneeslider says

    I’m guessing this may not be targeted to the high end cyclists used to the highest efficiency gear for competitive purposes but it may work well for a broader market of cyclists looking for a clean, quiet and easy to maintain setup.

  11. Paul says

    Efficiency is of utmost importance on a bicycle. Every wasted microhorsepower is a big deal.

  12. JSH says

    I personally don’t understand the appeal of triple cranks. A double crank effectively gives you a HI-Low set of gears. I guess a triple crank gives low for climbing, mid for flats, and hi for downhills.

    With a Shimano Nexus interal hub you can have 4, 7, or 8 speed. That is a gearing range of 184%, 244%, or 307%. The only difference is that the jump between gears is greater. I would think one of these would be great on a mountain bike. A NuVinci CVT would be even better. (I’ve ridden one of these bikes and the NuVinci CVT works flawlessly!) http://www.sheldonbrown.com/harris/nuvinci.html
    As to belt vs chain. I can’t really see how the belt is an advantage when mated to a internal hub. The only time I get my hands greasy is when the chain jumps gears with a cassette and derailer combo. I wouldn’t want the decrease in efficiency that the belt would cause. I would guess the belt would be quieter though.

  13. Jon says

    The new belt drive has a couple of advantages over a chain: it’s much lighter, and has less friction. They tested the friction against a new, clean, optimised modern chain, and it was better, and the situation only improved as the conventional chain got filled with gunk…

    Part of the reason that belts haven’t been used widely on bicycles before this was because prior versions were too stiff and needed really high tensions to work. This new GAtes belt is optimised for the bicycle application (Though it still requires more tension than a conventional chain.). Another drawback is the need to split the frame so that the belt can pass through.

    If I was looking for a new commuter bike I would be very interested in this. (Or a single-speed racer.)

  14. Tyler says

    Hell I dig it, I gave up on serious hard riding years ago, and my wife and son aren’t in need of a competitive machine, but I do get tired of the kid knocking his chain off, or even worse the inevitable lube-slung back wheel that needs to be repeatedly cleaned. I use wax based lube, FWIW, but it still happens. As to replacing it, well if the belts on a buell will last 100k, I think this will outlast the frame. I realize it is smaller/thinner.

  15. tim says

    I also have seen this before (Spot bicycles): You may also be interested to know that there is a 14 speed internal gear hub out of Germany which is similar weight to the Shimano or SRAM 7 and 8 speed internal gear hubs. The big issue for me (as a previous owner of a Rohloff hub) is that it makes the rear wheel very heavy. So you get a lot of pinch flats especially on a hardtail A minor adjustment in riding style to accommodate that, decent thick tubes, and its not that big of a deal.. If you were touring or for a serious commute: the perfect drivetrain has to be the belt and the Rohloff hub, surely?

    If you are interested in some very cool engineering, plus a great engineering drawing, check out http://www.rohloff.de/en

  16. says

    I am very much into internally geared bikes, they have significant advantages over a dangling derailleur, especially in off-road uses. A belt drive bike seems to make good sense in this application. Simple can be very effective and rideable.

  17. stu says

    The global financial situation is putting more and more normal people on pushbikes, and belt drives like this will satisfy them no end. No oil on their work trousers, no faffy cleaning, no loss of efficiency over time.

    Regarding gearboxes, I think the cycling world is on the brink of a gearing revolution. So far internal gearboxes have suffered from weight and efficiency drawbacks, but as technology is moving on they’re getting better all the time. Now the big S (shimano) seem to be getting more on board, particularly with it’s Alfine gearhub, we might start seeing some interesting changes.

    The tin-hatted consiparcy theorist in me has always assume Shimano make a bit too much money from selling replacements for worn our derailleurs and chainrings to be desperately rushing into the gearbox market. I can’t help but think they’ve likely had something good under wraps for years, and it’s only now the other manufactuers are looking into it more seriously that they’re being pushed into releasing it. After all, who wants to sell products that last for ever these days?

    Personally I can’t wait for the first reasonably light 6″ travel mountain bike with gearbox-concentric-pivoting single-sided swingarm and enclosed drivechain. Bring it on :o)

    Anyone interested in that kind of thing, do a google search for ‘Millyard’.

  18. MBM says

    As was observed above the right side dropout or chainstay has to be split to allow use of the belt. If the bike is designed for it then no problem but it makes retrofitting such setups to regular bikes almost impossible. Bicyclists are inveterate component swappers and spend big bucks on upgrades. This system can’t be retrofitted so the aftermarket won’t be very interested in adopting it.

  19. says

    Corratec introduced belt driven bicycles in 2003 or 2004, already with the Shimano 8 Speed Hub. The Model was called “B-Drive” and they are still availible.
    So Corratec made a multispeed belt driven bicycle years before Trek. But the Trek Soho looks like a very nice bike.

    http://www.corratec.com

  20. todd says

    What would be real sweet is having the “transmission” at the crank. That way the wheel hub can be left nice and light and simple. There’s just the pesky problem of getting the shifter cable into the end of the crank without it wrapping up around your leg. Time for servos… That or just move the tranny above or to the rear of the crank. Didn’t Honda do this?

    -todd

  21. grayband says

    belts arent widely used on bicycles for 2 reasons…the first is that derailleur based shifting systems are proven, relatively inexpensive, and lightweight and chains have the ability to move across a cassette of sprockets with easy and with minimal noise. This is something that belts are unable to do at this time mostly due to their lack of ability to move laterally . the second reason is that belts don’t have the ability to come apart which allows them to be snaked through the gap separating the drive side chainstay, seatstay and seat tube. In order to install a belt there must be some way to creat a gap in the frame without compromising a frame’s design and structural integrity. and truavative is now making a 2 speed shifting system that will eventually be able to be mated to a belt system and rohloff makes the finest internal hub system available ….

  22. Robert says

    I just rode one of these Trek Soho’s back to back with the Trek Soho Single speed chain drive. I was very impressed with the belt drive and could not really detect any loss of efficiency. The back hub definite adds a bit of weight but the split frame regains some strength because the hub, from what I can tell , becomes a rigid member of the frame. If is was $300 less I would have bought it but it just seems really pricey. The gearing ratios seemed very good but the bike was not loaded with all the gear I would normally carry so hard to tell. The jump from 5 to 6 seemed a little tall. The only odd thing I noted was there seem to be some torque backlash in the front fork and I think it was due to the design of the front brake. I noticed it when playing with the bike while standing still but did not notice it as bad when I was riding the bike.

  23. harley says

    The belt drive is from Gates. They do a good job of showing the advantages in mud and comparing the performance to a chain drive. http://www.carbondrivesystems.com/ It is equivalent in weight and efficiency and superior in longevity and maintenance. Belts work well with internal drives or fixed gear bikes, but I’ve seen mixed reviews on all of the internal drives except the Rohloff ($1000). The belt drive will not be able to be used on a bike with rear suspension unless the frame is built so that the distance from the crank to the rear hub doesn’t change with rear axle movement or there would have to be a tension wheel for the belt.

  24. Crow says

    I am looking for a Bike that will work well to pull an adult trailer (cycle tote) for my 12 year old son with special needs. I have been looking at this belt driven SOHO, now that I read this, I wonder if a bike with more gears is more practical? normal usage would be a commuter bike for me, using it on weekends to pull my son.

    Any thoughts on the type of bike best suited for this? You can email me directly at iowacrows@yahoo.com

  25. Richard Harris says

    I have a Trek Soho with just the front of the bike modified, put on carbon fork with disk mount installed an XTR disk brake up front, I am a bike mechanic, so I have made a few changes to suit me. I have put on 3200klm on this bike commuting belt shows no wear, the nexus 8spd hub is smooth and shifting flawless, does it get any better than that, it works great in the rain, no oil from a chain, as the belt cares not. Best commuter bike I have ever owned. It does need a few upgrade from stock to get it there.

  26. Ben says

    I thought about getting this bicycle to ride in the winter so the salt doesnt get into the components and screw everything up. The problem is you need to purchase a new bicycle. For those who would like less hassle with their drivetrains and the ability to retrofit an existing bicycle, I recommend a Shimano Nexus internal hub with a Hebie Chainglider chaincase.

  27. kest56 says

    now if belt drive came with 8 speeds and a hammerschmit 2 speed crankset on a trek Y foil type frame?

  28. Chris Morris says

    Don’t mean to rain on Trek’s parade, but belt drive commuter bikes are standard stuff in Japan for the last 20 years. All 3 of the big bicycle manufacturers make them (Bridgestone, Miyata and Maruishi), usually with 3 speed hubs and their own patented belt tensioning systems. I bought my Bridgestone Lacrosse in 2000, and it has over 8,000 miles on the original belt with no visble wear.
    Try that with an exposed chain in a wet climate!
    But it’s great to see US bicycle manufacturers discovering the belt.

  29. Muscular_Beaver says

    I have to say , as a daily , year round rider in Maine , whatever sort of corrosive , toxic crap they spew on the roads here to try and keep the idiot car drivers safe from themselves will destroy a chain and derallieur in just a few days . The belt drive , with an internal gear rear hub is a major step in the right direction . Otherwise , I really need to bring my bike inside , and let it thaw next to the wood stove , and then hose it off in the shower …not what I want to do at eight in the evening after a long day at work , and six hours with no meal !

  30. Burgeonyt says

    Where are all these people getting the idea that chains are more efficient than synchronous belts? The average efficiency of a Gates poly-belt is 98%, and that’s over the LIFETIME of the belt, not just when brand new and in perfect operating conditions. You might get 98% efficiency out of a roller chain when it’s brand new, properly lubricated, correctly tensioned, and the sprockets are in perfect shape. An industrial white paper I read a decade ago said the average roller chain runs about 93% efficient in U.S; that’s probably the reality of all bicycle chains out there as well. Chains have their benefits and drawbacks just as any drive system will; but saying that a chain is more efficient than a synchronous belt drive goes beyond ignorance and borders on propaganda parroting.

  31. Chris says

    Bicycle chains are up to 98.6% efficient, according to a 1999 Johns Hopkins University study, compared to Gates’ claim of up to 98% efficiency for their belt. Also, derailer gears tend to be more efficient than internal geared hubs with several gears. So for riders looking for maximum efficiency, a belt driven bike isn’t the best choice.

    Belts offer no significant advantages over chains if a full chaincase is used, such as those common on European city bikes. Even without a chaincase, dry chain lubricants work very well to keep chains from transferring dirt and grease to clothing. Chain noise isn’t an issue on the overwhelming majority of reasonably well maintained bikes out there.

    Chains are inexpensive and can be replaced very quickly and easily when they wear out, which isn’t all that often. Other regular maintenance typically requires the rear wheel be removed from the bike from time to time during the life of a chain, which is most of the work required to replace a chain (and even wheel removal isn’t always required).

    While there is probably a niche market for belt driven bikes, in general they appear to solve only minor problems for which better, more practical solutions already exist. Belts require special frames to do even that much.