Tapered Roller Bearings - Why?

[850 Combat]

Tapered rollers are way easier. I've had the loose balls roll about and then get dirty, and I have to clean them, etc. I have wasted time and daylight looking for them. Caged bearings are easy. Commandos have sealed roller bearings. They don't appear to be tapered, but you can't see in.

I'll always replace with rollers if I need to get in there.

[mrbill5491]

Tapers last longer, handle loads better and as far for the extra friction is concerned it's negligible.

[Steve]

Yep tapered rollers might last longer, but they are not invincible.

This is what came out of my son's 650L:



.

[BentRod]

If the stock bearings are in good shape I'd regrease them and call it good. Tapered rollers are cool and all, but millions of bikes got along just fine with ball bearings in the steering neck.

I am going to preface this by pointing out that I usually respect and sometimes, even support the advice that Nessism lends. Definately has helped me out from time to time.

BUT: Please, unless you are familiar with the stress/stain calculations for axial and trust bearing loads, please do not, anyone, go redesigning these critical parts of your bikes.

A pair of tapered roller bearings locks the steering stem from moving up and down. Ball bearing will always ave a small amount of play, even if preloaded. The larger contact area and inclined angle of tapered roller bearings also increases the stiffness of the rotating joint - less flex/better feel

[Nessism]

I am going to preface this by pointing out that I usually respect and sometimes, even support the advice that Nessism lends. Definately has helped me out from time to time.

BUT: Please, unless you are familiar with the stress/stain calculations for axial and trust bearing loads, please do not, anyone, go redesigning these critical parts of your bikes.

A pair of tapered roller bearings locks the steering stem from moving up and down. Ball bearing will always ave a small amount of play, even if preloaded. The larger contact area and inclined angle of tapered roller bearings also increases the stiffness of the rotating joint - less flex/better feel

Tens of millions of motorcycles have been sold with nothing more than special design ball bearings in the steering neck. I agree that taper roller bearings will be more durable, but I wouldn't go off replacing the ball bearings that came with the bike from new unless they are worn out.

[TooManyToys]

Yep tapered rollers might last longer, but they are not invincible.

This is what came out of my son's 650L:



.

That looks like the bearings were set without proper preload.

A number of years ago a US auto manufacturer was hanging an issue with it's new vehicle platform launch were the vehicles were having excessive warranty for bad front wheel bearings in a short time after purchase. Came to find that the bearing races were developing the same condition during rail and truck transport. While the first assumption was that the bearing supplier was providing races without the proper hardening, it later turned out the the bearing torque spec was improper during vehicle assembly, allowing the constant hammering of the rollers against the races was the issue.

[TooManyToys]

i am going to preface this by pointing out that i usually respect and sometimes, even support the advice that nessism lends. Definately has helped me out from time to time.

But: Please, unless you are familiar with the stress/stain calculations for axial and trust bearing loads, please do not, anyone, go redesigning these critical parts of your bikes.

A pair of tapered roller bearings locks the steering stem from moving up and down. Ball bearing will always ave a small amount of play, even if preloaded. The larger contact area and inclined angle of tapered roller bearings also increases the stiffness of the rotating joint - less flex/better feel

+1...............

[UncleMike]

As it turns out, my boxes of parts for these bikes came sans-steering stem bearings, so it looks as though the tapered upgrade will indeed happen.

Anyone have recommendations for a good brand/source?

[Sandy]

As it turns out, my boxes of parts for these bikes came sans-steering stem bearings, so it looks as though the tapered upgrade will indeed happen.

Anyone have recommendations for a good brand/source?

A company called Alls-Balls???? Has stuff on ebay quite often with fitment for most bikes. Tapered is the way to go but on a bike that size it's probably not necessary but if you're changing them anyway....... Honda even used balls on the early CBX and VF bikes

[UncleMike]

I though 'All-Balls' was supposed to be cheap Chinese crap?

[Sandy]

I though 'All-Balls' was supposed to be cheap Chinese crap?

I don't know that for a fact, but wouldn't be surprised. Maybe see if they have a fitment chart with the bearing numbers or just take the old bearings or measurements to a local bearing shop and they can probably match up a set from stock. Either way, shouldn't cost much.

[UncleMike]

These seem a pretty good deal, but they don't list the '78 as an application.

However, looking at these it seems they all use the same dimensions?

Agreed?

[Steveb64]

These seem a pretty good deal, but they don't list the '78 as an application.

However, looking at these it seems they all use the same dimensions?

Agreed?

No guarantees... But they should be OK. I found the manual I was referring to above - an old Clymer one - it just shows balls being used - but it only covers up to 1976. But back in those days, Yamaha was pretty good about 'standardising' as much as they could across model years - and across models too, if they could!

It would be an idea (if not too much hassle?) to try and fit seals to the steering stem too - one above the top bearing, and one below the lower one - which is the usual setup for OEM standard tapered bearings on dirt bikes.

[Agemax]

i know these are in the uk but these seem a pretty good buy. both bearings, 2 seals and bearing grease.

http://www.ebay.co.uk/itm/Yamaha-DT175-74-86-Steering-Head-Bearings-SEALS-/390315519022?pt=UK_Motorcycle_Parts&hash=item5ae09e2c2e#ht_1576wt_1271

[mrbill5491]

I kind of remember back in the early and mid 80s there were some upgrade tapered bearing kits being offered to replace the old ball type bearings in the steering heads. I don't know if those are still around any longer since most bike manufactures have switched to the tapers.