[shancz]

The uniqueness of this issue has led me to create this thread in the hope that it might be useful to anyone who faces it. Could also be valid for other scooters but not sure on this.
Apologies in advance since I don't have any pics to show(although visually nothing seemed out of place).


Vehicle : Suzuki Access 125 (late 2017), ~11500kms at the time of repair.
Problem : After taking a U-turn the vehicle experiences a weird tugging to the left or right for 15-20 seconds.
Observations :

• Weird : Happens for 15-20 seconds after the U turn and then disappears as if nothing happened.
• Tugging: It was like a series of short tugs to a side instead of a constant pull like it happens if the alignment is gone.
• The duration and severity of the "tugging" was proportional to the lean-angle, with rolling U-turns causing most pronounced tugs for 15-20 seconds.
• It wasn't lean direction specific, U turns lean to the right but the side-stand leans to the left.
• Over inflating the tyres slightly helped but not significant.
• It was weird but not dangerous as I just had to hold the handlebars a bit firmer than usual during the issue.
• Things that were ruled out were damaged wheels/tyres, incorrect tyre pressures and suspension leaks.

Background : This had been bothering me for a long time but since the severity was very low and the the usage is rare it was never a priority. It was mild at start and then progressively became worse(talking a time frame of 8-10 months/~1200kms) to the extent that even if taking a high lean turn or if the vehicle was parked with an high lean the the problem would start the moment I set off.

But it kept "tugging" on my mind as to the why was this happening.
I took it to a nearby dealer's workshop(Mahalaxmi Suzuki, Ranchi) who have a senior mechanic(Mr. Alam) who went on a TD with me and confirmed the issue.

Diagnosis and Repair : A very slightly bent fork(cannot determine visually), which was taken to a lathe under a workshop repair item.
Resolution : The problem was fixed.
Cost : ~ Rs. 500

Probable Cause : As mentioned by the senior-mechanic, normally forks bend in an accident but can also happen if you hit a pothole hard enough(the cause IMO).
For any issue with such handling issues, after checking the wheels, tyre pressures and suspension(for leaks) this is what they do. I asked him how can he order a repair when he wasn't sure of the cause. He said the "tugging" that he experienced was characteristic of a bent fork but he didn't know why it disappeared after 15-20 seconds. He was going by the symptoms and solutions he knew of one by one. But he was confident that it would solve it and it did. So thanks to him for solving it and answering my barrage of questions.


Unanswered Question : Why did it disappear after 15-20 seconds ?

Would be great if any BHPian can answer it, I will update if I can find the answer as well

[Jeroen]

No idea, but I sure would like to understand how a bend fork can be straightened on a lathe!

Jeroen

[vrprabhu]

May be the bent fork resulted in (slight) malfunction within impeding the fork oil flow (restricting oil flow and resulting damping) which got corrected after about 15-20 seconds of driving straight? Most likely the causes could also be due to the spring inside the fork and the fasteners not aligned properly - removal and refit cured the defect as opposed to fork straightening?

BTW, the bend, if any, most likely would have been in the inner tube - and is more often than not result in oil leakage.

Jeroen is right - you can't straigthen a fork on a lathe. Most likely that the tube was checked whether it was 'truly' straight!

[shancz]

Thanks for replying guys, appreciate it.

Originally Posted by Jeroen

No idea, but I sure would like to understand how a bend fork can be straightened on a lathe.

I think that they took it to a specialised workshop which also has a lathe and they just refer to it as "the lathe".
I don't think the guys here are that well versed in technical terms. I will ask him specifically when I visit them next.
All is saw was the front fork taken out of the workshop to somewhere else and in a couple of hours was brought back and fitted.

Originally Posted by vrprabhu

May be the bent fork resulted in (slight) malfunction within impeding the fork oil flow (restricting oil flow and resulting damping) which got corrected after about 15-20 seconds of driving straight? Most likely the causes could also be due to the spring inside the fork and the fasteners not aligned properly - removal and refit cured the defect as opposed to fork straightening?

I am guessing something like this as the mechanic himself wasn't sure of the cause. In my mind I was thinking that it had something to do with the suspension based on the logic that it corrected itself.
This seems like the most probable cause, Thanks

Originally Posted by vrprabhu

BTW, the bend, if any, most likely would have been in the inner tube - and is more often than not result in oil leakage.

Yup, I tried to check for any visible cues when it was taken out but couldn't, the mechanic also said that even after it comes back you won't see a difference but should solve the issue.

[2000rpm]

Quick questions

1. Does it happen on both sides?
2. Is the pulling of consistent magnitude or bumpy? (dont know how to articulate this)
3. Does doing something resolve it faster?

[shancz]

Originally Posted by 2000rpm

Quick questions

1. Yes it happened on both sides. Usually after a U turn the left pull was more pronounced than the right but I also distinctly remember once after a U turn it started tugging right more than the left.
   
2. In simple words it felt like the scooter was drunk
   Attempting to articulate, an example sequence would be : TL-TR-TL-TR-TL-TR(most cases TL was stronger than TR but not always)
   where TL : Tug Left, TR : Tug Right and each Tug would was probably 1-2 seconds of almost similar magnitude before vanishing. I cannot confirm whether the sequence started with a TL or TR could've been either.
   
3. Honestly couldn't try anything intentionally as after the U turn I had to accelerate away from traffic and by that time it was gone. But braking/accelerating/swerving although not intentional didn't make any difference.

I actually want this issue to resurface so I can know more about it. It happened over almost a year during lockdowns so although aware I couldn't focus on it. I will also bug the mechanic again when I go there next.

[bejoy]

Is the brake/speedo cable getting into play here? Like trying to flex back to its position after a U-turn?


Unrelated: Last time my wife reported random 'drunken' behavior from her Honda Dio when going on straight road, I could finally figure out being caused by those groves on the middle of the road cut for laying the fiber by Reliance during mid 2000s. Those groves are narrow, deep and along the direction of road and almost invisible, causes an imbalance when the tyres get in and out.

[shancz]

Originally Posted by bejoy

Is the brake/speedo cable getting into play here? Like trying to flex back to its position after a U-turn?


Unrelated: Last time my wife reported random 'drunken' behavior from her Honda Dio when going on straight road, I could finally figure out being caused by those groves on the middle of the road cut for laying the fiber by Reliance during mid 2000s. Those groves are narrow, deep and along the direction of road and almost invisible, causes an imbalance when the tyres get in and out.

I don't think that the brake/speedo cable can cause that also there was no change in them since day one. this issue started happening much later I guess after the second year of ownership.

I have experienced those grooves too but not on this vehicle. This issue happened over smooth and flat roads.

[vrprabhu]

Bejoy,
I too had similar thoughts on cable flex - but he says there is tugging towards both the sides; unlikely that cable flex resulting in such kind of mild 'wobbling' (if that is the correct way to describe this phenomenon) on both sides.

Another cause could be faulty bearing in steering race - but that will usually announce itself in the form noises arising in the handle bar.

As regards your wife's Dio, the behaviour is 'tramelling' - happens when the front tire treads find a groove (fault line) in an otherwise even surface, the rotation of the tyre tends to stick to the groove resulting in a wobbly feel of the steering.

[shancz]

Originally Posted by vrprabhu

Another cause could be faulty bearing in steering race - but that will usually announce itself in the form noises arising in the handle bar.

It wasn't the bearings, they checked that when it was opened.
Thanks for the term, I didn't know what it was called.

[vigsom]

Originally Posted by shancz

After taking a U-turn the vehicle experiences a weird tugging to the left or right for 15-20 seconds

Have you checked if the front brakes are tightening when the handle is moved to either extreme (L or R)?

You could check this with the vehicle standing on stand. With the front wheel off the ground, see if the wheel rotates free with the handle bar in the center position, and then check the same with the handle bar turned to extreme left and extreme right. If the wheel rotation isn't free, just loosen the brake adjuster by one or two turns and then check.

Sometimes, at service, technicians re-adjust brakes to make the lever travel low and this creates a new issue like what you just reported.

[sameerpatel90]

Even I had experienced this with my 4 year old access. While riding the scooter was driven over a bad pit occurred all of a sudden on a smooth main road at a nominal speed 30-40kmph, riding past a few meters I felt the scooter was pulling one side and difficult to manoeuvre in the turns or changing lanes. The same day I took it to the workshop and it was found out that the fork itself had displaced from its position and there was a bend in the fork and repair cost estimate was provided was 50% of part cost.

Immediately I called up the insurance co. & registered the claim and got the frontal damage covered note, the fender and light which were old damage I bore the cost, as it is the owner's duty to claim a genuine damage and not to fraud the insurer.

I have attached my vehicle photos for reference about the build quality of Indian manufacturers degrading day by day with vehicle costs soaring high.

[spgv]

Originally Posted by shancz

Thanks for replying guys, appreciate it.


I think that they took it to a specialised workshop which also has a lathe and they just refer to it as "the lathe".
I don't think the guys here are that well versed in technical terms. I will ask him specifically when I visit them next.
All is saw was the front fork taken out of the workshop to somewhere else and in a couple of hours was brought back and fitted.

Usually such work shops have hydraulic press as well but referred to by mechanics as "lathe" .

[Rocketscience]

In probability it didn't go away after 15-20 seconds, it is just that you would have picked up normal speed by that time and it no longer remains noticeable.

I say this from experience as i'am noticing a weird pull from the rear in my r15v3 at low speeds and it just comes and goes, it feels as if someone is physically pulling my bike to one side from rear. For further diagnostics i went to empty/deserted roads and just left the handle to check (many might bash me for this as it is not safe to do so) and the bike stayed in line at speeds of about 50-60 but the moment the speeds got below 30 or 20 it started pulling towards left, i replicated it atleast 5-6 times to be sure and it happened everytime, perhaps it is an alignment or fork bend issue like yours but the point relevant here is it went away completely after 30 Km/h and the bike was arrow straight beyond that.
In my case it is not that severe and my dad says it could be because of natural incline of our roads (towards left) for water drainage, i checked on different roads as well but the problem could be replicated, now i'll get the forks checked too, if it bothers me in the future.

[shancz]

Originally Posted by vigsom

Have you checked if the front brakes are tightening when the handle is moved to either extreme (L or R)?

Unfortunately the "bent fork fix" that they did in workshop has fixed it. It doesn't happen anymore so cannot test it.
Normally while cleaning the wheel rotation was free but I didn't check the extreme case.
Thanks for the tip.

Honestly I had not imagined the brake/brake-speedo cables to be capable of causing something like this, but reading the posts here I learned something new. Will keep this in mind. Thanks

Originally Posted by spgv

Usually such work shops have hydraulic press as well but referred to by mechanics as "lathe" .

Correct, watched some videos on fork straightening and the machine was a hydraulic press.
Will visit them soon for a service and FE concerns, will check with the mechanic in detail what exactly was done.

Originally Posted by Rocketscience

In probability it didn't go away after 15-20 seconds, it is just that you would have picked up normal speed by that time and it no longer remains noticeable.

Less likely because the most common use case was :
U turn -> 20kph, tugging starts -> maintaining 30kph, still tugging -> tugging stops, 30kph-> slow down to 10kph for a left turn -> continue at 20kph to the destination(colony roads), no recurrence.

Originally Posted by Rocketscience

perhaps it is an alignment or fork bend issue like yours but the point relevant here is it went away completely after 30 Km/h and the bike was arrow straight beyond that.
In my case it is not that severe and my dad says it could be because of natural incline of our roads (towards left) for water drainage, i checked on different roads as well but the problem could be replicated, now i'll get the forks checked too, if it bothers me in the future.

If the road-bank is ruled out then a constant pull to one side could be the alignment/bent fork too. If possible try over inflating the tyres by 5 psi and see if it makes any difference.
Also in your case it is observed again when the speed drops to 30 but doesn't happen/seem to happen above that.
I am guessing it should be easily identifiable in the workshop, but please check in detail what the issue was. I regret not digging deeper when they were repairing it

Originally Posted by sameerpatel90

riding past a few meters I felt the scooter was pulling one side and difficult to maneuver in the turns or changing lanes.

I think the potholes caused it in my case too. But was yours a constant pull or did it vanish after some time ?
Agree the suspension does seem a bit fragile but don't know how other telescopic scooters are doing.
Thanks for the pics.