23skidoo

I'm trying to get a bike boxed up for shipment and a Cinelli 1R stem is proving a major impediment as I just can't get the bar/stem/lever array safely inserted into the box without loosening the bar clamp to rotate the stem 90 degrees or so. I've loosened the clamp bolt and can remove it completely to see what appears to be a small rod inside the stem but can't budge the bars at all. Do I need to remove the plastic logo insert to get at a hidden bolt or am I just missing something really simple here?

Otis

Do not mess with the plastic insert, it has nothing to do with anything. The bars are held by a wedge that's driven forward by the clamp bolt, and it sounds like it is stuck. I would shoot some lube or penetrating fluid in around the bars and up through the clamp-bolt hole. Give the top of the stem a good whack with a rubber mallet, and hope it gives. You might be able to pry the wedge back with the bolt out, but be careful not to scratch things up in there. I do not have much experiance with 1R's, so maybe somebody else will have more to add.

blaise_f

The wedge is known to seize / corrode. It's the main flaw in the 1R design. Your best bet is as noted, remove the bolt and shoot some penetrating solvent in there. There's not a lot of other options you have. You could possibly remove the stem from the steer tube and turn it 90 degrees, but that depends on cable length, &c.

Jeff Wills

I think he's trying to loosen the stem's hold on the handlebars. I'd reinsert the bolt until it stops, then back it off a couple turns. Whack the bolt with a hammer. I bet the wedge and clamp come loose.

23skidoo

I lubed it up with WD40 since I didn't have a can of PB Blaster on hand; now I just have to dig out my rubber mallet....I'll update with results.

cranky old road 

Seems like that's what he's trying to do, but if the object is boxing the bike it seems like he's trying to do the wrong thing. Sounds like he needs to loosen the stem bolt in line with the fork tube, tap it, and rotate the stem so the handlebars will be parallel with the wheel?

No. I guess he's trying to rotate the bars down so the brake levers will not jut out?

miamijim

The handlebar wedge 'wedeges differently than the steerer tube wedge.

The steerer tube wdge move up/down, if it gets stcuk all you do is loosen the bolt a few turns and wack the bolt head with a hammer and you done. The 1R handlebar wedge moves foward ans the bolt is tightened but as the bolt is loosened there nothing to pull the wedge back becasue the bolt/wedge combo is friction fit. If the wdege is stuck loosenen the blot and wacking it with a hamer will only drive the wedge in tighter.

Sometimes with the 1R the wedge will defrom the bar and get stuck in the deformation preventing the bar from rotating. In this instance complete removal of the bolt is neccessary and then try rocking the bar to free the wedge.

1R's have alot of issues, be very carefull or you will break something.

RobbieTunes

Take the bolt out.
Spray some WD-40 up in there.
Rubber mallet, whack the bar from the front towards the back, along the axis of the top of the stem, just a few times.
Then, grip the bar in both hands and rock it backwards and forwards just a bit.
You're trying to massage the wedge back into the cavity.

Whack it a couple more times, rock it a bit.
You can also take a smaller allen wrench, insert it through the bolt hole and try to move the wedge with angular force.
Sooner or later it will free up.

It's been trying not to let you down, and holding on so you don't have a mishap.
Now you have to convince it that it's OK to let go.

ColonelJLloyd 

+1 A poor design all around in my book.

• Expander nut? Inferior to a wedge.
• Aluminum alloy stem bolt? I've snapped one. You don't snap steel.
• Plastic handlebar binding wedge? Why?

Cinelli 1R = FAIL

23skidoo

All the advice has been very helpful, including some that came via email and the side chatter is always a treat. After an overnight marination in some WD40 one whack with the BF rubber mallet popped the wedge loose. When I'm shipping an entire bike I remove the stem and bars completely and zip tie them into the center of the main triangle positioned so the narrowest dimension is presented to the width of the box.

Chombi

I've heard about the quirkyness of the 1R design.........maybe that's why I never "upgraded" to it and kept the trusty model 1A I have on my Peugeot all these years.....

Chombi

RobbieTunes

There's a cost to being a slave to fashion.

RobbieTunes

I've matched up the advice given here to the successful strategy, and claim 2nd place. I believe Otis takes the guru cake.
Otis was my favorite on Andy Griffith.

Gonzo Bob

Aw, you got it before I had a chance to post the 1R drawing I made for the mechanics forum a few years ago. I'll post it anyway

miamijim

Another quirk is that once the wedge takes set into the bar thats it, you can never tweak the adjustment.

miamijim

Chombi

My Titan sem seems to have a siimilar but still different idea on how a stem's bar clamp should be designed:


Might have the same consequences with the bar getting distorted when the clamping blocks are tightened against each other.
Never seen this design on any other stem......maybe it's not that good?

Chombi

mikemowbz

Glad to hear the opinions on the 1R - here's a pic of the one you sold me on my '85 Nishiki, Colonel

I'll be sure to keep this thread on record in case I ever need to jar the wedge loose to free those bars...

Otis

This is where Rodney Dangerfield says, "uh, it looks good on you though".

kroozer 

I have two 1R's although I have yet to use either one. They do look nice, although it sure seems like an overly-complicated design. And people always seem to be losing their wedges. The good ol' 1A looks just as good and never lets you down.

Glennfordx4

Is this the same design of the Shimano 600EX stem, I picked one up for my Centurion but have yet to install it and wasn't sure how well it works or exactly how it works.

Glenn

Drillium Dude 

Somehow I missed this thread, but I damned sure have got some input

First, many 1Rs come with steel stem bolts with steel expander nuts. Later models had the aluminum ones, with the requisite larger bore. There were also upgrade kits from OMAS and FT Bologna.

Second, I've heard the exact opposite that the expander nut is superior to a wedge in that it distributes the clamping force equally. Dunno if this is true, but it seems to make sense.

Third, I know of no 1R that uses a plastic binding wedge - every version I've ever come across has an aluminum wedge. They were known to crack, however, I've only come across one cracked one ever. Not to say it doesn't happen more often than I've seen.

I run them on nearly all my bikes. I honk up hills regularly with them. One of mine has been supporting me for over 15 years. A little creaky under hard load, but that's it.

Bottom line, at least in my book: they work, they last and they look great. Personally, I think the design is one of the most ingenious out there.

DD

steine13

I know this thread is ancient, but it was there when I needed it. Had a handlebar good and stuck in an old 1R and the information here helped me get it out. In hindsight, it would have been good to unscrew the wedge bolt and whack it, driving the wedge upward and unloading the force on the bar. As it was, whacking the closed end a few times with a non-marring hammer after spraying some PB Blaster in the hole worked just fine.
Thanks! -mathias

SJX426 

I, like some others here, listen to the opinions and practices/preferences of others on this forum due to the experience base. Being mechanically inclined since childhood and then reinforced with a BSME along with a fair amount of practical experience in my garage and driveway, I come to my own conclusions about design. Using a mental FBD (free body diagram) in my head when looking and designs, both mechanical, systems, and even loosely process has served me well, most of the time.

I like the concept of the 1R and have several as a result the influence of a BFr who uses them. I like the whole hidden fastener concepts in the designs when structural integrity is not compromised and the ROI makes sense from a sales perspective.
The design issues with the 1R, from my perspective, is the lack of buttressed support on the clamp back side around the ramp. The lack of it results in increased likelihood of the clamp surface breaking. As hard as the clamp is, it is AL with very little elasticity and as such does not distribute the clamping force like other designs. The other clamping surface is on the opposite side of the bar, of course. If the diameters of the bar and 1R are not close, and they rarely are, then the top and bottom of the bar really don't have much force on them. It is like pinching the bar on the front with two fingers and the back with the thumb.

IIRC, the bolt is a fine thread, which is good from a mechanical advantage utilizing a low incline ramp approach to pulling the wedge down. I always lubricate the face of the wedge with the clamp ramp.

It is easy to use a 26mm bar on a 1R. Be careful when you do. Even a 26.4 bar in the 26.4 1R is a bit hard to accept.
P1030528 on Flickr

It didn't help that relief features were required so the bar could be inserted. This is true for the 1A as well.
P1030525 on Flickr

As great as the 1R looks, I think the XA is a bit more elegant until the length is too short, <100. At least the clamping forces are distributed around the bar more evenly, like the 1A. The plastic gasket is a bit disruptive. It should be flush with the stem surfaces.
P1020201 on Flickr

I have yet to see a quill stem that looks as good but has a removable front plate. I believe there are some that come close but look a bit bulky.