Dear Uncle Dave: Why aren't Brand New Frames Straight?
Dear Uncle Dave:
I have bought a few aluminium full-suspension frames from well-renowned brands in the last decade, and I'd say that the two most expensive ones were not super well aligned and finished. For example, on the latest one, I'm talking seatstays that pull 1/4" to one side, defects in the forged parts and paint/clearcoat lifting off in some spots. Ultimately, when assembled and bolted together, the frame is straight and the pivots' action is smooth, but I expect better quality control than that when I'm paying two grand for a bare frame without shock. If fact, I have bought a complete full-suspension bike for the same amount of money two years ago and the frame was surprisingly straight and well finished. Was it luck?
Am I the only one that inspects a new frame to see if everything is straight before building the bike ? Has the manufacturing quality been going down in recent years, is it bad luck, or has it always been like that and I need to lower my expectations ? Or most poeple see it but they don't care ? When built up, I don't think about it while riding, but instead of getting stressed out about the manufacturing quality when ordering or building a high-end frame I should be excited!
What are your thoughts Uncle Dave ? Thanks!
Dear Crooked Man:
I'm often surprised by some of the things that I now accept in my older age compared to when I was young. I'll happily eat things these days that I wouldn't have touched even as a poor, drunk student living in a dump. I'll use washrooms that would have previously had me clenching and praying. And, worst of all, I'll roll down a trail on any sort of sub-standard bicycle, as long as it has two 29" wheels, a dropper post, some decent rubber and electronic shifting.
I used to be soooo particular about my bike set-up. I would insist on all of my contact points being the same across every bike that I owned. I got freaky obsessed with bar sweep. I hated to ride a bike that wasn't mine and that didn't feel like an old pair of slippers.
In many ways, I think I'm better off now, with my ability to hop on most things and feel relatively comfortable within a couple of minutes. The flip side to that, however, is that I find myself paying a lot less attention to the details. I care way, way less about any particular component on any bike that I own. I don't try to make personal statements with my build choices. Stressing about a few mm of alignment on any bicycle that I ride is just not something that enters into the equation for me any longer. So to answer your question, I have no idea.
But I know somebody who might!
Hi Noel. Thanks for agreeing to do this. We'll start with an easy one. When the average consumer goes out and purchases a new frame/bike, how concerned should they be about the alignment? What sort of impact might a poorly aligned frame have on the performance of their bike?
Noel Buckley - Founder and Owner of Knolly Bicycles. Makers of high quality bicycles, built of many different materials, for many different genres.
Thank you for including me in this discussion!
I feel that customers expect that the product they purchase should be at a certain quality level and one of those things is that the frame is relatively straight. It should ride properly and it shouldn't destroy rear shocks. Unfortunately that's not always the case. What we (as customers) forget is that bikes - like almost all other products - are made in a production environment and while quality control should be a "Go or No Go" discussion, it's actually a giant bell curve. Actually, it's lots of bell curves and product gets spread across these curves. Every once in a while, you end up with product on the fringes of the bell curves aligning and this is where things can go from tolerable to nonfunctional. Where quality control comes in is defining those parameters, what is acceptable and what isn't, and trying to ensure that worst case scenarios don't make their way to end user customers. It's kind of like stacking a bunch of slices of Swiss Emmentaler cheese together: you want to ensure that there are no holes that go all the way through.
In the background are a bunch of bike brands, a bunch of factories (predominantly in Asia), contract engineers and designers, quality control departments, working within business constraints of MSRP, perceived value / performance, cash flow pressures, profit margins, delivery timelines, capacity issues, etc... All of these can put pressure on the production process to cost down the product. The real art is how far can you cost down the product without affecting perceptible quality or delivery timelines, or any one of a dozen other metrics that are important not only to the customer, but to the brands and their resellers. There is certainly a point where manufacturing is just inefficient, but once you get most of the inefficiencies out of the process, then cost down ultimately means compromises in the actual product. The trick is finding the sweet spot (for your intended customer base) where the compromises aren't noticeable and the price is the lowest it can be.
One of those compromises is of course "how straight and aligned the frame is". Others could be things like weight, the type of paint used, bearing quality, finish on linkages, frame manufacturing materials and techniques, etc... There are a lot of variables and alignment is just one of them.
How would a customer know that their frame is NOT aligned? Price is probably a good starting point. Price doesn't guarantee that an expensive frame is good and a cheap one is bad, but a higher price typically means more money is available for quality control (though in reality it could be spent on anything, including marketing). I don't think it would be useful to show up at your dealer armed with a protractor, plumb bob and micrometer: that is not going to tell you any real information. We're in a world where there is incredible confusion and misinformation about something relatively simple like actual vs. effective seat tube angles: trying to measure a frame's alignment is way more difficult. Without a flat surface and a reference, there isn't really any way to get a good feel for how aligned a frame is. Even unbolting part of the shock and cycling the suspension through its travel isn't a great indicator. So what are obvious signs that something isn't right?
Riding: the frame will feel like it's pulling one direction. It might feel "OK" when cornering, or when it's not cornering, or when it's in the air (ha ha!) but somewhere, something is telling you that the bike isn't tracking correctly. If you've ever driven a badly aligned car, it has a sense of pulling or it corners differently when turning left compared to turning right.
The other indicator is having reliability issues with rear shocks. Now, at Knolly, we're not a suspension manufacturer and we're a very high end relatively small bike brand so we can focus heavily on product quality, which we're not afraid to charge for. And, I don't want to speak for suspension manufacturers because they have their own metrics that they have to design to and the biggest of these companies are massive compared to a business like ours. But I would imagine that they are in a tricky spot because they want to ensure that their product is as reliable as possible across as broad a range of products as possible. That means frames that will be at the top level quality wise and probably a lot that isn't. A really well designed rear shock will be able to handle some amount of misalignment but how much is too much, I don't know. I do know that trunnion shocks have made this more difficult because the i2i distances are shorter and the trunnion part of the shock is heald much more rigidly than a shock with two eyelets.
That's interesting. Looking at things as a sum of the parts makes it more clear as to how a small challenge at the front triangle can turn into a nightmare by the time you reach the rear axle. It feels to me that we had a pretty good sense of how to make straight bike frames back in the days of steel and aluminum hardtails. Most of the horror stories that I've heard involve full suspension bikes. For the modern, full suspension bike, what is the biggest challenge in making a straight frame? Is it fabricating a straight front triangle? Making sure all your pivots line up? Consistent chainstays, seatsays and linkages? From your first response, I can understand that we probably shouldn't be looking at these in isolation, but I'm interested in understanding what the biggest headache is. And since you make both aluminum and carbon fiber bikes, does one of these materials pose more of a challenge compared to the other?
Noel Buckley - I think the biggest challenge just comes down to SOP (standard operating procedures) and what the customer deems to be "good enough". By customer I mean bike brand and by "good enough" I mean what they are prepared to accept from the factory as being acceptable for them to sell to their resellers and / or end user customers.
Hardtail frames aren't immune to alignment issues by any means. In some cases, they are more difficult to correct (because the rear end may be overall stiffer) or they're more expensive to correct because once you finish a hardtail you can't just replace a component like you can on a full suspension bike. Case in point: at Knolly, we now make frames from all four common materials used in bikes: steel, titanium, aluminum and carbon. By far the highest risk frame from a cost and production standpoint is a titanium hardtail. When you're getting near the end of production on a bike like that, the total manufacturing cost on one part is higher than the total cost of a high end carbon frame with a high end rear shock. If a mistake is made and you have to scrap the entire frame, it's a huge cost to throw out. At least on a high end carbon full suspension frame you can replace the part that's defective and get the frame back into acceptable specification. So, things like this - especially the cost driver of the vendor having to scrap a frame - may mean that stuff that shouldn't make its way to end user customers, does make its way to the general public.
For full suspension bikes, again, it just comes down to the capabilities of the vendor and what the customer (bike brand) wants. Part of this is driven by cost: more precision = most cost. More checks = more costs. Advanced production machines to ensure higher levels of quality = more cost. More manufacturing operations to make a frame better (stronger, lighter, sexier, more sophisticated suspension, etc...) = more cost. Often you can have the same vendor making differing levels of quality product simply because they have multiple customers who have different demands. Sometimes there is a capacity issue as well: when a brand gets really, really big, they become very limited on the vendors they can use due to capacity issues. I remember a friend who works for a clothing company with $1B in sales telling me that they had trouble dealing with "the best shoe factory" in China because they were competing with huge brands like Nike and Adidas for manufacturing time. That kind of really puts it into perspective when a $1B revenue company deals with these kinds of issues. So, when you're a big company you might have all the leverage in the world in terms of dollars to throw about and QC teams that you can build and really knowledgeable engineering staff: but you might be limited to literally one or two vendors simply due to capacity and you have to work with the vendor to get the quality at a price that you want.
For bikes I think there is an inherent desire to think that carbon frames are more "accurate" than alloy frames because they come out of a mold and the mold itself is CNC machined so it should be pretty much perfect. But typically there are still parts of the frame that need to be machined post curing and again the overall precision can vary quite a bit. Conversely, if you think of an alloy frame where there could be a 1mm of shrinkage on the frame through the welding procedure, but the vendor is really good at controlling that by figuring out the welding sequence ahead of time and then CNC machining all critical points on the frame in only one or two setups after welding, you could easily end up in a situation where the alloy frame is more accurate than the carbon frame.
The main issue with full suspension bikes (and what I think you're getting at in your question) is that they have lots of parts that are bolted together and hence there is opportunity for what we call "tolerance stack up" to happen. This goes back to my previous answer where if you just happen to get all of the parts that have the worst combination of tolerances then you get some unhappy customers. It's unlikely that any individual frame would be the "worst case scenario" but when you're building frames in batches of hundreds or thousands or tens of thousands, there will be some that will always be some outliers quality wise. It's just a question of how high is the percentage of outliers.
So. There you have it. To be honest, I thought we'd hammer out more than a couple of questions, but Noel has a lot of information and I didn't want to subject you to much more than the 2400 word count we're bumping up against. If I had to summarize what we learned here today, it would be thus:
- There's not really much you can do to measure this on your own
- If you get a really poorly aligned bike frame, it probably won't kill you, but your shocks might start blowing up and your riding might suck a bit
- There's no magic bullet for a perfectly aligned frame. Every material has it's challenges. Small companies can have problems. Large companies can have problems
- If you feel wronged by the alignment of your bicycle, scream about it loudly on the Internet, and maybe somebody might help you out.
Uncle Dave's Music Club
In these trying times, I thought we could use some happy music. Maybe happy is the wrong word. Pleasant?
Twee as Fuck.
Not many things created around the turn of the century give me as much happiness as the phrase "Twee as Fuck". And only one band springs to mind as I bounce this phrase around my head in 2020: Belle and Sebastian
Not Belle & Sebastian. Not Belle + Sebeastian. Belle lower case and Sebastian.
During that strange time in the late 90's, I struggled a bit with my love of Belle and Sebastian. This was a time for me of cheap beer, loud music, sketchy shows, bad decisions and, somehow, Belle and Sebastian.
Now, if you're bored one afternoon, looking for excitement, track down an aging hipster of a certain persuasion and loudly proclaim "It goes without saying that If You're Feeling Sinister was the last Belle and Sebastian album worth listening to." You'll either get an enthusiastic head nod, or a dismissive sneer. If you frequented Zulu Records in the late 90's, Belle and Sebastian was inescapable, and you fell into 1 of 3 camps.
1 - Those who think If You're Feeling Sinister was the last Belle and Sebastian album worth listening to.
2 - Those who think the decline of Belle and Sebastian began an album or two after that.
3 - Those who don't give a shit about Belle and Sebastian.
Me, ever the contrarian, fit into a 4th camp. I happen to believe that the decline of Belle and Sebastian began immediately after Dear Catastrophe Waitress. I know! Crazy talk. But hear me out. My argument is thus: Everything up to and including Dear Catastrophe Waitress was pretty good. Everything thereafter, not so much.
And I'm not going to argue that Dear Catastrophe Waitress was all gems, but there's some pretty great fucking songs on this album. First up, Piazza, New York Catcher is beautiful, and totally fucking bonkers. I mean, where does a Scottish guy get off singing about baseball? With some kind of nuance? You don't hear me going off about the intricacies of caber tossing, now do you? That's Scottish, right?
Next, Step Into my Office is easily the poppiest song that Belle and Sebastian has ever written (that I've bothered listening to more than twice). And it's a great fucking song! But totally fucking bonkers! I mean...shit...just listen to it. It's a potential sexual harassment complaint in song!
You win a prize! And it's not a mangled 10 speed.*
Your frame may not be straight, but it can remain pretty over the long term thanks to Bikeshield Phoenix frame protection. That's a sweet prize, but if you are looking to go deeper you could do something as shown below, which is a custom order from a customer commemorating the Gulf Oil liveried Ford GT40 that won Lemans in 1968 and 1969.
*that's what old people call cheap road bikes
Send us an email to claim your prize.
Do you have a question for Uncle Dave? It seems harder and harder to engage him, so you'd better make it good. Or funny. Both to be safe. But... if you have a trashy garbage question, like "what colour grips should I put on my Yeti," don't hesitate to send that as well. Send all of them to firstname.lastname@example.org