XS650: Steering-head Bearings

Many of our girls have been steadily rolling those kms by year after year. Others have been doing regular service on flattracks, in sidecross, as offroaders etc..

Today, as we uncover these grand ol damen, years of riding and often neglect have taken their toll. A common complaint is ‘positive click’ steering, great when you only want to go straight.

 

positive click steering … dry

 

 

Original balls and races are commonly replaced with tapered roller bearings. The upper and lower have differing dimensions so dont mix them up.

 

bearing dimensions

 

 

• Upper:  25 x 48 x 15.2
• Lower:  30 x 48 x 15

 

tapered roller bearings

 

A word of advice. The roller bearing races are not as wide as the ball races. Makes it difficult to tap them out when replacing later. Before pressing the roller races in, cut 2 notches in the steering head race seats. Top and bottom.

If you dont do this you might have to weld tabs on the races so you can get them moving before removing them next time.

 

handy tool … actually for my downhill bikes

 

I had one of these lying around. I use it for my and my mates Downhill bikes. Pack the new races with those you removed, they’re the same OD so will clear the insides of the steering-head end flanges. This works great too.

 

a bit of old threaded rod … use the old races as spacers

 

If putting your machine together from bits n pieces don’t mix the early and late triple trees. They both take the same bearings. The early are for 34mm fork tubes. The later for 35mm tubes. The earlier shaft is shorter too.

 

early and later stems … early is threaded all the way and shorter … won_t fit into a later steering-head

 

The tapered roller races are somewhat narrower. This could be a problem if needing to remove them. Something like this may come in handy.

 

 

removing races

 

So

 

Now, if you’re serious about handling, are looking for that exstra little handling advantage, steeringhead and swingarm bearings will be one of the first places to look for results.

This is all well and good, and for the average rider, gives positive results for sure.

Problem is that the stem bearing seats themselves are often found from new to have up to 0.1mm play between them and the bearing ID.

And, as the roller races are so thin, they get squeezed out-of-round when pressed into the steering head. This is what gives the infamous clacking sound commonly heard in roller bearings. Point loading. Not good. Run a 48mm ream around the inside of the race-seats to rounden them up – no tight spots. If necessary spin a little off the outside of the races – just so they can drop into place. Glue with something like Loctite 638. Work quick. Get the triples in before the glue sets – insures the races are in line.

 

 

up to 0.1mm play from new … easily 0.15mm with wear

 

Emil Schwarz produces precision bearings with this in mind. Bearings are pressed onto steeringhead nuts and tightened down for a perfect form fit. No tolerance. No play. Use Type 5 for the XS650.

 

 

upper bearing

 

Emil Schwarz also produce precision swingarm bearings. Couldn’t find a listing for the XS650. They provide an installation service and state….

Wir geben eine 100.000 km Garantie auf Spielfreiheit dieses Lagerumbaus !!!

We give a 100,000 km No-play Guarantee on this modification!!!

They sure believe in themselves.