Belt Drive vs Chain Drive Technologies

[RooiWillie]

Yay! More like minded people.

 

I am actually busy with the very same thing, and was also looking at Gates and some other alternatives.Unfortunately, you need the frame and quite a few other goodies, never-mind the +R2K to get just the drive of the system.

 

SO, I have started with a locally fabricated product. I will quite possibly have the bike finished in the next month or two, as the parts have to be machined. Once done, I will be able to give a rough idea of taking an old aluminium frame, "breaking" it, and converting to belt drive.

 

For my project, I will be using a GT Avalanche frame. Hopefully the end product will be as per my thoughts.

 

Prost:

1. No Oil

2. Lasts between 2 and 10 times longer than a chain

3. Only replace the worn belt

4. It is quieter than a chain drive

5. +- the same weight for the full system.

 

Cons:

1. You need the correct frame (or you have to modify it)

2. Belt cannot be broken (shortened or lengthened)

3. It will be a little pricey (looking at roughly R1300 for the full drive system - has to be confirmed first)

[Guest Omega Man]

Nothing like creating a solution for a problem that doesn't exist hey. What exactly is wrong with a chain?

[nathrix]

Nothing like creating a solution for a problem that doesn't exist hey. What exactly is wrong with a chain?

 

Nothing.

 

Nice to try something different.

[Wyatt Earp]

Nothing.

 

Nice to try something different.

 

I agree, also have no problem with this.

But us good old S.A. plaaskinners are always the first to hop on the bandwagon.

 

I must say, as much as I hate chains and chain lube, this technology has to prove itself first.

[Velouria]

I've been dreaming about a belt drive SS/geared bike for ages.

 

Check out http://spotbrand.com/bikes/

 

[RooiWillie]

I must say, as much as I hate chains and chain lube, this technology has to prove itself first.

 

Oh my belt drive SS will become my weapon of choice at the Critical Mass events...

[Wyatt Earp]

Oh my belt drive SS will become my weapon of choice at the Critical Mass events...

I would like to see it Willie, your price makes the need to try something new much more amicable.

[RooiWillie]

Ok, so here it is... After lots of fights and so, I will not be doing the SS Belt drive...

 

I have conferred with several engineering firms, belt suppliers etc, and very few people want to help you out if you build a prototype (1 of something). Unfortunately I do not have the right connections.

 

SO I will take the bucks, and blow it on red chainring bolts etc...

[Wyatt Earp]

Ok, so here it is... After lots of fights and so, I will not be doing the SS Belt drive...

 

I have conferred with several engineering firms, belt suppliers etc, and very few people want to help you out if you build a prototype (1 of something). Unfortunately I do not have the right connections.

 

SO I will take the bucks, and blow it on red chainring bolts etc...

 

Can't blame you.

I had a long chat to a chap on the weekend who owns a drive belt bike .

After listening to how unhappy he was with the resistance he feels from the system and how he actually hates it for proper off road riding, I have made peace with my initial impressions and own conclusions.

[RooiWillie]

Can't blame you.

I had a long chat to a chap on the weekend who owns a drive belt bike .

After listening to how unhappy he was with the resistance he feels from the system and how he actually hates it for proper off road riding, I have made peace with my initial impressions and own conclusions.

It is actually a shame... On paper there is so many benefits. But ja... Chains is here to stay for a while longer...

[RooiWillie]

ps... I will post some pics of my Chained SS as soon as it is done...

[nathrix]

Here's a full review thanks to twentynineinches http://twentynineinches.com/

 

Posted by Guitar Ted on June 14th, 2011 07:57 PM

 

As you readers of Twenty Nine Inches know, we have done several posts on Gates Carbon Belt Drive bikes and have tested their “traditional” set up in the past. (See some of theses posts here, here, and here.) We also have reported on the positives that the new “Center Track” technology was to bring to the system. Here we can finally say that Center Track bikes are currently available, (first from Spot Brand Bikes, others later in 2011), and after market belts and cogs to convert belt drive bikes out there already to Center Track will become available in July.

 

http://twentynineinches.com/wp-content/uploads/2011/06/CenterTrackcloseuptopview-500x223.jpg

 

What Is “Center Track”?: The previous versions of Gates Carbon Belt Drive were very similar in appearance to automobile applications of belt and pulley set ups. There was the rounded tooth profile of the belt’s inner run that mated with matching profiles molded into the Gates pulleys. These “cogs” also had a flange on one side to help keep the belt from “walking off” the cogs due to flexure in the bicycle frame, or from slightly misaligned cogs.

 

Obviously, as you can see from the image above, there are no more flanges on the front or rear cogs, and rear cogs are now machined stainless steel in their entirety now. Front rings for Center Track are all aluminum. The cog features a center ridge which mates into a slot molded into the center of the belt. The belt itself is now 12mm wide to accommodate the “center track” and to avoid the carbon strands which are placed every two millimeters from belt edge to edge and which run laterally along the length of the belt in an unbroken circle. These carbon strands prevent the belt from stretching. Gates claims a “20% increase in tensile strength” over the older version of their belts, but this may simply be an outcome of having an extra carbon strand in the 12mm belt versus the 10mm ones before it.

 

http://twentynineinches.com/wp-content/uploads/2011/06/CDX-CTfullsystemgreen-500x332.jpg

 

Because the belt now runs in a track, it is more tolerant of mis-alignment and flex incurred by frames which can slightly mis align cogs while under hard pedaling forces. Another benefit of Center Track is that it can be used at slightly lower tensions than the older Gates Carbon Belt Drive Systems could be run at.

 

he new Center Track belt and cogs can be retro-fitted to current belt drive bikes as long as there is clearance for the wider belt. (Gates claims a “slimmer profile” for the cogs, but the belt is 2mm wider than what the older system had.) As of post time, we were told that Center Track cogs and belts would become available in July. No word on pricing, but be prepared to spend more than currently available Gates Carbon Belt Drive parts sell for.

 

Gates says the initial product launch for after market parts will be focused on the most popular sizes and will be expanded through the second half of 2011. For more information about Carbon Drive go to the Gates blog http://www.gatescarbondrive.com/blog/

 

Gates Carbon Drive Center Track: On Test

Posted by Guitar Ted on July 4th, 2011 10:41 PM

 

As regular readers of this site well know, we have been experimenting with the Gates Carbon Drive for some time, and in several iterations. Now comes the newest development from Gates, the Center Track, which we’ve made mention of before as well.

 

Gates has promised several advancements in belt drive technology with the coming of the Center Track design. We’ll get into that in our next post in more detail, but it is obvious to see that the “cogs” are radically different now. The belt itself, while basically the same, has now gotten a “groove” in the center, with the addition of 2mm width over the older 10mm belts.

 

Gates Carbon Drive Center Track:First Impressions

Posted by Guitar Ted on July 19th, 2011 10:10 PM

 

I announced the arrival of some Gates Carbon Drive Center Track components earlier this month, and here follows my technical and First Impressions report from the few rides I’ve put in on it so far. Let’s take a look at the advancements made over the previous Carbon Drive belt set ups.

 

http://twentynineinches.com/wp-content/uploads/2011/07/Carbon-Drive-July-11-001-500x303.jpg

 

First, if you have not seen our post on Center Track from June, you should check that out here and read up on some of the particulars. I’ll be focusing on some of Gates’ claims made there in the following paragraphs. Back at 2010′s Interbike show, we actually sat down with Spot Brand’s Wayne Lumpkin, (formerly of Avid), and Gates Carbon Drive engineers to discuss the original Carbon Belt Drive and the Center Track that is now available, but was just announced back then. Here’s what we had to say in one of our Interbike 2010 posts:

 

The Center Track was an outgrowth of Gates involvement with Spot Brand owner, and former owner and founder of Avid, Wayne Lumpkin. Mr. Lumpkin was brought in as a consultant on how Gates could improve upon the performance of their Carbon Belt Drive.

 

The outcome was Center Track. As you can see, it dispenses with the flanged cogs and replaces that with a central “fin” that runs in a “track” molded into the center of the belt. The belt itself was also increased in width slightly to improve upon engagement. The tooth profile remains the same as before, but Mr. Lumpkin described the new arrangement as being far more tolerant of lateral misalignment between the cogs and as an added bonus, it actually repels dirt and mud better than the older “windowed” cog system.

 

An Evolving Design: I think it is also important to note that during our sit down meeting at Bootleg Canyon, the Gates engineers were very forthcoming in their responses concerning our criticisms of the then current Carbon Drive in single speed mountain bike usage. They also were refreshingly honest about telling us their goals. First, the criticisms we put forth were met with reasoned responses. Basically, we were concerned with our own experiences, and that of others, where belts “ratcheted”, and sometimes broke. Gates’ engineers told us that coming into the bicycle designs they were suddenly made aware that the single speed mountain bike had a reverse demand on design than anything else they had developed. Normally, they were used to “High RPM-Low Torque” applications, whereas single speed mountain bikes were “High Peak Torque- Low RPM” machines. The resulting issues encountered led to the development of the wider belts, and ultimately, to Center Track. (Amongst other things like frame specifications and tests for manufacturers interested in equipping their models with Carbon Drive belts)

 

http://twentynineinches.com/wp-content/uploads/2011/07/CenterTrack_closeup_topview.jpg

 

As for Gates’ intents, they voiced to us that they want to succeed in giving mountain bikers, and all cyclists, an alternative to a chain drive that is reliable, efficient, and reasonably priced. They also said they were not out to replace chain driven bicycles, but they obviously believe their product has the potential to be a better alternative. Are they arriving there with Center Track? This is the question we will seek to answer here.

 

Our Experiences: My concerns with using the older Carbon Drive belt concerned belt tension and wear on the rear cog. The tensions required to keep the older 10mm wide belt from ratcheting was quite high. High enough that premature wear on the rear free hub bearing was happening and could be evidenced by the crunching and snapping sounds emanating from the hub due to the high belt tension. No doubt the bottom bracket suffered as well, since the crank had little free spin. When this same crank was unloaded from the belt tension, it spun quite freely. I wasn’t impressed with the extra effort required to turn the crank and the prospects of wearing out bearings faster than I would have with a chain.

 

http://twentynineinches.com/wp-content/uploads/2011/07/gatesfail-001.jpg

 

I also was concerned with the original Gates design for the rear cog. Both Grannygear and I experienced a chewing up of the interface on the cog with the steel free hub body. This was after only a few months of riding. So, while the interfacing teeth of a Gates rear cog and belt would likely outlast a chain, it was obvious that the cassette interface would fail far before a chain/cog would, thus negating the advantage claimed by Gates.

 

http://twentynineinches.com/wp-content/uploads/2011/07/northfield11-0301-500x281.jpg

 

The Promise Of Center Track: Now with the new Center Track design, a few things have changed that may make some headway in overcoming our concerns. First, the obvious change to the belt and cog design will, as stated above, allow for more lateral intolerance. (But make no mistake, you’ll still need to be dead on with your “belt line” from front to back.) The new design should be more tolerant of frame flex, so this is good to see. Obviously, the mud shedding abilities are much appreciated here as well. Secondly, the wider belt, along with the tolerance for a slight amount of flex means slightly lower belt tensions will be necessary, which should make all free hub bodies and bottom brackets last longer and spin freer with the Center Track. Note: Gates says it isn’t that the Carbon Drive Center Track takes “less tension”, but that it doesn’t need to be over tensioned. Okay…..you say tomato, I say “toe-mah-toe”.

 

Finally, the cog has been rendered in CNC’ed stainless steel, which should eliminate any of the chewing up of the cog’s splined interface that we had experienced before. Overall, the entire system is more refined looking and feeling, in my opinion.

 

What Is Missing?: So far, so good, eh? Well, Gates is still trying to crank out different choices in the Center Track cogs and belts. This, by their own admission, will take some time. So, if you rush out as of the writing of this post to find a Center Track set up, the choices available now might not suit your desired gear ratios. Also, Gates has ballyhooed the iPhone ap for tensioning the Center Track, (and other Carbon Drive set ups), but not everyone carries an iPhone, (Yes- believe it or not!), and beyond the “gee-whiz” factor, this fails to address a practical means that every rider could use to tension the belt. This is critical to success, so I would like to see Gates come up with some mechanical means to determine a consistent and proper belt tension. Finally, beyond the scarcity of choices at this point, Center Track isn’t cheap. (At post time, I couldn’t find any MSRP’s on parts, but as we were told, Center Track is considered Gates “premium” product, and will be more expensive than Carbon Drive is now.) Assuming that prices for Center Track will top current belt drive component prices, you can figure that one could buy a couple complete chain driven single speed drive trains for the same amount of money it takes to set up one Center Track bike.

 

http://twentynineinches.com/wp-content/uploads/2011/07/Carbon-Belt-Drive-July-004-500x208.jpg

 

Ride Impressions: With all that discussion now behind us, the real question is, “Does it work?” Well, the old system “worked”, but with caveats. The Center Track does seem to be better from a couple of standpoints. First: The belt set up does spin better with Center Track’s lower tensions. In fact, within the belt’s necessary “tuning range” of 70-85Hz, I could get my crankset to spin backwards as easily as it would with a chain driven set up.

 

The other thing was that there was no weird noises, no feared ratcheting, no popping, nothing but sweet silence. The belt felt smooth, and after a bit, I began to feel more confidence in the system, and was doing everything I would have done with a chain set up. Again, this sounds really promising, but the niggling issues with set up and tensioning still remain. For instance…

 

http://twentynineinches.com/wp-content/uploads/2011/07/belt-ikon-july-004-500x281.jpg

 

When I first got the Center Track components, and tried fitting them to the Sawyer, the first belt I received was juuussst too short. It would have been nice to be able to run the shortest possible chain stay length dimension. The next belt came, a size up, and it put the sliders nearly all the way back in the throw. Hope I like 18″ chain stays! If I don’t, well, at least for now, Center Track wouldn’t be for me.

 

As for tensioning, I do not own an iPhone, so I actually tuned my belt to 70Hz with the aid of a bass guitar and a tuner. (That would be a scene in the pits at your local XC race! ) Obviously, if I had a bike that required re-setting the tension after removing the rear wheel, or if/when Gates gets more cog options, and you want to change a belt/gear, etc, then tensioning the belt becomes a matter of some guess work on the part of someone. Especially in the field. It may not be a big deal in some situations, but it could be. What I am saying is, it should never be, for a premium system like Gates Carbon Drive. This needs to be addressed to make the system more practical for users.

 

Performance-wise, this seems very dialed. I will keep up riding it for awhile until I come back with a Final Review. We will see how it holds up in the longer term.

 

Gates Carbon Drive Center Track: Final Review

Posted by Guitar Ted on August 28th, 2011 07:51 PM

 

With plenty of rides now logged in on the Gates Carbon Drive Center Track set up on the Trek Fisher Collection Sawyer, I am ready to finalize this review. If you want a refresher on my previous thoughts, you can check out the First Impressions here . This post will be focused primarily on the performance of the Center Track system since I have been riding it.

 

The Set Up: The Fisher Collection Sawyer, (see review here, was a perfect test bed for the Center Track system, since it came with a belt drive compatible drive side drop out. This drop out design is very well done and caused no issues with regard to the ride quality of the Sawyer, and no issues with the looks as well. In fact, a lot of folks are surprised when they look at the frame, since the slot is so well hidden amongst the sliding drop out mechanism.

 

The Center Track cogs caused no issues with regard to belt line up, nor did they force me into any funky shifting over of the crank set, spacer use, nor did the cogs have to be run in an odd way to make things work. As it should be. I should say that we have had to do all of the above with Gates older Carbon Drive belt system.

 

There was the one issue with being able to fit the bike with the shortest chain stay set up possible. That is something a belt driven system will have a hard time getting you. In a practical sense, it would be nearly impossible to accomplish this shortest chain stay set up unless every manufacturer designs around belt drive parameters. A chain set up is much easier to tweak in this regard, considering half links and all. Obviously, not everyone will care to have that dimension be as short as possible, but for those that do, a Center Track set up might be a limiting factor.

 

However; it has come to my attention that once Gates gets more options out and available, this will be addressed. (Latest word is that several more belt lengths will be out in October.) The difference in two belt teeth is slightly less than two chain links. (22mm vs 25.4mm) So, given that the availability becomes as Gates has promised, your Carbon Drive set up might end up becoming more precisely adjustable. (You’ll still need extra belts to accomplish this, where with a chain you’ll only be required to purchase one chain and a few quick links, a half link, or a chain tool.)

 

-Ride Performance: Obviously, Gates has a long list of benefits of running Center Track for you to consider. There are only a few that really matter though. Here are the benefits that Center Track does provide a single speed rider.

 

-Lighter Weight: For maximum weight savings on a single speed racing bike, Center Track does shave grams with the belt itself, and the cogs a wash in regards to chain drive cogs, ( Considering that a cassette free hub wheel must be used as a carrier for the belt cog, we are not comparing to a free wheel/cog set up). It is especially a closer difference now that the rear cog for a Center Track set up is CNC’ed stainless steel. Essentially, the biggest weight savings now is between that of the chain and the belt. (And that is significant, by the way.)

 

Durability and Reliability: Finally, I can say without hesitation that this version of Carbon Drive, Center Track, is totally worth my trust. It hasn’t caused me any concerns when riding trail. The tension necessary for the belt to stay put is not as high as it needs to be on former Carbon Drive iterations, and therefore the component life should remain normal, not affected by excessive tension. The belt is said to be a much longer lasting component than a chain, so as time rolls on, we shall see how this pans out, but I have no reason to doubt this claim at this time.

 

Only an unfortunate accident, or perhaps an ill timed rock might cause an issue. Damage to the belt is a concern, so I will be watching this as time goes on as well.

 

Efficiency: In the cases where a chain may be affected by moisture, grit, and grime, the Center Track should be a system that retains efficiency and has less problems with severe conditions. I’ve yet to get this one I have into those situations, but that will be tested. Obviously, if the Center Track doesn’t have anything to attract dirt, or places for it to hide, one would assume it will perform with better efficiency and better results than a chain would. Our contributor, c_g, seems to feel that Carbon Drive is well suited to tackling these situations, so I feel confident Center Track will perform well in this regard.

 

Just Getting Started: In some ways, this Final Review is really another new beginning. As mentioned above, there are a few things I’d like to tackle with Carbon Drive that I haven’t had a chance to…..yet! That will come later. However; there is the issue of how it works now, and in that regard, I only have one complaint. That is the lack of currently available choices for ratios, and the necessary belt/cog combos I would have to accumulate to satisfy my set ups.

 

Once Gates gets enough options produced, the choices should be covered. (Latest word is by Christmas 2011 this should happen) The thing that gets to be a bit of a hindrance is that with some combos, I will need to have not just a cog, but a belt to fit the choice. With a chain, adjustability and flexibility is much better in regard to changing ratios, but it isn’t impossible with a belt set up. It’s just going to cost more. There, I said it! Carbon Belt Drive is a premium product that will not come cheaply. If the benefits make sense, (and you have an appropriate frame ), the system may be worth it to you to check out.

 

Conclusions: I like this version of Carbon Drive. It addresses all the issues of the past, and renders all previous editions of Carbon Drive as sub-standard in my opinion. This may sound harsh to those already invested into Carbon Drive systems, but Gates has raised the bar on performance, fit, and function with Center Track. Period. It surpasses anything else they have made that I have tried hands down.

 

Once Gates gets a good selection of ratio combinations readily available, this system should be high on the list for those seeking a premium performing single speed bike set up. There still are a few “prerequisites” to owning a belt set up, and primarily that is having a frame compatible with Carbon Drive. Fortunately, there are several good choices in 29″ers that will accommodate you here.

 

I wouldn’t recommend this to folks converting a geared bike, converting a non-carbon drive frame to belt drive, or to folks who adhere to the roots of single speed philosophy . It might appeal to you from a weight savings stand point, and from a durability/longevity stand point. Whatever it does to appeal to a particular individual, one thing can now be said that couldn’t be said before with certainty: That is, Center Track is a viable, high performance system you can rely on without any “negative baggage” that came along with previous versions of the belt drive.

[kandui]

http://www.carbondrivesystems.com/ http://www.carbondrivesystems.com/images_us/CenterTrack170x173.jpg

 

OK, I'm just gonna put it out there for those who are interested, as I have been trolling the interwebs for as much info as possible and here is the short and long of how everything works and fits together

 

Obviously you need to have a frame with a split dropout rear end/chain-stay as the belt cannot be broken and reattached

What's your thoughts on using a belt drive system?

Anyone have a belt drive system fitted to there bikes, where did you buy it and what bike do you have (pictures please)?

 

Carbon Drive System Calculator

http://www.carbondri...lator/index.php

 

They even have a iPhone Tensioning App Available http://itunes.apple....d438346486?mt=8

 

http://a5.mzstatic.com/us/r1000/115/Purple/b4/f5/8b/mzl.ekvqbfym.320x480-75.jpghttp://a1.mzstatic.com/us/r1000/090/Purple/39/a8/cd/mzl.twoorxbq.320x480-75.jpg

 

Carbon Drive™ Technology

 

The carbon cords inside the patented Gates Carbon Drive™ belt offer, for the first time, the necessary tensile strength and high modulus to provide the smooth, clean, and long lasting ride advantage of a “belt” driven system in a bicycle application. The specially designed tooth pitch and meticulously engineered pulley profile afford the belt efficiency equal to that of a standard chain, with the low tension necessary to prevent unnecessary bearing load on other components.

 

The super-light pulleys are finished with a new coating specifically formulated to provide unmatched durability even in abrasive conditions. Already referred to as a “magic Item, that will change many of the bikes we ride,” Gates Carbon Drive™ offers a truly revolutionary technology that already has created an amazing amount of end-user interest and demand.

 

 

http://www.youtube.com/watch?v=MPoKawd1y9M&feature=plcp&list=PLCCFBE93195B01006

http://spotbrand.com/

[kandui]

Spot Brand Bikes

[nathrix]

Spot Brand Bikes

 

http://www.carbondrivesystems.com/contact.php?lang=us

[nathrix]

Seven Spotlight Berlin Show Bike

 

http://www.sevencycles.com/images/articles/berlin-bike/berlin-bike.jpg

 

http://www.sevencycles.com/images/articles/berlin-bike/berlin-bike--light.jpg

 

Limited Edition: Seven Earth Day Bike

 

http://www.sevencycles.com/images/articles/090320_earth_bike_left_small.jpg