Tapered steering head bearings -- worth it?

[xwhatsit]

'Lo,

My front end feels a bit loose. Hit some bumps at around 110kph on the Northern and went into a weave. Steering head bearings no doubt; they get a thrashing (gravel roads, shit suspension -- and today, running too hot into a left hand side road (sleepy), front wheel pushed on some leaves, ran wide and mounted the 45-degree kerb traffic island ). I know if I tighten them up, I'll notice that they're notchy.

Anyhow, classic 70s tech, ball bearings. I'm told taper bearings do wonders for handling -- are they really all that? I can get new ball bearings for bugger all; taper bearings are going to run me £23 from David Silver (bonus prize if you can find me a cheaper kit). Worth the money? Or stick a new set of balls in?

Do I need special tools to do the bearings at any rate? Haynes starts talking about applying heat, which worries me somewhat. Probably induce some frustration. I don't have `heat', whatever that means. Any kind souls with a garage and some `heat source' want to drink some beer they didn't pay for and help me do it?

Cheers guys.

[Ixion]

Hm

This is a VERY long standing discusion. Some bike are MUCH improvd by taper rollers in the head stock. Some bikes it makes bugger all difference.

Generally, changing is not not trivial. Expect to need access to arc welders and such like .


My own opinion FWIW, is that that a rider is better to focus on improving rider skills, rather than expecting a change from one type of bearing to another to produce wonderful improvement without rider effort.

After all, if using a different type of head stock bearing would produce such an enormous improvement in handling, would not the manufacturer have done that in the first place?

EDIT: However, given the identity of the OP, it may be assumed that all reasonable rider based initatives have already been actioned.In that case, a more rigid headstock may be of advantage. For lesser riders than the Persian gentleman , forget it,

[xwhatsit]

Because it's ancient and they weren't using them back then?

I understand where you're coming from, but I'm not looking for a peg-scraping sort of handling improvement, just a bit more, er, steering stability perhaps. I'm well resigned to the flaws of my motorcycle, forks and swingarm flexing, suspension bottoming out mid-corner and causing pegs to make contact with the ground. Not worried about, just ride around it and enjoy the experience

Arc welders? Shite. Thought one would just pull out the balls and shell then drop in the taper bit. I'll show you what I'm talking about -- http://www.davidsilverspares.co.uk/p...ts/part_28287/

[xwhatsit]

EDIT: However, given the identity of the OP, it may be assumed that all reasonable rider based initatives have already been actioned.In that case, a more rigid headstock may be of advantage. For lesser riders than the Persian gentleman , forget it,

Ahaha you flatter too much -- we haven't gone for a pootle yet, I want to learn from the master of thrashing old shit

EDIT: Looky, here's some on Yahoo Japan. UEDA RACING has got the good shit for 250RSs. Square section swingarms and Keihin CR33s. $60 is a bit much, though. I'm just really convincing myself, aren't I? http://page17.auctions.yahoo.co.jp/jp/auction/v54307170

[Ixion]

Yeah, it's the "pulling out the outer race" that's not so easy.

If you can replace ball races with taper rollers , go for it, nobody ever regretted it.

But it won't make bugger all difference to handling except as part of a bigger picture. I think you understand that, most won;t

[xwhatsit]

Ah, cheers. The race being the little `ball cup'? I'll do a bit more research then.

Thanks for the advice. Can't make it handle too good, otherwise I might as well buy an RZ250.

P.S. 6-speed XR250R gearbox and crank/counterbalancer is on its way

[xwhatsit]

Oh! I must ask while I'm at it, swingarm bushes! What's the done thing there? Bung in the four-poond-fifty standard ones? Phospher bronze or whatever it is -- merely an improvement in longevity? I can't find any movement in the swingarm on the centre-stand, but if I do them now and grease them nicely then I won't have to worry about them for a long time.

At least the swingarm spindle hasn't seized.

[Kickaha]

Thanks for the advice. Can't make it handle too good, otherwise I might as well buy an RZ250.

I haven't ever found a noticable difference in handling converting bikes to tapered rollers and I have done a few, most sets from a bike shop were about $80

The old bearing races are easy to get out with a long drift, the bearing races from tapered rollers on the other hand are quite often a prize prick to remove

[Taz]

What year is that XR250R gearbox? Thought only the XR250A was compatible with the CB250RS?

[xwhatsit]

What year is that XR250R gearbox? Thought only the XR250A was compatible with the CB250RS?

This would be the pre-RFVC XR250R, 1981/82. Same motor as the earlier XR250s/XL250s, but very slightly modified (until now I didn't know they were any different, look identical from the outside). 6 gears and only one counter-balancer, which is gear driven instead of chain driven (yay! No more of adjusting those pricks!).

Hence needing the crank, too.

NordieBoy (who has done the conversion) thinks maybe I'll need to machine a bit off the inside of the cases too.

@Kickaha -- thanks for the info! So just a long drift and tap out the ball cups. As for putting the tapers in, I'm thinking about using a socket or PVC tube or summat and tap them in gently. May not be a handling difference, but in terms of longevity it should be worth it.

You guys rock. Cheers.

[FROSTY:Me]

$25 for a set of head bearings thatll probably last the lifetime of the bike. (whats left of it) sounds value for money to me.
Now to get the old race out--Yep I agree with kickaha 100%
ya heard the song --"some days are diamonds some days are stone" ? getting head bearings out is a bit like that--some are straightforward some a pain in the arse.
Couple of tips for fitting the tapered bearings.
1)as soon as you get em home bung em in the freezer--next to the frozen peas.leave em there as long as you possibly can--ie Hours/days.
2) clean up your headstock checking for burrs from when you removed the ball race.
3) when fitting the top bearing shell make sure you put it in dead flat.Best way to do it is to use a bearing press.
4)once its all together dont be at all suprised if it all loosens up again after a short while.You usually need to retension em twice.

One advantage of taper roller bearings is you can crank em down a few extra pounds. Making your steering a tadd heavier but acting to a degree as a steering damper.
Whilst yer doing em why not change ya fork oil and check yer front wheel bearings?

[geoffm]

The advantage of rollers is they don't go notchy as quickly as ball bearings. There is no difference if they are both as new.
The bearing sizes are usually oddballs, so no going to SKF and buying drop in replacements - you are stuck with the aftermarket replacements, which are average quality bearings.
As Frosty said, since the front end has to comeo off anyway, strip and clean out the forks. Check the slider bushes for wear and slop.
I used a piece of threaded rod to pull the new bearings into place without mangling them. I also usually field a couple of grooves in the headstock socket so a drift could knock them out later.
A mig welder is the best way of getting old taper roller races out if they don't want to play - a squirt on th inside of the race makes them shrink and they drop out. A sharp chisel or air grinder (Dremel) takes care of the other half.
Should be an easy job.
Geoff

[xwhatsit]

$25 for a set of head bearings thatll probably last the lifetime of the bike. (whats left of it)

What does that mean? Cheeky man! This bike is Grandfather's axe

I've actually done the forks completely (seals, oil, the works) in November or December or something and the front wheel bearings (and new wheel) a month or two ago. Might pop spacers in the top of the forks though, set the preload. If I can find some springs cheap I'll be happy.

Cheers for the advice everyone. Not $25 though, 23 British pounds plus shipping from David Silver Spares. Anything that reduces maintenance is a plus though, I do cover some reasonable mileage and expect to keep the bike as long as I'm still alive.

Alright, sounds like I can do it then Nothing wrong with a bit of education.

Anybody have any thoughts on the swingarm bushings?

[FROSTY:Me]

HMM--Been thinking about this whilst tinkering in the gargre.
If you have a spare frame why not measure up the dimensions of the factory bearings.
The idea being to get a tapered roller bearing with same height and same ID possibly slightly bigger OD. Then get the outer race machined to the correct OD.In the perfect world youll find a bearing at saeco or auckland bearings which is exactly what you want/need -and I bet heaps cheaper than 50 odd bucs

[xwhatsit]

Hey, that's not a silly idea. I keep meaning to do something with the spare frame -- mostly I end up just measuring it for silly things like you say