SemiAccurate will depart from our typical chip reporting to convey you a take of abject engineering stupidity. This time the silly considerations bicycles and comes courtesy of Trek.
For these readers who don’t know me, I’m an enormous biker, about 2500 miles a 12 months give or take just a few hundred. About two years in the past, July 11, 2023 to be precise, I changed my worn out no-name bike with a Trek Domane SL 6 Gen 4 bike. From the start it was a turd, issues you’ll return a $79 Costco bike for have been frequent. The seat submit creaked and consistently sunk. The digital shifter simply stopped in the course of a trip. Twice. And extra.
Mileage stats from my Garmin (bleargh) App
If it wasn’t for the actually glorious service at my native store, I might have returned it. That stated it was out of service for a lot of weeks whereas Trek dithered on what to do and elements have been ordered. Just like the most interesting of Nineteen Sixties British sports activities automobiles, the bike has been fairly dependable for the previous 12 months or so. Once more just like the automobiles, that is primarily as a result of half the elements it got here with have been changed by correctly engineered replacements. Sadly for the bike, that final bit is simply virtually true.
The bike died virtually precisely right here
The issue occurred final Friday on an extended trip on a path a few mile from the closest exit. Scenic however hardly the spot the place you need this sort of factor to occur. I used to be using down a easy paved path as all the time after I heard a snap. I assumed I ran over one thing and coasted alongside ready for the inevitable face filled with tire sealant compound which by no means got here. As quickly as I began pedaling once more, the bike moved beneath me, the body was not carbon, it was jello.
The seat submit visibly wobbled however didn’t sink, the precise reverse of after I purchased it. The mechanism was visibly intact and did maintain the seat tight in each instructions so I made the decision to bike dwelling. Slowly. Off the seat. The body misplaced sufficient torsional rigidity to make this a really attention-grabbing and distinctive feeling expertise however sluggish and regular was the one technique to get dwelling. About 100 yards later I hear some extra noises because the elements the bike shed hit the path.
Why did this occur? Trek’s abjectly silly engineering decisions. Why make issues easy, efficient, and low cost when you are able to do overly complicated mechanisms that don’t actually work, price so much, and are rife with product high quality points? Lets have a look at what Trek did and what they SHOULD have completed on this case. It’s a story of company stupidity made actual by engineering idiocy.
The Trek Domane SL 6 Gen 4 Service Guide Web page 16
To start out off, all the drawings for this are from the Trek Domane SL 6 Gen 4 service guide discovered right here, web page 16. When you have a look at the drawing above, it’s for one thing Trek calls IsoSpeed, a mechanism to ostensibly designed to make the trip smoother. Whether or not it does or not is an open query, the trip is certainly smoother than my final bike however I attribute that to 75PSI tires vs 115PSI on the outdated bike. In any case it’s a very complicated mechanism that places the seatpost on a spring. Type of.
When you have a look at the teardrop formed bit that’s enlarged within the circle, that’s the IsoSpeed mechanism. It bolts to the body on the entrance and the seat submit goes although the again. Elements 6, 7, and eight maintain issues to the body itself. The seatpost retention mechanism that failed a number of instances after I first obtained the bike are elements 12 and 13. This mechanism is each complicated, costly, and dumb. It’s principally two wedges that you simply pressure along with a screw. They slide sideways and apply stress to the seatpost and the friction, and a few carbon holding compound, retains the seat submit in place. On paper this can be a good concept, actuality confirmed the alternative is true.
From there, a hole metallic pin goes by way of the middle of the IsoSpeed mechanism slightly below the seat submit retaining wedge mechanism and a bit forward of the submit itself. That is what helps the seat submit and the rider, it’s a spring, damper, and pivot. Elements 2, 3, 5, and 6 are the pin, 1 and 4 are the tube it resides in. The entire mechanism is roofed by an ostensibly weatherproofing rubber gasket, half 10, and a plastic cowl with two magnets within the ‘wings’ to carry it on, half 9. To date so complicated.
Dangerous design and unhealthy materials
Now lets get into the silly engineering. As you’ll be able to see from the above, the pin isn’t match for function. It’s a low cost alloy that doesn’t take kindly to repeated small stresses. Sadly that’s what the entire mechanism was designed to take care of, each bump and enlargement joint you hit on the bike places quite a lot of weight on that pin, assuming you’re on the seat. The flex of that pin ostensibly absorbs a few of the shock of excessive frequency impacts, a minimum of so far as I can determine. The ends of the pin have at tapered edge which implies stresses alongside a second axis stretch the spring as nicely, however this isn’t proven within the diagrams. Sigh.
The pin broke with out warning, that was the snap I discussed. The alloy they used was low cost, very low cost, so low cost that for the primary hour or in order that I used to be it, I assumed it was plastic. You may see the posts I made on Bluesky on the time. I solely found out that it was metallic when the magnets within the wing, half 10, caught to it. The elements that littered the bike path have been elements of the damaged pin, the wing, the magnets, and the washers. The lengthy a part of the pin stayed on the bike however not in place, extra on that in a bit.
I can’t see my home from right here
Why is that this incomprehensibly silly engineering? Let me record the methods. No actually, I’m going to undergo most of them, be happy to e mail me if I missed any. The primary and most evident is to make an element meant to take repeated impacts, and to damp them, out of an insufficiently robust alloy and never put sufficient in. I get the hole half, you need it to flex a bit to soak up shock, assume anti-roll bars in automobiles. This may be tuned up or down however no matter you do, you could make it robust sufficient. Trek clearly didn’t. Then there’s the forces alongside a second axis which doubtless didn’t assist the scenario.
Then there’s the seatpost retention half which failed repeatedly a number of instances when the bike was new. Whereas I can’t say if the mounted elements differ from the unique, I’ve my suspicions. In any case a standard bike has a hoop clamp that holds the seat in place and provides infinite changes. Metropolis bikes and train bikes are inclined to have a pin that goes into holes within the seat, straightforward to make use of, unattainable to under-tighten, and slightly strong. Each mechanisms have ups and downs, have been frequent for many years, and simply work.
Trek took a distinct path with their IsoSpeed. The seatpost will not be normal, IE not spherical, assume a fats teardrop with the taper on the rear. That is each good and unhealthy, the nice being that you simply don’t should fiddle with the angle of the seat, it all the time is aligned proper. The down aspect is which you can’t get an off the shelf seat submit, Trek solely, and you may’t use a hoop clamp on it.
So what do you do when you’ll be able to’t use a easy, efficient, and low cost ring clamp on the seat submit? You design a posh, costly, failure-prone mechanism just like the wedge system within the Trek IsoSpeed. That is dumb, actually actually dumb, an avoidable error. Earlier than you say {that a} ring clamp on a carbon seatpost is a nasty concept, you’ll be incorrect for 2 causes. First the seatpost in query is metallic, for the reason that bike is within the store I can’t say which metallic, simply not carbon. The second difficulty is that the final bike I had did have a spherical carbon seatpost held in place with a hoop clamp. It labored nice, all you wanted was somewhat carbon grit/grip compound and all was good. Trek wins on avoiding annoying alignment foibles, the apparent approach wins on price, ease of use, and complexity.
Then it’s a must to ask the apparent query of why Trek made the IsoSpeed mechanism within the first place. Certain unhealthy decisions led to extra unhealthy decisions on the seat submit retention half, however the suspension bit is a head scratcher. Does it damp excessive frequency shocks that come by way of the body? I’m positive trek has knowledge that claims it does, I’m not questioning that bit. The primary half I’m questioning is that the pin within the tube has rotational freedom on one aspect however is mounted on the opposite so it might’t rotate. It’ll transfer a bit when the IsoSpeed tongue, half 14, the teardrop bit, flexes. A correctly designed carbon fiber layup could be significantly better in each approach, and less complicated extra on this later. Damping the impacts with a cloth meant to take action is far smarter concept and would cut back the half depend so much. Once more, the trail Trek took is simply dumb.
When you tackle face worth that the IsoSpeed does damp these impacts and my view that the decrease stress tires did orders of magnitude extra is incorrect, then there’s nonetheless one other downside. The IsoSpeed mechanism solely damps shocks that come by way of your behind, admittedly factor. Your fingers on the handlebar and your ft on the pedals don’t profit from this mechanism. It’s complicated, failure-prone, and costly nevertheless it retains the seat correctly aligned so, yeah no, it’s shit.
So why do I harp on about silly engineering? All of this may very well be prevented with two straightforward and low cost adjustments. First make a spherical seat submit with a hoop clamp, higher in each approach however alignment. Then put a scribe mark on the submit and the clamp so you’ll be able to align issues by eye. Issues solved, price saved, and complexity vastly lowered.
That nevertheless does nothing about excessive frequency impacts. These might be mitigated, doubtless significantly better, by the use of a skinny layer of gel or reminiscence foam on the seat itself. IsoSpeed solely shields your (euphemism for a donkey) so why not do it immediately? Cheaper and might be tuned to be rather more efficient however Trek took the opposite route. Idiots.
Then comes the ‘wing’, half 9. This fiddly piece of plastic has a tab on the again finish and the 2 circles on the within clip on to the bolt, elements 5 and 6. There are two magnets to in these circles held on by glue, and held is a little bit of a stretch. The plastic itself is inflexible sufficient to carry the wing in place by itself with out the magnets. How do I do know? Each magnets fell off inside weeks of me proudly owning the bike. They add weight, price, and have a 100% failure report, pattern amount 2. Why Trek, why? Dangerous engineering there as soon as once more.
Transferring on to the Wedge Cowl, half 10. It’s a rubber gasket meant to weatherproof this complete Rube Goldberg system Trek designed. The issue with it’s that seemingly weeks into possession it went from rubber to one thing at rivals the power of the damaged pin. It’s laborious, and I imply so laborious that it’s almost unattainable to get it to sit down in place as a result of it’s so stiff. Transferring the seatpost requires way more work due to this materials, one thing that’s annoying however livable. Once more Trek made actually unhealthy materials decisions.
Carbon doesn’t like gouges
The final bit is probably going probably the most problematic and it includes the little bit of damaged pin that didn’t make a bounce for freedom on the path. That half, both 5 or 6 (with a part of 5 connected), stayed in and was doubtless why the bike wobbled like jello after I pedaled. Within the 100 or so yards it took me to determine what occurred and cease when the elements shed, that bolt wiggled round a bit. And gouged the carbon body. Deeply.
The image doesn’t present it nicely however the chunk is a number of layers in nicely previous the paint. You may really feel the tip of the fibers sticking up. If you understand something about carbon fiber, you understand why that is lethal. The place it occurred might be the second highest stress little bit of the bike, the primary being the realm across the crank. It’s immediately within the load path for the shock the IsoSpeed is supposed to damp too. This gouge will probably be deadly to the body, it’s a matter of if not when. The one query I’ve now’s what excuse Trek will use to disclaim the guarantee, anybody wish to begin a ballot?
So ultimately we now have shit engineering on Trek’s half. Issues that will cross on an affordable no-name bike don’t cross on a $5000 excessive finish bike. The overly complicated engineering for no purpose coupled to flat our incorrect materials decisions are solely worsened by severe high quality management points at Trek. Keep in mind that the issues listed above are solely SOME of those that affected this bike from the manufacturing facility, I haven’t even gotten into the edges and tires. Or the painful documentation. Or… or… you get the concept. The one vivid spot right here is the actually nice service from my native seller who I’m not mentioning so unwarranted grief doesn’t fall on their head. How did Trek get this dumb? How did they get this unhealthy?
They’ll do it the best approach, see?
In case you are now pondering why Trek doesn’t know higher, they really do. When you have a look at the Madone collection bikes pictured above, they do issues in another way. The shocks are absorbed by the form of the body and the supplies used. The underside of the seatpost space sits on a carbon extension of the highest bar. Supplies and layup decisions imply that bit is a spring that serves the operate of the IsoSpeed debacle with zero elements, and doubtless does it higher. If you would like the main points, seize the service guide right here, web page 18.
The seatpost is held in place by a clip and a screw, two low cost elements as an alternative of a posh badly designed, fiddly mechanism within the Domane collection. Given the price of these bikes, house owners usually are not going to take evenly to a number of failures and high quality management points that plague lesser bikes. That stated I didn’t benefit from the crap high quality that Trek put out both however on the Madone line they appear to have prevented the engineering flaws if not the fabric selection points. Trek may have completed issues worse however it’s a wrestle for me to see how.S|A
Up to date July 23, 2025 @ 9:45am – Trek did the best factor, type of. Between the time this was written and posted, Trek notified the store that the body will probably be changed. That’s the excellent news. The unhealthy information is that I picked the bike I did as a result of it isn’t flashy or hideous like a number of comparable fashions. Shiny will get stolen extra typically too.
Trek says the black body I’ve/had is not accessible, my decisions are blue and white. The blue isn’t too painful however that’s backordered for a number of weeks. The gray is in inventory and it seems to be like crap. In simply over every week I ought to have my bike again with a brand new body in gray that appears like crap. *SIGH*
