How much play is acceptable in rear triangle single pivot suspension?

[Skylark]

There was what I thought was a fair amount of play in the rear suspension of my old Shova single pivot frame, I decided to replace the bearings, I had previously replaced them with Chinese bearings not so long ago so I thought that was the issue, this time I got high quality Japanese NSK bearings. The old and new bearings(before I pressed them out) did seem to be slightly loose in the bearing housing, the bearings are press fit into the rear triangle so that was a concern.

 

New bearings are fitted, I did pack them full of grease before fitting and there's still just about as much side to side play as before, if I use the leverage of holding the end of the triangle at the dropouts with the rear wheel removed I can get that metallic thunk/click sound. I did specifically remove the rear wheel to isolate the suspension play from any wheel bearing play, I've been caught by that one before and in the past needlessly replaced the bladdy wheel bearings, don't forget that if you have a similar issue!!

 

I'm assuming there should be a small amount of play but not much, how much is normal/safe?

[dirtypot]

Is it not a knock/play from the shock mount?

[Mongooser]

tighten everything then try,

otherwise buy a new spi 2 and replace all your bushings

 

https://morewoodbikes.myshopify.com/collections/spares/products/spi-2

 

my shova lt is stiff as a brick

There should be no play on it

[V12man]

Locktite make a product specially for bearings that are a bit loose in the housing - if thats the place the play exists, give it a try.

 

http://www.loctite.co.uk/retaining-9171.htm

 

They have a few varients - not sure which is the right one - but you probably don't need high temp resistance - there is a selection guide somewhere on this site.

[David Marshall]

Both the above.  I would replace the bolts and use a Locktite product.  Cannondale specify Locktite 609 for their bearings.

[Skylark]

Is it not a knock/play from the shock mount?

I took the shock off to take that out of the equation, there still is play/knock.

 

tighten everything then try,

otherwise buy a new spi 2 and replace all your bushings

 

https://morewoodbikes.myshopify.com/collections/spares/products/spi-2

 

my shova lt is stiff as a brick

There should be no play on it

Everything is torqued tight, as was it when I loosened it to replace with the NSK bearings, definitely not loose bolts or fasteners. Didn't know Morewood still sold spares, my SPI bolt is perfect though, it still has a machine fit into the bearing inner and has no play or wear.

 

Both the above.  I would replace the bolts and use a Locktite product.  Cannondale specify Locktite 609 for their bearings.

 

This is what I was planning on trying, I have some "LOCTITE 641 RETAINING COMPOUND" on the way, medium strength that allows future disassembly.

 

Looks like it's the bearing housing, strange thing because there is no signs of wear or ovalising inside the housing, it still has the surface rust stain that the original factory bearings left after I removed them, ie no further wear since then.

 

[DirtyFrank]

Is it not a knock/play from the shock mount?

First thing i would also go, the alu bushings on the Giants/fox top pivot mount always fail and knock, replace with needle bearing upgrade or else you have to replace that cheese every few months if you are a heavy/hard rider. Not sure about Showa design but it used to drive me crazy on my Giants.

[DirtyFrank]

I suspect your bolts are slightly worn.

[Heel Drop]

depends who you playing with

[DubbelBuys]

Serviced my brother's Shova a few weeks ago & the bearings fitted fairly loosely into the swingarm. Secured it with Loctite's Threadlock & it doesn't move or make a sound.

 

Doubt the washers (that fits between the frame & the bearing) have worn out, but worth a shot to try & move the swingarm sideways at the SPI. If it does then it may either be the washers or the bearing (width)

 

It may even be that the bearings are slightly narrower than the original bearing or that your bike's swingarm (where the bearings are fitted into) is machined (slightly) deeper than other Shovas.

 

Also use a clean cloth as a tiny grain of sand can cause a creaking sound that'll drive you nuts trying to search through everything from BB to pedals!

 

Keep us posted.

[Skylark]

Serviced my brother's Shova a few weeks ago & the bearings fitted fairly loosely into the swingarm. Secured it with Loctite's Threadlock & it doesn't move or make a sound.

 

Doubt the washers (that fits between the frame & the bearing) have worn out, but worth a shot to try & move the swingarm sideways at the SPI. If it does then it may either be the washers or the bearing (width)

 

It may even be that the bearings are slightly narrower than the original bearing or that your bike's swingarm (where the bearings are fitted into) is machined (slightly) deeper than other Shovas.

 

Also use a clean cloth as a tiny grain of sand can cause a creaking sound that'll drive you nuts trying to search through everything from BB to pedals!

 

Keep us posted.

The washers are still perfect, black anodised and no wear. I still have the factory bearings and measured them with a vernier, they match the Nsk bearings to the tenth/mm.

 

Interesting that you also noticed the bearings fit quite loose even once they are seated I can move them in and out a few mm by hand, did you apply loctite to the outer race of the bearing or to the pivot lock bolt?

 

One thing I did differently this time is I didn't put grease in the bearing housing, I did the last time and that would take up any small spaces/reduce play in the housing but then eventually get pushed out, the Chinese bearings felt fine at first and then seemed to develop play.

 

Could I use medium blue loctite as retaining compound, I did consider it!?

[Skylark]

First thing i would also go, the alu bushings on the Giants/fox top pivot mount always fail and knock, replace with needle bearing upgrade or else you have to replace that cheese every few months if you are a heavy/hard rider. Not sure about Showa design but it used to drive me crazy on my Giants.

Shock removed, same issue.

I suspect your bolts are slightly worn.

Bolts/spi pivot is perfect, definitely isn't that.

[V12man]

The washers are still perfect, black anodised and no wear. I still have the factory bearings and measured them with a vernier, they match the Nsk bearings to the tenth/mm.

 

Interesting that you also noticed the bearings fit quite loose even once they are seated I can move them in and out a few mm by hand, did you apply loctite to the outer race of the bearing or to the pivot lock bolt?

 

One thing I did differently this time is I didn't put grease in the bearing housing, I did the last time and that would take up any small spaces/reduce play in the housing but then eventually get pushed out, the Chinese bearings felt fine at first and then seemed to develop play.

 

Could I use medium blue loctite as retaining compound, I did consider it!?

You could use it - but rather use the correct product - there is no way that you should be able to move the bearing in the housing by hand easily - 641 should sort it out.

[DubbelBuys]

The washers are still perfect, black anodised and no wear. I still have the factory bearings and measured them with a vernier, they match the Nsk bearings to the tenth/mm.

 

Interesting that you also noticed the bearings fit quite loose even once they are seated I can move them in and out a few mm by hand, did you apply loctite to the outer race of the bearing or to the pivot lock bolt?

 

One thing I did differently this time is I didn't put grease in the bearing housing, I did the last time and that would take up any small spaces/reduce play in the housing but then eventually get pushed out, the Chinese bearings felt fine at first and then seemed to develop play.

 

Could I use medium blue loctite as retaining compound, I did consider it!?

Yes I applied the loctite to the outer race & a little bit inside the swingarm.

 

Applied grease to the SPI bolt & inner race.