Taper Roller Ring Removal

[Stephen Harris 5Participant @stephenharris5]

Colin.

I live near Droitwich, Worcestershire and if you can get to me I have welders, a lathe , various pullers and an hydraulic press. Should be able to get it apart somehow.

Steve Harris

[COLIN MARTIN 2Participant @colinmartin2]

Hi Steve,

That's very kind of you. I will get around to looking at the job sometime in the Winter (I'm still riding at the moment) and will assess the situation!

Thanks for your help,

Colin

[COLIN MARTIN 2Participant @colinmartin2]

Update!

I have finally got around to doing this job (which involves a lot of parts removal). The situation is worse than I remember from doing the last one.

I will try to describe the set-up as best as I can.

 

The headstock is a length of large tube which is machined at each end for the taper roller rings to be fitted – so far, so good, but the problem is that there is a steel ring welded inside the tube at each end which the bearing rings butt up against, and this ring is a smaller id than the bearing ring, which means that a punch cannot be located against it because it is obscured by the steel ring. Quite why the Spanish company (Mototrans) decided to make it this way I do not know, probably to add rigidity to the headstock?

Now for the good news – both bearing rings are out! When I replaced the bearings previously on my other bike with the same set-up, I fashioned a punch out of a very large screwdriver which I heated and bent so that it would gain a purchase on the bearing rings; it took days to find a way to get them out and this punch was my final attempt before I gave up, and it only worked after I ground through the old rings first. So, I thought that this time I would give it a try just to see if the rings would move, and the bottom one came right out; great! The upper one was more difficult because I was punching upward and had to hold the punch in place with a piece of tube as a lever, but after a while it began to move. I think that it was easier this time because the rings have been replaced in the past, so the housings are a bit looser and they were not rusted in, but boy did they need replacing!

The question now is should I just fit new rings and forget about making the job easier next time? At my age and with the miles that I do, there probably will not be a next time, but you never know… I could grind two recesses in the steel rings that will allow a punch to gain a proper purchase on the bearing rings, but will this weaken the headstock? It is subject to some strong braking forces and those steel rings are probably there for a purpose. Possibly Mototrans used to make a tool that may have expanded into the recess and would have enabled the bearing rings to be extracted; something like a giant circlip would do the job.

Anyway, thank you for all those who offered help and advice.

 

Cheers,

 

Colin

[bernard towersParticipant @bernardtowers37738]

Definitely grind a couple of recesses while it is apart it may not be you in the future but whoever it is it will make them smile!!

[noel shelleyParticipant @noelshelley55608]

It’s always good to hear the outcome of a problem, thank you. If grinding a recess x2 I would position front and back, or make a plug and drill say 1/4″ on the joint line.  Good luck. Noel.

[Howard LewisParticipant @howardlewis46836]

can only agree with those recommending producing diametrically opposed gaps in the backing rings, to allow access for a punch or puller, should the need ever arise again.

Howard

[John Doe 2Participant @johndoe2]

I really would NOT drill any holes or file any slots in the headstock.

As you say, the rings will have been added for a good reason. If you weaken them and one day the headstock collapsed or split under heavy breaking or cornering, it could cause a fatal accident, or severe injury to someone.

That might not be you but it could happen to the next owner.

I would not risk creating a stress riser in the headstock, a failure of such a high stress part whilst the bike is being ridden does not bear thinking about.

But, if or when there is a next time, buy or rent a welder to extract them. Or while the bearings are out; machine up a spreading collet that will expand outwards and contact the tiny ridge there is under each bearing, in order to pull them out with a hydraulic puller next time.

[COLIN MARTIN 2Participant @colinmartin2]

Thanks for the replies! I am still thinking about what to do while I wait for the new bearings to arrive. I have examined the old bearing races and the were not worn, but water has rusted them and allowed the rollers to create recesses. This bike had been stood for ten years, so I believe that condensation could have caused the damage.

 

Cheers,

 

Colin

[David George 1Participant @davidgeorge1]

Hi Colin have you managed to remove the bearing rings.

David

[Taf_PembsParticipant @taf_pembs]

Hi Colin,

Glad you got them out.. and nice one for the update.

Having previously owned a motorcycle shop I have replaced countless head bearings.

Headstocks are generally only 2 types, with alloy frames the headstock is generally a cast and machined part and the seats for the upper and lower bearing cups have opposing ‘half moon’ recesses machined into them, usually but not always with the sharp edges rounded (usually the steel framed bikes that didn’t).

Steel framed bikes had the structural steering tube with, as you say, what is essentially a large washer welded in as the bearing seat while the frame is in the jig or the bearing seat was formed into the tube with enough room for a drift to get to the bearing. They also have the same recess’s cut into it.

The recess is generally about only 3mm ish less than the inner diameter of the cup, just enough for a decent drift to get a bite.

Looking down on the lower baring seat, a bit like this.. (sorry, quick jobbie in Paint!)

The upper one being the same.

We didn’t do a great deal of vintage bikes so I’m not really in any place to comment on their set up.

Then the budget imports began to arrive from the far east.. and it wasn’t long before I decided that for our own sanity and to prevent the easily foreseeable problems we would advise people on them but would not work on them as most of the time if you could get parts they were often worse than what you were taking off! Before we stopped, the headstocks on them would usually have just a plain ‘washer’ welded in as an after thought as the bearing seats (and rarely true to the headstock tube!) preventing any reasonable means of removing the bearing cups (basically a proper bodge).

Obviously I can not recommend that you file yours in a similar fashion for the reasons clearly stated above by J D 2 but it might be worth talking to your local bike shop for advise as they will see many differing set ups (ignore the newer sports bikes, they have adjustable insert bearing carriers to allow geometry changes to the rake and trail etc). They may well take a look and say go ahead or advise against it based on the set up.

Anyway, it’s a good excuse to have a wander to a bike shop for a cup of tea.. 🙂

[COLIN MARTIN 2Participant @colinmartin2]

Hi David, yes got them out – see my above post for a description.

Hi Taf, my frame has the washers as you describe (well, more like a  round ring welded in) but there are no recesses to enable a drift to be located – the bearing rings are completely obscured. When the frame was made in Spain, the factory never bothered to mask off the  the bearing recesses, and they simply drove the bearing rings into them over the paint, making them almost impossible to remove.

 

Cheers,

 

Colin

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