Go Back  Bike Forums > Bike Forums > Folding Bikes
Reload this Page >

Strange problem with Viking folding bike

Search
Notices
Folding Bikes Discuss the unique features and issues of folding bikes. Also a great place to learn what folding bike will work best for your needs.

Strange problem with Viking folding bike

Thread Tools
 
Search this Thread
 
Old 01-04-26 | 04:49 AM
  #1  
Thread Starter
Senior Member
5 Anniversary
Community Builder
Community Influencer
Active Streak: 30 Days
 
Joined: Apr 2019
Posts: 3,877
Likes: 1,477
From: UK
Strange problem with Viking folding bike

Hi

A mate has this bike and I took a look at it yesterday because he couldn’t get the bars to stay in.

It has a quill steerer and the wedge can’t be tightened because it has a maybe 9mm nut at the top of the rod to do so - which is theoretically accessible in the tube at the point it folds open but there’s a screw that comes in horizontally, for the hand tightened clamp which holds the two halves together, blocking anything from getting to that nut. The furthest you can loosen that still leaves it very much in the way, it’s not possible to completely remove it to get a socket down there.

Anyone know how this is supposed to be done?

I should have taken a photo, sorry.

Last edited by choddo; 01-05-26 at 01:50 PM.
choddo is offline  
Reply
Old 01-04-26 | 05:06 AM
  #2  
Highly Enriched Driftium
5 Anniversary
Community Builder
Community Influencer
 
Joined: Apr 2017
Posts: 6,832
Likes: 2,214
When you are talking about folding, I assume you mean the handlepost folding at its base, not the bike frame in half.

A quill stem with wedge usually installs and comes out the top; You loosen the long bolt just a couple turns then give it a downward tap to loosen the wedge, if needed another turn and tap, and remove the whole quill, wedge and all, where you can do adjustments if needed, before putting back together. Don't remove the bolt completely, as then tapping on the wedge will damage the last thread and you won't be able to get it back together, plus, the wedge will drop free if not on the bolt.

If the above doesn't apply, pics would help.
Duragrouch is offline  
Reply
Old 01-04-26 | 08:01 AM
  #3  
Schwinnsta's Avatar
Schwinnasaur
15 Anniversary
 
Joined: Dec 2006
Posts: 1,946
Likes: 355
From: New Orleans, LA
You may be dealing with rust. Spray a penetrating solvent in and let sit for a few hours. Turn the bike upside down and spray into the fork from the bottom after removing tire and fender. Let it sit a few hours. Loosen the bolt a turn or two. Try tapping it from above. This procedure may have to be repeated multiple time. The solvents need time to work. Good luck.

Last edited by Schwinnsta; 01-04-26 at 08:08 AM.
Schwinnsta is offline  
Reply
Old 01-05-26 | 09:03 AM
  #4  
Thread Starter
Senior Member
5 Anniversary
Community Builder
Community Influencer
Active Streak: 30 Days
 
Joined: Apr 2019
Posts: 3,877
Likes: 1,477
From: UK
Got my friend to take a photo

hopefully you can see here how the nut I need to tighten (as suggested above) is visible in the steerer tube, but how the threaded rod for clamping the two halves of the handlebar post together obstructs access to it. This is as far out as that rod will go when you turn the handle, I assume it has some kind of limiter on it to prevent it falling out and being lost?



do you think that should just be able to be extracted further? I tried turning it with a decent amount of force and it seemed very “nope” but it closes up fine so it’s not stuck in position.


Last edited by choddo; 01-05-26 at 09:15 AM.
choddo is offline  
Reply
Old 01-05-26 | 09:25 AM
  #5  
Highly Enriched Driftium
5 Anniversary
Community Builder
Community Influencer
 
Joined: Apr 2017
Posts: 6,832
Likes: 2,214
(above) I don't see the threaded rod you speak of, that clamps the hinge closed. However, my folder (Dahon Speed with old style handlepost) does have a threaded rod like that, when you open the hinge, it spans across the open area; There is sufficient space to get underneath to use a 10mm allen wrench on the headset preload bolt. But if I needed better access, like for a socket wrench on yours, I would simply unscrew the female threaded rod (it's right and left hand threaded like a turnbuckle), or remove one of the pins that connects it, I think one stays in place due to the threaded rod, and the other is held in place by circlips on each end.

EDIT: Now I see the threaded rod. Different setup. But yeah, figure out how to unscrew that to get access to where you need. Look for some sort of pin or snapon clip that limits its removal. You may need to screw it all the way in to see that.

Last edited by Duragrouch; 01-05-26 at 09:29 AM.
Duragrouch is offline  
Reply
Old 01-05-26 | 10:38 AM
  #6  
Schwinnsta's Avatar
Schwinnasaur
15 Anniversary
 
Joined: Dec 2006
Posts: 1,946
Likes: 355
From: New Orleans, LA
Thread it back and then back it out a couple of turns . Use solvents. Using a block of hardwood or dowel and hammer strike the bolt hard .lf it is stlll stuck , apply more solvent and wait a day. Repeat .
Schwinnsta is offline  
Reply
Old 01-05-26 | 11:14 AM
  #7  
Highly Enriched Driftium
5 Anniversary
Community Builder
Community Influencer
 
Joined: Apr 2017
Posts: 6,832
Likes: 2,214
My grasp of this is that the long quill bolt does not thread into the wedge, but instead has a nut underneath the wedge, that needs to be held to loosen or tighten, it's probably a nyloc stopnut. If true, it may not come apart out the top. Like I said, there should be a way to undo that cross-bolt further, to get access to the nut there.
Duragrouch is offline  
Reply
Old 01-05-26 | 01:53 PM
  #8  
Thread Starter
Senior Member
5 Anniversary
Community Builder
Community Influencer
Active Streak: 30 Days
 
Joined: Apr 2019
Posts: 3,877
Likes: 1,477
From: UK
Couldn’t find a nut at the bottom of the wedge. That was my first thought too. I’ll try threading the side clamp in to look for a collar of some sort, good suggestion.

I’m 99% sure it’s not stuck. This thing has been basically unused from new, sat in a dry shed for 3 years.
choddo is offline  
Reply
Old 01-05-26 | 02:16 PM
  #9  
Schwinnsta's Avatar
Schwinnasaur
15 Anniversary
 
Joined: Dec 2006
Posts: 1,946
Likes: 355
From: New Orleans, LA
Originally Posted by Duragrouch
My grasp of this is that the long quill bolt does not thread into the wedge, but instead has a nut underneath the wedge, that needs to be held to loosen or tighten, it's probably a nyloc stopnut. If true, it may not come apart out the top. Like I said, there should be a way to undo that cross-bolt further, to get access to the nut there.
Other than modern Ahead type, I am only familiar with expanding wedge type.
Schwinnsta is offline  
Reply
Old 01-05-26 | 11:14 PM
  #10  
Highly Enriched Driftium
5 Anniversary
Community Builder
Community Influencer
 
Joined: Apr 2017
Posts: 6,832
Likes: 2,214
Originally Posted by Schwinnsta
Other than modern Ahead type, I am only familiar with expanding wedge type.
I'm guessing they have a wedge type, but perhaps the wedge itself is not threaded, but instead a nut beneath it. I've also seen a "cone" in place of a wedge, expanding the bottom of the quill tube which is slotted longitudinally.

Aheadsets are awesome, one of the great inventions.

Dahon handleposts like mine, the fork steer tube is threaded *internally*, and the handlepost base has a huge special bolt with 10mm allen, that engages there for preload, and then one bolt (steel base, I think perhaps two bolts on aluminum base) on the side that clamps the handlepost base around the smooth steer tube exterior. It's a good system that works as easily as an Aheadset.

Last edited by Duragrouch; 01-06-26 at 12:47 AM.
Duragrouch is offline  
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.