FSA Chain Rings

In this post - chain rings - I moaned about the cost of chain rings. This was in light of the fact that the 50T rings were worn badly on both the Scott and the Giant. They end up being at least £30+ each and seem to be rarely in stock at most of the major internet retailers.

For the Scott which is my best bike and hence the one I tend to fuss over, I ended up getting a new Shimano 5700 Compact chainset to replace the FSA Gossamer chainset as described in the post. This still left needing a new 50T ring for the Giant. I looked over a period of weeks to see when and what was available and recently found a reasonably proved supply in stock on eBay here: sprocketsuk

To be fair it arrived very quickly and was as advertised. I think the teeth are less complex that the original FSA or Shimano teeth - they look much more regular and more like the plain teeth on the inner (34T) ring. Only time will tell if this affects the shifting quality. The design is similar to the original FSA rings but slightly different in the area of the webs.

It took about 30 minutes to fit, mostly because I struggled to hold the back of the chainring bolt still whilst undoing with an Allen key. I had to resort to using the very large socket screwdriver bit from my impact driver to hold the back still whilst using the Allen key as I had no other suitable tool. However once I had rigged up something for this it all came apart easily enough. I applied a small smear of Copaslip (other brands and suppliers are avilable) to the threads before reassembly.

All was OK with the shifting once it was all back together. 

Closer inspection of the removed item showed how worn it was (its done about 10-12,000 miles in about 3 years or so, through all seasons):

The original ring

Shark Teeth

With teeth this worn it was going to start chewing through chains at an accelerated rate so this is why I spent £30. It was going to be of the order of £60-70 to replace it.

The FSA Vero is a square taper chainset - the bottom bracket it uses is discussed here and the square taper crank sets are getting less common now. I briefly considered fitting a new ring to the FSA Gossamer that came off the Scott together with the Mega Exo BB and considering it as an "upgrade", but given the short life of the Mega EXO BB compared the the original Truvative BB-06-SQ-LE-108/68 BB on the Giant (now replaced with a Shimano UN55) I decided that the durability would be compromised. I was also unsure whether the BB faces on the Giant might need facing off I fitted an external BB like the Mega EXO compared the to cartridge type it is currently running

Giant Defy Headset Bearings

This post is also a follow up to this post: Focus Cayo Bike Weights

Back in February I got the Giant of the rack in the garage:

only to find that the steering was stuck in the straight ahead positions. Clearly after 4 years and 4 winters the headset had given up the ghost, got rusty and siezed. Fortunately a little gentle twisting action loosened it again but it was clearly time to replace the bearings. A couple of days later I got the bike in the workstand and dropped the fork out to get to the bearings. I was hoping that they'd be marked up and I could read the part numbers of and source replacements easily, but unfortunately they were completely unmarked. I measured them up as best as I could, cleaned and applied some grease and re-assembled. I got the following data:

Upper Bearing - ID = 30mm, OD = 42mm, Height = 6mm
Lower Bearing - ID = 34mm, OD = 46mm, Height = 7mm
In both cases I estimated the taper at about 45° but had no way of measuring this. I used a standard steel ruler for the measurement - so within +/-1mm is the best I could do.

I also looked on the internet for information. The best I found was this Bikeradar Forum article: http://www.bikeradar.com/forums/viewtopic.php?t=12955189&p=18696395 where it identified the bearings as:

TOP BEARING 41.8mm x 6mm 45° X 45° MR136 (1 1/4")
LOWER BEARING 47mm x 7mm 45° X 45° MR137 (1 1/2")

This was close enough to my measurements to give me confidence that I had measured correctly:

Here's a few pictures of the bearings:

New Top

New Bottom

Old Bottom

Old Top

The bearings were OK again with the re-greasing, but this was obviously just a short term containment so as soon as I got the replacements I did change them. 

It was surprisingly hard to source some bearings. The best shot I found was here: Aire Bearings on EBay. I can't fault them for price, delivery and customer service - I would use again. The cost was £15.54 for a top and bottom bearing. Bearings seemed good quality and there was no issue with fit. Only time will tell for longevity but at that price I'd be OK with a couple of years given that the Giant is used all year round.

I took the opportunity to thoroughly clean and service the bike at the same time as I changed these bearings (new chain, new jockey wheels on the rear derailleur, replaced the short length  of gear outer cable at the rear derailleur etc and general tweaks). I also put the Cole Rollen Wheels back on after the Winter.

Because I had some of the bike apart I also weighed some of the components for comparison when I stripped the Focus/built the Scott.

Giant Defy Weights
Components	Detail	Actual Weight (kg)
Cole Rollen Wheel (Front) with skewer, inner tube and Continental 700cx23mm Gatorskin tyre		1.28
Cole Rollen Wheel (Rear) with skewer, inner tube and Continental 700cx23mm Gatorskin tyre, and 12-25 105 Cassette		1.77
	total	3.05
Giant Wheel (Front) with skewer, inner tube and Continental 700cx25mm Gatorskin tyre		1.92
Giant Wheel (Rear) with skewer, inner tube and Continental 700cx25mm Gatorskin tyre and 12-27 105 Cassette		2.27
	total	4.19
Weight saving due to Cole Rollen Wheels		1.14
Crank RH (drive)	FSA Gossamer (Scott)	0.55
Crank LH	FSA Gossamer (Scott)	0.25
Crank RH (drive)	FSA Vero (Giant)	0.64
Crank LH	FSA Vero (Giant)	0.42
Weight difference between Gossamer and Vero		0.36
Focus Weight		8.52
Giant Weight (Cole Wheels)		10.62