Stuck bars

[ericonabike]

Hi

Not posted for a while, but always impressed by the collective knowledge here.
I volunteer for a disability cycling charity. We've been given a Draisin Twister, which sells for £6k new, and is a two person, recumbent trike. It's great, except that the bars, which should slide back and forth, held by QRs like a horizontal seat post, are stuck solid.

I've tried putting penetrating oil on them and applying (gentle!) taps with a hammer, to no avail. Grateful for any ideas...

[Jdsk]

How about heat? But what could be damaged by that?

And can you get a decent grip on each bit?

Jonathan

[ericonabike]

I'm guessing heat would need to be applied to the external tube, which is painted . The bars are easily gripped, but hard to apply a twisting force — only one of them steers (obvs!) and the other is centred by a rivet (I think) which I don't want to break. I'll try and get close up photos when next at the storage unit.

[mumbojumbo]

Use a mallet or place some soft wood over bars before striking ..Given the value of item use a bike shop.

[alexnharvey]

How about heat? But what could be damaged by that?

And can you get a decent grip on each bit?

Jonathan

And maybe also cold, in combination? Warming the outside tube and using freeze spray, dry ice, etc on the inner piece.

[PT1029]

Not clear from the photo,
1 Are the tubes on contact with each other? From the photo the inner tube looks too thin to be in contact with the outer tube (so it is just in contact with the black clamp gubbins, and possibly some spacer/sleeve inside further down?
2. Can you get penetrating oil in from the front/headset end?
Have you contacted Draisin for advice? They might have seen this before and have a simple answer. info@draisin.com
If it is due to oxidation, water makes the oxide swell (so things become tight). Gentle heat (repeated often if needed) should eventully drive out the water, causing the oxide to shrink.
As always, blue can wd 40 not good enought here. A proper unsiezing oil should be used.
If the system uses plastic shims/spacers, penetration oil might induduce plastic swelling, so making the problem worse.That said, I would have thought the black clamps would be metal!

[thirdcrank]

I hope this isn't patronising but are you in a position to contact the previous owner to ask about this? Perhaps there's something simple you have missed. Did they have this problem? Bearing in mind the current thread on slipping seatposts, has something been done to fix the bars at a preferred position?

Also, is it vital that the bars can be adjusted? If they are more-or-less OK, then risking wrecking the whole machine just to solve a challenge may not be worth it.

[ericonabike]

Thanks for these. The previous owner gave it to a local care home in Brighton, who never used it, then obtained by a local care home we do sessions for, who gave it to us!
I've emailed Draisin (in English) but no reply.
Have only used WD40 to date, wil try Plusgas or similar.
Will also do my best with heat and cold.
LBS we use, serviced it but couldn't free them.
Our customers vary a lot in height, so adjustment would be useful. But yes, certainly not worth getting the adjustment by wrecking the machine!
Its actually difficult to work out exactly how the mechanism works, other than that there is a QR that when released should allow movement.

[Jdsk]

Its actually difficult to work out exactly how the mechanism works, other than that there is a QR that when released should allow movement.

Photos would be great. I'd like to see how that clamp works, the risk of damage with heat, and where you can get hold of the two bits.

Soaking in PlusGas is wise.

Jonathan

[thirdcrank]

Out of idle curiosity and in hope of going Eureka! I did a bit of googling and I see the makers list loads - too many to count - of agents on mainland Europe, although you never know how close the link. There's only the one in England, which seems to be a above all distributor

https://quest88.com/

Exploring that site brings up "Contact a product advisor" which refers to regional product advisors. That sounds as though they may be sales advisors but without trying, nobody knows.

https://quest88.com/pages/contact-a-product-advisor

I also googled for a manual and the computer says "no" but I expect that means there may not be an online version. Bearing in mind the nature of this machine and its intended use, I'd be amazed if there were not to be a printed manual. Even if that had to be bought in €€€, it might be useful in future

[squeaker]

Thanks for these. The previous owner gave it to a local care home in Brighton, who never used it, then obtained by a local care home we do sessions for, who gave it to us!

What are the tube materials? 'Brighton' = salty air, and my experience of similar concentric aluminium tubes in a salty environment is not good, especially if no regular movement or lubrication.
If there's no obvious anti-rotation feature, then I'd include wiggling in the above recommendations, but only after several days soaking in Plusgas, although I'm not sure its the best to soften the corrosion products. Looking again at your photo, how's the black clamp assembly attached to the white tube? Might be worth seeing if that can be removed to get better access to any corrosion?

[cycle tramp]

What happens if you wrap the white tubes in towels, pour boiling water (carefully) onto the towels to make the tubes heat up and expand and then try and free the handlebar tubes? It might take several goes.

[rjb]

I'm not sure what the problem is. Is the qr arrangement stuck or are the concentric tubes stuck. It may be possible to unbolt the qr mechanism from the external tube which may then help you identify if the tubes are seized together. I would not try to twist the 2 concentric tubes as they may have been designed with an internal pin so they can only slide within each other without twisting. Let us know how your investigations progress.

[ericonabike]

Thanks all. Will be a day or two before I can try any solutions as the machine is in storage a few miles away. Will report back....

[thirdcrank]

My take on this is that it looks like an impressive bit of kit to spread the pleasure of cycling. The downside is probably that anything you need in the way of non-standard spares or accessories will be in one arm + one leg territory. You are doing this for a charity. If you eventually learn that money is needed to keep this on the road, please post the details.