S*dding bearings

[Moff]

A mini poorly conducted rant....

Trashed the front wheel bearings on the road bike during last Beercycle Club BAM (Brewery-a-Month) ride, which was done in rather damp conditions amid storm Dennis.
Only having ridden it recently whilst hidding inside on Zwift, thought I'd replace the bearings in the hope's that I'll be able to get back out in the big wide open sometime soon.

Quick inspection of the wheel (partial hub strip down) revealed 61903 moulded onto the bearing seals - great 6903 are a straight swap, so ordered some lovely Enduro ones.....

......except they're not the same.....

.....spot the difference.....



Turns out the lovely(?) folks at Fulcrum have used an 18mm bore bearing which it turns out is a 18307 or a RT-004 bearing kit.

Frustrating waste of time, not that it really matters loads of time for twiddling thumbs at the mo, just glad I wasn't expecting to get out this weekend.

Anyway, new order placed with Wych Bearings for the Enduro versions. End.

[sean_iow]

It is annoying though. As the dub crank bearing thread also showed, it appears that the numbers don't always correspond to the bearing code, there should be a law against that kind of thing!

Luckily 6903s fit loads of things, Hope hubs I think from memory.

[survivor]

I learnt this one the hard way at work....

My new rule.

Measuring bearing then order off size. Not the code on the seal

[Moff]

I learnt this one the hard way at work....

My new rule.

Measuring bearing then order off size. Not the code on the seal

Being an engineer I should really have known better

Though I do find the mis-numbered seals a bit weird as that numbered seal doesn't fit between the two races, it's too big!

[AlasdairMc]

On the subject of bearings, I’ve just discovered the joys of a blind bearing puller. No more tapping around a bearing hoping for the best. Amazon have them from £22 up depending on the sizes needed.

[BigdummySteve]

Turns out the lovely(?) folks at Fulcrum have used an 18mm bore bearing which it turns out is a 18307 or a RT-004 bearing kit.

Ba****ds! First against the wall come the revolution

I had a vaguely similar thing with a bit of lifting gear, some bolt or other, obviously not metric so I get the pitch gauges out and measure the outer and core diameter. Not whitworth, BA or any of the parallel pipe threads. Proper scratching my head, an Aussie guy I worked with took one look and said “railway thread” working in the bush then a remote Scottish island you get good at fixing stuff.

[survivor]

. Though I do find the mis-numbered seals a bit weird as that numbered seal doesn't fit between the two races, it's too big!

It's fulcrum... From my experience they'll have probably got a batch of mislabeled bearings on the cheap from a supplier..

They have form