Help - bike is sending me up the wall

[Eichhörnchen]

I've had to assemble a flat-packed bike (a trike) - shouldn't have been a problem for me even though I know next to nothing about bikes.

Problem is the handlebars. They came with a plastic guard over the spline which I took off, also a thin metal shim behind the spline which I also took off. This following the advice of another purchaser who'd left a review saying that the instruction book was completely inadequate for anyone lacking engineering experience, so he gave this advice freely and what's more offered to write up a proper assembly sheet for them (Temu).

Well I then slid the handlebar stem into the cycle's frame post, adjusted for height, then tightened the top as firmly as I could with the large allen key provided.

It tightened up as expected - but then as soon as I turned the handlebars I found them to be loose - the front wheel pointing straight ahead - the handlebars not gripping. When I removed them again and shone a light into the frame post it was completely smooth inside. Now surely there should be vertical grooves in there to engage with those on the handlebar spline? Is this a defective product??

[Catfish]

Hard to say without photos, but I think this plastic bushing with the metal sleeve should (or whatever this is called in english) over the corrugated/striated(?) middle of handlebar belongs exactly there to fit to the diameter of the handle bar when the allen key is being tightened. There are several systems on the market so I do not know which exact one you have –

[Jimbuna]

Take a couple of pictures Glynn.

[Eichhörnchen]

Yes I'd best do that. I've seen another similar bike being put together on Youtube and I was doing everything right - all you have to do (supposedly) is tighten the handlebars with the allen key. Doesn't work :timeout:

Photos tomorrow

[vienna]

A quick suggestion: try looking on YouTube for videos for that particular bike/trike brand; try searching by brand name, model name/number etc.; I have often found videos for specific products that have good info and tips on the products including, sometimes, ways to overcome assembly problems...



<O>

[Eichhörnchen]

Thanks, mate - found a few which suggest there's a fault with the parts :yep:

[vienna]

Glad to be of help; I hope you find a good resolution to your problem; I don't about what its like out your way, but Temu doesn't really have a good reputation here in the US for backing up their products sold on their site...



<O>

[Sean C]

Sounds like you're talking about what's called a quill stem (https://www.google.com/search?client=firefox-b-1-d&sca_esv=59a6e62f1102fd89&sxsrf=AHTn8zosnQXnKI1uOaiVbymZ0WqzXuT-IQ:1738034468646&q=quill+stem&udm=2&fbs=ABzOT_CWdhQLP1FcmU5B0fn3xuWpA-dk4wpBWOGsoR7DG5zJBsxayPSIAqObp_AgjkUGqekYoUzDaOcD DjQfK4KpR2OIjj43mhrQBsMJgHY2LSx-SUj4wz68xSZ8iYTfqgrdxb3MJvHOMODdIcpti-xYMckL_DuO7Mno3LlWlsnznPPjfINcnPSb3s0mY1_Udv3xmGYG wDe_3zR2JNQT7OndwaUM5c3nJw&sa=X&ved=2ahUKEwjZsPH4upeLAxVaEFkFHSj2A30QtKgLegQIExAB&biw=1920&bih=1006&dpr=1). The allen bolt should pull the splined part toward the main body of the stem. The angled ends of the splined part and the main body push the splined part against the inside of the steer tube. The steer tube should indeed be smooth inside.



It does sound like something is defective. You can really crank down on those bolts without doing any damage, but you shouldn't have to make it extremely tight to keep it from slipping. As others have said, pictures would help a lot.


BTW, I work at a bicycle shop. Assembling and adjusting a trike is no easy task, even for a skilled mechanic. They're very finicky. Your best option would be to take it to a local bike shop and have them look it over. Our base fee for assembling a bike is US$110, but we'd probably charge a little more for a trike.

[Eichhörnchen]

Thanks, Sean - you covered everything - in particular my query about the smooth bore of the steer tube. I'll jiggle the parts about a bit just in case something hasn't engaged which should have. I got the allen key (allen wrench lol) good and tight & all seemed okay until I tried steering - we'll see

Thanks again for your help, shipmate :up:

Edit:
Also spot-on were the cutaway diagrams showing the quill stem in place - I can see from these that I've done everything right. This stem and wedge operate perfectly well in your hand but then won't grip the inside of the steer tube; why on earth don't they put vertical grooves inside these since this would ensure a lock?

[Reece]

Here's some music to play whilst building it: :D

https://au.video.search.yahoo.com/search/video?fr=sfp&p=pushbike+song#id=1&vid=91f94d58dd8ed4c3401faf7e1e765d5f&action=click

[Eichhörnchen]

^ Thanks, Reece - but I'll pass on that :yep:

[Eichhörnchen]

I just took it to a local guy who builds & fixes bikes. He examined the parts - could find nothing wrong - so took a dirty great torque wrench to it. It took some muscle (more than it should, he agreed) and it now seems to be holding. How long for is anyone's guess

[Jimbuna]

Now all you need to learn is how to ride it :)

[Buddahaid]

Now all you need to learn is how to ride it :)

So simple even an ape can.....nevermind. :shucks:
https://media2.riverfronttimes.com/riverfronttimes/imager/u/original/30804757/img_3670.jpg

[Jimbuna]

:haha:

[Reece]

So simple even an ape can.....nevermind. :shucks:
https://media2.riverfronttimes.com/riverfronttimes/imager/u/original/30804757/img_3670.jpg
I'm saying nothing!! :oops::D

[Eichhörnchen]

^ :haha: That's rich from Buddababy - he's the one who likes to dress up as a monkey

[Reece]

You don't say!! :hmmm: Any pictures? :D

[Eichhörnchen]

https://i.imgur.com/auIXN6A.jpeg

I know there's one of him & his mates dressed in these - he might be able to find it