big john

I have an Ultegra 6603 triple crankset and the middle ring is trashed. They seem to be unavailable and I might be able to use a standard double ring. It might be harder to shift from the small up to the middle because it won't have those ramps. Any insight? It's 130mm bolt circle and 39 tooth 10 speed. tia

70sSanO

I believe that TA makes a triple 130mm bcd set that should work.

John

2_i 

I freely mix rings between brands. There is a strategy in finding optimal orientation of the adjacent rings for upshifts. I necessary, I tweak the derailleur's cage. I do not understand the ramp comment.

big john

They aren't flat, they have ramps to help shift up from the small ring.

2_i 

I know, but in an indexed system every ring other than the inner should have those. Maybe there is something particular about the specific crankset. In any case, without modifications the derailleur is not likely to pull straight from the inner to the outer ring in an indexed system. I would just get the same size as the original middle, with pins. On Ebay there are many offers. The pins are more important than the ramps.

urbanknight

It seems that's his concern: that a double ring won't have the ramps and pins because it would be the inner ring for the system it's meant for.

I'm sure you can get middle rings like the TA ones mentioned above. They just might not match the brand you're using for the outer and inner, which may or may not be a problem, but they should work to some degree.

What tooth count are you looking for? There's this one here, and if it doesn't play nice with the outer, you can always just buy its companion as well (are you running 10s rear?)
https://www.ebay.com/itm/18468405161....c101195.m1851

dedhed

I'd think a 105 or tiagra would be compatible.
https://www.modernbike.com/shimano-1...le-ring-silver

DeadGrandpa

I'm not wishing to derail this thread, but I also have a need for a 39T middle chain ring, 10 speed for a Tiagra triple crankset. The bolt pattern is 4x offset. I see some availability of that size and bolt pattern for a 2x 11 speed Ultegra crank, but the lack of ramps and pins concerns me, plus the 10s vs 11s compatibility. I don't find any 39T, 4 bolt offset, in 10 speed.

I'm considering going to 2x11 or even 1x11 with a larger cassette instead, as drastic as that seems, because I need a new cassette anyway. Suggestions?

dsbrantjr

I curse them for doing this....

tomtomtom123

TA has middle rings for both the 5 bolt 130 and 4 bolt 110 shimano (not sure about 4 bolt 130). Sometimes the TA middle rings are also the same for outer rings. You can look at their website for more information. If it's dual use, you need to check if it has a counterbore on both sides of the bolt holes, otherwise the bolts will stick out and hit the chain if you mount the ring to the wrong side of the spider than it was intended for.

The one thing you should check is the offset difference of the teeth from the mounting surface of the ring. If your original is seemingly flat (usually around 0.5mm offset from the outer surface of the teeth to the outer surface of the ring) and the TA is also flat, then it should be comparable. But if the original has big offsets, then you'll get problems with alignment.

The TA has modest ramps on the 5 bolt 110 that I have. I can't remember but I think the ring was 4mm thick. If you are in the uk, spa cycles has cheap rings that are thicker by 0.5mm to 1mm or so and have wider ramps and more pins which made shifting easier when I was testing one in comparison to the TA.

big john

10 speed, 39 tooth.
Thanks guys, I didn't consider the 105 stuff yet, I thought there night be a difference so it wouldn't fit but those look very similar. Seems odd the Ultegra would be discontinued but not the 105. Guess I'll order one and see.

big john

Most of the other triples I've had just used flat rings. I thought if I ended up with a flat middle it would still work, just might not shift up as well.

Iride01 

I'd not have any reason to believe rings for a Tiagra 4703 or 105 5703 wouldn't work. Mostly I think just the material changed to be lighter for Ultegra and maybe more machining tolerances.

https://www.universalcycles.com/shop...s.php?id=42484

oldbobcat

Happy hunting, everybody. I'm finding the bigger problem is finding a supplier who actually has Shimano triple rings in stock. FSA makes a triple pair, 52/40, I believe. QBP has a few in stock, available on order at your local bike shop.

big john

I went into a local bike shop and he had an old Shimano triple crankset and he let me take the middle ring off of it. Crankset had no name on it but the ring said HG and the ramp things were bigger than the Ultegra and they were closer to the chain when it is on the small ring. I put it on and it seems to work fine so I'm pretty sure the 105 rings linked to above would also work.