I have a Witter bike rack that attaches to the towbar.

You put it on and at first its all loose and of course will lift off, then you tighten a big bolt which at first is really easy as it goes round for quite a few turns without much resistance, then as it grips the towball you give it a couple of really firm turns with the spanner to make it fully grip the ball.

Removing the rack is the reverse of the above where you apply big force for a couple of turns to loosen it, then lots of relatively easy turns to make it loose enough to actually come off the towball.

The problem is that once Ive loosened it enough to make the rack sag but not actually come off, the bolt starts to feel really tight again €“ almost as tight as it normally does at the last stage of attaching it €“ so much so that I feel as though I need to apply so much force as to damage the thing.

Im now left with the bike rack attached and sagging but cant remove it and Im wondering if anyone has any experience of this?

On 04/06/2021 21:01, Murmansk wrote:
I have a Witter bike rack that attaches to the towbar.

You put it on and at first its all loose and of course will lift off, then you tighten a big bolt which at first is really easy as it goes round for quite a few turns without much resistance, then as it grips the towball you give it a couple of really firm turns with the spanner to make it fully grip the ball.

Removing the rack is the reverse of the above where you apply big force for a couple of turns to loosen it, then lots of relatively easy turns to make it loose enough to actually come off the towball.

The problem is that once Ive loosened it enough to make the rack sag but not actually come off, the bolt starts to feel really tight again €“ almost as tight as it normally does at the last stage of attaching it €“ so much so that I feel as though I need to apply so much force as to damage the thing.

Im now left with the bike rack attached and sagging but cant remove it and Im wondering if anyone has any experience of this?


I suspect that something is getting in the way perhaps of a part that
moves when you losen the bolt. Maybe moving the rack when it is loose
will help. Alternatively phone Witter and ask for advice.


--
Michael Chare

On 04/06/2021 21:01, Murmansk wrote:
I have a Witter bike rack that attaches to the towbar.

You put it on and at first its all loose and of course will lift off, then you tighten a big bolt which at first is really easy as it goes round for quite a few turns without much resistance, then as it grips the towball you give it a couple of really firm turns with the spanner to make it fully grip the ball.

Removing the rack is the reverse of the above where you apply big force for a couple of turns to loosen it, then lots of relatively easy turns to make it loose enough to actually come off the towball.

The problem is that once Ive loosened it enough to make the rack sag but not actually come off, the bolt starts to feel really tight again €“ almost as tight as it normally does at the last stage of attaching it €“ so much so that I feel as though I need to apply so much force as to damage the thing.

Im now left with the bike rack attached and sagging but cant remove it and Im wondering if anyone has any experience of this?

Could be damaged threads or contamination. A grain of sand or small grit
can do this. Would it be possible to get some light oil into it? Maybe
apply oil then tighten and untighten a few times to work it along the
thread. Then untighten as far as you can before the resistance starts,
then go just a bit further, then back off, then go again, try to go a
bit further still, and so on. I've had exactly the same problem with
other things and this has usually worked, but it needs patience.

Bill

On 04/06/2021 21:01, Murmansk wrote:
I have a Witter bike rack that attaches to the towbar.

You put it on and at first its all loose and of course will lift off, then you tighten a big bolt which at first is really easy as it goes round for quite a few turns without much resistance, then as it grips the towball you give it a couple of really firm turns with the spanner to make it fully grip the ball.

Removing the rack is the reverse of the above where you apply big force for a couple of turns to loosen it, then lots of relatively easy turns to make it loose enough to actually come off the towball.

The problem is that once Ive loosened it enough to make the rack sag but not actually come off, the bolt starts to feel really tight again €“ almost as tight as it normally does at the last stage of attaching it €“ so much so that I feel as though I need to apply so much force as to damage the thing.

Im now left with the bike rack attached and sagging but cant remove it and Im wondering if anyone has any experience of this?

Sounds very like a bolt with a damaged thread (possibly a bent bolt).
Can it be economically replaced?
Alternatively you could take it all the way out and 'hand chase' the
threads. This may involve mounting in a lathe (local light engineering
firm for the cost of a couple of pints) and running a chase along it.

Just realised you 'say' you can't move it out at all. Maybe try oiling
and working the bolt in and out eventually freeing it (be prepared to
cobble up a hole new looking system as if the bolt is harder than the
threaded part it may well cut its own thread thus knackering any holding
function).

On 05/06/2021 09:59, soup wrote:
On 04/06/2021 21:01, Murmansk wrote:
I have a Witter bike rack that attaches to the towbar.

You put it on and at first its all loose and of course will lift off,
then you tighten a big bolt which at first is really easy as it goes
round for quite a few turns without much resistance, then as it grips
the towball you give it a couple of really firm turns with the spanner
to make it fully grip the ball.

Removing the rack is the reverse of the above where youÂ* apply big
force for a couple of turns to loosen it, then lots of relatively easy
turns to make it loose enough to actually come off the towball.

The problem is that once Ive loosened it enough to make the rack sag
but not actually come off, the bolt starts to feel really tight again
€“ almost as tight as it normally does at the last stage of attaching
it €“ so much so that I feel as though I need to apply so much force as
to damage the thing.

Im now left with the bike rack attached and sagging but cant remove
it and Im wondering if anyone has any experience of this?

Â* Sounds very like a bolt with a damaged thread (possibly a bent bolt).
Can it be economically replaced?
Alternatively you could take it all the way out and 'hand chase' the
threads. This may involve mounting in a lathe (local light engineering
firm for the cost of a couple of pints) and running a chase along it.

Just realised you 'say' you can't move it out at all. Maybe try oiling
and working the bolt in and out eventually freeing it (be prepared to
cobble up a hole new looking system as if the bolt is harder than the
threaded part it may well cut its own thread thus knackering any holding
function).



Whole not hole.
Locking not looking

Note to self :- Think, have you said everything and proofread before
clicking 'send'.

Use a chaser NOT a die to clean the thread (looks and operates rather
like a die but doesn't cut so much as 'clean'.

You can use a hand chaser (rather like a file with a thread pattern on
the tip) That way you only ,really. have to concern yourself with the
thread profile not, within reason, the actual diameter

OP here

Well, the bolt would only turn a quarter turn, I flooded it with oil and worked it for half an hour but no joy so with the help of my neighbour and a metre long bit of scaffolding pole attached to the spanner I eventually got the bolt out.

Every turn of the bolt took a huge amount of effort even with the scaffolding pole, the thread is knackered. Only question remaining is what the thread in the nut that's welded to the mechanism is like - probably knackered too!

I'll have to see if Witter will sell me a new mechanism

On 05/06/2021 11:08, Murmansk wrote:
OP here

Well, the bolt would only turn a quarter turn, I flooded it with oil and worked it for half an hour but no joy so with the help of my neighbour and a metre long bit of scaffolding pole attached to the spanner I eventually got the bolt out.

Every turn of the bolt took a huge amount of effort even with the scaffolding pole, the thread is knackered. Only question remaining is what the thread in the nut that's welded to the mechanism is like - probably knackered too!

I'll have to see if Witter will sell me a new mechanism

Sometimes the intention is for the bolt to be captive, but still give
the necessary amount of movement to pinch and release the ball.

Hopefully it's still in guarantee.

On 05/06/2021 11:08, Murmansk wrote:
OP here

Well, the bolt would only turn a quarter turn, I flooded it with oil and worked it for half an hour but no joy so with the help of my neighbour and a metre long bit of scaffolding pole attached to the spanner I eventually got the bolt out.

Every turn of the bolt took a huge amount of effort even with the scaffolding pole, the thread is knackered. Only question remaining is what the thread in the nut that's welded to the mechanism is like - probably knackered too!

I'll have to see if Witter will sell me a new mechanism


Not surprised to hear that this is your problem, from the original
description. If Witter are unhelpful nut condition can be estimated by
trying with a brand new bolt. I would strongly suggest using moly
disulphide grease on it, as that will reduce the risk of further damage.
If nut threads are bad, worth buying a tap and seeing if they will clean
up. Chinese carbon steel taps from eBay are available in a wide range of
sizes, much cheaper than "proper" HSS ones and OK if you only need to
use them a few times. I've bought a few for "odd" things (e.g. when I
wanted to fit "seat belt" threaded screw eyes into some angle iron).
Invest in a tube of Trefolex or similar "cutting" compound for tapping.

And use Moly grease on the bolts in future.

On 05/06/2021 15:58, newshound wrote:
On 05/06/2021 11:08, Murmansk wrote:
OP here

Well, the bolt would only turn a quarter turn, I flooded it with oil
and worked it for half an hour but no joy so with the help of my
neighbour and a metre long bit of scaffolding pole attached to the
spanner I eventually got the bolt out.

Every turn of the bolt took a huge amount of effort even with the
scaffolding pole, the thread is knackered. Only question remaining is
what the thread in the nut that's welded to the mechanism is like -
probably knackered too!

I'll have to see if Witter will sell me a new mechanism


Not surprised to hear that this is your problem, from the original
description. If Witter are unhelpful nut condition can be estimated by
trying with a brand new bolt. I would strongly suggest using moly
disulphide grease on it, as that will reduce the risk of further damage.
If nut threads are bad, worth buying a tap and seeing if they will clean
up. Chinese carbon steel taps from eBay are available in a wide range of
sizes, much cheaper than "proper" HSS ones and OK if you only need to
use them a few times. I've bought a few for "odd" things (e.g. when I
wanted to fit "seat belt" threaded screw eyes into some angle iron).
Invest in a tube of Trefolex or similar "cutting" compound for tapping.

And use Moly grease on the bolts in future.

Or copper grease, a very good suggestion.

Most greases stop pick up and balling of the material from two sliding
surfaces.

In article ,
Murmansk writes
OP here

Well, the bolt would only turn a quarter turn, I flooded it with oil
and worked it for half an hour but no joy so with the help of my
neighbour and a metre long bit of scaffolding pole attached to the
spanner I eventually got the bolt out.

Every turn of the bolt took a huge amount of effort even with the
scaffolding pole, the thread is knackered. Only question remaining is
what the thread in the nut that's welded to the mechanism is like -
probably knackered too!

I'll have to see if Witter will sell me a new mechanism
Have you cross threaded it putting it in?
--
bert

Have you cross threaded it putting it in?
--
bert

No danger of having cross threaded it as it's never been taken out - it just goes up and down through the nut which is welded to the mechanism.

Anyway, a call to Witter revealed that I can get a replacement bolt and the associated nut and its metal support for £15 including postage so I've ordered one.