Help - bike is sending me up the wall

Eichhörnchen · 01-27-25, 12:33 PM

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 · 01-27-25, 12:42 PM

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 · 01-27-25, 01:23 PM

Take a couple of pictures Glynn.

Eichhörnchen · 01-27-25, 01:50 PM

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

Photos tomorrow

vienna · 01-27-25, 03:25 PM

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 · 01-27-25, 04:39 PM

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

vienna · 01-27-25, 05:38 PM

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 · 01-27-25, 10:32 PM

Sounds like you're talking about what's called a quill stem. 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 · 01-28-25, 05:53 AM

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

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 · 01-28-25, 06:11 AM

Here's some music to play whilst building it:

https://au.video.search.yahoo.com/se...f&action=click

Eichhörnchen · 01-28-25, 08:30 AM

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

Eichhörnchen · 02-01-25, 08:47 AM

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 · 02-01-25, 08:50 AM

Now all you need to learn is how to ride it

Buddahaid · 02-01-25, 11:33 AM

Quote:

Originally Posted by Jimbuna

Now all you need to learn is how to ride it

So simple even an ape can.....nevermind.

Jimbuna · 02-01-25, 12:30 PM

01-27-25, 12:33 PM	#1
Eichhörnchen Starte das Auto Join Date: Aug 2014 Location: The Fens Posts: 17,381 Downloads: 5 Uploads: 0	Help - bike is sending me up the wall 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?? __________________

01-27-25, 12:42 PM	#2
Catfish Dipped Squirrel Operative Join Date: Sep 2001 Location: ..where the ocean meets the sky Posts: 17,766 Downloads: 38 Uploads: 0	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 – __________________ >^..^<*)))>{ All generalizations are wrong.

01-27-25, 01:23 PM	#3
Jimbuna Chief of the Boat Join Date: Feb 2006 Location: 250 metres below the surface Posts: 190,507 Downloads: 63 Uploads: 13	Take a couple of pictures Glynn. __________________ Wise men speak because they have something to say; Fools because they have to say something. Oh my God, not again!!

01-27-25, 01:50 PM	#4
Eichhörnchen Starte das Auto Join Date: Aug 2014 Location: The Fens Posts: 17,381 Downloads: 5 Uploads: 0	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 Photos tomorrow __________________

01-27-25, 03:25 PM	#5
vienna Navy Seal Join Date: Jun 2005 Location: Anywhere but the here & now... Posts: 7,711 Downloads: 85 Uploads: 0	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> __________________ __________________________________________________ __

01-27-25, 04:39 PM	#6
Eichhörnchen Starte das Auto Join Date: Aug 2014 Location: The Fens Posts: 17,381 Downloads: 5 Uploads: 0	Thanks, mate - found a few which suggest there's a fault with the parts __________________

01-27-25, 05:38 PM	#7
vienna Navy Seal Join Date: Jun 2005 Location: Anywhere but the here & now... Posts: 7,711 Downloads: 85 Uploads: 0	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> __________________ __________________________________________________ __

01-27-25, 10:32 PM	#8
Sean C Grey Wolf Join Date: Jun 2017 Location: Norfolk, VA Posts: 984 Downloads: 16 Uploads: 2	Sounds like you're talking about what's called a quill stem. 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. __________________ If you have a question about celestial navigation ... ask me! Celestial Navigation Spreadsheet

01-28-25, 05:53 AM	#9
Eichhörnchen Starte das Auto Join Date: Aug 2014 Location: The Fens Posts: 17,381 Downloads: 5 Uploads: 0	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 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? __________________ Last edited by Eichhörnchen; 01-28-25 at 07:59 AM.

01-28-25, 06:11 AM	#10
Reece CINC Pacific Fleet Join Date: Sep 2003 Location: Down Under Posts: 34,701 Downloads: 171 Uploads: 0	Here's some music to play whilst building it: https://au.video.search.yahoo.com/se...f&action=click __________________ *Sub captains go down with their ship!*

01-28-25, 08:30 AM	#11
Eichhörnchen Starte das Auto Join Date: Aug 2014 Location: The Fens Posts: 17,381 Downloads: 5 Uploads: 0	^ Thanks, Reece - but I'll pass on that __________________

02-01-25, 08:47 AM	#12
Eichhörnchen Starte das Auto Join Date: Aug 2014 Location: The Fens Posts: 17,381 Downloads: 5 Uploads: 0	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 __________________

02-01-25, 08:50 AM	#13
Jimbuna Chief of the Boat Join Date: Feb 2006 Location: 250 metres below the surface Posts: 190,507 Downloads: 63 Uploads: 13	Now all you need to learn is how to ride it __________________ Wise men speak because they have something to say; Fools because they have to say something. Oh my God, not again!!

02-01-25, 12:30 PM	#15
Jimbuna Chief of the Boat Join Date: Feb 2006 Location: 250 metres below the surface Posts: 190,507 Downloads: 63 Uploads: 13	__________________ Wise men speak because they have something to say; Fools because they have to say something. Oh my God, not again!!