De rosa sk pininfarina 2016

[iwsa]

Has anyone any experience with headset issues on these bikes?
the problem being is when applying the front brake the wheel is pulling back under load far to much. The headset and bearings have been changed but still the same issue.
the problem appears to be coming from the lower fork, in what appears to be a very dilly design on them. I cant find any tech docs online and De rosa are not coming back to me with info.
any help would be appreciated

 

[iluvmybike]

Put brakes on whilst static and check for any movement of fork - you may need to put a hand on the top & bottom bearings to feel it. Any play needs to be removed.
Also when fork was removed to do headset was it checked over - look especially at the crown where the steerer tube enters the fork lower body and inspect for any cracks. Check the fork ends for adequate thickness and no cracks.
Also have you checked security if wheel q/r?

 

[iwsa]

Yes all that done and all looking ok
I have a feeling the issue lies with the lower bearing seating. Does de rosa sk use any special fixings around this area which may have been lost on this bike

 

[AndyRM]

I have no idea about the specific frame or fork, but I know that doesn't look right or safe. If you bought it from a shop, take it back. If it was an online purchase, e-mail the retailer that picture, and perhaps another from further back.

 

[Deleted member 1258]

Yes all that done and all looking ok
I have a feeling the issue lies with the lower bearing seating. Does de rosa sk use any special fixings around this area which may have been lost on this bike

That definitely doesn't look right, has the headset been put together wrong?

 

[iluvmybike]

it does look like the bearing isn't sitting properly in there and that will likely be causing the play. The 'gap' should be even all the way around. The bearing should be inserted in there and fully homer with the bevelled side pointing upward. The odd shaping on the from crown is there just to ensure the fork clears the frame as your turn it. But the bearing doesn't look seated right

 

[Ian H]

Call me paranoid, but, looking at that, I'd want to check that the steerer is still firmly attached to the fork crown.

 

[iluvmybike]

It may also be that the crown race (if it isn't an integral one) is not sitting down on the fork crown snugly either

 

[boydj]

I would check that the fork is not the wrong way round. It's certainly not sitting correctly in the head tube.

 

[themosquitoking]

Yes all that done and all looking ok
I have a feeling the issue lies with the lower bearing seating. Does de rosa sk use any special fixings around this area which may have been lost on this bike

This is what it should look like, not sure what is happening with yours though. De Rosa importers into the UK at the time were i-ride.co.uk might be worth asking them.

 

[iwsa]

Ok thanks all.
its a nightmare trying to sort it. Ive put a new race crown on, new bearings and still its nowhere near. I was hoping someone with an sk on here could tell me what setup they had, bearings etc. Ill send the importers a message. Thanks

 

[iwsa]

Update
I ride have mentioned that the steerer may have detached from the fork????
has this happened to anyone on any bike?
the steerer feels secure enough on the fork and no obvious signs its detached

 

[iluvmybike]

It can happen and it is very dangerous! If that is suspected then do not use the bike - if it separates whilst riding then a very nasty spill would occur. The fork needs to be inspected by the manufacturer or a professional mechanic

 

[Ajax Bay]

If the OP has taken out the fork and given it a good check (as in putting a bending moment on it, all ways/both axes) - which they have - then it is reasonable to judge the risk of steerer/fork crown detachment as very very low. There is no evidence (sfaik) other than "call me paranoid" @Ian H looking at the gap and suggesting it was worth checking. The gap does look odd and the described symptoms of a headset 'not right' are unacceptable, and need to be sorted. The OP asked: "anyone any experience with headset issues on these bikes? " So far noone has.

 

[iwsa]

Ok
Im 99% certain that the problem lies with the lower bearing seating in the frame(integrated cups) It looks like the carbon has been worn away unevenly and this is the cause.
Now the question is how to fix this? I have used epoxy resin on a recent BB where the metal shims had fallen out as a result of carbon wear. Not sure this will work here though as i want to be able to sand it down etc to get a good finish and which side do you build up?
View: https://youtu.be/wkA3VTHYSUA