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If you were to choose between a Hope Pro 4 hub and a DT Swiss 350 or 240, purely based on their freehub types, ie Hope's pawl system or DT's ratchet system, which would you choose and why?

The main question is, which system is better, and why?

Just to be clear, these are the two types

Pawls System:

Pawls System

Ratchet System:

Ratchet System

  • I think both work reliable, so it comes down to cost and weight. DT Swiss 240 is 240g for 222€ while the Hope is 311g for 182€. I’d pick the DT Swiss (already have one ;) ). – Michael May 26 at 12:06
  • Thanks for the comment, cost and weight aside, this question is purely based on the pros and cons of the the freehub types. – abdnChap May 26 at 12:09
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    Weight is absolutely a pro/con of the two designs - that is definitely an answer. 70 grams isn't a lot, but it all adds up. – Criggie May 27 at 1:28
  • Ok, I meant the technical / mechanical pro and con of the system. If you think 70g should be included as a mechanical advantage, that's fine with me. But there must be other things, which make the two systems so different, apart from the 70gs – abdnChap May 27 at 14:43
  • With a €40 price difference, is if the design or build and materials that is making the saving. i.e. if they were the same price, how would the weight compare? – mattnz May 28 at 4:16
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Hope hubs are a very refined, reliable execution of the pawl design. They don't do much to illustrate the disadvantages of the concept that designs like the star ratchet are trying to address.

One potential downfall of pawl systems like Hope uses is that when things go wrong with them, either the pawls or the part inside the hub shell that the pawls engage, which I'll heretofore call the "drive ring" as it's named by some manufacturers, can become damaged. Typically the drive ring is a hardened steel piece threaded into the shell. Some potential scenarios:

  • If the pawl mechanism is underlubricated, contaminated, underpowered and/or imprecise, partial engagement between the pawls and the drive ring can occur. In this situation the pawls haven't sufficiently sprung up into the mating teeth of the drive ring at the moment the rider applies drive force. Instead the tips of pawls and the drive ring teeth ram into one another and may slip, potentially causing damage to either or both. Pawl-based drive systems can all do this under the right circumstances, it always has some destructive potential. It's also possible for issues with unequal spring tension, damaged or displaced springs, or other imprecisions to create a situation where some pawls get overloaded and become damaged or fail. Avoiding any such issue is one of the main goals of systems like the star ratchet.
  • There can be hardening problems with the pawls or drive ring. Sadly I've seen this on the drive ring once or twice on well-known, expensive, small production hubs, which were at least able to be warrantied. Issues of this sort are of course possible with other designs, but see below why it's painful with drive rings.

In either case, the teeth of either the pawls or drive ring can become chipped and deformed. At that point the problem can begin to build on itself. The teeth have to be sharp for the system to work as intended.

One thing about drive rings is that few manufacturers make them easy to replace if something does go wrong. When it is possible, either you need a new one plus a weird, expensive, proprietary tool that goes in and mates with the teeth, or in some cases you need to send your wheel in to the manufacturer. High-end aftermarket hubs and some wheelsets will typically give you one of those two options. Beyond that, neither option usually exists. You can find some high-dollar wheelsets where once the warranty period has elapsed, addressing a drive ring problem is difficult or impossible.

So while the drive ring is not technically a dynamic surface that's integral to the hub, in practice it might as well be in many cases, and my experience is they can be a little more damage-prone than people realize. Pawls and their hardware are typically more available, although sometimes they can only be replaced along with a new freehub body. And for older, lower end, or OEM hubs, they may be unobtainable.

More aggressive sealing and spring force are both design weapons against engagement issues on a pawl hub ever occurring. (Hope hubs take both pretty far). Reliability is increased at the expense of marginally increasing drag while coasting, the funny thing about coasting drag of course being that to a point, it's not a great concern in most riding disciplines where it's reasonable to split hairs about performance.

Systems like DT Star Ratchet and King Ring Drive, which I'm going to arbitrarily call "drive plate" designs, are trying to make partial engagement closer to being physically impossible, even with contamination and poor lubrication. Contact area is increased at every step of the torque transfer, and it's between two unified pieces, rather than separate pawls that are only as good at engaging all at once as their spring tensions are equal. Extant examples of drive plate hubs make all parts fairly easy to replace but very seldom need it, due to their efficacy at distributing load over more area. This quality is of heightened value in a hub one invests in with the intention of re-using indefinitely as rims wear out.

Pawl systems have an advantage at each approximate price point in the rate of engagement numbers they can obtain while still being reliable overall. At the high end, Industry 9 is a poster child, with ROE numbers down to 0.52°. Plate type systems have in contrast seemed to find their limit at 5-6° for a King or 240, presumably because their torque-transferring parts are smaller by necessity and so making the toothed/splined parts any smaller would sacrifice too much strength or otherwise become impractical.

Another way of looking at is that pawl and drive ring systems, and especially the highest performing ones, need to push everything to the limit in terms of materials, hardening, machining precision, matched spring tension, etc. The best ones are only the best because of how close they fly to the sun. Plate systems don't have that dynamic, but at least as far as what exists to date, they take a little hit on rate of engagement potential.

I personally feel that between the Pro 4 and 350 freehub, both are reliable but the star ratchet design gets there in a way that's more elegant and robust. But, the 8° ROE on the Pro 4 versus 18° for a stock 350 would be a reasonable deciding point. Different riders value ROE very differently, and for good reason.

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5

Both work fine. Technical explanation would lead to endless debate between people who don't know what they are talking about, so I'll go for economical one instead.

The patent for DT style star ratchet expired in 2015 and Chris King ring drive in 2017. Unlike innovations such as cassette freehubs, threadless headsets or three piece cranksets, other manufacturers haven't rushed (1) to build these once patents expired or were worked around. This suggests that these mechanisms aren't a huge improvement over the common ratchet and pawl design. On the other hand, these designs have been manufactured and sold at premium prices profitably for 25 years, so they can't be significantly worse either.

(1) Zipp has introduced their own variant of star ratchet after the patents expired. They are the only one that I know of. This might point to the direction that some star ratchet benefits might be real but it is too expensive to manufacture for common use.

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    Thanks for the answer, while I understand that a quick "this is better than that" answer will probably start a debate, how about listing some technical pros and cons for each system? – abdnChap May 26 at 13:01
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    @abdnChap I think the point here is that there are no significant pros or cons of either system and no real difference that a rider can discern. – Argenti Apparatus May 26 at 13:27
  • I'd rather not go there. Most of the claimed pros and cons are in favor of star ratchet variants, but I don't understand enough about mechanical engineering to judge how much of it is fact-based marketing and how much just made up. – ojs May 26 at 13:27
  • Disadvantage of the pawl system: The pawls are easy to lose and fiddly to install when doing maintenance. – Michael May 26 at 13:29
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    When they work properly, I agree that there isn't much of a practical difference. I would just note that for especially heavy riders (like myself at 105kg), shearing off pawls and otherwise mangling pawl-type hubs is a very real thing. Nathan's answer below gets at that point. Anecdotally, I have been mashing the pedals on a DT350 for almost 2 years now without issues, and that is about twice as long as the last 5 pawl hubs I've ridden lasted. I know plenty of ultradistance folks who ride the DT star ratchet hub because it has proven least likely to fail in the middle of nowhere. – Poquontchn May 27 at 9:01
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Small considerations

1) which one will have spare parts available in the future, should you need them? That's very hard to guess at this point. You might need to buy a new freehub to support a different sized cassette someday.

2) sound - some riders are all about the sound of their freehub as it coasts. It makes no difference to me cos I generally soft-pedal all the time, but some people like a loud clatter and some prefer a faster vizzz noise. This has no effect on function, but can be used in racecraft when trying to psych out other riders.

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  • Both of those are fine points, but this question really is just trying to focus on the performance difference bewteen the two engagement systems. – abdnChap May 27 at 14:50
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I would consider ease of maintenance a factor in your decision regardless of ratchet style. Obviously from the vast supply of information above, you get the idea that it is primarily a matter of taste and budget that will inform your final choice, as both styles have their strong points and weaknesses, but consider that I have to do routine cleanings of my Chris King hub using proprietary tools that were pricey, I think I recall paying around $160. I use my DT Swiss 350 hub on all the same trails, ride styles, etc, and I clean it less frequently, and even still it never diminishes in performance as it gets gunked up like my CK hub, and it doesn't require any tools to clean other than an old tooth brush and degreaser. The DT Swiss design is mechanically simpler and less expensive. I actually like how it performs better than the Chris King Classic. Most good brands float solid, quality equipment that works great when well maintained, but how mush hassle it takes to do so is a giant factor for me.

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