Belt Drive Tension Adjustment

Gates Tension Adjuster
Zoom

Because belt drives are a relatively new technology in the bicycle world, adjusting belt tension remains a bit of a mystery, with even some local bike shops not knowing much about it. Fortunately, with the proper tool and the tension specification from the manufacturer in hand, it’s a simple process that anyone can do in a few minutes.

The Gates tension testing tool looks similar to the tension testing tools you may have seen for automobiles (it looks nearly identical to the tool used for Micro V-belts). Using it couldn’t be easier. You simply place your finger in the rubber strap, place the tool on the belt equidistant from the front and rear sprockets, then press the tool against the belt until it clicks. Once it clicks, the leading edge of the arm indicates the belt tension. Gates is recommending 50-60 lbs. for an Alfine 8-speed IGH, but you’ll want to check the tension specifications for your particular drivetrain. I found it best to test a few times, rotating the crank a quarter turn each time, then averaging the results.

Norco Ceres Sliding Dropout
Zoom

If the tension is outside the recommended range for your drivetrain, you’ll need to adjust the tension. On the Norco Ceres shown in the photo, it’s simply a matter of loosening the allen bolts that lock the sliding dropouts in place (4 total, 2 on each side) and making small, equal adjustments on each side until the tension is within spec. Once the tension is set and the wheel is in alignment, tighten the 4 allen bolts and you’re done. The first time I tried, the entire process took less than 10 minutes. It’ll be even quicker the next time around. Of course, the method for adjusting tension varies from bike to bike, so you’ll want to check with the manufacturer on the specific method for your bike.

These new technologies can be a little intimidating, but I’m living proof that an old dog can learn new tricks (honestly, I love this stuff; it’s a blast learning new techniques and expanding my skills as a home mechanic). There’s no reason to fear change, and if a new technology appeals to you, I wouldn’t let learning a new maintenance routine keep you from diving in head first!

More @ Gates

12 Responses to “Belt Drive Tension Adjustment”

  • John Lascurettes says:

    Alan, you’re slowly going to turn yourself into the new-technology Sheldon Brown (R.I.P.) with tips like these. Keep it up!

    PS: what happened to your post preview? Didn’t you have one before?

  • Alan Barnard says:

    Hey John,

    That’s awfully flattering, but I could never hope to attain anything near the heights of the Great Sheldon Brown. He was truly one of a kind and a real genius.

    If you’re referring to the Bryant follow-up review, because the bike I had was their only prototype at that time (late 2009), and consequently I was only able to keep it for less than two weeks, I didn’t really have enough time on the bike to develop a full-on review. I’ll make up for it this year… :-).

    Regards,
    Alan

  • John Lascurettes says:

    Alan,

    I was referring to the fact that you made a conscious decision to replace your LHT with a Bryant with new-style components. No doubt you will be offering tips as you learn them. :)

    I’ve had a little frustration because I have a Novara Fusion with roller brakes, Nexus 8 and a dynohub and there’s been little guidance I’ve had on fine tuning or trouble-shooting some of those components – particularly the roller brakes.

  • John Lascurettes says:

    … Oh! What did I mean by the “post preview”? I thought you used to have a little post preview below the user replies while typing them. Am I imagining that?

  • Alan Barnard says:

    Ooops – sorry! I understand now… :-)

    You’re correct – I did have an “as-you-type” comment preview running. The plugin I was using didn’t play well with the “CAPTCHA” plugin, so when I added the CAPTCHA I turned off the Preview. I need to find an alternative, but so far, no luck. Sorry about that!

    Regards,
    Alan

  • Alan Barnard says:

    John,

    I’m curious, are you having specific issues with your Roller Brakes?

    Alan

  • John Lascurettes says:

    Alan,

    Performance-wise, I’ve loved my roller brakes. They’ve never failed me – even barreling down a 200 foot steep drop in the rain.

    It took me asking a mechanic what to do the first time they started squealing (like metal on metal squeal that cars can have) and that’s when I learned that the maintenance of those is simply to add a dab of grease to the bell of the brake drum. According to the bike tech at REI, the brakes will outlast the frame (he may have had tongue-in-cheek).

    Where I had issues is that I find them so very difficult to remove (particularly the back brake) that I was convinced that I was doing something wrong. Additionally, I just fumble my way through getting them back on and adjusted right. I’m sure there’s more efficient ways of doing it, but it takes me far longer than it should.

    I have so much difficulty in removing and installing them that I sprung for the extra dollars for the Schwalbe Marathon Supremes in order to minimize my flats risk. That turned out to be a wise decision; I think I’m pushing 4,000 mi of daily commuting and haven’t had a puncture flat on them yet.

  • Marcy Kutok says:

    Alan,

    Thanks for sharing this information on adjusting the Gates belt drive. Although, I don’t currently have a bike that uses this technology, I’m very intrigued. Thanks for helping me gather necessary maintenance tips so I’ll be prepared when I do finally take the plunge.

  • Nicasio Nakamine says:

    I just got my first bike in over 10 years, and went with the Raleigh Alley Way, in part because the belt drive seemed easy to care for. I was going to practice taking the rear wheel off and dealing with the eccentric bottom bracket (in anticipation of a someday-flat tire), but now that I know there’s a special tension tool, I think I’ll leave this well alone until I HAVE to take off the wheel. I imagine I can just bring it in to my LBS for proper tensioning in that event.

  • Joseph Eisenberg says:

    @John Lascurettes Re: Roller Brakes.

    I have heard that Shimano’s Roller Brakes (their name for a proprietary type of drum brake, which attaches to one side of hubs that are specifically designed for them) are strong and reliable enough, but make it difficult to remove or replace the wheel. Sturmey-Archer’s drum brakes have a much simpler quick release.

    Also, some people complain that the front Roller Brake is too weak, because it comes with a matching hub that has a “safety feature” preventing front-wheel-lock. This means you can’t go over the handlebars by slamming on the front brake, but it also limits front brake strength.

    Despite these problems, I’m considering changing to these brakes. I hate the black gunk on my rims, the squealing and the dirty rainwater thrown off by my linear caliper rim brakes. I’m not worried about the slightly lower strength of the roller brakes (Though I should test-ride them again, first). And I have gone over 1000 miles without a flat on Schwalbe city tires with puncture protection (they aren’t even the Marathon’s) despite hitting lots of glass and road debris every day… and the chaincase on my Breezer already makes changing a rear flat a pain.

    But I would consider the Sturmey-Archer front dynamo/drum brake hub for a bike without one. It is a very strong brake, according to reviews, and the generator in the hub is basically the same as Shimano’s, just with a different shell and bearings. And the whole hub is well less than $100, cheaper than most dynamo hubs without a brake.

  • Alan Barnard says:

    Hi Nicasio,

    You shouldn’t have to do anything with the eccentric while changing a tire. Because the Alley Way has a vertical rear dropout, all you need to do is disconnect the shifter cable, loosen the axle nuts, and drop the wheel straight down. Once the wheel drops down, the belt can easily be slipped off of the rear sprocket and the repair can be made. To re-install the wheel, place the belt onto both the front and rear sprockets, pull the wheel back while slipping the axle up into the dropouts, re-tighten the axle nuts, and re-connect the shifter cable. Because the belt adjustment doesn’t change in this process, there’s no need to re-check the tension each time. I find the process hardly any more difficult than removing a conventional wheel.

    Alan

  • Matt says:

    Its no big deal adjusting the belt tension. While gates does recommend their special tension tool they also describe a low tech method of adjusting the belt so that by pushing down on the belt with 5-10lbs of force the belt deflects approximately 1/2 inch. I recently got a trek soho and for whatever reason the belt was initially too loose, I don’t think the bike shop was very familiar with belt drives. Anyway, I just used the 1/2 inch deflection method and its been perfectly fine ever since. The horizontal dropouts followed the same concept as the norco ceres with four allen bolts to loosen and then equal adjustments on each side. Its not as exact without the tension tool but the belt doesn’t slip anymore and once I felt it was tight enough I just backed off the tension by a hair just to make sure it wasn’t over tightened.

 
© 2011 EcoVelo™