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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

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  • 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 '20 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 '20 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 '20 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 '20 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 '20 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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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 '20 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 '20 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 '20 at 13:27
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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 '20 at 9:01
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    @Paul H According to Juhist, your hub should have violently exploded by now, so who knows... 😄 – MaplePanda Jan 15 at 18:21
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Star Ratchet is better for a number of reasons.

  1. Synchronization / loading a single pawl - With a pawl based system (as others have pointed out), there is the potential for one of the pawls to engage out of sync with the others. When this happens, the freehub body gets pushed off-center, which loads up the freehub body bearings to the point where they can become damaged. If they're damaged, then they have more play, and the likelihood of a pawl to engage out of sync goes up further.

    1b. Synchronization - because a star ratchet system has all the teeth on a single piece, the likelihood of them not engaging properly is much much lower than a pawl based system

  2. Self centering - A star ratchet system, when engaged, will pull the two drive rings centered to each other (due to the geometry of the teeth / the fact that they're distributed radially out from a single center point). So the exact flaw that can destroy a pawl based system can not happen in a star ratchet.

  3. Points of contact - A star ratchet has 18 / 24 / 36 / 54 teeth, of which ALL of them engage every time. A pawl based system will have up to 6 pawls. Even if the pawls are multi-teeth, each pawl still only has one point of contact in the pawl pocket (where they sit in the freehub body).

    3b. Points of contact 2 - The outside diameter of the star ratchets have 26 splines on them. Again, much larger surface area to spread the load over.

If you want an interesting case study on this, look at fat bikes. The failure rate of pawl-based freehubs on fat bikes is insane. This is due to two issues. The tires offer immense amounts of traction, so the torque being transmitted is higher than ever, and the axles are quite long, so they flex a lot more. This means that pawl based freehub bodies are suspect to synchronization issues, and if you ever load up a single pawl, it's likely game over for that freehub body.

Now a beef - the new Hydra from Industry Nine. It intentionally uses mis-synchronization to offer even more points of contact (690). It engages 1 of 6 pawls, and then as the system flexes, the 2nd pawl will engage, and then the 3rd and so-on. I imagine that they will chew through freehub body bearings at an alarming rate.

Now a second beef - everyone is chasing high points of contact or low degrees of engagement. That's fine on a hardtail. On a dual suspension bike where suspension action often has an impact on chain length, these high points of contact can cause a lot of kickback at the pedals, where it would be unnoticeable with a lower POE.

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    This is a good answer, but I think that we would have heard about Hydra hubs chewing through bearing on the MTB forums by now. I also thinking that pedal kick back is an over-stated problem as you have to be going pretty slow and take a big impact to not out run the free hub. I say this as someone with a bike with a far amount of theoretical kick back. – Paul H Jan 15 at 4:16
  • @Paul H MTBs usually don’t get ridden as far as road bikes, so the wear might be less severe. As for kickback, it probably depends on your riding style. Someone who does slower speed riding probably feels it more than someone whose trails are naturally faster. – MaplePanda Jan 15 at 18:16
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    @MaplePanda i'm not a bearing expert, but my understand is that weird, off-axis loadings (not number of rotations) is what causes bearing to wear out. also, believe me, I'm plenty slow on my trail bike ;) Here's a great, in the weeds video about kick back (youtube.com/watch?v=grNUgu0H9YA) – Paul H Jan 15 at 18:26
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    @Paul H In the context of “freehub bending to engage different pawls”, I would imagine that the primary wear factor is the distance ridden while pedaling. Every revolution of the freehub under power would be one cycle of bending and thus one cycle of bearing wear. Not an expert either though. – MaplePanda Jan 15 at 19:41
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    @MaplePanda with that framing, that would make sense to me too. – Paul H Jan 15 at 19:44
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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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Interesting topic. Although some time has passed after latest comment i decided to tug in.

I have been participating for weekly group riders for few years now. I have not yet seen or heard about broken freehub with star ratchet like system. I have witnessed several pawl type hubs broken on a trail or frozen on a below zero & we conditions.

I have driven Emtb for 3 years and weight about 110kg with gear. I have broken 4 freehubs (maybe 8000km). I ride the roughest trails in any weather. One freehub propably broke due to riding with wrong gear and exerting myself when I was new with the MTB. Whole wheel was replaced. One broke clearly due to moisture that got inside the pawl system and froze in -10 degrees weather. I think only freehub was replaced on this case. Other two are Giant rear hubs that were known to have some weakness in the rear hub. Incomplete pawl engagement caused drive ring teeth to be shaved off. Again new rear wheel on both cases. As i have mostly ridden with pawl system freehubs and only had ratchet system for 1000+km this is not fair comparison obviously, but for me it is quite clear that next hub will have a star ratchet system of some sort.

I agree with the point with the engagement angle and if that would be e major decision point for me i could consider just choosing some good brands pawl system hub. But with shimano XT rear hub at ~100€ and DT swiss 350 at ~150.

For me this is a no-brainer. Due to the reliability, ease of self-service and peace of mind vs cost the star ratchet is clear winner.

p.s. Shimano has joined the club and uses the star ratchet system at least on the XT-hubs. I think it must have been a hard decision to adopt the competetiors key-technology. By doing so they admit that the competitors technology was better than their own.

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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 '20 at 14:50
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Pawl hubs are terrible.... anyone that torques their wheels and is heavy should refrain from pawls... i have a box of pawl style hubs to prove this... been riding my 4 sets of ringdrive hubs without any fail whatsoever on all mtbs and fatbikes including ebikes. periodic maintenance and one bearing replacement after 10 years on my king iso hubs.

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    Good work, thank you. Is a ringdrive hub a type of ratchet hub or is it a third option? – Criggie Jan 26 at 21:24
  • Pawl hubs are awesome. I've been riding them for 30 years and the only problem I've had has been with bearings. – ojs Jan 27 at 7:33
  • I don't think this is necessarily true. Plenty of pro riders with Hope hubs. Also have plenty of heavy friends who use Hope hubs without isses – abdnChap Jan 27 at 9:43
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Let us revisit what the goals of a freehub are:

  • To transmit rotational forces reliably in one rotating direction only
  • To do so silently
  • To do so with minimal backlash (quick engagement)

The star ratchet isn't very good according to those criteria:

  • Reliable
  • Noisy as hell
  • Backlash the same as the tooth angle difference in the ratchet rings

The pawl system is much better:

  • Reliable, unlike what the star ratchet fans would like you to believe
  • Can be made silent
  • If there are 4 pawls, it is possible to offset them in such a manner that backlash is one fourth of the angle difference in the ratchet ring

Based on these, a good implementation of pawl system is the superior choice and even the worst possible implementation of the pawl system is better than a star ratchet.

Unfortunately, many pawl system implementers fail to see that elasticity of the mechanism causes only one pawl and tooth to handle all of the load at a time. Thus, for example a system of 4 pawls is often designed in such a manner that all pawls engage at the same time, meaning the backlash is the same as the angle difference in the ratchet ring. This symmetrical placement of the 4 pawls achieves nothing (the intention is probably that all teeth would distribute the load evenly but due to elasticity it won't happen) while at the same time maximizing backlash.

Often times, star ratchet is much more expensive too. It is mainly made by DT Swiss at a great expense. For example Shimano hubs have a much better silent pawl freehub body and the right side bearing in Shimano hubs is very close to the right end of the axle, minimizing axle failures. Furthermore, Shimano hubs are far cheaper than DT Swiss. Of course this doesn't mean that all pawl hubs are cheap: certainly there are pawl hubs ten times as expensive as Shimano but not ten times as good.

Also, it is worth mentioning that no matter what freehub system you have, the freehub body must be made of steel. An aluminum freehub body will have the sprockets dig into the aluminum. So if you have a choice between star ratchet with steel freehub body and pawl system with aluminum freehub body, you are better of selecting the steel one.

Similarly, there are other considerations when selecting a hub too. One of them is the material of the axle: it should be chromium molybdenum steel. Any hub with aluminum axle will break in no time. Also hubs where the right side bearing is as close to the axle end as possible should be preferred, and cup-and-cone bearings should be preferred over industrial cartridge bearings because the cup-and-cone bearings have a full complement of balls.

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    Why is silence a goal? Whose goal? When riding in a tight pack, noisey freehubs communication very valuable information about changes in the group speed. When riding on the trail, noisey freehubs alert others to your presences so that you don't startle them. – Paul H Jan 15 at 18:29
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    Have you ever seen an XD freehub where the cogs have dug in? Didn’t think so either. And the Shimano Scylence freehubs got cancelled anyways, so they aren’t even available. Some people like the freehub noise too. – MaplePanda Jan 15 at 19:37
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    Not to mention the fact that some people, me included enjoy a ASBO enducing loud hub. Also it's known in MTBing that super quick engagement isn't always a priority and can make pedal quickback from some linkages worst. – abdnChap Jan 16 at 20:00
  • This answer also gets the effect of elasticity backwards. If the material was perfectly rigid, only one pawl could ever be in contact (because of limits in machining precision). Elasticity actually mitigates this effect, by allowing the system to deform so that the pawl and tooth spacings match. – RLH Apr 10 at 17:32

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