Gates Carbon Belt Drive: Everything You Ever Need to Know

Alee May 1, 2012 33

Gates Carbon Belt Drive has been developed over the last 25 years for applications on 6000hp drag racing cars, 150hp motorbikes and more recently, bicycle drivetrains. Although Carbon Drive isn’t for everyone, it certainly has a place for bike tourers and city riders who are after a no-fuss drivetrain which is lighter, easier to maintain and offers an exceptional wear life.

Gates Carbon Drive system is slightly limited for the bicycle touring market, as it is only able to be used with internally geared hubs such as the 14 speed Rohloff or 8/11 speed Shimano Alfine.

Our extensive experience with Carbon Drive has been on a two year, 31,000km trip between Europe and Australia. We started with belts on both our modified Surly Long Haul Trucker‘s and 10,000km later used dual belts on our Co-Motion tandem.

The Why

- Belts last up to 4x the life of a chain because they don’t ‘stretch’ and wear in the same way. This is because belts have no moving components like a chain, they’re constructed with continuous loops of carbon cord inside a nylon/polyurethane jacket. Chains lengthen over time as their components wear (pins, bushing, rollers) until eventually chains will no longer mesh well with the sprocket teeth. It actually took until 31,000km until we snapped our first belt!

- Belts require little to no drivetrain maintenance and don’t need to be lubricated (no greasy hands). The most maintenance we did was a clean our belts with a tooth brush whenever we got a lot of dirt on the drivetrain.

- Belts are essentially impervious to road grime and weather, and will not rust if you leave them in the rain!

- Belt drivetrains are almost silent on the road; they have a pretty cool humming sound.

- Belt drivetrains are considerably lighter than chains, in fact a cog/ring/belt is lighter than a chain alone.

The Why Not

- Belts can make a lot of noise on sandy, dry roads. We came across this problem in less than 10 short sections of our trip. Stopping the squeak is an easy fix, a squirt of water and a rub with your finger, but it sometimes needs to be done every 20-100km depending on the fineness of the grit. Silicone spray or Rohloff biodegradable chain lube is said to keep them silent for longer, but we never had access to these products when we needed them!

- Getting a spare belt at any old bike shop is virtually impossible. It’s a send-in job. But that said, most high-end bike components need to be shipped to you. We always carried spare belts because they are the most likely part to break, and really don’t weigh much, just 74g. We never carried spare chainrings or cogs as we had a low chance of damaging or wearing out those components.

- Belt drivetrains require a lot of tension resulting in a slightly less efficient drivetrain than with a chain. This tension is also said to damage bottom bracket and rear hub bearings but it is our experience that your bearings will wear at the same rate.

- You need a belt compatible frame with a built-in tensioner to run a belt drivetrain. Belt compatible frames have a ‘belt splitter’ in their rear triangle and should also be stiffness test approved.

- Carbon drivetrains are expensive, but we think they’re pretty good value if you consider the kilometres you’ll get per dollar invested.

- Belts can only be used with an internally geared hub, or as a singlespeed (not for derailleurs). This is primarily why the product is not mainstream.

- Belt lengths are fixed and only five lengths are available, limiting the drivetrain ratio options available.

- Belts can be mishandled; users should be careful not to twist or bend the belt – see below.

What do we think?

Gates Centertrack is perfect for road touring.

Given that 90% of our across-the-world-trip was on sealed roads, the silence, durability and maintenance-free nature of Centertrack outweighs the annoying squeaking we might get on sandy roads. That said, we generally recommend belt drive to people who ride the majority of their tours on sealed roads. Those who spend more time on dirt than us should stick with a chain, or risk having a squeeky belt drivetrain!

Here’s our review of the Centertrack belt kit (HERE), and tandem CDC (HERE) / Centertrack (HERE) timing belt kits.

Why aren’t belts common?

Chains are compatible with mainstream bikes, or more specifically, bikes designed around derailleur gearing systems. To get the same gearing options, belts must be used with internally geared hubs. Although internally geared hubs are brilliant for what we do, derailleur setups fit onto almost any bike frame type, are cheap, reliable, simple, and lightweight.

Belt Options

CDX Centertrack

First available in 2011, Centertrack is Gates second go at the bicycle drivetrain and it offers many advantages over CDC/CDX. The main difference is that Centertrack uses a central fin that runs along a molded track on the belt, rather than employing flanged cogs like on CDC/CDX. We’ve had much more success with longevity on the Centertrack kit.

CDX Centertrack weight:

Chainring (Gates 50t x 130bcd): 97g

Rohloff cog (Gates 20t): 94g

Belt (Gates 118t): 74g

Total: 265g

CDC/CDX

Introduced in the mid-2000’s, the CDC/CDX kit was Gates first go at carbon drivetrains. It uses flanges on opposite sides of the front chainring and rear cog to make sure the belt tracks straight.

CDC/CDX weight:

Chainring (Gates 50t x 130bcd): 71g

Cog (Phil Wood 20t): 181g

Belt: 98g

Total: 350g

CDX Centertrack > CDC/CDX

The Centertrack system is a vast improvement over CDC/CDX. It solves some of the problems of the CDC/CDX system, namely belts slipping on cogs under low belt tension and high-load.

The biggest difference to the CDC/CDX system is that Centertrack will allow for more lateral intolerance: This means that when your frame flexes slightly, the belt is still able to run efficiently without the chance of slipping even though tension is reduced.

The Centertrack belt runs at a lower tension: This reduces stress on your drivetrain, namely bottom bracket bearings, hub bearings and chainring/cogs, and improves efficiency.

The Centertrack belt is even quieter: I thought the CDC/CDX system was quiet, but I’ve found the Centertrack system even more silent.

The Centertrack system clears debris better from the cog and chainring: The open cog design of the Centertrack system actually repels dirt and mud better than the older flanged cog system on the CDC/CDX.

The Centertrack belt is very picky in terms of chainline: The CDC/CDX belt can be installed with a slightly out chainline, and as a result, people found their belts wore prematurely. With the Centertrack design, the tolerance is reduced. If your belt is slightly out, you know about it straight away as you can hear the rear cog making lots of unhappy sounds.

The Centertrack rear cog is stainless steel: There were problems with the CDC/CDX cogs which saw them wear out quicker than the belt itself! The new CNC’d stainless steel cogs should outlast a few belts.

The Centertrack system is roughly 3mm wider than the CDC/CDX system: This solves some issues for frame clearance as the front chainring sits out further from the spider.

The Centertrack system is cheaper, especially for Rohloff users: Previously Rohloff owners had to use a Phil Wood stainless steel cog to run the CDC/CDX system. Now Gates make a far cheaper alternative which is also stainless steel for Rohloff hubs.

 

Cleaning a Belt Drivetrain

Cleaning is as simple as getting a water bottle and an old toothbrush, and rinsing the belt/cogs down with water. No degreaser. No chain cleaner. No dirty hands. The cleaner the drivetrain is, the more silent and efficient it will run!

Handle Belts Carefully

You have to be really careful with how you handle carbon belts, as misuse can lead to internal fibre damage, compromising the strength of the belt. They are sensitive to crimping (1&6), twisting(2), back-bending (3), inverting (4) or zip tie’ing (5).

Belt alignment is essential. With the CDC/CDX, make sure that the belt is sitting perfectly on the chainring and cog. At full tension, it should be silent. You will be able to see if the belt is rubbing on either of the ‘windows’ on the chainring or cog. With the Centertrack system, you will know when it is misaligned – it will make lots of noise at full tension.

When you put the belt on, it is essential that you do not ‘crank it on’ like you may with a chain. You must essentially put the belt onto the chainring and cog before setting the tension. Simple for sliding dropouts and EBB, slightly harder for horizontal dropouts. Use the image below as a guide.

If you’re folding a belt, or unfolding a belt, you must be careful you do this in the correct manner. The belt should naturally sit in a loop which folds three times. See the below picture for an example.

Belt Drive Bike Frames

Not all frames can run belt drive. A belt frame has a few essential features that make it suitable.

- The first is that there must be a split in the seatstay, chainstay or dropout. Belts are one piece, so a frame split is essential.

- Next, there must be an adjustable chainstay length. This is commonly made possible through sliding dropouts, eccentric bottom brackets or horizontal dropouts (more below).

- Another essential frame feature is a stiff rear triangle. The less flex, the smoother the belt can operate under load and corners. Touring bikes generally have very stiff rear triangles as they need to carry heavy loads on their pannier racks.

Dropouts for Belt drive

Sliding vertical dropouts: Sliding dropouts are the best option for belt systems because they are easy to adjust to get the high tension that belts require. You also do not need to tension your belt every time you take your wheel out; it simply drops out and goes slots back in to the perfect tension.

EBB: Eccentric bottom brackets allow your wheel to slot in and out at perfect tension. EBBs require a bit more work than sliding dropouts to get the appropriate belt tension. Making small adjustments to tension is also a bit of a pain.

Horizontal track dropouts: You have to be really careful with belts in horizontal dropouts. If you are using belts and horizontal dropouts, you must have a minimum of 10mm left in the dropout before the belt is tensioned. This space is required to get the belt onto the chainring. Eg. If your chainstay is adjustable between 420-440mm, you must have your belt taut between 430-440mm.

Frame Modification

It is essential that a frame modification is done correctly. Not any old frame can be modified to run a belt drive, especially if you want to use it with a Shimano internally geared hub. Shimano IGHs have quite a narrow chainline and this often results in chainrings rubbing on the chainstay. If anyone pulls out a 40lb rubber mallet to flatten your chainstay… have a few words with them!

If you’re going to get this modification made, make sure to see a reputable frame builder. It will often cost around $500 USD to modify a frame including paint. We used Ewen Gellie for our work in Australia. Cycle Monkey in Northern California (USA) also does frame mods.

Chainline, Tyre and Frame Clearance Issues

One of the biggest challenges facing frame manufacturers and the use of belt kits has been frame clearance of the front chainring. This is seen mostly on bikes using belt drive with Shimano internally geared hubs. The gear selector on Shimano hubs is external and on the drive side, resulting in a really narrow chainline.

This is more of a problem for belt-bikes than chain-bikes as:

- Belts and belt cogs are wider than chains and chainrings

- Belt cogs do not get as small as chain cogs

- 46t or bigger is most likely required

- Belt drivetrains are fussy – they must be perfectly aligned

Chainlines of various internally geared hubs:

- Alfine 8 or 11: 44.85mm

- Nexus 8: 44.35mm

- Nexus 7: 43.05mm

- Rohloff with Phil Wood Cog CDC: 52, 54 or 56mm

- Rohloff with Gates Centertrack: 54mm

Working out what belt ratio to use

You will need to use the Gates calculator in order to work out what chainrings and cogs are available for your frame. It all depends on your chainstay length.

As mentioned above, if you are using the Centertrack kit and horizontal dropouts, you must have a minimum of 10mm left in the dropout before the Belt is tensioned. This space is required to get the belt onto the chainring. Eg. If your chainstay is adjustable between 420-440mm, you must have your belt taut between 430-440mm.

Belt Drive and Tandems

It is possible to use Gates Carbon Drive as a timing belt. This will save you about 250g over a chain and chainrings. In order for Carbon Drive to work on your tandem, the frames boom tube must be 724mm between bottom brackets and you will need to use 130bcd cranks. It is possible to run belts on both the drive and non-drive side of your tandem.

We believe tandem touring with belt drive is best left to sealed roads, as we’ve experienced noise on the timing side on both sandy, and dirt roads with fine dust. If you ride only a small percentage of your travels on dirt, then cleaning the belt with a bit of water every 50-100km won’t bother you too much and certainly doesn’t outweigh the positives of this system on sealed roads.

We used the CDC timing kit initially, but were quite disappointed by it – it only lasted 2000km (review HERE). Our Centertrack timing belt is going strong with little signs of wear after about 19,000km. You can read the Centertrack timing belt review HERE.

Belt Drive and Rohloff hubs

You can run belt drive with a Rohloff hub if you adhere to their rules. Not adhering will result in the chance that Rohloff will not be able to honour warranty replacement down the road.

Firstly, your frame must be built for the purpose of belt drive. In Rohloffs words, it must be ‘stiffness test approved’. A belt drive production bike or custom frame manufacturer will be able to use the appropriate tools in order to make it ‘stiffness test approved’.

Secondly, your Rohloff hub must be belt converted. This ‘belt conversion’ adds a Rohloff machined adapter to the hub to allow the use of third party belt components. Rohloff records the serial numbers of belt converted hubs and without this conversation you risk the chance of not being honoured warranty. If you already have a Rohloff hub, you can get it converted to belt drive for a fee.

A belt ‘snubber’ is required for Rohloff users. Belt snubbers prevent the belt from walking off the cog. The reason that these measures must be taken is due to the fact that Rohloff cogs actually incorporate a seal surface for the hub. With a ‘belt conversion’, the hub is sealed and ready for aftermarket components.

You are slightly limited in terms of ratios with a Rohloff, as there is only three cog size available (19t, 20t, 22t). This, in addition to the fact that you are limited with your chainstay length, means that there are only a few ratio options available. Manufacturers who produce belt-specific frame are generally aware of this fact and will produce frames with ideal chainstay lengths for their application.

Gates Centertrack: Gates offer the full kit for Rohloff, including a stainless steel cog.

Gates CDC/CDX: There are a few Rohloff aftermarket cogs available.

Tensioning the Belt

Gates Carbon Drive runs at quite a high tension. This tension varies between whether you use a singlespeed or internally geared hub and how powerful you are as a rider.

Tension variation (tight spots) may occur when the crank is rotated. Gates therefore recommends taking several tension measurements at different crank arm locations to find an average. Around a 10lb or 15Hz variation is considered acceptable . If significantly more variation exists, Gates recommended centring the chainring on the crank spider.

Measuring Belt Tension

iPhone app: If you have an iPhone, you are able to download an app which will measure how much tension your belt has! Simply hold the phone next to the belt and give it a few plucks. It will quickly give you an average frequency rating. We’ve also heard of people using a bass guitar and digital tuner to work out the frequency!

Gates tools (sonic tension meter, krikit gauge): You are able to use the uber fancy sonic tension meter, or cheaper krikit gauge if you are iPhoneless. The Krikit gauge is not as accurate as other measuring tools, but essentially you put your finger in the loop on the tool and apply pressure until the tool clicks. It will give you a rough estimate on whether to increase or decrease your tension.

Cost

CDX Centertrack

Chainring: $70-110 USD

Alfine Cogs: $110 USD

Rohloff Cogs: $110 USD

Belts: $90-110 USD

Centertrack Kit Total: $300 USD

Australian Shoppers: Contact Black Mountain Sports for a list of stockists.

Conclusion

We love our belt drivetrains! After 31,000km our Centertrack tandem drivetrain has proven itself and it’s durability. The simplicity, silence, long wear life and maintenance free design of the Centertrack kit makes it the perfect for bike touring. The significant advantages of Centertrack over CDC/CDX definitely make Centertrack our recommendation.

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  • http://velophileaustralia.wordpress.com/ Karl

    Belters are awesome! Team this up with a 14-speed Rohloff hub and you’ll be cruising. I love the idea of it being quiet, smooth and low maintenance. I’d like to build a bike in the future with a IGH and a belt drive combo.

    • http://www.cyclingabout.com/ Alex Denham

      We’re hoping to be able to tour around the world problem free!

  • Jeroen

    I am driving a Rohloff + Centertrack for half a year now, but the rear cog is pretty much worn out. I do ride a lot of mud nowadays… On average you can say I maybe ride 40Km a week, that just isn’t much. 

    • http://www.cyclingabout.com/ Alex Denham

      That sounds like it has worn a bit quick… we have both completed well over 5000km on our Centretrack drive trains with no noticeable wear on the rear cog. The front chainring is loosing its anodising now, it will be interesting to see how many kilometres we can get out of it. Are you using the stainless steel cog?

  • Paul Graville

    Awesome info, thanks! A question: do you know the difference between the CDX and CDC systems?

    • http://www.cyclingabout.com/ Alex Denham

      Hi Paul. The only difference between CDC and CDX is the width of the belt. CDC is 10mm wide and designed for city riding, and CDX is 12mm wide and designed for a MTB application. Having said that, make sure you ride Centertrack; it is leaps and bounds better than the older system. Alex

      • Roberto

        Hi Alee, I’m having hard time with Gates carbon belt system. Do you know if CDX and CDC system are exchangable? I’m asking because I was so pissed off with belt alignemt of CDC (after every ride I couldn’t manage to keep the belt perfectly in line) that I decided to go for CDX system. I haven’t finished to install everythings yet because it looks like there’s a misalignment of about 3mm on belt center line between CDX rear and CDX front cog, and I can’t figured out why this happen. I’ve just replaced the old parts with new ones. Thanks for your tips. Roberto

        • http://www.cyclingabout.com/ Alee Denham

          Hi Roberto. I am not too sure of the particulars, but once you’ve got it all installed you’ll be able to get a better idea for how much difference there might actually be in the chain line. You should be able to add or subtract chainring or bottom bracket spacers to get the alignment perfect. Alee

          • Roberto

            Hi Alee, thanks for your infos. I wish Gates Carbon (Europe) would have warned me when I asked them the ordering part number for the CDX having already the CDC system installed. Anyway, your info is really useful. I thook a photo to show you better the situation. I’ve placed a long ruler on the front pulley and measured the misalignment on the rear cog. I have 8,10mm from the center line that means more than 3mm of misalignment.in the chain line.
            Now because the internal hub is a shimano Alfine I don’t think I can shift the rear side. Can I??
            I’m not even sure if I can play with bottom bracket spacers because as default my bike is already mounting two spacers (5mm total) on the not-drive side (I guess to get chain line with the old CDC). According to your experience do you think will be possible to add a spacer of 3 mm?? The crankset is a Truvativ fireX GXP.
            Last option adding 3mm chainring on the spider, but here I don’t know the nuts will hold such big lengh. Gosh I’m feeling on the edge of a divorce with belt system.
            Thanks for your advice
            Roberto

          • http://www.cyclingabout.com/ Alee Denham

            Hi again. We had a couple of millimetres difference in chain line from the CDC to CDX. From memory I added a few millimetres to the bottom bracket on the drive side. It will take a bit of trial and error to get it perfect, so give it time! I don’t think you’ll need to divorce your belt setup just yet. We’ve done 26,000km on our current cogs and belt – the Centertrack system is a great!

          • Roberto

            Hi Alee, finally I could untie the knot of the chain line. I bought longer bolt but because they where too long I had to add double spacer (that weren’t so easy to find for the right thickness). In photos you can see all the stuff I bought to fix this issue. Anyway now everything is installed and looks it is working really good.
            Because of the money I have spent for the chain line system (CDC and CDX) and time installing it I wish I will ride more that 50000Km without touching anything anymore.
            Thanks for your information. I hope that it will be useful also for others riders.
            Roberto

  • http://www.facebook.com/kieran.madden2 Kieran Madden

    Hi Alex – I have been researching my next bike for a few months now, over which time I’ve read a lot about the Gates Belt Drive, and for some reason only just found your article today – it’s by far the most informative article on the system I have come across.

    I initially loved the idea of the Belt Drive but was then put off the system after reading what Thorn, a British manufacturer of touring bikes, think of it. I’ve since come back around to the idea a bit but it still bothers me that I haven’t seen most of the serious concerns raised by Thorn fully addressed properly elsewhere – which makes me wonder whether either Thorn are scaremongering or Belt Drive sellers are more interested to tapping into the low-maintenance market than selling something they genuinely believe in.

    The article can be found here http://www.thorncycles.co.uk/thornpdf/ThornLivingWithARohloff.pdf on pages 18 and 19. I’d be really grateful for your views on Thorn’s concerns, specifically:

    1. The supposedly expensive, difficult to find and heavy tool for removing the rear Belt Drive sprocket (I have been unable to find much/any corroborating info about this elsewhere).

    2. The apparently delicate nature of the belt, both during use and during maintenance for punctures etc (specifically, the damage caused from stones, twigs, knocking the drive with your legs or against a post. The Gates manual apparently says you need to “make sure that no components or objects can come into contact with the belt”, which sounds a bit daft in a daily use bicycle).

    3. Potential weakening of the right-hand rear chainstay from the frame split.

    Thanks :)

    • http://www.cyclingabout.com/ Alex Denham

      Hi Kieran

      I’m glad you’re looking at belts as an option – we have been running our Centertrack kit for a long time now without issue. We are wondering when something will fail, but we consider ourselves good guinea pigs given that we ride in all-weather conditions in lots of different countries.

      My guess is that Thorn haven’t spent a good amount of time on belts! Thorn are pretty well known for being staunchly for or against different things – disc brakes on tandems for example. We take their somewhat extreme reactions to certain matters with a grain of salt… ;)

      1. Regarding the rear sprocket, we do not carry a tool to take it off. But we don’t carry a chain whip when riding a chain driven bike either. Yes, it will be harder to take off our cog when we need to (realistically the tool will get sent from Germany to wherever we are), but we are gambling on the rear cog making it a long way yet.

      2. As mentioned above, we haven’t had any problems with with our belts… although we do cringe when multiple people per day twist our belts in their fingers. Intrigued locals like to give them a good yank, and still everything works fine. Delicate? No less delicate than a chain in our opinion.

      3. The only frames we recommend buying should be ‘Stiffness Test Approved’. I don’t think you’ll have any issues at the chain/seat stay with an approved frame that has been tested with the correct tool.

      Regards
      Alex

      • http://www.facebook.com/kieran.madden2 Kieran Madden

        Wow thanks for your quick, informative (and diplomatic! ;) ) reply on a year-old post!! You have almost completely set my mind at ease, especially as I don’t expect to do any touring.

        I say almost, as regarding your answer to q.1 – I hear what you’re saying when out touring but is it at least reasonably easy for a normal user to get hold of a tool when you’re at home living in the developed world?

        • http://www.cyclingabout.com/ Alex Denham

          We keep tabs on comments on the site, and like to reply as quick as possible – otherwise we get stuck with a backlog!

          It would be worth finding out who has tools near you. Like Thorn mentioned in their article, there may only be only one shop in your country which has the right tooling. But really, you won’t need to worry about taking your cog off for another 20000km+ – so maybe carbon drive will be available in more bike shops by then!

          • http://www.facebook.com/kieran.madden2 Kieran Madden

            Ahh OK – that’d probably be at least 5 years for me then so yes, hopefully the tool would be more available!

            If I may ask a couple of other things – regarding the frame stiffness in point 3, I had thought that was more to prevent the chain tension changing from moment to moment as the frame flexes, rather than to certify strength or point of material failure. Since a stiff material/join isn’t necessarily a strong one or one with a long fatigue life, do you know if this test includes a strength/fatigue test?

            (I accept too that the strength of the chainstay join is dependent on a given manufacturer’s design of the join, so maybe some are plenty strong enough while some aren’t – I imagine that if it’s as strong, say, as an S&S coupler, it shouldn’t be an issue. Also, if it was an issue, I’d have thought you’d have had a frame failure by now with all the travelling you’re doing on the Belt Drive.)

            Also, on a slightly different thing, I have been pondering the use of drop bars with Rohloff; I want Rohloff ideally, but have been considering the Alfine 11 as the idea of having to move my hands from the drops/hoods whenever I want to change gear seems a bit annoying. Maybe it’s not that bad but I would anyway like to have interrupter levers on the tops for negotiating traffic etc. During initial discussions with one of the manufacturers that have made my shortlist, though, they didn’t think that interrupter levers are long enough to clear the Giles Berthoud/Co-Motion drop bar shifters and, sure enough, all of the few interrupter levers I can find do look rather stubby. Have you any experience with this? Do you think it’s a workable option? Do you know of any levers that would meet my requirements?

            I hope I’m not taking advantage of your helpfulness & hospitality by asking yet more questions! Forums are of limited use when trying to get authoritative answers and it’s great to be able to get unbiased information from somewhere; having stumbled directly onto this page from google I only just realised that you’re in the middle of a tour of Europe and the Middle East. It’s amazing how you’re managing to run such a detailed blog while on the go!

          • http://www.cyclingabout.com/ Alex Denham

            You’re correct – the stiffness test is just a test of stiffness and that doesn’t mean the frame is strong. Never mind my point.

            From all I’ve seen on the internet, which is admittedly too much, I haven’t seen failures at the seatstay joins on belt frames. This doesn’t mean a frame with a split can break, of course, but I don’t think this should be a concern given how many belt drive bikes are around these days. Get your frame/bike from a reputable manufacturer backed with a good warranty and you should never need to worry.

          • http://www.cyclingabout.com/ Alex Denham

            We love questions! We are glad to be able to help, whether it be from home or on the road.

  • Walter

    What is the proper procedure for getting a cdc belt to track straight. Mine has a tendency to track 5mm to the inside while the small cog is tracking straight.

  • Paul Ferguson

    Thank you for a proper article. Their seem to be plenty of opinions
    about but little in the way of solid research. I’ve only just started
    looking into belts but defiantly more intrigued now.

    • http://www.cyclingabout.com/ Alex Denham

      Glad we can help.

  • LukaszKaleta

    Hi

    I bought bike with a belt drive.

    On one of mine trip I had a silly accident:
    Other belt from mine bike-bag get between wheel and belt. I did not see what actually happen under me but mine bike was stopped immidetaly! I look what happen and carbon belt was out of sprocket. I notice also that the belt hurt a little from the external side. But it was in one peace. I spent some time to get the belt on sprockets again. I start pedaling and belt simply rip off.

    Next I had very long walk.

    With the first opportunity I start to search for a new belt.
    Well … believe me that getting carbon belt in Norway is almost a miracle.

    I contact with Gates (manufacturer) and they give me price 110euro for belt and delivery.

    why the hell I choose belt ?
    It last much shorter than mine last cheapest chain.

    • http://www.cyclingabout.com/ Alex Denham

      Hello Lukas

      Sorry to hear of your bad experience. I suggest that you take a closer look at your belt alignment and tension. It sounds like something isn’t set up properly which had caused your belt to jump off.

      We have now completed over 25,000km on our current belt and are really happy with the longevity of the product – we’ve certainly never got this kind of distance out of a chain! As the belt is so lightweight (80g), we always carry a spare with us.

      Alex

      • LukaszKaleta

        Yeah … that’s mine bad experience.
        But it was setup correctly in Germany just before the trip.
        But I do not give up. Since it was sort of accident I will give the second chance to carbon drive ;)

  • Andrew

    Awesome write up Alex! And a great, inspiring website too.
    I’m having a titanium touring/mountain bike frame made up with provisions for the addition of a belt drive but am a little concerned about the noise created by grit and dust that you’ve mentioned. On the gates website they recommend cleaning the belt with water, letting it dry then lubricating with a dry silicone spray which should repel dust and elevate the noise problem. Did you try this? I know in the automotive industry it’s a standard technique used to deal with noisy belts.

    • Andrew

      *alleviate. Pretty sure you don’t want to elevate the noise problem!

      • http://www.cyclingabout.com/ Alex Denham

        Surprisingly, we haven’t tried silicone spray! It seems that the places that are sandiest are also the most remote – but thanks for bringing this information to the forefront of my mind. Will have to test it out soon.

        • Wendell

          Hi is there any lighter crank arm/set ?

          • http://www.cyclingabout.com/ Alee Denham

            I’m not sure what you mean. You can use cranksets from almost any manufacturer with Carbon Drive, even the lightest in the world.

  • Scott Burgess

    Alee.
    Great write up and your forum support looks exemplary too. I just imported a Single speed Cx bike from the US with CDX Centretrack. I was looking for a low maintenance commuter for my 14 mile jaunt into London every day and couldn’t find anything in the UK without paying a bespoke-build fortune.. I love it so far. I do wonder though about what seems to be a ‘reasonable’ amount of resistance I feel when hand cranking the pedal on the work-stand. Noticeable even if cranking backwards with no resistance from cranking the spinning wheel around. The tension is OK according to my iphone app. Is this resistance normal? There is no running noise. What is your experience please? There are no belters in the UK to compare notes with!
    Any help welcome.

    • http://www.cyclingabout.com/ Alee Denham

      If it’s running the right tension, then my advice is to leave it. That said, we run our belts slightly lower tension to reduce the resistance – we can get away with it on the touring tandem because we don’t accelerate hard too often. If you’re ‘just cruising’ and not taking off at the lights like a madman, you can technically get away with less tension.

  • Alex

    Hi Alee,

    I have a new Surly Troll frame which is suitable for a Rohloff IHG as it has horizontal rear drop outs and OEM 2 mounting plate. Originally I wanted to fit a Gates CDX Belt drive but got put off not knowing whether it was stiff enough or finding a suitable frame builder to modify it to include a break in the rear seat stay or modify the drop out to allow a belt to be fitted. First off is the Troll frame stiff enough and secondly is it easy to modify it to include a break for the belt?

    I plan to put a Rohloff OEM TS disc brake (solid axle) hub into my Troll frame and then ride around the world. But to keep the best clean I am going to try to fit a full chain guard as I can’t even be doing with the cleaning that might be involved riding in really dire roads.

    Thanks in advance for your help.

    • http://www.cyclingabout.com/ Alee Denham

      Hi Alex

      Regarding stiffness, I am not actually sure what chainstay and seatstay tubing is used on the Troll. Perhaps email Surly asking for tubing specifications? Or alternatively, bring your frame to a reputable frame builder to get their opinion on the matter. My initial thoughts are that the Troll would be a fine candidate, given that it is designed with pannier bags in mind…

      I would suggest putting a frame break into the seatstay rather than modifying the dropout. The dropout should stay one piece…

      Don’t forget to check whether your chainstay length will be ok for the ratio you are thinking of using. You need to have 10mm in the dropout in order to get the wheel out, so the axle needs to sit at 429mm or further on the Troll. I had a look at the Gates Calculator (http://www.gatescarbondrive.com/Apps/DriveCalculator/index.html) and it seems that you could run a 2.5/1 ratio (same us my touring bikes) with a 115t belt. That gets me up most climbs fully loaded!

      Alee