Foldable bicycle

[Victor68]

Hi, seeking help. Recently bought a pre-owned Cruis trifold bicycle. Didn't test and realize couldn't fold without entangling the chain. Any kind soul advise what to adjust? 

I am quite a handyman type. I believe I should be able to manage with good guides. Thank you in advance. 

[Heartlander]

On 6/1/2025 at 6:54 PM, Victor68 said:

Hi, seeking help. Recently bought a pre-owned Cruis trifold bicycle. Didn't test and realize couldn't fold without entangling the chain. Any kind soul advise what to adjust? 

I am quite a handyman type. I believe I should be able to manage with good guides. Thank you in advance. 

Best bet is to search for the particular Crius model under Youtube. There are many videos on how to fold the bikes and you can analyse what went wrong. Seems something to do with the chain from your picture.

[Victor68]

Video only shows how to fold which can be performed. But the chain got entangled because it is too loose. It should be the chain guide or some call it tensioner position. 

[mersaylee]

Check all cablings...make sure no entanglement when folded or unfolded...i once thot there's a seized brake when one cable was stretched and pulled on the brake lever...😅

[inlinesix]

That’s why Brompton ftw🤭

[Ody_2004]

On 6/1/2025 at 6:54 PM, Victor68 said:

Hi, seeking help. Recently bought a pre-owned Cruis trifold bicycle. Didn't test and realize couldn't fold without entangling the chain. Any kind soul advise what to adjust? 

I am quite a handyman type. I believe I should be able to manage with good guides. Thank you in advance. 

can show me the pic of how the rear derailleur look when not folded? this pic seem not right 

[Victor68]

On 6/1/2025 at 8:16 PM, Ody_2004 said:

can show me the pic of how the rear derailleur look when not folded? this pic seem not right 

 

[Victor68]

It supposed to look like this but mine the derailleur didn't seem to pull tight.

[inlinesix]

On 6/1/2025 at 8:16 PM, Ody_2004 said:

can show me the pic of how the rear derailleur look when not folded? this pic seem not right 

It seems like there is no tension in the derailleur 

[Victor68]

[Ody_2004]

On 6/1/2025 at 8:27 PM, inlinesix said:

It seems like there is no tension in the derailleur 

Chances slim but not impossible 

On 6/1/2025 at 8:36 PM, Victor68 said:

This look ok leh.: need see the bike liao

[Victor68]

I took it for a ride this morning, everything seems fine except when folded, the chain is too loose and entangled. The chain tensioner and derailleur supposed to pull the chain tight but somehow 'not aligned'. 

[Heartlander]

On 6/1/2025 at 8:12 PM, inlinesix said:

That’s why Brompton ftw🤭

I like Brompton design but really hate the internal gear hub. Granted it has its benefits like relatively maintenance free, but too many steps just to take out the rear tyre to replace inner tube. After a brief spell with burst inner tube every other week I got phobia just taking the bike out. And I always got the feeling that the cable tension on internal hub is not aligned properly thus gearing not correct, which happened time to time. So eventually got the alunminum G 山寨版 with external gear system haha.

[Heartlander]

On 6/1/2025 at 8:50 PM, Victor68 said:

I took it for a ride this morning, everything seems fine except when folded, the chain is too loose and entangled. The chain tensioner and derailleur supposed to pull the chain tight but somehow 'not aligned'. 

Your Cruis is which model?

[inlinesix]

On 6/1/2025 at 9:09 PM, Heartlander said:

I like Brompton design but really hate the internal gear hub. Granted it has its benefits like relatively maintenance free, but too many steps just to take out the rear tyre to replace inner tube. After a brief spell with burst inner tube every other week I got phobia just taking the bike out. And I always got the feeling that the cable tension on internal hub is not aligned properly thus gearing not correct, which happened time to time. So eventually got the alunminum G 山寨版 with external gear system haha.

Very likely you didn’t pump enough air in the rear tyre.

I use Schwalbe Kodak and it rarely puncture.

Most of the time I pump 90psi.

[Volvobrick]

On 6/1/2025 at 8:21 PM, Victor68 said:

 

Looks like you may have to shift to the largest cog BEFORE you fold. That should increase the tension in the chain. 

If still too loose, shorten the chain. 

Edited June 1, 2025 by Volvobrick

[inlinesix]

On 6/1/2025 at 9:17 PM, Volvobrick said:

Looks like you may have to shift to the largest cog BEFORE you fold. That should increase the tension in the chain. 

 

[Victor68]

On 6/1/2025 at 9:10 PM, Heartlander said:

Your Cruis is which model?

It is a 16 inches, 10 speeds Shimano tiagra gear model.