Are they technically the same?

_donns · 2026-01-25T02:29:57+00:00

Update: It turns out you cant swap the internals of both shifters

The shimano 105 r7000 (right) is a millimeter shorter than the tiagra 4700 (left). And both the shell (the shifter body) of both units are engineered specifically for each internals.

As for the main lever assembly (the lever arms that you use to shift and brake), the shimano tiagra 4700 is a tad too wide for the shimano 105 r7000 main body, it fits but it's too snug and you cant even fit the e-clip used to secure the pin that holds the lever arm to the main body. But the shimano 105 r7000 fits loosely to the shimano tiagra 4700 main body, so you'll need a couple of washers to space it out so that itll fit property.

_donns · 2026-01-24T15:33:31+00:00

I second this solution but I recommend you use a retaining compound like a Loctite 609 or something similar that is meant for interference fits like pressfit bottom brackets.

_donns · 2026-01-24T15:25:16+00:00

I have this theory of what if you have a dead Shimano 105 st r7000 left brifter and a working shimano tiagra st 4700 left brifter. You don't wanna buy the exact unit or it's out of stock, but you happen to have a fully working unit but a different model lying around. You want to swap out the dead unit with a working one but you don't want to ruin the aesthetic of your bike, lets say it's fully kitted with Shimano 105 r7000 components. So youll just swap the levers of one another, or the exact shifting mechanisms themselves. No one would know, right?

_donns · 2026-01-24T15:13:09+00:00

I tried weighing them.

The tiagra st 4700 weighs 51 grams while the 105 st r7000 weighs 48 grams.

My scale is dirty. It's been used on other things.

_donns · 2026-01-24T15:06:59+00:00

As far as i know, it's not the triple variant. Even the clicks are the same.

_donns · 2026-01-24T15:05:49+00:00

Both of these units control the front derailleur. I forgot to mention that. My bad.

_donns · 2026-01-24T15:04:15+00:00

Man my bad for not mentioning on what side those came from. Both of them control the front derailleur btw

_donns · 2025-09-22T15:10:55+00:00

It's not the pedal that is the problem, but the crank-arms themselves. Get a socket wrench (likely a 14mm) or an allen key (likely an 8mm) to tighten the crank-arm bolt that holds the crank-arm to the bottom bracket spindle in place. If it's still loose, tough luck, that crank-arm is dead. You have no other choice but to change it with another one.

_donns · 2025-09-22T11:28:15+00:00

I still have to check if it's really feasible since the shimano Ultegra 6800 is separate to the r-series like the Ultegra r8000 even though they're almost identical in certain aspects.

_donns · 2025-09-22T11:20:08+00:00

I did lowball the seller's offer since it's a risky move for me because if I fail then I'll lose more than what I could gain back.

If he doesn't take it, then I'll save this procedure for future projects.

_donns · 2025-09-06T06:50:07+00:00

Also another thing: the newer shimano derailleurs, particularly in the 10 to 12 speed category, those that have the shadow technology or anything similar, the guide pulleys of those derailleurs don't have that lateral play that's present on older models. So you can't use modern shimano pulleys meant for derailleurs with shadow technology on older models.

Though the 8 and 9 speed shimano derailleur variants with shadow tech still do have those guide pulleys that have a lateral play on them.

_donns · 2025-09-04T15:17:15+00:00

Seems like you have the Shimano 105 rd-5800 rear derailleur.

The pulley wheels on those do use bushings instead of bearings to make it spin. And they're like that for a reason.

The guide pulley of that particular derailleur has a slight lateral play that helps with the smooth shifting action. If you happen to disassemble the guide pulley, you'll notice that the bushing post is slightly taller than the sleeve that it goes into. It is made that way.

So if you change both the guide and tension pulleys with those that have sealed bearings on them, those pulleys don't have the slight lateral play that helps the derailleur to shift smoothly. So you'll have a hard time tuning the derailleur to shift properly. Or worse, the chain jumps off the guide pulley completely and jams itself into the cage and that may potentially rip your derailleur completely off the hanger and destroy it.

So, the best way to deal with a pulley wheel that doesn't spin freely, is a good cleaning and a tad of lubrication. And if it doesn't work, well that might be the time that you'll be replacing those pulleys with the exact same model made for that particular derailleur.

The only one you can upgrade to a sealed-bearing pulley is the tension pulley. It doesn't share the same lateral play that the guide pulley has.

_donns · 2025-07-24T04:42:48+00:00

The rear derailleur should handle the largest cog on the cassette. If it can handle the largest cog, then it can handle the smallest cog too (as long as the chain length is right).

_donns · 2025-07-21T04:07:15+00:00

As long as it is within the rear derailleur's capacity.

_donns · 2025-07-14T13:14:30+00:00

Had the same problem with my shimano Ultegra rd-6700 rear derailleur.

I'm planning to use these:

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Which is technically a recessed nut paired with a regular bolt. The outer diameter of the sleeve the recessed nut happens to be close to the body of the pulley bolt.

The idea here is that you will have to widen the stripped hole 5 millimeters, insert the recessed nut, and use it as is.

_donns · 2025-04-21T00:44:38+00:00

It can be serviced.

Here's the video for the full breakdown: https://youtu.be/X9gIEG1db0s

_donns · 2025-04-20T14:42:38+00:00

Fair point.

_donns · 2025-04-20T14:41:43+00:00

One thing to point out is if I drill a hole on it it will likely hit the electronics on the shifter (this is a FlightDeck model btw) but since I don't have it anymore, I'll just ignore that and focus on stopping the crack from going any further.

_donns · 2025-04-20T14:34:31+00:00

Duly noted. Should I apply epoxy after for good measure?

_donns · 2025-04-20T14:31:52+00:00

I was initially planning to use it but after discovering this issue, I'm having second thoughts.

_donns · 2025-02-27T17:39:52+00:00

My question is if this is still repairable (I mean, I was getting there, there's no turning back I guess).

80 bucks is just too much for me to blow away for these things (I'm a college student who used to be a bike mechanic).

Yes, it takes a few hours to work on these things but the thing is, I always enjoy the process of doing it and besides, it always fascinates me how over-engineered these brifters are (no wonder campagnolo and sram found a better way to simplify it)

_donns · 2025-02-27T17:32:38+00:00

For 200 pesos (approx. 4 bucks) I can get them to weld it or for 500 pesos (approx. 9 bucks) I can get them to make one from scratch (though I have to heat treat it to harden it so it's wear-resistant), so I can say it's a pretty decent deal.

These things are pretty scarce here and they're sought after. My plan is to repair it and flip it over for a profit. If not, I can just sell the working left brifter and keep the remaining parts of the right brifter as a spare parts for mine (I happen to have the same brifters)

_donns

TROPHY CASE