New Shimano 12-36 Cassette

[thook]

Not sure how well it will index? By that, do you mean how well it will shift in general? I guess what I'm getting at is that none of my bikes for the exception of one maybe two mtn bikes are/will be index shifted. They're otherwise all friction. If what you mean is just how well it will shift regardless of method/design, I've taken that into consideration. I figure with the spacing of the examples I've given, the second freewheel.....the seven spd....shouldn't be much of a problem. The first may be, but I've read somewhere about using a freewheel cog on a freehub cogset with a bit of modification to make it work. I don't remember where it was, but I figure once I get all my supplies together and actually start the building process I'll work out any kinks at that time. And, I'm figuring if I can use a freewheel cog on a cassette, the actual design of the cassette cogs (the ramping) will help with the wider gaps. As far as a rear mech, I just recently won an auction on a Huret Duopar in great shape for less than $25 shipping included. So, that does put index shifting out the picture, really.

BTW, golly......thanks for taking your time to do some research. You certainly didn't have to. Quite helpful.

[DoctorRad]

Friction shifting should be fine, although the shift from 28 to 38 and vice versa may be a little 'agricultural'.

Using a freewheel cog on a cassette is likely to be a no-go, as the size of the 'hole in the middle' of freewheel cogs is larger than that of cassettes. In my experience, however, I've run SunTour XC Pro Screw-On hubs on very rough terrain without problems; that is to say I've only had problems with axles breaking on freewheel hubs where the axle quality has been low-to-middle end. This was largely unloaded riding, however, and YMMV carrying luggage.

No problem with the research, it's a topic I have an interest in. In terms of durability I feel that components have made little progress - and have largely even gone backwards - in the last 20 years. The likes of Jeff Jones of Spaceframe fame are making 2x6 set-ups (see bottom of page) to reduce wheel dish by putting 6 cogs from a 9 speed block on a 'singlespeed' hub. My preference would be for a 6-speed 'Ultra' spaced block - i.e. taking up the same width as a standard 5-speed - on a respaced SunTour XC Pro Screw-on rear hub, to give a significantly smaller top cog than 17 teeth. I can understand those who would not wish to go with obsolete / NOS technology, but $160 for a 17-34 cassette which then needs a Chris King hub is somewhat less economic. The Screw-On XC Pro solution provides for sealed bearing hubs which are field serviceable with a needle grease gun.

[jimfab]

Now that the Shimano 12/ 36 has ben out for some time now what is everybody's thoughts? I have had one and loved it.... except the weight. over 400g is a bunch. I have ben looking into ways to beat this weight without dropping all the cash for the XX-9 or the XTR. I wanted to keep the 34T but reading through this thread found where it will not work. My other thought was to take my old dura ace 12/23 apart adding the bigger gears from my SG 12/36/ I was also thinking about cutting down some gears from the HG / 36t and drilling / tapping the spider from an old xt kinda making a xt-36t. Or just drilling a bunch of holes in my hg-36.


So... what have all you inventive folks out there come up with?

Cherio-JF

[AZTtripper]

I am happy with the gear ratio but made the mistake of putting it on a king hub and now I am stuck with it for a while. Good thing it seems pretty beefy. Take the one cog off of the boat anchor and run it behind a standard 32 cassette. I would skip the 34 if buying new the boat anchor makes that jump I am happy with the change I feel.

[DesertDog]

Now that the Shimano 12/ 36 has ben out for some time now what is everybody's thoughts?

I haven't even paid attention to the core bike tech the last few years.  Still running 11-32 XTs on both my bikes.  Didn't even know there was a 36t out there.

Did run an 11-34 for a few initial rides when I got my 06 Stumpy.  Just those two extra teeth made quite a difference and allowed me to climb some stuff in 2-1, otherwise I would have had to downshift to 1-3, maybe even 1-2. 

Gotta believe you could almost climb anything with 36t.  However, do you even move fast enough to keep from having to do something of a track stand to keep your balance when climbing in true granny 1-1?

[AZTtripper]

Gotta believe you could almost climb anything with 36t.  However, do you even move fast enough to keep from having to do something of a track stand to keep your balance when climbing in true granny 1-1?

What wheel size are you running. I doubt I would want/need the 36 if I still had 26" wheels. Though I have heard of people running 20 rings with a 34 on 26" bikes.

There is definitely some low speed balance involved but you are still moving so it's not a track stand. With a 20x36 granny I do feel like I can spin my way up more stuff but it is pretty slow and there are times when it's too slow. Like at a step up in a climb you can't pick up enough speed to get over some things. If it's a long non tech climb it works great and I can always drop a couple of cogs in the back to get the speed up when I need it and then back to granny to spin and rest up for the next one.

Recently went to a 30 as my middle/big ring. I really like the way 30x36 feels but I need to remember to drop down a cog or two at times. Basically just had to readjust which gear to use for certain things.

I am a spinner not a masher so it works good for me. Especially with the extra weight of a bikepacking kit.  

[jimfab]

I had the same thoughts as Mr. Az Tripper. The 36 gets my big but and heavy loads up some amazing hills. The track stand thing is about right, it takes some getting used to. However i noticed my low speed tech skills jumped 2 fold after developing that low speed balance. I went back to a normal 11/34 the other day and really missed my 36... more so, my 32 the ( second cog on 12/36 ) that i use for most climbs. the 30 ( second cog on the 11/34) felt weird.

The 30T middle chainring on a 29er for me is the ultimate. I ran a 20-30-40 triple with a 12/36 a while back and LOVED it. The only problem was the weight from the 20 year old sugundo 94mm BDC square taper cranks and the unreliable shifting on non ramped salsa rings. ( they worked great until they got dirty ). Other than that... I LOVED it. Perfect (for me) for general riding and bikepacking.

Anybody know if action tech makes a 20T that fits the newer XT hollowtech 2 9 sped tripple's. I think it is 5 bolt. For some reason i thought it would not work due to the wide BDC and bolt clearance issues? Hope i am wrong about that.

Cherio- JF

[AZTtripper]

Yep being able to nearly track stand has definitely improved my overall riding skills. And the 36 tooth helps to keep or restart me moving on those techy climbs. Also went back to King hubs after running XT for awhile having the fast engagement really helps as well.

[DoctorRad]

@jimfab - weight of older crank arms... are modern ones really so much lighter? I'll have to weigh my SunTour MicroDrive 20-32-42 set to check!

Anyone remember Mountain Tamers? Used a freewheel cog as a chainring and would go as low as 17 teeth! Still available: http://abundantadventures.com/mt_triple.html

Also on that site, 20t inner rings for 58bcd 5-arm and 64bcd 4-arm: http://abundantadventures.com/quads.html#CHAINRINGS

But don't you find that there's such a thing as too-low a gear? Where you either can't start out riding once you've stopped, or walking / pushing would be quicker. I guess perhaps a loaded bike = more traction = easier to start off (sometimes)...

[AZTtripper]

But don't you find that there's such a thing as too-low a gear? Where you either can't start out riding once you've stopped, or walking / pushing would be quicker. I guess perhaps a loaded bike = more traction = easier to start off (sometimes)...

Unless it's really steep I'll have to shift down a few cogs as soon as I am rolling but I can start out in 20x36. I can also ride behind someone who's walking, it even helps me to practice going slow keeping the RPM's down. Otherwise it's easy to hyperventilate from over revving. Loaded or unloaded works either way. Sure walking would be quicker but I get enough walking on the AZT so it's nice to have a super low gear to keep riding as much as possible.

Interesting links if I could go back and start over with the buying process I could see going with the 17x34 setup. 

[jimfab]

Dotor Rad. Wow that stuff is cool! I did quite a bit of searching a while back looking for just that but was unable to find it, Very cool.

On the weight's. The arms themselves are not that different, but the package as a whole ( BB, bolts ect.) is a noticeable difference in your hand (compared to a modern XT triple). I don't have a scale so i cant say for sure what the difference really is. The weight was a small complaint, The poor shifting when dirty was the nail in the coffin. It would work if you were very very careful about it, but you dont always have that option. It was a fun experiment, and i am not sure why the big companies haven't taken on the 20-30-40 to 12/36 yet. I know the new double 10 speed is supposed to be the answer but it still not in the range of a 20/36 that 90% of average riders would enjoy.

On another note.. I have ben riding a 11/34 the past week or so after about a year on a 12/36. It is strange. i continue to find myself in a harder gear that i would like ( lower cadence than i am used to ) and really miss the 32/36 gear. But.... I have noticed it has forced me to keep a move on. I find myself having to go faster in some areas than i normally would. How this will relate to energy used at the end of a long long day i don't know yet. I think having a 20 up front could be a good thing.

Cherio-JF

[DoctorRad]

I did some research: the claimed weight of a top-end 1992 SunTour XC Pro crankset and bottom bracket was around 1kg = 2.2 pounds. Yes, modern triple crank / bracket sets can take maybe 200g / nearly half a pound off that weight, but heck, they're costly, and you don't get grease injection on the BB bearings 

Bad front shifting? Two words: thumbshifters.

Check with the makers, but I think the cogs for the Mountain Tamer are SunTour - how'd you guess - freewheel cogs of type 'A'. Keep a look out on eBay or ask at your old-time LBS.

I have a similar thing from the early 90s called a Limbo Spider, will be trying it on an old set of XT cranks sometime soon if I can get a front mech low enough without hitting the chainstay. Imagine 17-26-38 up front with something like 11-30 in the back: closer ratios, lighter cassette, and a very similar bottom gear to 20/36. Looooong BB axle needed, mind you...

The coolest chainrings I have, though, are Highpath Engineering Oval Eggrings:

http://www.highpath.net/highpath/cycles/ovals01.html

Biopace done right, expensive, but they DO work. Sheldon Brown said they might hurt your knees though...

Dr. Matt, Retrogrouch.

[jimfab]

Hey

My biggest problems with the shifting was chain suck at the slightest sign of dirt or when trying to shift under somewhat of a load ( a load that any modern triple could handle). I tried everything i could think of to make it work short of machining in shift ramps. I tried 4 kinds of oil, polishing and de burring the rings, KMC , scram, And shimano chains. Blueprinting the cranks, and 3 different front mech's at all different heights. Nothing solved the problem. Great concept, just needs some refinement. Could have gone with the Surly Mr. Whirly to get to the same point but with so many hard to find parts and high cost defeated my hypothesis that you could make a reliable, affordable (<125$), 20/30/40 triple with easy to find and replace parts that any bike store would have. It was a fun experiment. I am convinced that it is the ultimate for 29ers, just needs refinement.

For the front mech hitting the CS. I was darn close.... 2-3 mm from my CS on the front mech cage on the 40T. I tried an older LX, an x7 and an x9. all about the same. This was on a frame i built myself with a smaller profile in the CS with this idea in mind. I am sure there are shorter cages out there that may work better?

Best O Luck- JF

[DoctorRad]

9-speed chain on 8-speed front rings? That would cause chainsuck: 9-speed rings have thinner teeth, 10-speed thinner again.