Shimano 46/34?

[r_mutt]

Hello all-

I have a compact Ultegra 8000 crankset and I want to swap out the 50 to a 46 to run a 46/34 combo. Are there any conflicts here?

Thanks!

[oldpotatoe]

Hello all-

I have a compact Ultegra 8000 crankset and I want to swap out the 50 to a 46 to run a 46/34 combo. Are there any conflicts here?

Thanks!

Nope, should work great if you can find the 46t that fits this crankset. Hopefully, if your frame is a brazeon front der, it's 'long' enough to get the fder low enough for the 46t..

[saab2000]

Hello all-

I have a compact Ultegra 8000 crankset and I want to swap out the 50 to a 46 to run a 46/34 combo. Are there any conflicts here?

Thanks!

I have done the same thing. You will need to find the right pieces but they're readily available. I love the 12-tooth jump between gears the chainrings. Shifting is great and the jump isn't as drastic as the usual 16-tooth jump.

You will need to shorten your chain by a couple links. Not a big deal but something I noticed when I did this on my bike.

A 46-tooth outer ring is incredibly useful and I wish it were available on more cranksets.

[GregL]

Hello all-

I have a compact Ultegra 8000 crankset and I want to swap out the 50 to a 46 to run a 46/34 combo. Are there any conflicts here?

Thanks!
No conflicts, it will work with no issues. I have an Ultegra 6800 crankset set up 46/34 on my gravel bike and it works perfectly. You will need the special chainring bolts for the 46T chainring (Shimano part # Y1W898090).

Greg

[r_mutt]

I have done the same thing. You will need to find the right pieces but they're readily available. I love the 12-tooth jump between gears the chainrings. Shifting is great and the jump isn't as drastic as the usual 16-tooth jump.

You will need to shorten your chain by a couple links. Not a big deal but something I noticed when I did this on my bike.

A 46-tooth outer ring is incredibly useful and I wish it were available on more cranksets.

what would I need other than the chainring/new link for the chain, and to drop the FD a bit?


thanks gents for the answers!

[saab2000]

what would I need other than the chainring/new link for the chain, and to drop the FD a bit?


thanks gents for the answers!

There are pieces for the chainring bolts because the 46 isn't the same as the 50. Look for the Ultegra 46-tooth cyclocross chainring. It's often sold as a set with a 36 inner but you can keep your 34 and it works just fine.

https://cdn11.bigcommerce.com/s-ox79uhj/images/stencil/1280x1280/products/37540/94595/Shimano_6800_Chainring_Set_46_36__81988.1478897069 .JPG?c=2&imbypass=on

[GregL]

what would I need other than the chainring/new link for the chain, and to drop the FD a bit?


thanks gents for the answers!

Chainring bolts:

https://www.ebay.com/itm/Shimano-Ultegra-R8000-Chainring-Cap-and-Bolt-Set-for-46-36t-chainring-Set/123555927363?hash=item1cc481d543:g:HuEAAOSw9pNcyul S

https://specialites-ta.com/kits-de-caches/114-kit-de-caches-specialites-ta-pour-pedalier-shimano-ultegra-r8000-3662458009133.html

[r_mutt]

again, thanks all

[palincss]

All front derailleurs are not equally good for use with 34/46. I built my new-to-me JPWeigle with a 24/34/46 Rene Herse triple and a Campagnolo front derailleur. Front shifting wasn't as good as I would have liked: it was reluctant to shift to the 24 and sometimes upshifting between the 34 and 46 and downshifting from the 46 to the 34 was also reluctant, even though the spacing - height above the chain ring - was exactly on spec.

I brought the bike up to Velo Classique in Purcelleville Va and Wayne Bingham went through a dozen boxes of front derailleurs until he found the one that best matched the curve of the 46T ring, which happened to be a Shimano Tiagra. With the new derailleur, shifting improved dramatically - no more hesitancy or reluctance.

I know you'll find plenty on the net to the effect that it doesn't matter, all front derailleurs work equally well, if you can do it with a stick or your foot how hard could it be, etc., but in this particular case it did make a difference, and not a small difference either.

https://live.staticflickr.com/65535/46921359254_2bc0dc5f33_c.jpg

Now I'm left with the guilt of having a bike with a Campagnolo decal on the seat tube but no Campagnolo parts at all, but I'm resolving that guilt by having a set of failed Ergo levers gutted and converted to brake levers.

[jtbadge]

If you buy the molded chainring bolt covers, you can use the same chainring bolts you already have.

If you don't want to pay for those chainring bolt caps, you can just use regular double chainring bolts with this ring combo. I did the same on my 6800 cranks until I switched to a Praxis subcompact.

https://www.pedalroom.com/p/thrive-cycles-fillet-brazed-allroad-36885_27.jpg

[Ralph]

Can your FD go low enough for a 46. Is it a braze on?

[r_mutt]

it is a braze-on FD mount and a CX frame that's been repurposed by the manufacturer as a "Gravel" frame so I'm assuming that I can.

[NHAero]

What are you using for shifters, barcons?

I used Dura Ace barcons on multiple bikes for years with a Tiagra FD on 48-36-24 set-ups, finding it to be the best working FD for that set-up.However, when I converted my old Bob Jackson to Shimano 10 spd STI shifters I found that it didn't work well at all and I switched to a matching 10 spd Shimano 105 FD, mo' better.

All front derailleurs are not equally good for use with 34/46. I built my new-to-me JPWeigle with a 24/34/46 Rene Herse triple and a Campagnolo front derailleur. Front shifting wasn't as good as I would have liked: it was reluctant to shift to the 24 and sometimes upshifting between the 34 and 46 and downshifting from the 46 to the 34 was also reluctant, even though the spacing - height above the chain ring - was exactly on spec.

I brought the bike up to Velo Classique in Purcelleville Va and Wayne Bingham went through a dozen boxes of front derailleurs until he found the one that best matched the curve of the 46T ring, which happened to be a Shimano Tiagra. With the new derailleur, shifting improved dramatically - no more hesitancy or reluctance.

I know you'll find plenty on the net to the effect that it doesn't matter, all front derailleurs work equally well, if you can do it with a stick or your foot how hard could it be, etc., but in this particular case it did make a difference, and not a small difference either.

https://live.staticflickr.com/65535/46921359254_2bc0dc5f33_c.jpg

Now I'm left with the guilt of having a bike with a Campagnolo decal on the seat tube but no Campagnolo parts at all, but I'm resolving that guilt by having a set of failed Ergo levers gutted and converted to brake levers.

[palincss]

What are you using for shifters, barcons?

I used Dura Ace barcons on multiple bikes for years with a Tiagra FD on 48-36-24 set-ups, finding it to be the best working FD for that set-up.However, when I converted my old Bob Jackson to Shimano 10 spd STI shifters I found that it didn't work well at all and I switched to a matching 10 spd Shimano 105 FD, mo' better.

Yes, 10 speed Shimano indexed bar end shifters. I have several bikes with XTR M900 cranks and 9-speed 24/36/48 or 26/36/48 triples, with bar end shifters in all cases. With those bikes I've found the Campagnolo Racing T to be the best front derailleur. With this crank set up as a triple, Rene Herse specifically recommend against STI.

Personally, I don't like integrated dual-control brake/shift levers, but of the three main types, for some odd reason I find Shimano STI to be the most confusing. Campagnolo Ergo seems much more comprehensible to me. I've never quite figured out why.

But now, I'm going to have Ergo -- just that they're going to be converted to brake levers only, the shifting guts having been removed.

[NHAero]

I got the 105 STI set-up to work, Sugino AT crankset 48-36-24, TA rings, and 105 FD. 9 spd XTR RD. But it was fussy to set up.

Yes, 10 speed Shimano indexed bar end shifters. I have several bikes with XTR M900 cranks and 9-speed 24/36/48 or 26/36/48 triples, with bar end shifters in all cases. With those bikes I've found the Campagnolo Racing T to be the best front derailleur. With this crank set up as a triple, Rene Herse specifically recommend against STI.

Personally, I don't like integrated dual-control brake/shift levers, but of the three main types, for some odd reason I find Shimano STI to be the most confusing. Campagnolo Ergo seems much more comprehensible to me. I've never quite figured out why.

But now, I'm going to have Ergo -- just that they're going to be converted to brake levers only, the shifting guts having been removed.

[Gummee]

FWI've seen, the new 8000 crank has a slightly different profile on one arm than the 6800 crank.

If you're running an outer ring for the old crank, you'll have to break out the Dremel

M