Wednesday, January 25, 2017

Trek 720 Recall

Just a brief post today about another new bike (and wheel) recall. Trek has announced a safety recall of their 2015 - 2017 720 touring model equipped with disc brakes and Bontrager 24 spoke wheels. Apparently the front wheels have been suffering many broken spokes, and the concern is that the broken spokes can lodge in the front brake caliper, causing an immediate stop and likely a "header." The Bontrager TLR 24H disc wheels, which are standard equipment on the 720, but are also available separately as aftermarket wheels, are part of the recall.

You know the drill. Immediately stop riding the bike (or the wheels) and go to the nearest Trek dealer for replacement. After new wheels are installed, the affected owners will be given a coupon worth $100 in Trek/Bontrager merchandise. Hooray.

The full text of the recall notice can be found at Trek Bicycles.

I don't know how many Retrogrouch readers would be riding the latest 720, but I assume they're more likely to be on a 720 than the latest carpet fiber Madone. Readers might recall that I wrote about the current 720 and compared it with the original 720 grand touring machine last year. If I were presented with a choice between the old and the new, I (and most readers) would probably choose the 1980s original.

One thing that this recall brings to my mind is the sense of using 24 spoke wheels on a "touring" bike. Seriously - who thought that was a good idea? Yes, compared with a lot of the latest high-end boutique racing wheels (where as few as 16 spokes is becoming commonplace), 24 spokes might seem like a "sensible" choice. But to me, it's just another case of "racer mindset" working its way into bikes where it doesn't belong, and having 24 spoke wheels makes me question whether the bike is really intended for touring.

It's worth mentioning that the replacement wheels are also 24 spokes. Pssshh.

Realistically, I know that the spoke breakage problem isn't necessarily the result of the spoke count. There are a variety of factors that could be leading to the rash of breakages - but it does make a person wonder. Also, keep in mind that the stresses on a bicycle wheel with disc brakes are different from those on a bike with rim brakes, so that may be a contributor.

Obviously I'm pretty conservative when it comes to wheel design. My "ideal" set of wheels for a touring bike would use 36 spokes front/40 rear. For general road use, I love 32 front/36 rear. If I still weighed what I did in college (125 lbs!) and wanted a real killer set of racing wheels, I might have gone for 28/32, and still I would have saved them only for racing, and only on good roads. Readers may notice that I favor using slightly fewer spokes on the front wheel than the rear, as I like to balance the number of spokes with the weight distribution or load that each part of the bike carries. Some people are big on symmetry and go with equal numbers front and rear (and of course, hubs are usually sold in "matching" sets like that - so if you want to mix it up like I do, that sometimes creates a little extra work in sourcing components). But to my mind (and eye), having the spoke count match the load presents its own kind of symmetry.

Okay - I guess this wasn't that brief of a post after all.

16 comments:

  1. If the human race is good at anything it is "uninventing" well thought out ideas!

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  2. I would love a nice old 720, if the opportunity ever presents itself. The new ones don't interest me at all. I've seen the notices on that recall and it had me scratching my head that what is ostensibly a touring rig was being sent out w/ 24 spoked wheels. Nuts to that.

    I have an '80 5xx frameset that has gone through numerous builds in its time with me. It finally landed on a touring-ish build and I had a set of really nice wheels made for it. I got crazy and went 36/36 on the spokes! haha, I normally follow tradition and do the same spoke counts that you do, but the rims forced my decision.


    Wolf.

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    1. it's much easier to find matching sets of hubs and rims -- either 36/36, or 32/32. Mixing them means hunting around to find pieces one at a time - or buying pairs and ending up with extras.

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  3. 24 spokes....dangerous and dumb for a touring bike

    Builtin obsolescence mentality which is obscene in my opinion

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  4. Thing is the new ones retail at $2400 ...so not cheap. Also noticed that a few of the reviewers had wheel issues...surprise, surprise

    Maybe it's an OK bike for credit card touring where you're not carrying anything or you have sag support but marketing it as a touring bike is egregious. Maybe they mean it's a bit more of a touring than a racing geometry?

    Whereas the old 80's Treks and Specialized touring bikes were superb ...older Cannondales were pretty decent, too. Designs then factored in reliability

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  5. I'm glad to know I'm not the only one who rides 36/32 or 36/36. Or any wheels that aren't pre-made.

    24-spoke wheels on a touring bike? I wouldn't have ridden 24 spokes on a racing bike even when I was young, skinny--and racing.

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    1. Exactly - like I said, I'd have been cautious about using a wheel with 28 on the front, even though I was a flyweight.

      Funny thing - but rims today seem to be heavier. They've cut the number of spokes, but made the rims heavier to compensate. Rims like the old Mavic GEL280 rivaled the weight of the best carbon fiber rims today -- but the carbon rims are lousy for braking, so they are the real reason for the big push to disc brakes (which are also heavier).

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    2. They also had to make the rims heavier to make them strong enough to handle the amount of dish that rear wheels need.

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  6. I just go for the 36/36 anymore on everything. Hubs of vintage quality of this count are cheap on eBay, especially the freewheel ones that I prefer.

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  7. 36/36 laced on my RACING bike. Too many potholes on the roads, especially after winter and I'm tall and heavy.

    I have limited experience with purely racing rigs (i.e. lightweight everywhere) but my understanding is that if one is tall, heavy and stong enough, there's no way lightweight components will last for any prolonged period of time. Pity that few mfgs place info about weight limit.

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  8. 36/36 for me too.

    I am heavy (100 kg during winter, 90 during summer) and i ride a lot of cobblestones so less than that and the wheels just fell appart. Hell, my touring bike still has 650b with "ballon" tires. Not fast, but far stronger than 700 rims.
    Carbon fibers wheels just are not up to the task. A friend of mine just has to change a zipp rim at 500€ after just a few kilometers of cobbles.

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  9. MY bike has whatever wheels were in stock for ISO 559 tires, but that was years ago, before I discovered the Retrogrouch and developed an appreciation for high-spoke-count wheels. I haven't counted the spokes but they're most likely 36s. Nowadays, if I were searching for a new wheel, I wouldn't go for anything less than 36, and would go with 40s front and rear if I could find them. I ride damn near everywhere and I need indestructible wheels.

    I can't remember clearly the last time that I broke a spoke. It was at least 4 years ago, probably more, and it was on a 36-spoke wheel. A single broken spoke did not end my ride nor did it appreciably bring the wheel out of true. I rode the bike daily for a week before I had time to bring it to the shop for a replacement spoke. It also has rim brakes, where's no chance of a loose spoke getting caught.

    The chance of a spoke getting caught in a disc brake does make me wonder: have any of the disc-brake proponents thought of that possibility? I've heard from many sources about disc brakes' supposed meat-slicer capability in a crash, but none of them to my knowledge have warned of the danger of loose spokes.

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    1. I had broken spokes in my practice and also had caught spokes in chain as well. Stainless steel is fairly soft material, so all safety concerns aren't as serious, which is a good thing. Broken spoke will just bend. It isn't strong enough to throw you into header in case when it traps into rotor.

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  10. I am not saying 24 spoke wheels are a good idea for touring bikes, but spokes break due to fatigue, not because of excessive load. I would bet it is a poorly built wheel with either inadequate tension or too much play at the spoke/hub interface. A carbon fork bothers me more than 24 spoke wheels!

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    1. The problem with low-spoke-count wheels is that the effect of a broken spoke is more pronounced than with 32+ spokes. A single broken spoke is more likely to make a wheel go out of true, and consequently less rideable, it has only 24 (or fewer) spokes in the first place.

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  11. I have the great pleasure of riding an original style 720, model year 1985.
    It is one of the best bikes I have ever ridden.
    I did some upgrades, swapped to 700C wheels (36 -36 spoke count, hand built by myself and went to 8 speed cassette index bar end shifting, but overall kept the "flavor" of the original intact.
    I initially felt some excitement when I heard Trek was resurrecting the model 720 as a touring bike but when I saw a review I was stunned by the low spoke count wheels.
    I knew after reading that initial review that Trek was only trying to grab some of the old legend as a marketing ploy and their new bike was little more than the same old same old from the new and modern bike designers.
    I am not impressed.

    Fellow Grouch,

    Randy R

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