Silt is a relatively new company based in Northern Ireland. They were founded by Alan Graham, previously of Nukeproof and Hunt, to be a direct to consumer wheel manufacturer that offers both value and performance. They sell a whole array of wheels, with XC, enduro and e-bike offerings available in a selection of alloy or carbon.
To say that they’re merely cheap and cheerful would be a grave disservice though. Through my dealings with the company, there seems to be a genuine and earnest desire within Silt to give the customer a well made yet budget-friendly product. The wheels themselves certainly are not short of tech, either. They come it at a very reasonable £370 and weigh a competitive 1869g for a 29 inch set. 27.5 and mixed sized sets are also available.
Silt AM Alloy 29 • 30mm internal rim width
• Weight (actual): 1885g
• Spoke Count: 32 front/rear
• Spokes: Sapim Double Butted
• Price: £370
•
Siltmtb.com The flagship of their design is undoubtedly their Ratchet Drive Hub Technology. There are other pieces of genuinely good design throughout the wheel, such as a nicely ramped edge on the well of the rim, which is there to help tires initially seal and then get up on the bead while you inflate them.
The hub technology itself is not completely different from what some other brands are doing. The main difference would be the leaf spring, as opposed to a coiled spring that you may find in other hubs. One ratchet is secured into the hub and then then the other rotates and engages as needed. The main advantage of a system such as this is that when the faces of the ratchets engage with one another, they engage all their teeth near-instantly under power. This, in turn, helps spread the load across the mechanism which should help with longevity. A more traditional ratchet and pawl mechanism does not benefit in this way.
Removing the freehub is relatively easy and just requires a 3mm allen key and a 17mm cone spanner. Once loosened, everything is very easy to access and clean, should you need to. If you wanted to remove the affixed ratchet disc, or indeed the bearing behind it, you would need a special tool. Silt makes a point of offering this as cheaply as they can, which I think is a commendable approach. They have a
spares section of their website which all seems reasonably priced.
The wheels use a 30mm internal width rim; the hubs were assembled with a very adequate amount of aqua grease to ensure a good barrier to corrosion as well as minimal drag. Here, you can see the leaf spring used.
The wheels use a mixture of 6902 and 6802 cartridge bearings. They have a contact seal to face outwards to shield the innards from unwanted grit and moisture. I tested these wheels over an uncharacteristically wet Portuguese winter. Not only did this mean that the bike got dirty but it was also cleaned after most rides. Despite this, the bearings still spin as smoothly as the day the wheels arrived. The end caps on the front wheel use a well-fitting seal to not only protect bearings but also to secure the caps in the hub. Again, this is a nice touch and balances function and form.
The wheels use 32 Sapim double butted spokes front and rear and are genuinely “tubeless ready”, in that they come pre-taped and the valves are provided. The wheels also come with spare spokes for each of the sizes used.
Performance Initially, when riding the wheels, I found them to be very stiff. Comfort sometimes can be overlooked, especially in wheels. That being said, it is subject to a myriad of different factors - weight, bike, setup, location etc. I do find though, that wheels can come too highly strung from the factory.
It’s a bit of a thankless task for wheel builders, I suppose. If they go too low then it can deliver a vague sensation to the rider and even lose tension over time. Too tight and comfort and deflection can be a real issue. That’s also not to mention how spoke tension will work inversely to tire pressure, which is impossible for them to predict. I do tend to run my bike's suspension very firm, which may not have helped. Essentially, when a tire tracks the terrain it’s sending information to the rim, spokes and subsequently axle. If there is too much tension there, sharp spikes in compression don’t have their edges taken off and it’s all loaded through the axle and I think it can overwhelm the fork - giving a very unsettled and fatiguing the rider. You can have the best suspension setup in the world, but if the information that is being passed on is predominantly large spikes of force then it won’t feel very good.
After initially riding the bike on rockier, firmer trails, I thought that I would venture off to find something a little softer if only to see how the wheels coped. On these trails, the feeling was vastly improved. However, if ever there was a section of rock or roots, I did feel as if I was being bounced off line. For your reference, I was running an Assegai 2.5 WT Exo+ at 21PSI in the front and an Aggressor 2.5 WT DD at 25PSI in the rear with a small insert.
They did ride well on softer terrain, and if you wanted to put large amounts of side load through the back of the bike, the stiff platform meant you could really carve into things.
Now outfitted with the information with how the wheels rode on softer terrain, I went to do some back to back setup changes on a trail that’s particularly rough and demands a lot from both body and bike. After several runs I found my ideal setup to be with half a turn of tension removed from the front and a quarter from the rear. Sadly, where I was living, I didn’t have access to a spoke-tension gauge so this is hard for me to quantify. With this amendment, it transformed the wheels and I got them to a place where I found them to be very comfortable and offer a vastly improved performance. I think the rim is adequately stiff to enable it to do most of the heavy lifting in terms of lateral stiffness and support. This is good news as it allows you to fine-tune the spoke tension to suit the rider and strike a balance between compliance and stiffness.
I spoke to Alan Graham regarding this issue and he explained that the wheels I received were tensioned to 130KGF, as opposed to the 120KGF standard. He went onto explain that knowing that the wheels were going to be bashed into goodness-knows-what over a few months they wanted to give me the most suitable tension. When I backed off the tension, I probably went back to the stock tension. For my weight of 83 kg and my riding style of ‘hit things’ this tension seemed a great compromise between stiffness and compliance.
Interestingly, Silt hopes to one day offer custom-tensioned wheels to customers. I’m not quite sure how they will execute this but it sounds like a great idea. As you may have guessed, it’s something I think about when going between wheels and really believe it can have a huge impact on the performance of your bike. As ever, if you’re not sure how, or indeed what to do, then please go and see a trained mechanic before grabbing the mole grips and applying liberal amounts of elbow grease.
ReliabilityI was initially given the choice between the alloy or the carbon AM wheels. The carbon, while not ridiculous in the context of other options, are dearer at £800. I felt that the alloy wheelset, which costs less than half, was a better representation of what I would personally buy and would be more relevant to a lot of readers.
The Silt wheels were used with several different tire brands; the dings weren't big and the rim always soldiered on but after 2 months of riding there were multiple of a similar size.
Whether or not alloy is more reliable is a contentious subject but it does not tend to fail in such a spectacular manner when it does eventually give up the ghost. That said, alloy rims do respond to impacts in different ways. I think I’m quite realistic with my expectations of a rim and I don’t expect it to come out unscathed if the riding is rough. A recent
Pinkbike poll would suggest that I’m not alone in this outlook.
I suppose in an ideal world, I would have a rim that is impervious damage that is a competitive weight. However, I understand that everything is a compromise. The Silts took some serious knocks over the course of testing and, while the rim is dinged and dented, it never ruined or stopped a ride.
The first impact to damage the rim was solely down to rider error but did leave me concerned for the longevity of the wheels as it happened very soon after I received them, but throughout the test they seemed to hold up well. After two months the Silt AM Alloy wheels still happily keep air pressure and stay in a ridable condition, even if slightly worse-for-wear; this is a vast improvement over my previous rear rim from another company that lasted less than a month before it wouldn’t hold air. By that comparison, the Silts robustness seems very reasonable.
I expect some people may be horrified at my short expectations of wheels but I really want to emphasise how rocky and flat-out horrible some of the trails were. Great to ride but they were nothing short of abusive to wheels. In other places, this wouldn’t be a concern. Some rims are made of cheese, and I think it would be very unfair to level that accusation at the Silt AMs. After all, most things will break if you hit them hard enough - it all comes down to what's a reasonable expectation.
Once I reach a certain threshold of impact resistance, my next concern is how they react to impacts. Do they fail straight away? Crack? Lose air? Make seating tires impossible in the future? Even though the Silt rim did take something of a beating, I would never say it failed. Even at its worst, with 3 dings in it, seating tires was never too much of an issue. I believe this was helped by the ramped profile of the bead.
As mentioned the internals stayed smooth and drag-free for the duration of the test. One small quirk, however, was the freehub would come loose when I took out my rear axle. This was quite annoying, especially as I was taking my wheel off every day during a tire comparison. I initially was torquing it with the cone spanner, but after a few times I realised finger-tight was just as effective (or maybe as ineffective). This, in a way, meant that it became a minor issue. It wouldn't become loose during a ride, only when I removed the axle. If ever I forgot to check, the leaf spring would ensure that the gears didn’t slip, even if the shifting was inconsistent. I’m loathed to put thread lock on fine threads or unknown alloys so I left it as it was. It was an irritant though. I tried to reduce friction on the axle by regularly cleaning it and applying fresh grease. This helped but only in the immediate short term.
I spoke to Silt regarding this issue and they explained that this can be remedied with a small drop of thread lock. They also added that they now include this step for all of their wheels in production.
Pros
+ Reasonably priced
+ Good weather sealing
Cons
- High initial spoke tension led to harsh ride
- Freehub loosening during wheel removal
Pinkbike's Take: | I'm a big proponent of companies that value their customers and have a no-bulls*** approach to products. I really feel Silt occupy that kind of space. To say there weren't some teething issues would be untrue, and the issue with the loosening freehub is still ongoing, but with all that said, for the value, they're still a good option.
If this was a wheelset twice the price would I be so forgiving? Probably not. But do I think that Silt, with maybe a little refinement, could be in place to ruffle the feathers of the status quo? Absolutely. I enjoyed great and constant communication throughout the test. I know you might think that this is always the way due to the fact that I work in the industry, but I can assure you it is not. They were also humble and very happy to receive the feedback, which is also an encouraging trait. — Henry Quinney |
For me, I would say, as I reference in the article, that an adequately stiff rim is very important. Of course, there are multiple directions that we could be refering to, which doesn't help. When I talk about stiffness in relation to the spokes, as I do in this article, it's largely how the spokes transmit information or feedback to the rider. In that instance, spoke tension does have large effect in terms of both performance and comfort. That said, if you had a very flexible rim then I don't think spoke tension alone would save you. I hope that was clear through out the article but am genuinely curious for you feedback. Thanks
If I'm honest, and excuse me for being quite direct, I'm not theorising in detail how spoke tension changes ride quality only that in this instance it did. I felt it relevant to include as I feel that a competent rider would feel this change.
Thanks for the info though - I'll be sure to check it out. Cheers.
This is just me thinking aloud so please pinch some salt in anticipation... although the hub does hang, I think of it as the hub moves what would be "up and down" in relation to the ground within the rim, instead of the rim moving around the hub. In my head this is how I build wheels - not for the rim to be true but for the hub to be perfectly central and aligned. I would hazard a guess and say that although the hub is only moving "up", and as you say pushing into the load bearing spokes, it is also almost tethered by spokes to the side. If it were a clock face then the spokes from 2-4 would affect how easily that hub is to move "up and down". I would also suggest the third cross in the lacing also adds stiffness and is affected by spoken tension. You might have seen that some straight pull hubs have spokes that don't touch. This also affects overall wheel stiffness. There is a calculation I'm sure, but I don't know what it is. Haha.
A wheel is a curved beam on a elastic foundation as first described by Winkler in 1867.
Maybe I have formulated too harshly, I‘m sorry for that but this and a few other things get told time after time even after proven wrong more than once.
As others have already pointed out, it has to do with the behaviour of the spokes when loaded, see Young‘s modulus or also stress-strain curve. Basically, to create a different feeling, you have to get one of two load cases:
1) Some spokes are so loose that they are not tensioned anymore when the wheel is loaded. This will lead to a drastic drop in stiffness of the wheel and to a few other problems like nipples coming loose if there is no additional threadlocker involved and decreased lifetime of the spokes because of the different load case.
2) Some spokes are tensioned so high they get above their elastic limit when the wheel is loaded, leading to plastic elongation of said spokes and: a) a slightly detensioned wheel operating in the regular window, b) spokes that are enlongated enough and dentensioned enough to fit in to case 1) or c) broken spokes.
There have been quite a few experiments for that, for example www.sheldonbrown.com/rinard/wheel_index.html
While riding over straight perpendicular bumps you won't notice a difference with lowering spoke tension. If you don't ride hard enough you also won't notice a difference - the classic theory applys.
We find that especially on rough natural trails with off camber sections and rough/bumpy corners you do notice a difference at some point. "At some point" means that you have to go really low, about 700-800N on the steep spoke angle side to make it obvious. What's happening isnt that the spokes "flex/bend/stretch", but rather that the rim can move around more in relation to the hub. I get that in theory you think that the rim can only move in relation to the hub when the spokes stretch but in reality an aluminium rim goes into a "potato-chip" shape. This completly relieves some spokes from all their tension which allows for the rim to radially and axially move around the hub.
This is in our mind also the main difference why carbon can be harsh and shallow aluminium rims are more forgiving and this rim deformation in a lot of cases also is the reason why you get tire marks inside your rear triangle during hard cornering.
Almost all carbon rims don't go into that "potato chip" shape during riding due to their inherent axial stiffness and especially shallow aluminium rims do this very easily. There is basically zero difference when you measure vertical deformation of a wheel, no matter the rim material or rim height so that "vertical" compliance" doesnt come from literally radial deformation of the rim. A Stans rim doesn't compress more than one of those older Enve rims under radial load at the hub axle/tire contact point (ok, maybe a few hundredth mm).
I hope it gets clear what I am trying to say as for me it gets kind of difficult to find the proper English words for some things I am trying to say.
I admit it's counter intuitive!
What bothers me the most about this review and, and many others like it on wheels, is that they ever so lightly skim build quality. The reviewer will speak to how they 'feel' or how the wheels 'feel', they speak to spokes popping, nipples loosening every so often, but they never REALLY address build quality. Build quality is as material a factor in wheel performance and durability as the parts they are made of. Pinkbike has an opportunity to make this tangible and clear to readers, but make little effort to do it in an objective manner. Here the reviewer 'feels' there may be tension issues, but the reader gets "Sadly, where I was living, I didn’t have access to a spoke-tension gauge so this is hard for me to quantify". And then you call the manufacturer and just take their word for it?! I am embarrassed for you guys. Pinkbike ( @mikekazimer @brianpark @sarahmoore @mikelevy ), if you are going to review wheels you need to put tension meters in the hands of reviewers like @henryquinney . Otherwise this is just the blind leading the blind. Why theorize when you can pull the data and demonstrate quite easily if you have an issue, and whether or not the wheels you received are well built, or need work?
@seb-stott @henryquinney instead of getting fancy and academic with telemetry, why not start with the basics. Get some tension meters, and come up with a process by which you test and document build quality. That would be far more valuable for the average reader, and you'll be keeping manufacturers honest while your at it.
Also none of us are greg minnaar and wouldn't notice the amount the tension was reduced. We aren't talking much. 1/8th turn all the way around. If they went too loose they would wreck rims every run.
Maybe @levy has to do another one of his myths things after some research.
Manufacturers who are slapping parts together with no QC (of which there are many) need to have some light shun on them. Manufacturers committed to build quality should be recognized as well, I think.
@privateer-wheels - hello there. You've raised some great points in your comment and some of it is fair. I suppose I would very strongly dispute that the difference is nil. I don't really know what to say other than I felt it, I have also detected over tensioned wheels before and would back my ability to do so again. So, although the science is really interesting and I think this has been a great discussion, there's clearly something going on there that nobody has yet been able to explain to me and no amount of "it doesn't make a difference" is going to change that. I know I can tell the difference so to be told that I didn't is... well it's a bit like the whole thing about "wisdom is knowing a tomato is a fruit and knowledge is not putting it in a fruit salad". I don't really want to get into an argument over the internet but to kind of be called out in an accusatory tone isn't all that great.
I would say that the most "basic" thing a rider can do is feel. I felt them to be too harsh and subsequently remedied it and they subsequently feel different, and in my opinion better. Honestly, this isn't some bizarre skill specific to me and it's not uncommon for race mechanics to tweak tension depending upon rider feedback for a very tangible gain. I'm genuinely surprised that people feel so confident in telling somebody they can't feel something just because they perhaps don't tend to. That to me is strange, if I'm completely honest, and certainly isn't the way that I go about reading reviews. But hey, there is obviously an element of lack-of-trust there and that's fair enough - I'm just some stranger on the internet, after all. I've taken your feedback on board and will genuinely re-address some of the things you've raised in my own methodology. Truthfully, every day is a school day and hence my genuine interest in what people have had to say. I think it's been a great discussion. I've got some new wheels currently on test and I hope I can go some way to building that trust in future reviews.
Thanks to everyone for taking the time to read and comment but that's enough internet for me today. Cheers.
The wheels arrived to you, with high-tension. Over-tensioned even. But you really can't quantify that, as you mentioned. Silt says 130kgf, bur perhaps they were higher...or lower. Who knows really? You go on further to say "When I backed off the tension, I probably went back to the stock tension". This is highly speculative. Not trying to attack you here, but you really don't know where the tensions were, and you don't know for certain where the tensions ended. Perhaps the change in tension was more substantial than you think, greater than 10kgf. Maybe this is why you are feeling a difference, because the change was larger than 10kgf. Perhaps significantly larger. Again, who really knows? Alternative 3 is that change in tension was more than you think. As we, we don't have enough evidence to say one way or the other, apart from feeling and speculation. Real data would be helpful in this case - I am sure you would agree.
The point I am trying to drive home is that nearly all wheel reviews look like this. This is not a you problem, this is a general wheel review issue. Many have this gaping hole. And for me, as a wheebuilder, yes that makes it hard to trust a review. That probably also makes my perspective a little different, and perhaps a little less forgiving. I see a lot of wheels from factories well over and well under save tension limits. In the last week alone I've seen a pair of wheels with average tensions of 150-160kgf on the high tension side of a wheel - tensions that void many rim and hub warranties. And I am not talking cheap wheels, either. So to see reviewers noting high/low tensions, or symptoms of high/low tensions, and strictly speaking to feel without grabbing the data to give these feelings and manufacture clams some substance, it's hard for me anyway not to want to ask questions. And drive home the fact that wheel reviews need more analytics and focus on build quality. I'll reiterate that doing so is pretty cheap and easy adds to reviews, and Pinkbike should step up and put tension meters in the hands of wheel reviewers.
Henry, I'll go a step further. If you want to continue reviewing wheels and Pinkbike isn't open to putting a meter in your hands, I will buy you one personally. Just reach out behind the scenes for a quick wheel chat, and I will make that happen for you in fairly short order.
Whenever someone says they have tensioned to X, keep in mind, it is really x +/-20%. Brandt being the dedicated engineer he was found no difference in stiffness of wheels when tensions were changed. What he found was there were two important tension, the first being the one when exceeded that caused the wheel to fail, the second being when going below, the nipples would back out. Because of the asymmetrical build of most wheels, the low side tension is 60-70% of high side. Even with this there is a pretty wide range of acceptable tensions.
Far more important is equal tension. This can be had without a tension meter, plucking the spokes and getting the tone matched gets you equal tension (even more than a tensionmeter will).
Personally, I use tone/acoustics to help when I build, in tandem with a very good meter. It's important to note that variance in spoke thickness of even 0.05-0.10mm can change the tone of two spokes at equal tension (if you have a good ear), and it's not uncommon to see such variance in spoke thickness in one spoke to the next in a bag of 500 blanks. Or at least this has been my experience having consumed many bags of spokes, and using tone and measurement instruments in sync work best for me. It's worth noting that I have met many wheel builders and have never met two with the exact same methods. Many don't use acoustics at all.
The fact that there is a margin of error in use, does not justify to not use the tools at all, and you know this of course because you went and bought a meter. On the Jobst Brandt style meter, good on you for wanting to own a good meter. I know a good handful of people with them, and I know three people alone who build or have built them. We have several here, a WheelFanatyk which is great for recording the radar graphs for a quick diagnosis, as well as a couple of custom-made European units which are quite likely the most precise custom-made meters you'll find, significantly more accurate and precise than the WF largely due to the THK roller bearing installed on the backside which make them virtually frictionless, high quality springs and dial indicators. We use these in combination with a swiss made calibration jig to create a custom tension chart for each meter and each spoke being used for any particular wheel build. Of course it also matters how you treat these tools in use as well...consistent technique...yadda yadda. We do what we can to minimize error and increase precision and accuracy.
There is room here to really go down the rabbit hole on fine details, tools, work methods, etc. I think we need to step back from the deep dive however, and acknowledge that currently wheel reviews do not attempt to quantify or even qualify substantially, build quality. And it would be nice if it could be addressed, and doing it with tools that have a margin of error is better than not doing it at all.
Basically, most people can at best feel a 6-7 percent difference. This is a ~4% difference in feel if the relation were one to one. The difference, if there were one with a direct relation to spoke tension, is a ghost feeling, a placebo effect and a mind game at worst.
I get it, cheese is soft, some wheels are soft. In future can we have some other analogies please.
Stilton.
Or Silton? I get confused.
youtu.be/Hz1JWzyvv8A
Or perhaps I should switch to “the consistency of melted butter “?
Crunchy extra nature Cheddar, Wensleydale, Cornish Brie, etc.
Tut!
One thing to consider for the manufacturer - it looks like the fixed side of the ratchet is installed with a pin spanner. It'll be all but impossible to remove it, whether for service or for change of POE. Speaking from my experience with a new set of DT EXP hubs, which in many ways are a similar design, you have to use a MASSIVE amount of torque to remove the threaded part, as it's constantly being tightened by drivetrain forces - clamping a hardened steel tool into a vice and using the whole wheel for leverage. There's no way you'll apply that kind of force with a pin spanner.
The tool on the site looks burlier than what the diagram suggests, hopefully it stands up.
(shimano only make CL afaik)
cdn.shopify.com/s/files/1/0314/9234/1900/products/Race_Disc_Wheel_with_Silt_graphics_REAR_1_dfe4855f-748e-48b0-b803-f07384cd6285_1904x@2x.progressive.jpg
bike.shimano.com/en-AU/product/component/duraace-r9100/SM-RT900.html
youtu.be/ZeJDl1pGMaQ
But maybe the bigger question is why roadie rotors at all?
please find a 350/511 wheelset, built for this price.....
Majority of time that takes to build a wheel comes from menial labor threading spokes and screwing nipples.
fitwheels.eu/wheelset-dt-swiss-350-cl-ex511-27-5-1885g-p-19.html
DT 350 boost SP hubs: 930PLN / 210EUR (DT4YOU)
XM481 Rims: 2x69EUR (wiggle)
Sapim Race spokes: 40EUR
Nipples: inc with rims
In this case they were self built. But in Poland at least, the difference (320 -> 415EUR) would easily cover a wheelbuild from someone reputable.
I've long found that an equivalent wheelset from parts is cheaper than the ready built system wheel when you buy parts and can either do the build yourself or have a reputable wheelbuilder locally. My points of reference were XM1700 & XM1501 wheelsets, and the config above falls somewhere between these - basically it's an XM1501 with 350 hubs.
If they lace them up themselves then spoke tension based upon rider stats and proposed feel isn't difficult and is what any good wheelbuilder does already, but interestingly I don't think any of the online only wheel suppliers offer this. I can remember bike shops building wheels up for road sprinters with crazy high tensions and soldered spoke crossings to make them as stiff as possible.
You need to have the humility to say “well, the simple model says that spoke tension is irrelevant but pro riders are fiddling with it and they’re not all delusional so maybe there’s something I haven’t considered...”
How do they sound?