Options to replace the chainrings in my FC-6603
 

I have a 2008 Madone 5.5. I put about 5000 miles on the original compact double but never liked the CD. I also had the parts from a wrecked 2007 Pilot 5.2 which included an Ultegra FC-6603 triple (52-39-30 and a 12-25 cassette). I had my LBS swap in the FC-6603 in place of the CD and have been happy with that combo for the last 8000 miles. With over 11,000 miles on the FC-6603, I'm getting some shark-finning on the 39 and 52 and realize my time with this is limited going forward.

The LBS tells me parts for the FC-6603 cannot be found... and I have searched in vain online myself. The LBS says the 105 would work, but that will also be hard to find parts for within the next year and that a Tiagra CD is likely my best bet going forward. That or a new bike. ;)

Do I have any options to keep my triple (and my beloved gear position indicator)? Or am I gonna have to move to a Tiagra CD when the old FC-6603 is done?

For out of production parts, I look on ebay. Look for 52t and 39t 130mm chainring on ebay, probably an FSA. You can get an FSA ProRoad 52t outer and 39t middle, and a Shimano Ultegra 6603 30t.

John

I already looked there and came up empty. Unless I was looking for the wrong thing. I fear I know just enough to be dangerous but not enough to be intelligent. As usual, the devil is in the details.

I think my 30T is still is good shape. I ebay searched those FSA chainrings you mentioned. I hope they will work! ~ $100 for the 52T and 39T chainrings. Plus shop labor and a new chain. Maybe new bearings too.

Ugh, older FSA chainrings are nothing to look forward to. If the chainrings aren't skipping on the new chain and are shifting OK, leave them in place until one of those things comes up. Maybe set up an automated ebay search for the actual correct rings.

Options for road triple are really drying up. Specialties TA still makes things that will fit your crank: https://www.peterwhitecycles.com/ta-...ings.php#alize . To be honest I've never seen them and don't know how they shift.

I might recommend you pick up a FC-4703 crankset, honestly. They're still around. You may want to pair that with the matching front derailleur, as they're shaped differently for 52 vs 50t big rings.

FC-4703 says 50-39-30 but I don't see it in 130mm BCD. Only 110 and 74. Don't I need 130mm BCD?

BCD is not a factor, and anyway 4 arm cranks are all 110 BCD. You just need the chainring sizes that you wish to use

If you are buying an entire new crank you don't need to be concerned about the BCD. That's only material if you are replacing rings on your existing crank. I wouldn't bother with FSA replacement rings. If you can't find Shimano replacements, almost any level of new Shimano crank will be better. I don't know what you didn't like about the compact double but many former triple users, myself included, have moved on to that w/o complaint.

It would change your top gear and you would get better shifting with a matching front derailleur but there's no reason you need 130bcd of you're switching cranks.

If FSA are not very good, admittedly I’ve had limited experience with them, maybe 5700 105’s would be a better option.

Since I rely on eBay, I did see some 10 speed 130mm 5700 52t and 5703 (middle) 39t on eBay.

They are not matched, but neither are the TA’s (have looked at them over the years). Shifting between chainrings is really a skill. While matched pins and ramps can be really nice, they are only necessary if you don’t know how to shift, or are truly racing and split seconds count.

John

I found the 34T too in-between for me. I much prefer the 39T, but that's too tall for my legs in serious hills. Ergo the 30T fall back for me. And I really like the 52T chainring. The 50T was ok, but I just really like my options with the 52-39-30.

Or maybe I'm just old and stuck in my ways. ;)

I was hoping to just replace the worn rings and keep the existing crank. But that may not be feasible. If I have to go back to a CD, I"ll live with it. But I sure will miss my gear position indicator. I really like knowing what cog I'm in without having to look back to see.

ah, so BCD is only important if I wish to keep the existing crank and just replace some of the chainrings. Gotcha.

Well I'm just an old phart and racing is not my thing. I'm more of an endurance rider and like to go out there and just conquer the road, mile after mile. My triple has been exemplary. I really hate the thought of losing it, but I may be forced back to the world of compact doubles. I never realized that parts would be hard to find. I figured parts were parts. Oh well.

https://si.shimano.com/pdfs/ev/EV-FC-6603-2366E.pdf




TA has a different chainring for middles of triples , or inner of doubles 7075-t6 aluminum is the right way to go..

Always preferred friction FD shifting on cranksets, myself..








:innocent:

Don’t ditch your triple. I’m 68 and run a 48-38-30. I would never go to a compact since I can run a 48-38 for most everything and then have the 30t for those times when I really need it.

I don’t care about top end anymore, so I run a 14-34. Index rear with friction front XTR derailleurs. Except for top end, it’s the best setup I’ve had; but that is an easy fix if I wanted to speed it up.

I haven’t gone for the TA’s because I haven’t wanted to spend the money, and I’ve got ample stock in hand. It’s your bike build it how you want.

John

Honestly, I'd never heard of the TA groupset until it was mentioned in this thread.

I'll talk to my LBS and see what they think. I'm still ok for now on the Ultegra... but I know the day is coming when I'm gonna have to change it out... and I'd like to be prepared.

For all practical purposes, I mainly use the 39 and 52, and just occasionally the 30T. In the rear, I mostly use 14-25. I don't use the 12 and 13 cogs all that much.

Sigh. I hit the big 7-0 this year.

To be frank, you probably don't need the 52 over a 50. A 52 is only really useful if:
-You're trying to avoid needing an 11t cog, but 12 and 13t starting cogs are getting rare anyways.
-You legitimately need to be competetive in group sprints in the context of a road race.
-You're on a tandem.
-Your cadence is significantly slower than the average road rider.

Most riders encounter situations where they can spin out 50x11, but they're going so fast that they'd usually go faster by concentrating on being more aerodynamic and not on pedaling.

I particularly like the 52-19 and 52-18 gearing. That seems to be a sweet spot for me in the area I normally ride.

FC-4703 is around $80-85 around here.

TA and Stronglight both make 5 bolt 74/110/130 BCD chainrings that could work. The chainline may come out a little different than the original, but you could try to play a little with it with DIN 988 shims for $2-5 for a pack of 100 pieces. In Europe the TA and Stronglight are around $20-25 for the inner ring, $25-35 for the middle, and $30-40 for the outer. In the US, they're more expensive (because they're made in Europe). So you could buy the FC-4703 for about the same price.

Or search eBay for alternative brands.
The ones from Spa Cycles are probably similar to Driveline. 29 GBP outer, 20 GBP middle, 12 GBP inner.

So you just have to decide if you want to buy a whole complete chainset with crank with whatever size comes with it for the same price as a little more than replacing only the chainrings on your existing crank.

I imagine you're right. That FC-4703 will probably be my best bet. I'm not interested in piece-mealing a hodge podge of parts. I just want it to work and with the least amount of fiddling on my end. That chainset is not that expensive.

https://cimg7.ibsrv.net/gimg/bikefor...8324bf79eb.png
Stop being a curmudgeon, shift up one gear and you'll have the same gear within a gear inch or two. Only downside is top end.

It's not a 'groupset'* just makers of cranks & chainrings..

*Defined as being an inclusive set of derailleurs shifters hubs, brakes and such..

But I like being a curmudgeon!

I used to have that chart, but don't recall where I found it. Do you have a link?

speedlever : I’m glad you are sticking to what you like with your 6603 Ultegra. I wore out the 39 tooth on mine and it was beyond shark tooth. Mine had a wide U shape with a flat gullet at the bottom. Made my new chain disengage while standing on the pedals, very dangerous since it happened in traffic when starting from a dead stop at traffic lights. My 6603 crank had ~16,000 miles on it at the time. I was able to locate a replacement (last year) from “Mike’s Bikes” in California. I checked back after I bought one and decided I needed more only to find that they are sold out now.

I’m with you about the beloved gear display (Flight Deck) being something you don’t want to give up on. If Shimano would listen and bring back a road triple group with these exact ratios on the crankset, I suspect they would sell well.

One thing to consider about the middle 39 tooth ring is that it is pretty close for a 39 tooth 130mm BCD chainring for a double. It is just missing the shifting ramps for downshifting to the 30 and upshifting to the 52. So I suspect you could run your 6603 “forever” just by replacing the rings with ones that are of the correct BCD. But I’m like you and the idea that you can’t get a matched triple set for these cranks kind of stinks.

In your searching for replacement parts on eBay, you might also search for “6604” cranksets or chainrings. This was the same as the silver 6603 but in a limited production champagne brown anodized color. About a year ago there were several sellers selling complete NOS 6603 or 6604 cranks for ~$150.

It occurred to me that an aftermarket chainring manufacturer could step in and produce a matched set of triple road rings for Shimano. I emailed Wickworks a while back to see if they made this item and they replied that they did for a short time but that they were discontinued because they didn’t sell. But they had no old stock of them either. Wickworks matches their chainrings and they have their own version of pins and ramps to quicken upshifts and downshifts. We need a crowdfunding group to prompt a machine shop to CNC mill or even 3D print these (somewhat) proprietary rings. It gets a bit exhausting on these forums when you say you like a particular configuration of gearing and then folks are minimizing your choice lecturing you that something else is “just as good”.

Lol. I hope you framed that 39T chainring and put it on your wall!

Thanks for the tips (and the support). Maybe I'll get lucky. I'm trying to be pre-emptive before failure. I don't have 16,000 miles on my chainrings... only a bit over 11,000... but it all adds up. Got about 5000 miles on the chain which kinda surprises me... but it still measures in spec. I probably just have weak legs. ;)

I don’t understand why this has become so tough. They are just chainrings. Get 10 speed 52t outer and 39t middle and be done with it.

Does anyone really believe any 10 speed chainring is going to throw the chainline off significantly? By .1mm, .2mm, .5mm?

But, if I’m looking for something I save a search on eBay and if it comes up at a good price I buy it and put in the parts bin. If you are planning on waiting, you have to keep looking.

John