Di2 Fit File Decoder V1.1.0.4

Just a small update to add the distance ridden in each gear combination:

No other changes (some very minor code tweaks only)

Installer file available from this link

Fulcrum Racing 7 (Disc) Wheel Bearing Replacement

Riding my bike to work a few weeks ago I happened to glance down a the front wheel and saw the Though Axle starting to come unwound. This was a pretty concerning observation to say the least so I stopped and reset it only for the same to happen a bit later. The third time I actually removed the wheel properly to look further and realised that one of the bearings had siezed. This was a pretty major issue given that I was still 7-8 miles from work and 10 miles or so from home. I refitted the wheel and carrie don riding cautiously to some squealing and noise, however this seemed to disappear after another mile or so. Checking on (a safe) arrival at work I reasoned that whatever had caused a bearing to fail had eased itself off and whilst not a perfect position to be in I could at least to get home again - as long as I remained careful and went the most direct route

Getting home I removed the wheel again and looked at the bearings. Both sides spun freely although one was clearly more "notchy" than the other. Given that one bearing had siezed solid albeit briefly there was no point in hoping that all was well - I knew that I needed to get them out and replaced.

The manual for these wheels is pretty poor - however once you know what to do its not too bad. First remove the disk brake. Then on the non-disk side use a small (2 or 3mm I think) allen key to undo the cap head grub screw. Loosen this a reasonable amount - its actually a pinch bolt for the bearing load cap. Once it's loose, still with the allen key in the screw use the allen key to unscrew (anti-clockwise) the pre-load completely off the axle,. You can then push the axle through and out the disk brake side. Here's an image of the axle removed (note that I have pushed the bearings back on here so it won't look like this when the axle alone is pushed through):

On the lefthand side is the black preload cap, The right hand end of the axle (the brake disk end) has a ridge not seen in the photo above, so that the axle is pushed in it locates on the ridge in the inner diameter of the bearing.

Having pushed the axle out it's then necessary to knock the bearings out. Given they are scrap (that's why we are removing them) we can be firm but careful. To do this I used a 6" 1/2" drive socket extension and plastic mallet, with the wheel resting on a block of wood. Take care to tap all around the bearing and avoid just trying to knock it out from a single location. Neither of the bearings were tight and both came out easily. The photo below shows the bearing on the disk brake side being removed, the non-disk side bearing is already removed

Having removed the bearings I both measured them and read the part number off the bearing. Here's the bearing part number - it's a 6903RS but what matters is the 6093:

Using my preferred EBay bearing supplier (AireVelo) the specification came out at OD = 30mm, ID = 17mm, depth = 7mm:

However my measurements disagreed with the 6903 spec - the ID was a nominal 18mm:

Stupidly I believed that the bearing serial number must be correct and ordered a pair. Quite why I did this when I had measured I still don't know, but not surprisingly when they arrived they did not fit, so I had to search for the right size

This came out as a MR18307 - same external dimensions but with the required ID of 18mm

Fortunately the bearings are not expensive and I did not need the bike for a couple of weeks whilst I waited for each set to arrive

When the 2nd (correct) set of bearings arrived I refitted the bearings - basically the reverse of removing them but with the need to be more careful and not damage the new ones when refitting. There were 2 choices to refit - presss in or knock in. I thought about making a small press with washers and using a G Clamp but decided that as they were not tight I would tap them in carefully. My 1/2" drive 21mm socket was almost exactly the right size to sit over the outer race but still fit in the bearing housing

So again with the whell resting on a piece of wood I tapped the bearings in fully and then reassembled the axle. When applying the pre-load with the cap it took a few iterations to make sure that it was tight enough but not too tight. However this design was significantly more tolerant to preload than a traditional cup and cone design, where what can seem like a little extra tighten turn siezes wheel and a little loosening makes it wobble. I also applied a little grease to the bearings when I re-assembled the wheel, however there was none visible when I stripped it down. There was no rust visible in the bearings either sugegsting that the failure was not due to water ingress (and I had ridden the bike a lot all through the year).

In more general terms I have not been overly impressed with these wheels. At 11 months a spoke broke on the rear wheel. I went back to Wiggle to complain and did not get the best initial response. However they agreed to refund the repair costs from my local bike shop. The spoke broke about 3000 miles and then this bearing failure occured at about 3500 miles. Given that I have had other wheels do over 10000 miles with no issues this does not bode that well for the future. Any further failures and they may well go in the bin I suspect (and hate to say). Poeple might say that these are "cheap" wheels and what do you expect, but I expect better durability than that to be honest