Lower Gearing for Ultegra 6603 Triple?
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My issue is the Shimano 11-13 gap vs the SRAM 12-13 1 tooth gap. Both have 13-15 which are on the edge of acceptable, at least for me.
Plus a 52-12 high gear ratio is probably fast enough. Other than downhills, it is close to a 35mph gear on the flats.
John
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#29
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If your middle ring is a 39, swap your 53 outer for a 46, and your 30 for a 26, or even a 24. (The 26 puts you back within the 38t chainwrap of your rear derailleur, but the 24T is only +2, and you're at +3 right now.)
This gives you a range from ~104" down to about 21.5", and your existing derailleurs should handle it just fine. The road triple front should play nice with the 7T difference between the middle and big rings, and your rear derailleur already works with the 30T big cog. Plus, 130 and 74 BCD chainrings are cheap... a 46Tx130 and a 24Tx74 should come out under 75 bucks if you shop around. Way cheaper than a new 10 speed cassette and a new rear derailleur.
Take a couple of links out of the chain, lower your front derailleur a bit, adjust the front shift cable, and Bob should be yer Uncle.
--Shannon
This gives you a range from ~104" down to about 21.5", and your existing derailleurs should handle it just fine. The road triple front should play nice with the 7T difference between the middle and big rings, and your rear derailleur already works with the 30T big cog. Plus, 130 and 74 BCD chainrings are cheap... a 46Tx130 and a 24Tx74 should come out under 75 bucks if you shop around. Way cheaper than a new 10 speed cassette and a new rear derailleur.
Take a couple of links out of the chain, lower your front derailleur a bit, adjust the front shift cable, and Bob should be yer Uncle.
--Shannon
For all of my local rides I basically use the 39 as a 1X and very seldom the 52 or 30. It is only on tours or up in the mountains that I would need lower gearing. At my age I am not "racing" down hills so rarely need the 52.
#30
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I used to work for a shop that also had a Pyrenees bike tour once a year. We commonly swapped the customers' chain, cassette and rear derailleur for the trip, than swapped them back out when the travelers got back to Wisconsin. The whole swap took 20 minutes and was relatively cheap to do on either SRAM or Shimano bikes. Same crank, FD, shifters, cables, wheels, etc.
So If I leave the front as-is and put a 11-34 or 12-36 cassette I'll need a RD with a 45-46 capacity which puts it into MTB territory for sure.
Steve_sr , I don't know if has been explained clearly, but that Deore derailleur is just called "9 speed" because that was how it was packaged as a group set. But the derailleur is agnostic and you use it with a 10 speed cassette if you have 10 speed shifters, or 8 with 8, etc.
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This was my original thought as a temporary change only on hilly tours.
I think that I may already have a 9-speed 11-34 in the parts archive.
So If I leave the front as-is and put a 11-34 or 12-36 cassette I'll need a RD with a 45-46 capacity which puts it into MTB territory for sure.
This says that the cog spacing is equivalent between 8-9-10 speed. What ultimately determines compatibility is the parallelogram travel being sufficient to cover the number of cogs on the cassette.
I think that I may already have a 9-speed 11-34 in the parts archive.
So If I leave the front as-is and put a 11-34 or 12-36 cassette I'll need a RD with a 45-46 capacity which puts it into MTB territory for sure.
This says that the cog spacing is equivalent between 8-9-10 speed. What ultimately determines compatibility is the parallelogram travel being sufficient to cover the number of cogs on the cassette.
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So this proposal looks like it just converts the road crank to a MTB crank. This sounds like a viable solution as long as I can find a 24 and 46 tooth ring for the front. Does Shimano have the 24 and 46 rings still available? How would I find the part numbers? Any other quality alternatives?
I don't know if Shimano makes a 46Tx130mm chainring, but lots of other companies do. The Suginos are even ramped and pinned, although they're twice as expensive as the non-ramped ones. Even plain chainrings should shift pretty well over a 7 tooth gap, but it's probably worth the extra 30 bucks on an STI bike. Front indexing needs all the help it can get. The granny can be the cheapest one you can get, they don't need any shift aids, and most don't have any. There's even a school of thought that says that your granny ring should be steel, because the smaller the ring, the faster it wears, and, being small, the weight penalty is negligible. That's probably overkill for a recreational road bike.
--Shannon
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Correct. I was thinking RD compatibility and incorrectly included shifters and cassettes as well.
#34
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More of an old-style touring triple than an MTB crank, by my lights, but yeah, kinda.
I don't know if Shimano makes a 46Tx130mm chainring, but lots of other companies do. The Suginos are even ramped and pinned, although they're twice as expensive as the non-ramped ones. Even plain chainrings should shift pretty well over a 7 tooth gap, but it's probably worth the extra 30 bucks on an STI bike. Front indexing needs all the help it can get. The granny can be the cheapest one you can get, they don't need any shift aids, and most don't have any. There's even a school of thought that says that your granny ring should be steel, because the smaller the ring, the faster it wears, and, being small, the weight penalty is negligible. That's probably overkill for a recreational road bike.
--Shannon
I don't know if Shimano makes a 46Tx130mm chainring, but lots of other companies do. The Suginos are even ramped and pinned, although they're twice as expensive as the non-ramped ones. Even plain chainrings should shift pretty well over a 7 tooth gap, but it's probably worth the extra 30 bucks on an STI bike. Front indexing needs all the help it can get. The granny can be the cheapest one you can get, they don't need any shift aids, and most don't have any. There's even a school of thought that says that your granny ring should be steel, because the smaller the ring, the faster it wears, and, being small, the weight penalty is negligible. That's probably overkill for a recreational road bike.
--Shannon
I also have a 9-speed XTR 952 crankset on my loaded touring bike and it is similar in design to the 6603 but definitely non-symmetrical and is offset left-right.
Here is a photo of the 6603 crank arm.
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I just looked at my 6603 crank and there may be another issue. The big ring is integrated into the crank arm. I am also not sure if it is offset left or right. It also looks like the bolt attachment area is thicker than the ring. While the inner ring can be easily changed the outer one is not looking like an easy swap. Am I missing something? It looks like Shimano intended it this way to make it difficult or impossible to modify.
I also have a 9-speed XTR 952 crankset on my loaded touring bike and it is similar in design to the 6603 but definitely non-symmetrical and is offset left-right.
Here is a photo of the 6603 crank arm.
I also have a 9-speed XTR 952 crankset on my loaded touring bike and it is similar in design to the 6603 but definitely non-symmetrical and is offset left-right.
Here is a photo of the 6603 crank arm.
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Maybe it’s an FC-6703?
John
John
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#39
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Here is an interesting tidbit that popped up on a Ebay search...
https://www.ebay.com/itm/305344946968
A dura-ace 46T outer ring! Unfortunately, It doesn't appear to go with the mentioned FC-7800 as all of those I see are the standard 53-39 doubles. Anyone recognize this ring? Too bad it is on the other side of the pond.
https://www.ebay.com/itm/305344946968
A dura-ace 46T outer ring! Unfortunately, It doesn't appear to go with the mentioned FC-7800 as all of those I see are the standard 53-39 doubles. Anyone recognize this ring? Too bad it is on the other side of the pond.
#40
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This rear derailleur works well with shimano 10speed setups, and you can use it with a 34tooth cog. I've done it.
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Here is an interesting tidbit that popped up on a Ebay search...
https://www.ebay.com/itm/305344946968
A dura-ace 46T outer ring! Unfortunately, It doesn't appear to go with the mentioned FC-7800 as all of those I see are the standard 53-39 doubles. Anyone recognize this ring? Too bad it is on the other side of the pond.
https://www.ebay.com/itm/305344946968
A dura-ace 46T outer ring! Unfortunately, It doesn't appear to go with the mentioned FC-7800 as all of those I see are the standard 53-39 doubles. Anyone recognize this ring? Too bad it is on the other side of the pond.
That 46T chainring is designed to mount on a FC-7800 crankset, and was sold as an accessory rather than packaged as a crankset. So it is a replacement for the 53T the crankset came with or for a crank that came without rings. It will mount on your crank. So will many aftermarket rings:
I was a shop mechanic and service manager for a very long time. I'm speaking from a lot of experience.
Last edited by Kontact; 02-08-24 at 09:41 PM.
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Leave the big ring, Absolutely no reason to mess with that. You should have a 39T middle ring, good. Go with a 26T granny ring. Try that on a hill before you change out the cassette. Ignore the specific recs for chain wrap, etc. I've run a 53-39-26 front and a 11-40 cassette on our tandem for many years, no problem. Only an idiot would use small-small. We should presume you are not an idiot. I had to use the MTB RD and a Wolf Tooth to use that 40T cassette, but it all works fine. On my single my low is 30-26 on a 9-speed triple rig. That's been good for long pass climbs for a few years. I'm 78, no great athlete, just ride a lot. If you need a Wolf Tooth to run a bigger cassette, it just lowers your RD pulley, so you have to mess with chain length, but no big deal. Works fine. But I'll bet you'll like the 26T granny. It's cheap fix.
On my tandem and single, I only use the granny on the 4 largest cogs and don't use the big ring on the three largest cogs. The middle ring can run the whole cassette. On my single, I can go big-big though that's a pilot error. On the tandem I can't go big-big, but I have a Shimano Flight Deck - I can't see the cassette at all. You wouldn't need one on a single.
On my tandem and single, I only use the granny on the 4 largest cogs and don't use the big ring on the three largest cogs. The middle ring can run the whole cassette. On my single, I can go big-big though that's a pilot error. On the tandem I can't go big-big, but I have a Shimano Flight Deck - I can't see the cassette at all. You wouldn't need one on a single.
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If you need more chain wrap and biggest sprocket capacity, find a Shimano 8 or 9 speed mountain bike derailleur that will handle the 34 or 36t 10 speed cassette you're looking for. It will work perfectly with your 6600 shifters. It's a simple swap: install the new 8 or 9 speed derailleur and 10 speed cassette, new (longer) chain cut to proper length, adjust derailleur and shifting.
I've done it several times - MTB 8 or 9 speed RD (Deore, XT, etc.) with 9 and 10 speed road shifters - cassette matching the shifters, not the derailleur. 10 speed derailleur won't work.
I've always just found good used Deore, XT, etc. derailleurs on EBay or the sales forums on this site. I happen to have a brand new 9 speed XT derailleur I found at a local bike swap I'm "keeping in reserve"
I've done it several times - MTB 8 or 9 speed RD (Deore, XT, etc.) with 9 and 10 speed road shifters - cassette matching the shifters, not the derailleur. 10 speed derailleur won't work.
I've always just found good used Deore, XT, etc. derailleurs on EBay or the sales forums on this site. I happen to have a brand new 9 speed XT derailleur I found at a local bike swap I'm "keeping in reserve"
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I agree not to mess with the big or middle chainring, or try and mate an XTR crank to this bike.
Your initial issue was lower gearing, so you should stick with that. You only have 3 considerations…
1. Getting a 9 speed MTB rear derailleur and chain to run with your 10 speed shifters.
2. Getting an 11/12 to 34/36 10 speed cassette.
3. Either run your current 30t inner chainring, or go to a 26t or 28t. This doesn’t need to happen right away. It is not going to impact your chain length.
Yes you might have a chain wrap/capacity issue, but who cares. Don’t use the small-small or the small-2nd, or wherever the RD folds back on itself.
When I went to a 28t ring and 36t cog I couldn’t use the small-small, so I don’t. Being a triple it is a pretty severe angle anyway.
John
Your initial issue was lower gearing, so you should stick with that. You only have 3 considerations…
1. Getting a 9 speed MTB rear derailleur and chain to run with your 10 speed shifters.
2. Getting an 11/12 to 34/36 10 speed cassette.
3. Either run your current 30t inner chainring, or go to a 26t or 28t. This doesn’t need to happen right away. It is not going to impact your chain length.
Yes you might have a chain wrap/capacity issue, but who cares. Don’t use the small-small or the small-2nd, or wherever the RD folds back on itself.
When I went to a 28t ring and 36t cog I couldn’t use the small-small, so I don’t. Being a triple it is a pretty severe angle anyway.
John
#46
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You've got a lot of room in the inner chainring bolt circle, to go a lot smaller. Like you have, closer gap between inner and middle, than middle and outer, just gives you more duplicate gears (though may be proper for same percent difference). The wider the gap the better, IMO (to reduce duplicate gears), provided the system will accommodate that. By the way, what you currently have is the opposite of "half-step plus granny".
Seeing pictures posted of that crank, that may be the last great Shimano crank, one that I would buy. I don't like the assym 4-bolt cranks, both aesthetics, and construction.
Last edited by Duragrouch; 02-08-24 at 10:47 PM.
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Leave the big ring, Absolutely no reason to mess with that. You should have a 39T middle ring, good. Go with a 26T granny ring. Try that on a hill before you change out the cassette. Ignore the specific recs for chain wrap, etc. I've run a 53-39-26 front and a 11-40 cassette on our tandem for many years, no problem. Only an idiot would use small-small. We should presume you are not an idiot. I had to use the MTB RD and a Wolf Tooth to use that 40T cassette, but it all works fine. On my single my low is 30-26 on a 9-speed triple rig. That's been good for long pass climbs for a few years. I'm 78, no great athlete, just ride a lot. If you need a Wolf Tooth to run a bigger cassette, it just lowers your RD pulley, so you have to mess with chain length, but no big deal. Works fine. But I'll bet you'll like the 26T granny. It's cheap fix.
On my tandem and single, I only use the granny on the 4 largest cogs and don't use the big ring on the three largest cogs. The middle ring can run the whole cassette. On my single, I can go big-big though that's a pilot error. On the tandem I can't go big-big, but I have a Shimano Flight Deck - I can't see the cassette at all. You wouldn't need one on a single.
On my tandem and single, I only use the granny on the 4 largest cogs and don't use the big ring on the three largest cogs. The middle ring can run the whole cassette. On my single, I can go big-big though that's a pilot error. On the tandem I can't go big-big, but I have a Shimano Flight Deck - I can't see the cassette at all. You wouldn't need one on a single.
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I confess to having a steel 26T granny ring on the tandem. Reduces wear. I don't think they make them anymore though.
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I think a lot of non-road use steel, so I think still available, depending on crank standard. My aftermarket 50/34 double was supposed to come with aluminum rings, showed up with steel, I wrote polite WTF letter to amazon seller, pointing out the ad said aluminum rings. No problem, no need to get amazon involved, we'll send you aluminum rings. Took a month from China and through their Nevada distributer or customs agent, but they arrived. And they promptly changed their amazon ad to reflect the actual material. No longer sold on amazon, but same crank is on ebay, choice of steel (cheaper) or aluminum (only about $8 more if I recall). So steel is still around. I didn't want the weight of steel, but they turned out to be a lot thinner than cheap-bike steel cranks, and have held up well.
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Too many people go by numbers. What does that even mean? Assuming one is smart enough not to go small-small. It works fine. I have a 10 speed FD on our tandem and a 9 speed on my singles, works just fine on both. On the tandem, I call out "spin it up" before the granny to middle shift, uh, not necessary on my single. Many tourers use a 24T granny and I've heard of 22T but not seen it.
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