# 10T sprocket to make a 10x34 cassette



## Ausable (Jan 7, 2006)

It will solve the gearing problems associated with running a 26/40 with a standard 9sp cassette.

On some races it's easy to spin out the 11x40, especially if you are on a peloton on long straightaways - so replacing the 11T with a 10T will be very beneficial; 

The 40x10 will be used as an "overdrive" or "recovery" gear so the jump between the 10T and 12T will not be a problem in my opinion.

What do you think? And, most important, is there any 10T replacement cog commercially available?
Thanks


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## dcb (Sep 19, 2005)

It's not available yet, but Hope is coming out with a 9-34 ten speed cassette. http://www.hopetech.com/page.aspx?itemID=SPG194
I think you would need to have a Hope hub to use it though.


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## dirthead451 (Jun 5, 2009)

Build a Shimano Capreo laced wheel and special cassette.

http://www.sheldonbrown.com/capreo/index.html


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## Guest (Oct 22, 2010)

dirthead451 said:


> Build a Shimano Capreo laced wheel and special cassette.
> 
> http://www.sheldonbrown.com/capreo/index.html


For weight weenies that enjoy a 400g rear hub without a disc mount. 

I think we could really benefit from a Capreo-like modification to the existing freehub. It wouldn't need to encompass so many cogs or even allow smaller than 10T, but getting the smallest cog down to 10T would help the range of 10 speed systems. 9 would be better but may require two cogs below 11T. If the change were small enough it may retrofit on existing hubs and allow cassettes to ship with both mounting options.


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## dirthead451 (Jun 5, 2009)

I bet cannabalising the axle and hub body and grafting it onto another shimano hub would work.


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## fernandoj (Mar 19, 2008)

Even 9T is possible:

http://www.bikeradar.com/news/article/eurobike-2010-hopes-new-cassette-with-integrated-freehub-27582


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## Ausable (Jan 7, 2006)

Oh, that's the reason 10T arent easily available - I should have imagined that :madmax:

_Quote: The Capreo Freehub has a special body designed to accommodate then smaller diameter of the 9 and 10 tooth sprockets. Otherwise, it appears pretty much similar to other Shimano Freehubs._

But then, is there a way to modify the 11T lockring? I think Ritchey proposed a similar solution when they launched the first 2x9 conversion back in the day - I need to dig that pile of old magazines to find out


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## culturesponge (Aug 15, 2007)

not much space left to go any smaller than 11t with a shimano/sram freehub

...my work around for a faster spin-out was to purchase 42/26 chainrings


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## DeeEight (Jan 13, 2004)

The limitation on shimano hyperglide freehub sizing for 11T cogs is because of shimano's reliance on proper sized hub bearings, inside the end of the freehub body supporting the axle.


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## j_gantzer (Oct 20, 2005)

Someone back in the day made a 10t. It combined the lockring and cog and threaded on.


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## DeeEight (Jan 13, 2004)

TNT and Ultimate Machine had the thread-in 10T & 11T cogs which replaced the lockrings, but they were meant for converting 7 speed cassettes into 8 speeds. I was a dealer for both brands and still have an NOS TNT Ti 11T thread-in cog in my collection of goodies.


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## TigWorld (Feb 8, 2010)

DeeEight said:


> TNT and Ultimate Machine had the thread-in 10T & 11T cogs..


I have swapped out a number of shimano 7spd freehubs for 8/9 speed freehubs over the years, so there is no reason you couldn't go back to the 7 speed freehub, run most of a 9 speed cluster and then use the thread in 10t. Some machining to the 10t may be required to provide the bit of extra room the 8speeds from a 9 spd cluster will require (compared to the 7speed with its wider spacing).

DeeEight - take some pictures of your "NOS TNT Ti 11T" and give us vernier measurements of the width from cluster interface to where the teeth start and also the thread depth to the screw in part and it should be a pretty easy matter to see if a 7spd freehub body + 8spds from a 9 speed cluster + screw on 10t would be a go-er.


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## Ausable (Jan 7, 2006)

So if a screw-in, 10T cog is bolted in place of the lockring, can it be machined with an right-side offset so it will replace the 11T sprocket position? 
I think this will be requied not to screw up the current spacing of the 9sp cassette, thus allowing the use of the standard 9sp shifters-
It is very promising ground for some experimental prototyping (mattias did you get that  )


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## TigWorld (Feb 8, 2010)

Ausable said:


> ...can it be machined with an right-side offset so it will replace the 11T sprocket position?...


That's the question. We need some measurements from anyone that has one of these.


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## Ausable (Jan 7, 2006)

Ok it seems that also the big guys are thinking about that:

http://www.pinkbike.com/news/9-36-cassette-prototype-2011.html


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## DeeEight (Jan 13, 2004)

Gee... four months after Hope revealed their 9-36 10 speed cassettes at Eurobike... and which are going into production already and will be available for existing Hope Pro 2/3 rear hub owners. They've already announced the retail price will be 150 pounds sterling when they go on sale this spring.


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## culturesponge (Aug 15, 2007)

Ausable said:


> Ok it seems that also the big guys are thinking about that:
> 
> https://www.pinkbike.com/news/9-36-cassette-prototype-2011.html


nice find :thumbsup:


pic copyright pinkbike



https://www.pinkbike.com/news/9-36-cassette-prototype-2011.html said:


> The spread above uses a 36 tooth large cog on the low end and a tiny 9 tooth cog for the highest gear. This is where the ingenuity comes in, because as anyone who's had their cassette off may well know, the smallest cog that would previously fit would be an 11 tooth version due to the freehub's diameter. This is where DT Swiss steps in with a custom made freehub body that accepts a smaller cog. As of right now the actual design of the freehub remains unknown, but to get an idea of what it may look like, have a gander at Shimano's commuter intended Capreo group that also uses a 9 tooth small cog. I'm betting that the DT Swiss freehub is also stepped and that the bottom few cogs are a single unit. The very special freehub body has been manufactured by DT Swiss solely for the R & D that Specialized is doing for this project, you won't see it anywhere else anytime soon.


brilliant!

wasn't so impressed with that putrid green cnc one piece alloy Hope cassette - this looks like a better alternative to extend the range of a cassette you'd probably own already + also could re-use on another when it wear out

hope it makes it to the marketplace + at a reasonable price


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## Guest (Jan 8, 2011)

While I think the expanded range is just what 10s needs and it's great to see someone other than Hope looking into it, that Specialized cassette is a hack. It's just a proof of concept with terrible gear jumps in the middle. It would be great to see this brought to market but we'd need real cassettes with proper gear spacing.

It would be cool to see a new hub standard that could take the new, smaller cogs but still use existing cassettes with an adapter. I'd buy it.


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## rockyuphill (Nov 28, 2004)

The Capreo rear hub with the stepped freehub is apparently currently available as is the 9-26T 9 speed cassette. the Capreo hub is 135mm wide.

It would be interesting to see if the Capreo freehub could be fit into an XT 755 hub body.

The Capreo cassette is 9-10-11-13-15-17-20-23-26T with the four largest cogs pinned together so you might be able to take a standard HG-70 MTB 9 speed cassette and custom build the bottom 4 cog stack.



Sheldon Brown said:


> The Capreo Cassette
> 
> The 5 largest sprockets of the Capreo cassette are standard Shimano cassette sprockets: 15, 17, 20, 23 and 26 teeth. They are individual sprockets, not linked by a spider, but the 4 largest (17-26) are held together by rivets. There is, however nothing preventing an adventurous user from grinding off the heads of the rivets and customizing the bottom end of the gearing.
> 
> The 4 smallest sprockets, 9, 10, 11 and 13 teeth are all special.


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## Mattias_Hellöre (Oct 2, 2005)

IMHO: current offererings with 11T as lowest gear is enough I think.

The 11t is suitable to almost all modern cassette bodies.

Taking it down to 10 or even 9T when mated to a bigring at front, you can think about the power losses, it will be quite signficant, not so much more than 11T though but sometimes smaller rear cog is not a better idea.

My solution to this problem is common and boring: bigger chainring up front, bigger cog/ring is better for the chain and cogs itself, if not for the power loss perspective.

When companies does develop this such cassette with a 9-36T, it´s for the demand of the public, most people don´t know or don´t care for the power loss perspective.


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## Guest (Jan 10, 2011)

Mattias_HellÃ¶re said:


> When companies does develop this such cassette with a 9-36T, it´s for the demand of the public, most people don´t know or don´t care for the power loss perspective.


There's one thing I do know, there are no power losses in a 9T when it is not used. When it is, some power loss "not much more than 11T" is better than not having it. I may not know what those losses are but it seems you don't either and it doesn't disqualify 9T as an option for Shimano.

The purpose of 9T or 10T is to give a bigger range on the cassette. Without it you would need to go a lot bigger than 36T which would cause problems with rear mechs, add chain length, degrade shifting performance, and add weight. Changing out chainrings does nothing to to improve cassette range. The top 9T or 10T cog is for occasional use so its efficiency is not a primary consideration. I agree that manufacturers need to consider going beyond 36T, but realistically they won't be doing 44T anytime soon IMO.

The fastest way to 400% is a 9-36 or 10-40, not 11-44 which will likely require a new rear mech. 400% is reasonable and desirable with 10 speed, it offers a usable 16.6% average spacing and increases the usefulness of 1x front drivetrains. Of course, we could get by with 11-40 just as we make do with 11-36 now, it would be better than nothing, but if you're going to re-engineer something, I'd rather accommodate smaller cogs than bigger ones. Both options would be nice.


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## rockyuphill (Nov 28, 2004)

That sort of information is available, and they do show that larger diameter sprockets provide more efficient transfer of power.

http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

_It was found that larger sprockets provide more efficient transfer of power while smaller sprockets proved to be less efficient. Simple, frictional loss models were developed that gave sprocket-size loss variations that agreed with those variations measured experimentally. Typically, a 2-5% loss difference was measured between the 52-11 and the 52-21 sprocket combinations depending on the drive operating conditions._









and later http://www.ihpva.org/HParchive/PDF/hp52-2001.pdf


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## Guest (Jan 10, 2011)

The question is what the effect is of 9 or 10T compared to 11T is on a smaller chainring typical of MTB use. Using the cruder of the equations in that article so as to not spend too much time, I came up with:

28T chainring: 9T: 16% 10T: 7.2%
32T chainring: 9T: 16.5% 10T: 7.4%

Of course, that's just a mathematical WAG that doesn't consider all sources of power loss and it may not satisfy some of the assumption made in the article. Use at your own risk.

So it's about 7% or 16% more frictional loss due to the smaller radius of the cog. Assuming 92% drivetrain efficiency for 11T, it's about an additional 1/2% or 5/4% with the smaller cogs. I used smaller chainrings because you would typically consider that with smaller cogs. The smaller the front ring, the smaller the difference because efficiency is worse anyway. Clearly larger rings and larger cogs are more efficient and we've always known that. They also have downsides.

It's not clear why 2x and 3x users would bother with this and it's not clear why racers would be using 1x. It's also not clear why non-racers would care about 1/2 - 1% additional loss the 2% of the time that they are using their tallest gear. Hammerschmidt users are worse off.


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## whybotherme (Sep 12, 2008)

seems to me that the idea of 1x is sound:

less chance of issues with FD shift and chain drop
less weight/complexity

i ran 1x9 for a while (riding and racing) and found that for racing it didn't provide me enough of a range. i am switching from 3x to 2x this year. hoping that 2x10 gives me all i need for races.

now the 2x users shouldn't care about 9t and 10t so much IMO. would be much more efficient to tune in exactly the right ratio on the cranks.

IMO a new rear hub standard is not a move in the right direction unless it gives some other advantage other than just "9t or 10t small cog". added cost to manufacturers and distributors and shops doesn't make sense (tooling, stocking, etc).

i for one can FEEL the difference when riding and i get down into those small cogs. (i get a clunky feedback, lacking in any other way to describe it, and i know that is part of the inefficiency of being in those gears). 

i am however part of a very small group: "MTB racers". 

the majority of MTB riders might want that extra gear spread in the back so that they can reduce complexity and run 1x setups.

i am not a fan of the idea of a 9t or 10t option.


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## Mattias_Hellöre (Oct 2, 2005)

It´s only my opinion and my stomach feeling was just right, I don´t use the 11-14T sprockets in the trails anyway.

Stomping with big power on these tiny sprockets is no good for the drivetrain either.

But there´s benefit with 10 or 11 speed bigrange cassettes, of course but efficient, don´t think so.

Two diametrically different things.


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## rockyuphill (Nov 28, 2004)

Shimano's rationale for the Capreo grouppo as a way to provide reasonable gear ranges for small wheel (20") folding commuter bikes makes sense. Other uses... :skep:


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## Guest (Jan 11, 2011)

Mattias_HellÃ¶re said:


> But there´s benefit with 10 or 11 speed bigrange cassettes, of course but efficient, don´t think so.


Who has made the argument that we need 9T because it's efficient? We know it's your opinion that efficiency is a killer but do you have any further insight other than gut feel? It seems to me that the ~1% loss, if true, is of little consequence especially when it's seldom used. You need to make the case that 9T is somehow bad for the drivetrain.

If you don't use your 11-14 offroad then you carry 3 more high speed gears than you need. That kind of wasteful gearing doesn't interest me but it might tickle you to build in some extra, useless capability. Clearly, if you go from 11 to 9 on the top end you'd need to reduce your chainring sizes to get value out of it. I would seem you could do that now.



rockyuphill said:


> Shimano's rationale for the Capreo grouppo as a way to provide reasonable gear ranges for small wheel (20") folding commuter bikes makes sense. Other uses...


Yes, without the need for huge chainrings, but so what? Some argue that 10 speed itself is a waste and that increasing range is needed to fix that. You gotta either go bigger or smaller (or both) or give up on wider range. For 2x and 3x bikes, it seems neither wider range nor 10s itself is really useful.

Fact is, Capreo is a functional proof of concept that disproves Mattias's assertion that efficiency makes it uninteresting. The problem with it is that it's 9s only, lacks cassette choices with wide range, and locks you into the bottom 4 cogs if you want to make your own. I'd find the Capreo hub interesting if there were viable 10s MTB cassettes for it.


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## Mattias_Hellöre (Oct 2, 2005)

craigsj: I buy off the shelf Shimano stuff and is satisfied with them as far.
I have the option to use all 10 speeds at rear OR not, I don´t have to use them all.

My gut feeling is often correct as my calculations, that´s called experience, I had survived the time Suntour Microdrive was there 
By the way, introduced stuff is no proof that WAS right, why aren´t most of all old tech still there?
How often has SRAM and Shimano introduced stuff then letting that go away next time?

I often see things resurrect then vanish, this time not so much different only more advanced technologies.

by the way, wrong subforum for drivetrain efficency discussions, it´s weightweenies here


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## Guest (Jan 11, 2011)

I think that's fine, but it doesn't qualify you. Buy off-the-shelf gears that you don't need if that's what you want, but using chainrings that are so large that you can't use the smaller cogs doesn't mean that smaller cogs are useless for everyone.

I would love to see your calculations that confirm your gut feel that 9T is too inefficient to be useful, and BTW I "survived" microdrive as well. There is still active demand for 20T chainrings and BCDs smaller than the current 4 bolt stuff.



Mattias_HellÃ¶re said:


> by the way, wrong subforum for drivetrain efficency discussions, it´s weightweenies here


Then why did you bring it up?


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## Mattias_Hellöre (Oct 2, 2005)

craigsj: your choice to use a so small rear cog and end up with quicker wearing drivetrain.

My experience and stomach feel does just say I was correct as per your calculations.

People does use ceramic bearings with that small performance hike like downsizing rear cogs.

For me 9-32T 10s rear cog is a not good idea just because of incompatibility with current freehub bodies, quicker wearing drivetrain , less efficient than 11-32.

I don´t care about the gearing range it MIGHT give, adjust your speed with the cadence, it worked fine until now.


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## Guest (Jan 11, 2011)

Mattias_Hellöre said:


> craigsj: your choice to use a so small rear cog and end up with quicker wearing drivetrain.
> 
> My experience and stomach feel does just say I was correct as per your calculations.
> 
> People does use ceramic bearings with that small performance hike like downsizing rear cogs.


Agree with all that. I don't know if my numbers were close, but they seem intuitively right and came from a formula from rocky's article. My interpretation is that the difference is nominal, but significant compared to ceramic bearings and alternative spockets, as you say. Perhaps we actually agree here, hard to say.



Mattias_Hellöre said:


> For me 9-32T 10s rear cog is a not good idea just because of incompatibility with current freehub bodies, quicker wearing drivetrain , less efficient than 11-32.


I agree that 9-32 is not a good idea since you can get that range with 11-39 and still be compatible with existing components. I have advocated for 11-39's or 11-40's before and wish that was a 10 speed option from the start. The value in 10T or 9T is in going beyond about 350% since it's not clear to me when a large cog gets too big for existing drivetrains. I believe Hope, in doing a 9-34, is trying to keep the magic 25T spread of an 11-36. I think that's uninteresting. I believe there's only value in going below 11T when you are trying to expand the usefulness of a 1x drivetrain and you've exhausted the big end of the cogs already.

Of course, as you say, this is weight weenies and that means weight is a prime consideration, but I'd rather it work with my existing stuff too. I'd take 9T if I could get it, but only if it actually got me something worthwhile. There are clearly downsides.


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## AM631 (Dec 29, 2020)

dcb said:


> It's not available yet, but Hope is coming out with a 9-34 ten speed cassette. http://www.hopetech.com/page.aspx?itemID=SPG194
> I think you would need to have a Hope hub to use it though.


could u just use a feehub that will be compatible?


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## dcb (Sep 19, 2005)

AM631 said:


> could u just use a feehub that will be compatible?


In October of 2021, yes you could. In October of 2010, the options were more limited.


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