Chef1978

Hello everyone, im trying to find clear answer to my problem, I.looked up on the net ,but no clear explanation. I have shimano sora shifters that have to be replaced its 8 speed in tje back and 3 in front question is, can I replace the shifters with any shimano 8x3 shifters without changing the derailleur? Do I have to change the whole system? Thanks.

70sSanO

You can use Claris 2403 or 2030 shifters. You can also use the older 2303 shifter with the thumb shift button.

Shimano SIS road front and rear derailleurs from 6 to 10 and SIS mtb rear derailleurs from 6 to 9 will work. You don’t have to change anything but the shifters.

John

Chef1978

thank you so much for the explanation, I was going out os my mind to try to figure it out!!

70sSanO

One more point the “3” in 2030, 2403, and 2303 designate a left shifter compatible with a triple crankset.

The rear right 8 speed shifter is technically 2000, 2400, and 2300. Depending on how you buy them, set or individually, they will be listed as one or the other or both. Just make sure it is for a 3x8.

John

icemilkcoffee 

All Shimano 3x8 brifters are interchangeable. So that includes 105 1056, RX100 A553, RSX A416(?), Sora 3300 (8 speed, not 7 speed, which has the same 3300 part number!), 3400, Claris R2030.... and Microshift R8.

The only thing in the 8 speed universe, which does not play well with others, is the current Claris R2000 2X8. The 2X8 left brifter has a different (ie 4700 series) pull ratio. But luckily the 3X8 still uses the old pull ratio. Same with the Sora R3000 series - the 2x9 is not backwards compatible but the 3x9 is.

Chef1978

woow ,thank you soooo much everyone for taking the time to help me,can uou tell me where can I learn all this? Is there a books or websites to educate myself more? Cheers everyone

icemilkcoffee 

Shimano's compatibility charts:
https://productinfo.shimano.com/#/
And also mostly by wasting time on the forums

70sSanO

The basics of index shifting are the shifters pull a certain amount of cable and the rear derailleurs have actuation ratio. For older Shimano index rear derailleurs, that ratio is 1.7. The derailleur moves over 1.7mm for every 1mm of cable the shifter pulls.

7 speed shifters pull more cable than 8 speed, which pulls more than 9 speed. In a sense, the rear derailleur just reacts to what the shifter does.

As far as what you should get, keep in mind that in the real world older Shimano 8 speed STI levers from the 90’s are hard to find, super expensive, and tend to be gummed up by the old grease.

Research new shifters you can actually get and pick one based on the reviews; either 3x8 Shimano Claris or 3x8 Microshift R8.

John

rokisr

Hey! I have Sora RD3300 and FD3300 derailleurs with 2x8 setup and I wonder which shifters would fit my bike. Is there a tech sheet somewhere where compatibility is listed?
/R

KCT1986

Shimano has 'Compatibility' pages on their web site. Only cover 2004 forward. Note that the way Shimano presents this info is not totally inclusive of all prior models that may be compatible. It generally just includes compatible product that are currently available or were recently in their offerings.

Here is a sample screen grab from the current models page affecting your question. On the site use the link in the area that I highlighted in yellow for prior years.



So, of the current line-up, the shifters that I marked in green should be OK. The reds are NOT. Note that the numbering has changed from xxxx to Rxxxx in the more current models.

Also, see post #5 in this thread for some other older models that would work.

Edit: Forgot to note that regarding post #5 info. RSX had 7 speed version also, so need to be sure it is the correct 8 speed one. As mentioned in #5, ST-3300 had 7 and 8 versions. Also, the ST-3400 is for 9 speed in 2005, don't recall of there was an 8 speed version of the ST-3400.

icemilkcoffee 

You can use any Shimano 2x8 brifters EXCEPT the Claris R2000 ones

rokisr

Thank you both KCT1986 and icemilkcoffee.

The reason why I posted the question here is that I am not able to find specific FD and RD models in the compatibility sheets. My expectations was (and still is) that Shimano provides a full overview of compatibility of old models as well. But I guess thats not the case?
/R

70sSanO

Here are the choices I have found. All of the Shimano 8 speed shifters that are compatible are discontinued, although you might find new Claris 2400 at some shops.

You can technically use Claris r2000 with an r2030 triple left shifter and just use the inner and middle shifter positions.

Other than that, or Microshift shifters, eBay is probably your best source.

You can get NOS st-3300 shifters that are the same as what you have. The only concern with old shifters, even NOS, is having the grease harden and needing to flush them out with WD40 and re-lube them with TriFlow. Depending on your current shifter issue, that might even be worth a try; if you already have the old shifters.

There are also at-2300, that are similar to the st-3300 but without the same trim functions.

Shimano made an “r” non-group series that I think is from the mid-2000’s. They seem to be somewhat obscure and are 2/3 compatible for the left shifter. The 8 speed is r500. They are sometimes on eBay.

And the 2400 can be found on eBay.

John

Edit added: An issue many people don’t consider with older shifters is the availability of shifter hoods. The further back you go the harder, or impossible, to find.

Personally, I’d go with the r2000 (rear)/2030 (front)