Synapse Freehub issue

[fraz101]

So my friend has a Cannondale Synapse and he asked me to take a look at it for him.

When moving the pedals backwards the chain goes slack….also when freewheeling there are some nasty noises from the wheel.

I removed the rear wheel and found the cassette had a lot of free play in it, also when I turned the cassette it is rough as toast.

I am presuming the 2 issues are likely both related to the same problem?


Is it likely I can remove the cassette,remove the Freehub ball bearings and clean,re grease and refit or replace the bearings or is it likely the Freehub body will need replaced altogether? The wheel bearings feel perfect when I tested these,just to add.

Also I presume the only special tool I will need to carry this out would be the cassette removal tool?

 

[Cycleops]

You'll just have to remove the freehub and see what you find. Remove the axle and then the freehub. Most are held on with an Allen key, 9 or 10 mm I think.
You may find it's worn and needs replacing.
Plenty of videos on on YouTube.
And yes you'll need a cassette tool and a chain whip.

 

[fraz101]

Thanks.

It has 11speed 105 and a through bolt axle on it.

Are the Freehubs readily available and would I need to buy the ball bearings seperately?

 

[T4tomo]

It's possible a shagged wheel bearing, nothing to do with the freehub, and the wheel bearing is likely to be a press fit sealed unit, which your LBS can replace.

 

[Cycleops]

If it's a Shimano a replacement should be readily available if you can find the part in stock. Other brands may be more difficult to source.

 

[fraz101]

It's possible a shagged wheel bearing, nothing to do with the freehub, and the wheel bearing is likely to be a press fit sealed unit, which your LBS can replace.

The wheel bearings feel perfect?
I can only feel free play from cassette and roughness when turning cassette with wheel removed

 

[Cycleops]

Bearings would be felt at the rim. What you describe is likely a freehub issue.

 

[fraz101]

Would I have to buy ball bearings as well as a Freehub if replacing?

 

[Cycleops]

I shouldn't think so. You might find this list useful in finding your freehub. It appears Cannondale use their own freehubs:
https://www.cannondalespares.com/freehub_finder
It seems that Formula hubs were used as well in the Synapse. You might find this previous thread interesting:
https://www.cyclechat.net/threads/cannondale-synapse-2020-freehub.269447/

 

[fraz101]

Thanks!
Out of stock until October….Yikes

 

[Cycleops]

Sorry, all too common story with Shimano parts right now. You could always lace in a new hub.

 

[fraz101]

Sorry, all too common story with Shimano parts right now. You could always lace in a new hub.

I’ll buy the cassette tool and see where I’m at with it.
Thanks for replies

 

[si_c]

Probably worth spending the time to disassemble and regrease/reassemble the freehub if the lead time is that long, a quick google shows that whilst other sites list the item they also show it out of stock.

 

[fossyant]

Would I have to buy ball bearings as well as a Freehub if replacing?

If lucky, the freehub may have cartridge bearings which are simple to replace and will fix the play and roughness

 

[fraz101]

If lucky, the freehub may have cartridge bearings which are simple to replace and will fix the play and roughness

Where is good to buy cartridges?