# DT240 Rachet upgrade 18 vs 36 vs 54



## Srode (Aug 19, 2012)

I'm annoyed a bit by the slow engagement on the stock 240 hub, even on a road bike going from coasting to hard pedaling the clunk of the 18 tooth just seems like it's unnecessarily hard on the entire drive train so thinking about going to 36 or 54 tooth. I've listened to the sounds on youtube, but hard to judge if that's going to be annoying, if it's louder when freewheeling or if it's going to add significant drag. Looks like they coast down faster than the 18. Thoughts?


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## Jay Strongbow (May 8, 2010)

Srode said:


> I'm annoyed a bit by the slow engagement on the stock 240 hub, even on a road bike going from coasting to hard pedaling the clunk of the 18 tooth just *seems like it's unnecessarily hard on the entire drive train *so thinking about going to 36 or 54 tooth. I've listened to the sounds on youtube, but hard to judge if that's going to be annoying, if it's louder when freewheeling or if it's going to add significant drag. Looks like they coast down faster than the 18. Thoughts?


It isn't. Do what you want to do but if that's the reason it's a complete waste of time and money,


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## November Dave (Dec 7, 2011)

Here's my take, for what it's worth. For CX and mountain biking, I like the higher points of engagement. In those types of riding, you're likely to have to ratchet your cranks to get through an obstacle (rock garden, for example), and you're likely to have to accelerate quickly from low speed. Both of these things are assisted with more points of engagement. Nothing in life is free, though.

Increased points of engagement cause more friction, with the pawls being forced to spring 2x or 3x more frequently. More points of engagement also means shallower engagement - just look at the drive rings to see this, it's obvious. Most of the time, on a road bike, you start pedaling after going through a corner or starting to lose momentum after a downhill, times when the bike is already going fast. 

At some point I did some calculation to figure the whole thing out based on that use case and concluded that in a standard crit, the extra engagement would have a top end benefit of something like 50' in the course of the race - assuming you picked the right gear when you started pedaling (sort of easy to do after the first couple laps of a crit, otherwise not as easy). I couldn't calculate losses from increased friction, which must be around the same. 

I can't see how drivetrain wear would be affected at all, apart from the extra wear going on inside the hub with extra points of engagement.

One of the things that really stood out to me when we were researching whether we wanted to start offering I9 hubs as an option is that the _decreased_ points of engagement on their road-oriented hubs. Clearly they put some thought into it, and of course I liked that they came to the same conclusion that we did, for the same reasons.


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## cxwrench (Nov 9, 2004)

Srode said:


> I'm annoyed a bit by the slow engagement on the stock 240 hub, even on a road bike going from coasting to hard pedaling the clunk of the 18 tooth just seems like it's *unnecessarily hard on the entire drive train* so thinking about going to 36 or 54 tooth. I've listened to the sounds on youtube, but hard to judge if that's going to be annoying, if it's louder when freewheeling or if it's going to *add significant drag. Looks like they coast down faster than the 18. * Thoughts?


Seriously?


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## MMsRepBike (Apr 1, 2014)

Road is supposed to have lower engagement, as Dave points out. However I can't handle the 18t personally, I hate the sound of it. It sounds to me like I'm moving slowly or slowing down quickly, I just can't enjoy the sound at all, no matter how muffled I get it.

Personally, for road, I prefer around 7.5 degrees of engagement. An 18t is 20 degrees, a 36t is 10 degrees and a 54t is only 6.66 degrees. So for me, 20 degrees is out of the question, that's way too much dead space for my tastes, over twice too much. The 36t is what I use personally in my DT road hubs. The 36t sounds fine to me and the 54t is too much for me. 

I have a hub with 7.5 degrees and I love it. Love the sound and the hub, fits me really well. For comparison's sake the "angry bees" sound of the Chris King hub is 8 degrees, which is pretty much bang on what I prefer. I do not like really loud hubs at all though, so quieter 7.5-8 degrees is what I go for. 10 degrees is about my limit.

TLDR: If 18t sounds/is too slow for you, switch to 36t. 54t is faster than even the angry bees and should probably left to MTB/Cross.

Oh, and I don't care about increased drag or wear or whatever it is, I doubt it makes that much of a difference at all for someone like me.


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## Srode (Aug 19, 2012)

Thanks everyone, Guess I won't worry about the drive train wear reason - it just seemed to me listening to the bang every time I go from freewheeling to full on hammering it had to be accelerating wear on the chain, cogs and carrier. 

I probably wouldn't care/notice as much if it was quieter - maybe relubing it would quiet it down - there's only a couple thousand miles on them now though so seems a bit early to need to lube them. I've had a number of different wheels and these have have the biggest engagement 'clunk' of any of them so far, so maybe I'll do the 36 tooth for the aesthetics.


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## MMsRepBike (Apr 1, 2014)

Srode said:


> Thanks everyone, Guess I won't worry about the drive train wear reason - it just seemed to me listening to the bang every time I go from freewheeling to full on hammering it had to be accelerating wear on the chain, cogs and carrier.
> 
> I probably wouldn't care/notice as much if it was quieter - maybe relubing it would quiet it down - there's only a couple thousand miles on them now though so seems a bit early to need to lube them. I've had a number of different wheels and these have have the biggest engagement 'clunk' of any of them so far, so maybe I'll do the 36 tooth for the aesthetics.


You can get the same bang with a 36t, just not quite as easy. And it's you doing it, it's not the freehub, it's your pedaling style and lack of smoothness. I try to avoid doing it.

Yes, if you open it up and clean out all of the grease and put in new DT grease (use the DT red/pink grease) on the rings and springs it will quiet down. It'll probably only be quiet for a few days though before returning to previous sound. Unless you put too much grease than it might stay quiet longer. I would do it now. I do it every 2000 miles or so. It doesn't need it that often but why not? It's as easy as it gets, zero tools. (You can just grab the cassette and pull it and the freehub right off with your hands)

I think you'd probably like the 36t, I do. I can't stand the 18t.


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## TJay74 (Sep 9, 2012)

Any hub I have the is DT based or is a DT Swiss hub has the 36t star ratchet in it. I don't like the free wheel take up when pedaling, I do plenty of MTB racing/riding and CX racing/riding that I can appreciate the quicker free wheel take up on the 36t star ratchet.

As said get the DT Swiss star ratchet grease (it isn't super cheap but it is what DT Swiss recommends) and use it. No matter though, it will wear down some and the ratchet noise will come back. It doesn't bother me, but I know it does to some people.

Unless you can get a discount expect to pay around $105 for the 36t DT Swiss ratchets, you will be getting the back cut and hollow 36t star ratchet and 2 new springs.


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## davidka (Dec 12, 2001)

November Dave said:


> Increased points of engagement cause more friction, with the pawls being forced to spring 2x or 3x more frequently. More points of engagement also means shallower engagement - just look at the drive rings to see this, it's obvious.


The different tooth counts don't offer any more or less engagement, they only change the pitch of the engagement teeth. The interval and throw of the engagement / disengagement are what changes to allow for different rotational throws between engagement intervals. Technically, since the overall area of the ratchet faces are is the same, coasting friction should be reduced by the smaller cycling throw of the system.


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## November Dave (Dec 7, 2011)

I disagree


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## TJay74 (Sep 9, 2012)

Actually he is correct Dave, not sure if you have even seen the DT Swiss hub system but it doesn't use a pawl system like other hubs use. The outside of the star ratchet has splines, the face has ramps unlike hubs that use pawls on the hub and ramps in the hub shell.

Resistance is nor more or less going from 18T to 36T.


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## November Dave (Dec 7, 2011)

My statement was more relevant to spring-and-pawl type hubs (having said "the _pawls_ being forced to_ spring_..."). We don't sell DT hubs, although we have and I'm familiar with their drive mechanism. But my statement is also true of CK hubs, which use a ring drive mechanism. CK's site copy says their ISO (mountain-oriented) hubs have 72 POE for "near instant engagement" while their R45 (road-oriented) hubs have 45 POE for "virtually drag free engagement." And the drive rings of pawl-and-spring type hubs absolutely do have shallower engagement, which as I said all you have to do it look to see. So if I'm incorrect specifically in regard to DT, so be it, but for others more POE equals more drag and shallower engagement. It may be theoretically possible to increase POE in a spring-and-pawl hub by changing drive ring pitch, but no spring-and-pawl hub of the many of which I am aware does it that way.


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## Srode (Aug 19, 2012)

Thanks everyone, I did the switch to 36 and it's much much nicer. This is what they should come out with stock IMHO.


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