I'm trying to upgrade, but the Shimano Deore is too expensive... The problem with the other brands is that their rear derailleurs does not have good tension... so can I use a Shimano Tourney in a 1 x 11 (11 - 52ish) rd?
3 Answers
Not a chance.
Rather than asking for each one, here's how you work it out for yourself.
- Google up
shimano tourney RD-TX800 specor whatever model you're looking at. - There will be some link to shimano.com that shows the specifications - for our RD-TX800 example it is https://bike.shimano.com/en-US/product/component/tourney-tx800/RD-TX800.html
- The important numbers are:
| Description | Value |
|---|---|
| Low sprocket_Max. | 34T |
| Low sprocket_Min. | 28T |
| Max. front difference | 20T |
| Top sprocket_Max. | 14T |
| Top sprocket_Min. | 11T |
| Speeds | 7/8 |
This derailleur is rated at taking a cluster with a small between 11 and 14 teeth, and a maximum cog of 28-34 teeth. So your big gears won't officially work.
Now it is well-known that shimano's quoted numbers are what will definitely work well. This RD could probably run a 36T and maybe even a 38 if you don't mind a bit of clatter and poor shifting. 51 tooth is right out.
Max front difference doesn't matter to you because you have one chainring so the difference is 0. For a double, it would be the tooth count difference between chainrings.
Doubtless other component makers have similar published statements for each part.
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1What a nice and educating answer. I wonder, the last row "Speeds: 7/8", means that it works for 7 or 8 rear gears, and OP requires 11?– WtowerCommented Feb 16, 2022 at 11:21
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1@Wtower correct. That mech is rated to have enough travel for 7/8 speeds, so it would work for 6 as well which has the same chain width and spacing. It won't work for 9 or more because the spacing changed. OP wants 11, which requires 11 speed parts everywhere.– Criggie ♦Commented Feb 16, 2022 at 20:52
No, you can't. The Tourney is not designed for cassettes of such dimensions, and doesn't have a clutch, which is a requirement for single chainring transmissions. Deore M-5100 is the lowest range at Shimano that meets the requirement for single chainrings .
If your limiting factor is budget, I would recommend to have a look at Microshift Advent X (10 speed, 11-48) and Microshift Advent (9 speed, 11-46). I haven't tested them personally, but reviews are very positive about them.
The issue here is cable pull, or looking up in the tourney and deore spec sheet whether they are compatible, shifter-to-shifter and RD-to-RD. Obviously you'd only have 8 speeds if you opted for a Tourney shifter.
If you are using a friction shifter then you avoid the problem of cable pull between individual gear changes, but you'd have to make sure the friction shifter can move enough for the RD to reach all 11 sprockets. (That is to say, the entire pull range of the friction shifter must be larger or equal to ten times the Deore shifter's individual gear change cable pull.) If not, you could end up with fewer usable gears.
The tourney RD spec sheet will also tell you the cog sizes it will officially support (taking account the front chainring and the largest rear cog).
