I wanted a new stem to go with a new fork I just ordered.

Picked up this New Deda Einstein Stem on Eb** for $55.00 shipped.

I think they were discontinued however places are still selling them for really high prices.

I think it looks pretty nice. Anybody have any experience with one of these..hope I didn't buy a piece of cr**.

Deda specs the bolt torque to be 71in-lb for all the bolts. Can this be right? I know they probably tested this however if I remember my Specialized 4 bolt is something like 35-42 in-lb. I just don’t want to strip out the Ti bolts.

Thanks

I'd be more concerned with how much torque to put on the steer tube and handlebar if they are carbon. In many cases the torque specs for the stem is too much for the steer tube.

Al

I'd be more concerned with how much torque to put on the steer tube and handlebar if they are carbon. In many cases the torque specs for the stem is too much for the steer tube.

Al


I agree!!

My first experience with a carbon/carbon steerer fork resulted in my, ahem....

Using my gorilla like strength while cracking the steerer.... I now am the proud owner of a torque wrench. AND I follow the specs on the fork not the stem....

I agree!!

My first experience with a carbon/carbon steerer fork resulted in my, ahem....

Using my gorilla like strength while cracking the steerer.... I now am the proud owner of a torque wrench. AND I follow the specs on the fork not the stem....

Torque is a unit of rotational force, as in tightening a screw. There are no screws on a fork, so fork specs can't possibly show torque values. Also, the fork manufacturers have no way of knowing what stem the customer is going to use. Fork manufacturers can only recommend to "follow the stem manufacturer's torque values" and hope that the folks who wrote the stem installation instructions did their homework.

Torque is a unit of rotational force, as in tightening a screw. There are no screws on a fork, so fork specs can't possibly show torque values. Also, the fork manufacturers have no way of knowing what stem the customer is going to use. Fork manufacturers can only recommend to "follow the stem manufacturer's torque values" and hope that the folks who wrote the stem installation instructions did their homework.

There is a limit to how much a carbon steer tube can be compressed, and that limit can be expressed as torque on the stem pinch bolt(s). The stem can usually withstand more torque than the top of a carbon steer tube. Those who do not understand this may learn the hard way. Carbon fiber forks can be quite expensive, mine was $850, and the same fork now sells for more than $900.

But depending on the number, size, pitch of bolts, their mechanical advantage, among other things, the same torque value for a bolt between two different makes or models of stems may result in vastly different clamping forces to the bar/steerer tube. As Wim points out, fork/bar makers defer to the stem maker's clamping specs - we have to take a leap of faith that stem makers know how to safely clamp onto delicate steerer tubes/bars without causing damage.

Just tried adjusting my stem height by removing a spacer. I have a Deda Newton stem, and to be safe I went out and bought a pretty nice torque wrench from Sears. When replacing the stem I kept turning, and turning, but no "click." I loosened the stem and tried again. Still no click. Loosened again and lowered the torque setting. It finally clicked so I knew the wrench was working. Reset the value to Deda's specs and started tightening until finally the bolt snapped. The way it sheared off made it impossible to remove (and still use safely) so now I've ordered a replacement.

Reading this thread has me worried about my CF steerer tube, though. Aside from obvious cracks is there any way to tell if it's toast? I've looked it over pretty thoroughly and it looks ok. Hate to have it break while riding!

With all this in mind, is it safe to say manufacturer torque specs aren't necessarily set in stone? I know when my new stem gets here I plan to start out about 1/2 of what Deda recommends.

Just tried adjusting my stem height by removing a spacer. I have a Deda Newton stem, and to be safe I went out and bought a pretty nice torque wrench from Sears. When replacing the stem I kept turning, and turning, but no "click." I loosened the stem and tried again. Still no click. Loosened again and lowered the torque setting. It finally clicked so I knew the wrench was working. Reset the value to Deda's specs and started tightening until finally the bolt snapped. The way it sheared off made it impossible to remove (and still use safely) so now I've ordered a replacement.

Reading this thread has me worried about my CF steerer tube, though. Aside from obvious cracks is there any way to tell if it's toast? I've looked it over pretty thoroughly and it looks ok. Hate to have it break while riding!

With all this in mind, is it safe to say manufacturer torque specs aren't necessarily set in stone? I know when my new stem gets here I plan to start out about 1/2 of what Deda recommends.

My couple of cents:

1. Torque values consider a new (or very clean) and greased stem bolt and thread.

2. Did you approach specified Deda values alternating the screws? If you apply 8 NM to (let's say) the upper bolt and let the lower one loose, chances to hear a crack are very likely.

Regards

Now after reading all this and the other poster breaking a stem bolt I am wondering if Deda's specs are a little on the high side.

Make sure you are using an inch pound torque (in-lbs) wrench not a foot pound (ft-lbs)!!!

I checked last night and on my specialized 4 bolt stem the bar bolts are speced at 40 in-lbs and the stem at 50 in-lbs. Deda specs 71 in-lbs for all bolts.

In all reality that is not that tight and even at 71 in-lbs shouldn't snap any bolts.

Thanks...

The torque wrench I purchased is inch/lbs, although I was concerning myself with newton/meters. According to Deda, all bolts should be at 8 N/m. I did alternate the bolts, so I'm not sure where everything went wrong. When I put the new stem in I will try using some install compound which should enable me to secure everything at lower torque. I have read on other threads these type compounds can help.

Just a thought. You can use some anti-seize on the bolts which I find to be pretty messy or just go with some quality grease or heavy oil to prevent binding.

Another thing to check is make sure the bolts are not binding or bottoming out in the tapped stem holes.

I assume you are using the correct style compression plug and top cap for carbon steer tubes versus the star nut type for alloy steers which prevents the stem from collapsing the carbon steer tube.

Also make sure there are no sharp edges or corners on your new stem at the pinch joint that touch the steer tube. These edges can stress load the tube at these points. If you find any just hit them with some fine sandpaper or a fine file to break the edge.

If you are going to pitch your damaged stem let me know and I'll pay the shipping to send it my way if you don't mind. I'd like to see if I can fix it and use it on my winter bike.

Thanks

I'd be a little suspicious of the torque wrench, the conversion from N/m to In/Lbs, or in reading the torque wrench scale, as unless those bolts were made from butter, I find it hard to believe that they broke with less than 8Nm of torque.

Also, 8Nm (or what ever this particular stem maker specifies) is typically the *Max* torque value. When clamping to CF bars or steerer tubes, I'll go to the lesser of what feels right or the max torque value.

It looks like a Newton stem with a carbon face plate. Some maunufacturers went the other way, c.f stem with an aluminum face plate. I use Newton stems on my old bike, never used a torque wrench, never had a problem. I really don't know what that c.f. face plate does,other than looking nice..

If you like your CF fork stop at 5 or maybe 6 nm. You won't need 8 nm.

But depending on the number, size, pitch of bolts, their mechanical advantage, among other things, the same torque value for a bolt between two different makes or models of stems may result in vastly different clamping forces to the bar/steerer tube. As Wim points out, fork/bar makers defer to the stem maker's clamping specs - we have to take a leap of faith that stem makers know how to safely clamp onto delicate steerer tubes/bars without causing damage.

Well my Colnago Star fork cracked at 8 nm, the stem torque spec. I using a 1/4" drive Park torque wrench and brought the torque up very gradually, alternating from bolt to bolt.
8 nm was too much. I used 6 nm on the replacement fork. Specialized recommends 5 nm, and that's enough.

Got the new stem last night, and in reading the specs Deda recommends tightening everything to 5 N/m first, then continuing to 8 N/m. Well, I used some Syntace friction paste and simply stopped when I got to 5 N/m. Took the bike out today and did a short 22 mile ride involving some serious climbs. No problems. Purposely spent a lot of time out of the saddle cranking away on the climbs, then punched out some sprints in the flats, but not a budge. I think 8 N/m is absurdly high, and a number closer to 5 is more realistic. Thanks for everyone's help.

KKowalsk... the old stem is a Deda Newton 130 mm. (In a way I was lucky: I was looking to go longer anyway, and the new one is 140. Feels GREAT!) Still interested? Just to let you know, I do live in Hawaii!

Get this
http://www.excelsports.com/image200/Ritchey%20Torqkey%204mm%20head%205Nm.jpg
and worry no more.

Ritchey Torque Key (http://tinyurl.com/2o3ogf)

I received my new Einstein today and was installing it with a new fork. When starting to lightly torque the bolts to hold the handlebars the clear coat on the carbon faceplate around bolt holes began to separate as the bolts were tightened. The bars were still very loose and the bolt tension was low. Upon inspection of the faceplate I noticed the same separation of the top clear coat layer on three of the four bolt holes, the side of the plate and the interior clamping surface. I am unsure if this is a common problem or just an issue with my stem.

What a bummer the stem is very nice and beautifully machined.

I emailed Deda this evening and have to wait to see what happens.

I might just chalk it up as a loss and order a Reynolds Ouzo Race stem. Not the sellers fault. Guess that answers my initial question...piece of crap...at least right now.