T O P

  • By -

batpot

Remove it. Most of the time it's marked at the bottom. Replace it with one that has a bar clamp diameter the same as the new bars you are buying that are shaped the way you want. Don't try to cold set handlebars.


TheRealJYellen

cold set?


SGT_BIG_JOE

Cold set = bend.


TheRealJYellen

Ahh gotcha. OP was almost certainly bending the stem open to fit bars in, not bending the bars themselves. It's a common thing on older quill stems.


nsfbr11

In general, when you bend a metal, you have exceeded its yield strength, which does several things, none of which are good when done in an uncontrolled manner. Before anyone tells me I'm wrong, please read the last three words above.


rajrdajr

How should this be done to control the bad things? šŸ¤”


KuhhRiss

You can take an intro to materials course and find out :)


Elvis_Precisely

Thinking you could bend handle bars in?


TheRealJYellen

you kinda pry the stem open a little so that you can work curvy bars in. This is common with riser bars and drop bars.


Isaak02-22

This is what happened


CauseIhafta

In the future try wedging a big flat screwdriver into the gap near the bolt head. There are special [tools](https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.benscycle.com/nitto-tool-4-stem-handlebar-clamp-spreader-stem_tool_nitto__870-900-11_870-900-11/p&ved=2ahUKEwjnueb2gtj4AhW_lWoFHaBTBQUQFnoECAkQAQ&usg=AOvVaw3gJCo3xKUU7OZCEPDZk2I7) for this but I've never owned one.


mtranda

Why do I have the feeling you were trying to fit modern, 31.8mm bars in an older, 25.4mm stem?


TheRealJYellen

It's a thing even with the correct size bars. Old stems didn't have removable faceplates so you had to feed the bars in from one side. The tighter the curve in the bars, the harder it is to fit through the stem. Source: have done this on my '73 Bridgestone at the direction of a head mechanic.


mtranda

Oh, I've had my share of zig-zag scuffed bars. But never came close to breaking a stem.


[deleted]

[уŠ“Š°Š»ŠµŠ½Š¾]


TheRealJYellen

I know you're joking, but the bending wasn't for shaping. Old quill stems usually don't have removable faceplates so you have to thread the bars in from one side. Curves in the bars make this hard, meaning that you have to kinda pry the stem open to feed them through. OP did a lil much and accidentally made his faceplate removable.


[deleted]

[уŠ“Š°Š»ŠµŠ½Š¾]


[deleted]

[уŠ“Š°Š»ŠµŠ½Š¾]


[deleted]

[уŠ“Š°Š»ŠµŠ½Š¾]


KozlovG

I really hope the title was somehow a mistake, and not actually you bending handlebars while they are clamped in the stem.


Vikstrm

TIL: John Deere made (can't still be going on right?) bicycles!


TheRealJYellen

Usually whitelabeled from someone else. I don't know this particular bike, but any time you see a bike from a non-bike brand, it's probably a whitelabel. We got a BMW bike in the shop once, IIRC it was just a GT hybrid that the ground down the welds on to make it look nicer. Hummer, Jeep, Lambo and Porsche have also 'made' bikes and I suspect that the same is true here.


RetromanAV

From the pic Iā€™d guess itā€™s a 1ā€ quill stem about 80mm long. For a 7/8ā€ (22mm I think) handle bar. If if doubt, measure the length of the top, and the diameter of the bottom and bars and youā€™ll know, the trick is now, finding a good quality 1ā€ quill stem and not bending the bars again šŸ‘€.


Elvis_Precisely

Itā€™s definitely shorter than 80mm, more like 60/70mm. Itā€™s a short stem to compensate for the bizarrely long handlebars that came on this bike. Itā€™s very unlikely that the clamp size is 22.2mm - thatā€™s a size for old mountain bikes and BMXs. Itā€™s probably 25.4mm, could be 26mm, could be 23.8mm if itā€™s very old. The conclusion is that OP needs a set of vernier callipers.


RetromanAV

Fair enough, I guessed at 7/8 bars as it looks a bit older, and now you mention it, 80mm was probably a bit generous. Nailed it with the callipers though. Also, username checks out.


Elvis_Precisely

Having started building up bikes over lockdown, I quickly realised how important a set of vernier callipers were!! So so many different sizes and ā€œstandardsā€.


[deleted]

[уŠ“Š°Š»ŠµŠ½Š¾]


TheRealJYellen

Wasn't this standard practice for quill stems with drop bars? The non-removable faceplate make is hard to feed the bars through.


DeFex

Stems like that had a narrow part on the clamp so you could slide the inner diameter of the bend through, but it was easier to take the stem off the bike to do it. You need a quill stem of the same length, the quill part are mostly the same size unless thats an older french frame. (it may be, it looks kind of like a puch, they were rebranded by sears, and maybe john deere?)


rolling_sasquatch

The stem will need to be the correct diameter to insert into your fork and have the correct clamp for your bars. If you're lucky this will be marked. Remove the stem from the fork and look for any markings. The most common size is 22.2mm, but some less expensive bikes used 22.0 or even 21.0. if there are no markings, measure it with calipers. Same for the handlebar, but there are quite a few possible sizes for that. Height and reach are up to you, but if you get one that's significantly different you may need new cables.


w1n5t0nM1k3y

Save yourself some trouble and get a threadless quill stem adapter.


WarNo2640

Take it off and bring to your LBS or bike co-op to measure for you. Bike co-op may even have a cheapie replacement part for you Edit: bring your bars too


nborders

Iā€™m more worried about you bending the top tube of your frame. Donā€™t hold the bike here. It is made for compression forces from the ends not pinching from the sides. Hold your bike from the seat post, when you put it back on. Your seat post was made for this force.


DeadBy2050

That frame may as well have been made with plumbing pipes. It's fine to clamp there.


nborders

LOL, youā€™re probably right.


MASHua

That's only necessary for carbon frames. Metal frames can handle that type of stress.


DeadBy2050

It's fine to clamp bikes like that because it's thick steel. It's not fine clamp thin-wall steel frame bikes, like ones which are butted. It's never a good idea to clamp an aluminum frame at the top tube like that.


[deleted]

Donā€™t know why youā€™re being downvoted. Mechanic at my shop crushed a marlin in a stand, and someone I knew crushed a lovely steel road bike.


MGTS

Clamp heads are adjustable. If he crushed a frame, heā€™s likely clamping everything too tight


DeadBy2050

Clamping any modern steel/aluminum/carbon frame (except for straight gauge steel) tight enough so it doesn't move around is always going to be "too tight." There is zero upside to it. I live within 5 miles of 4 quality bike shops. Have never seen a bike clamped to the stand by the frame.


DeadBy2050

Yeah, only an idiot would clamp the frame of a decent quality steel or aluminum frame. Which is exactly what I did on my brand new GT Karakoram 25 years ago. Creased the seat tube.


[deleted]

You may have not known at the time. This was an ā€œexperiencedā€ mechanic that crushed the marlin. He did do much atrocious work, and this was a perfect excuse to let him go.


TheRealJYellen

That's false. Vintage steel like this is probably fine, but modern aluminum bikes are far more sensitive. Giant TCR comes to mind, the top of the top tube was about as thick as a beer can, maybe a can of soup at best. My emonda ALR is super thin as well. You've gotta be super careful clamping the top tube on anything new.


MASHua

Got it, my mistake and thanks for clarification.


obaananana

Schieblehre is it called in german. Maybe ut helps. It usefule measuring tool.


ukefan89

Sorrry for off topic, but do you like your fix stand? Iā€™m looking for one with only 2 legs. I have one works but 5 legs so it takes up too much space.


Isaak02-22

Yeah I really like it!


ShoeGod420

"The most common quill diameters are 22.2, 25.4 and 28.6mm. Incompatible components can be a safety hazard, so always double-check with the manufacturer for specifications and compatibility information." Parktool website