Fulcrum 5 front cartridge bearing replacement

rjkflyer Posts: 102
edited August 2017 in Workshop
Posting this here as there seems almost no useful info on this subject almost across the www.

Fulcrum's TechDocs aren't right and/or are unhelpful, regarding these "Industrial Bearings" - i.e. cartridge bearings - and many Board posts are plain wrong - referring to unscrewing imaginary nuts.

Friend has Fulcrum 5s and after washing the bike, the front wheel barely rotated a day later. Bottom line was that one bearing cartridge was COMPLETELY solid - the wheel was turning only due to the cartridge bearing rotating on the axle!

To service:
1. Remove wheel and skewer
2. Using two blunt levers (to avoid damaging you and the wheel, and to provide even lift) prise up and out the axle end caps (the bits with knurled ends which register against inside of fork). They will come out slowly as they have O-rings set into a groove, and reveal the aluminium axle.
3. Undo the Allen screw in the end float adjuster - no need to remove
4. Unscrew the end float adjuster off of the aluminium axle
5. Prise out the plastic bearing cover from each end, revealing the bearings (which reside under a shiny washer)
6. Remove the axle from the opposite side of the wheel (there's a raised ring on that end, which registers against the centre face of the bearing)
7. Note that a washer will come off each side and make sure you note which way around it is - it is NOT reversible!

At this point you can either GREASE or REPLACE the bearings. If you've gone to this trouble, replace them! They're freely available as a 6903-2RS bearing from many decent suppliers, for a few pounds each and these are quite good wheels. Don't buy some Chinese junk - buy SKF or similar, or even splash out on some ceramic ball - stainless cage ones.

To remove bearings:
(a) Find a rod that will *just* slide through the axle hole - such that you can get a decent registration against the INSIDE of the bearing on the OPPOSITE side
(b) Place wheel with hub down against something non-damaging like hardboard or hard rubber
(c) Insert your rod through one bearing down to the inside of what is ow the 'bottom' one
(d) Use your choice of soft-ish hammer to drive the bottom bearing out of the hub - a couple of sharp taps should do it
(e) Turn wheel over and repeat.

We actually haven't got to putting the new ones in yet as they're in the post!

However, various options:
(i) Use a piece of threaded rod with washers and nuts to draw new bearings in in parallel
(ii) See if you can do similar with rear skewer (it's longer) plus washers
(iii) Drift it in using a large socket which registers against the OUTER race

Key point with replacement is that you want pressure on OUTER or both races of the new cartridge - NOT the INNER. It's the outer face that is frictionally fitting to the hub - so don't be tempted to drive them in off of the inner race. (When we remove the bearings we hit off the inner face as we don't really care since they're being changed).

Then add all the stuff back - and adjust end float etc.

Hope someone finds this helpful.


  • robertvb
    robertvb Posts: 1
    edited August 2017
    As the friend of RJKflyer who has these wheels, I would also add that these appear to be the same or similar to Campag Scirocco/Vento wheels. Wiggle even sell the end caps listed as "Campagnolo Scirocco Front Hub Axle End Caps" for £10.99. The pictures on their web site show the rubber O ring that retains the caps on the axle. The Campag web site has far better diagrams of the hub assembly so for those that thought these wheels were "throw away" and unrepairable, hopefully you still have them!
    I am replacing the bearings with stainless/ceramic which I obtained for around £25 at Wych Bearing Ltd in the UK

    UPDATE. Have fitted the bearings and used a socket that just fitted the outer shell and the skewer with a strip of steel and a hole drilled in it at the other end to push the bearings in. Very easy and whole job no issues. When adjusting the "slack" I tightened up the adjuster and backed it off by 90 degrees. No idea if that's right but the supplier of the bearings said not to over tighten due to heavy wear. I will take it for a run and re-adjust if required.
  • trekvet
    trekvet Posts: 223
    Your socket method is good for inserting bearing. Years ago when putting new taper roller outer rings in car wheel hubs, I used to put hubs in oven and rings in freezer for a while, then they would drop in.
    The Wife complained for months about the empty pot of bike oil on the hall stand; so I replaced it with a full one.
  • ayjaycee
    ayjaycee Posts: 1,277
    Well done on that - I suspect it will help some people who need to do the same job as the amount of on-line guidance supplied by Fulcrum is somewhat lacking (to say the least).

    It's been a fair while since I did my Racing 5 LGs and I can't remember whether I exactly followed your route to extract the original bearings but when it comes to fitting the new ones, I can highly recommend the 'threaded rod method'. IIRC, the 1M length was about £4 and I already had the right size nuts and washers to hand and it made the whole job a doddle to complete.

    As an aside, I'm not sure that it's really worth using ceramic bearings on the Racing 5s (or maybe even any other wheels either!). I doubt you would ever notice any difference between them and 'ordinary' bearings, they reputedly don't last as long and cost a fair bit more which, to me, would be alright if they improved performance but.....
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  • ashokc
    ashokc Posts: 1
    RJKflyer and robertvb,
    Thank you so much for your posts (2017).
    They helped us undo a Fulcrum Racing Quattro (2020) in India. And yup, we found the posts super helpful.