threading handlebars through stem
 

Hi, I got some new ergo handlebars and I can't get them through the stem. The bends are too tight to fit. My old handlebar had smoother curves and I got it off without too much fighting, but the new one I can't figure out how to get on. Any hints?

It's an older quill stem without the faceplate that comes off (that'd make life too easy).

You might be able to make it work by carefully prying the stem open just enough to pass the bars through. There's really no other fix except a different stem.

I've been prying, but that's not working. I'd rather not go the new stem route, but am fearing it's going to become a real possibility.

Lube the sticky sections of the bars well. Penetrating oil works better than grease for me. It's gotta be really slippery. And yes, prying open the stem a bit by rotating a big-bit screwdriver in the slot helps too.

Ok, I was at least able to pry it apart enough to get the bar out (couldn't make the bend though). If I have to get a new quill stem, where do I measure to know the size? I measured the outside of the stem as it rises and that's 13/16's and that's not a size I'm seeing. Either 1" or 1 1/8".

some of those anatomical bends are really tough to get into some stems.

I'd estimate if it's quill style, there's 99.1% chance it's a 1" stem. Seems to gybe with your measurement. I think the standard stem diameter for a 1" is 7/8", but 13/16 is pretty darn close to that.

Hopefully your stem isn't a 25.4 bar clamp.

Hopefully your "new" bar isn't a NOS pre-1998 Cinelli.

What else can you tell us about the bike, stem, old bar and new bar?

Well the bike is an old mongoose hard tail mountain bike (lbs bike pre xmart mongoose) that the previous owner put drop bars on. I don't know how he modded the stem to do so. The bar is 25.4 (both the old and the new) so that shouldn't be an issue, but the steel is old and I've been trying to pry in the pinch clamp area but it's just very had to get room.

That sounds like a .833 stem if you have measured correctly. The stem probably has the size shown near the wedge.

It's a new dimension 25.4 mm ergo bar I just got from jenson, so it's not a NOS cinelli. El cheapo bar definitely. The stem feels more or less frozen in place when I take out the long bolt at the top of the stem and loosen the collar, so I'm not sure replacing it is going to be an option.

I lack capilpers, so I just put an adjustable wrench around the base of the stem (right above the collar) then pulled if off and measured with my ruler that measures in 64ths

Hmmm, I guess it very well could be a .833 BMX stem considering Mongoose's BMX heritage. Does the bike have a model name? Original paint?

Seems like the really old Mongeese (early 80s action) would be the ones most likely to have a BMX stem. A lot of them are pretty recognizeable by their virtue of being all chrome. I know by 1988 most, if not all Mongoose MTBs had standard 1" stems.

It's a dark blue mongoose manuever hardtail mountain bike. so not bmx and yes original paint.

I'm pretty sure Maneuver didn't come out 'til the 90s. I'm not sure how complete the bikepedia is when it comes to the Maneuver, but they list it as 24" wheeled kids bike only up 'til 1996 which came in Dk blue and had a 1" stem. Check the specs against your bike in attempt to confirm, assuming the previous owner didn't strip a lot of parts off and just did the bar swap.

Since I can't imagine Mongoose using a BMX stem past 1985, if they ever did, on a MTB, I think it's safe to say it's a standard 1" stem, or at least the fork is designed for a standard 1" stem.

Either that or your measurement is WAY off for a 1 1/8"...

finally used the claw end of a hammer to bend the pinch clamp far enough open to get the bar through. Got scared that I'd bent it too far as it took a bit of work to get it closed tight enough. Thanks all. I'd still like to replace the stem at some point. Might have to take it into an lbs to have them look at it though.

thanks for doing the search. The previous owner did a lot of mods (biopace cranks and slicks among other things) so I don't know what's original. Having a hard time finding shimano model names on the shifters/deraillers. They are the older (thumb) shifters that used to be on mountain bikes though, not the grip shifters listed. The shifters got moved to the stem (a pretty good way of modding old mountain bike shifters to make them stem shifters). Basically he was trying to make a touring/commuting bike for himself and then for reasons he didn't want to discuss had to sell it.

Not sure any of those listed are quite correct, but that 1996 looks the closest as it's a 22" frame (so not the juvenile listed for 93 and 94), but it says it's Tange 4130 Chr-Mo frame with Hi-ten fork and bikepedia says it's only chr-mo seat tube and hi-ten everything else. Maybe that's what the stickers on mine means, not really sure. I guess I'll work with what I have for now (stem's a bit rusty - though that could be superficial and I'd prefer black stem and bars to go with everything else I have black now), but as I just bought these silver bars for $20, I'll let these go for now. Especially as the stem seems pretty stuck in there.

I started a similar thread over in C&V a few days ago and received a good number if tips:

http://www.bikeforums.net/showthread...=#post11426371

Most stems are less wide at the bolt side , and by turning that side towards the axis
of the radius of the bend, things may go better.

Was bummed that I ended up gouging the bar a little bit, but I ended up filing off the pokey bits and I figure the scratches will be covered by tape anyway, right?

You have to be careful because of notch-failure in aluminium. All cracks start at surface imperfections that cause stress-risers. You'll want to lightly sand the scratches and polish so there are no sharp edges.

It may be late to suggest this, but fietsbob's idea is right on. Easier to have the stem off the bike and thread it over the bar. Rotate the stem so its narrow clamp-section lines up with the tighter inside-bend of the bar and it should slide through easily. Then rotate the stem again to go around the next curve. It typically requires rotating the stem 2-3 times to get it all the way through depending upon the particular curves of the bar.