sysrq

The description on MKS Sylvan Touring Next pedals says that dustcap can be used to fine tune the preload on cartridge bearings to reduce play:

"The dust seal cap also functions as the bearing adjuster. If you loosen the cap, it may cause play and premature wear",

but there is nothing like that said about Allways pedals.

As always was expecting a bit higher quality for such a price.

Hard to avoid any cognitive biases but it seems like frequently running into defective products for some reason.

https://www.mkspedal.com/?q=en/product/node/308

FBinNY 

You don't offer details about your problem.

It seems that MKS doesn't want people to fool with the pedals, which I understand because it's so easy to axially overload radial bearings.

However, if you have play, you might reach out to MKS. Or, you might see if you can open the end cap, under which you'll find a nut to take up axial play. If you decide to adjust them, be careful to only take up play, but not to create preload.

veganbikes

Like FBinNY said there is no details on the problem. It could be something not the pedals is causing issues or it could be the pedals in which case the authorized dealer you purchased them from can start a warranty and get you new pedals.

MKS makes excellent pedals I have had two pairs of them and I have abused them and truthfully never maintained them (which I probably should eventually do) and one of my mechanics had Lambdas for years and years and years and years and I eventually bought him the Gammas because he had foot slippage and I don't think he installed them for a long time because his old pedals refused to wear out and he rode that bike everywhere for everything nearly everyday of his life and he probably had the pedals for at least a decade if not more.

If you keep running into "defective" products I would think maybe the products are fine and the person installing them or using them is the actual issue or it is possible you are just an unlucky lightning rod.

sysrq

Seems like there is only angular play, but no axial or radial play. I have red some rare comments which said that minuscule play is normal in cartridge bearing pedals. No way to tell without comparing all of them.

Looks like there is no preload tube which means that adjustment affects only the outboard bearing.

Andrew R Stewart 

I believe the version of these pedals that the OP has are of the "no tool release" design. If so there could be some play in that part of the axle, between the part that threads into the crank arm and the axle end that is inserted into the first part.

I would also not use the "defective" term when describing bearing preloads not being what the OP thinks they should be. Andy

FBinNY 

Huh?

How can you have angular play without axial or radial play?

OTOH if as Andy suggests, you have a quick disconnect pedal, play at the link is common, and can be considered a trade off for the feature.

sysrq

It's not a quick disconnect model. After repeated testing there is also some axial play.
If there is no preload tube between smallest outboard bearing and two bigger inboard bearings then the adjustment will affect only the outboard bearing.

The radial play is felt only around inboard bearings but not around outboard bearing.

Iride01 

Maybe the product isn't defective. Maybe it's functions at the level of performance that it needs too. Maybe you are making mountains out of molehills.

sysrq

I haven't found clear explanation how much play there should be in general or reports from other users (except: "the pedal keeps spinning for ages") so it's too early to tell.

FBinNY 

First of all, you need to understand a critical difference between the adjustable angular bearings classic to bicycle.

Angular bearings require preload to eliminate play. In radial bearings that's achieved in the bearing itself. These bearings cannot tolerate axial preload, which leads to rapid bearing failure. Radial bearings are used where no meaningful axial loads are expected, so one adjusts to minimize axial play, short of adding an axial preload.

I suspect the pedals are fine, and the issue is your misconceptions and expectations.

sysrq

In hubs we also have radial bearings and there is no play. Even the cheapest cartridge bottom bracket hasn't got any play and doesn't need any adjustment.

FBinNY 

As I said there is an adjustment to take out axial play, and you're wrong about needing to somehow load the inner bearings.

But they're your pedals, so feel free to ignore my attempt to help you, and continue to complain.

sysrq

This might mean that inboard axle dieameter or bearing bore is intentionally made too small to speed up the production or due to any other reason since hard knocking is being felt while testing for play.
Strangely in the factory video they show those two bearings being pressed in with a press.

FBinNY 

I can't say, since I don't have the pedals to examine.

OTOH - Have you subjected them to the acid test, namely installed them to see how they actually work? Otherwise, I've no stake in MKS, though I did import them some time ago.

You're clearly dissatisfied, and hint that this isn't the first time, so maybe your best option is to return them, and not buy MKS going forward.

TiHabanero

I looked at the pedal drawing in the link OP provided and don't understand all this talk about preloading the bearings. Not needed. As for the wording of the instructions the OP also provided, I have a better way of phrasing it, "Don't mess with the bearings. They are set up correctly by the factory for the service life of the pedals."

Duragrouch

Disclaimer: Cartridge bearing pedals may be different than the below instructions, which are for loose ball bearings.

EDIT: FBinNY has looked at the pedal schematic and convinced me that my normal procedures below for much older pedals might be damaging to the MKS. So disregard the instructions below and follow the manufacturer instructions.

EDIT: Below is only for old style pedal spindles:
I've rebuilt loose ball (angular contact) pedal bearings for decades. I've found I get much better bearing life with just a touch of preload, as the balls are very small and just the right preload spreads load over almost 180 degrees of the bearing balls under radial load instead of just a couple at a given time, and if the pedal housing is sufficiently stiff, you will engage even more bearings and the shaft rigidity will be increased as a result, providing better cone alignment under load.

With pedals off the bike and rotating spindle in fingers:
- with slack, easy rotation, but too loose.
- no slack, easy rotation, but not spreading load as evenly on the bearings as could be.
- very slight preload, you feel the slightest bit of greater "engagement" of the bearings, I call it when the bearing "sings". This is the goal.
- too much preload, the spindle feels "notchy", back off a tad until not notchy, slight preload.

Just my experience, based on bearing adjustment in other applications. I used to adjust all bearings with just the tiniest bit of slack; Dad used to say, better a little too loose than too tight. He was wrong, I learned, once I learned more.

YMMV.

FBinNY 

The issue isn't whether they're loose type or cartridge, but the configuration of the rolling elements.

Most cartridge bearings used on bikes are deep groove radial bearings, which can only handle rsdial loads, plus very light axial loads, more about staying located, than handling any thrust.

Unless you can expand the inner race, there's no way to change the radial preload, which is already built into them.

Axially loading them only pushes the elements sideways, forcing the balls to ride the sides of the grooves, and will rapidly destroy the bearing.

There are also angular contact cartridge bearings, which work the same as bike cup/cone systems, and therefore need proper axial preload. However, offhand, I don't know if any bike parts use these.

If you look at the MKS schematic, you'll see a pair of low profile radial bearings which carry most of the load, and a deep groove radial bearing at the end that keeps the pedal from sliding off the spindle.

This design simply cannot tolerate preload, and I'm not surprised that MKS doesn't want folks "fixing" them.

Duragrouch

I yield to your logic. I knew what I said might not apply to cartridge bearings unless the less common angular contact ones. But also what you said above does sound very different configuration than all the pedals I have serviced. Thanks.

grumpus

So did you try actually using the pedals? Some that I use have only a small ball bearing at the outer end to locate the body on the spindle - the main load is taken by a plastic bushing and it feels fine even with wear, despite the fact I can rattle it by hand. The double cartridge bearings in yours will probably last forever as long as they're not abused.

sysrq

Already returned two sets of pedals so trying to find something better at the same price point feels like too much of a hassle without testing them in person before buying. Local LBS sells only the cheapest most basic overpriced stuff or anything related to high end racing.

FBinNY 

You might shop for pedals with classic cup/cone bearings. These will meet your need for zero play adjustability.

MKS still has offerings of this type, though you may be turned off to the brand.

sysrq

As long as pedal strikes are avoided or allowing the bike to tip over is avoided. Shimano pedals might be better in this regard but those had dangerously sharp antislip spikes and were too heavy so had to be returned.

sysrq

With cup and cone you never know when they are perfectly adjusted. They are usually perfect at the beginning after overhaul but then after 100km they are loose again even with sufficient locknut adjustment while trying to avoid stripping the threads even with Deore level of precision. If you leave them tighter intentionally then they sometimes continue to self tighten.

Could it be that MKS is actually avoiding any interference fit on those two inboard bearings since otherwise it's impossible to share the load equally between them?

FBinNY 

Short answer no.

You might take a basic mechanical engineering course, focused on bearing design.

Double bearings are SOP in countless applications where space requirements preclude using a single larger bearing.

I don't know why you can't find pedals, but FWIW my cup/cone pedals by Campagnolo and Sun Tour have 10s of thousands miles behind them and NEVER developed any play, or excess wear. I also own various radial bearing pedals which do have trace play, but it's totally undetectable when riding.

So, I wish you luck finding something you like, but I don't think I can help you get there.

Duragrouch

I had these problems when I was not adjusting my cone-and-cup bearings properly. Leaving the slightest bit of slack, concentrated radial loading in fewer balls at one time and they wore more. Not loosening in 100 km, but perhaps after a couple thousand. In more recent years, adjusting with exactly the right preload, and they stay great for years and tens of thousands of miles, they usually only need to get rebuilt if I get caught in a big rain and water and grit make it past the well-worn seals. As I detailed previously, no slack, just enough preload to feel all the bearing balls engaged (hard to describe but you'll know it when you feel it, spinning the spindle with your fingers), but not so tight it feels notchy. Perfect preload happens by creeping up on it very slowly when adjusting the bearings (and needs to be with locknut engaged as the threads have backlash, axial gap between male and female threads), and if it feels notchy, backing off slightly until it doesn't. Hard to describe, but the first time you feel a perfectly preloaded bearing, you'll never forget it.

Again, as FBinNY has said, the MKS design is not like cup-and-cone, so the above is not recommended, in that case follow manufacturer's instructions; I haven't seen it, but it's very easy for me to visualize a design where one bearing manages axial play in addition to taking half the radial load, and the other bearing handles just radial load. This is similar to a "full-floating" axle design on trucks, which allows the axle driveshaft to expand and contract axially without affecting the bearing adjustment. It's a smarter design.