Sora 9spd 3500 derailleur - how can I tell if it is SS or GS?

daniel_b

Gifted the lovely little 44cm Bianchi to our 9 year old on Saturday, and delighted to say it is a really good fit - about 6cm of seatpost showing, so should be plenty of growing room.

It has a didi 60cm stem already fitted, and she is going to help me swap the 38cm bars out for some 34cm bars I bought, along with some super blingy bar tape.

I digress.

I noticed the bike has 50/34 but didn't look at the rear cassette, so was slightly surprised to see it had an 11-27 on the rear.

Looking up details on the Sora groupset (it's the old fishing line shifter setup, so not sure how that ages it) it would seem the SS can take up to 32, and the GS 34.

I have ordered her a 11-32, but am now wondering if the bike has a GS fitted, though I can see no clear way to find out. The measurement from the centre of one jockey wheel to the other seems to be pretty much 7cm - it looks relatively long to my eye, but I can't see anyway to prove which one it is.

If I was sure it was a GS I'd probably return the 11-32 and order an 11-34 to give her a proper 1:1 gear for climbing, as I'm trying to give her every possible chance to keep cycling and not lose heart.

Are these pics of any use........?

whyamihere

SJS have a cage measurement for the R3000 SS at 74mm: https://www.sjscycles.co.uk/derailleurs-rear/shimano-sora-rdr3000-9-speed-rear-derailleur-ss-type/

Yours may not be identical as it's a slightly different model, but they also quote the GS measurement at 95mm and it won't have changed a huge amount. I'd therefore say that you have an SS mech.

daniel_b

Genius, thankyou - I was looking to find somewhere that had measurement and was a bit surprised to find the Shimano tech docs had no mention in there.
Why they can't just add GS or SS to the etching on the derailleur body itself I don't really know.

Thanks for your help, I will stick with the 32 and see how she gets on - she is VERY light, and it's a fairly light bike, so hopefully she'll find the 34/32 combo enough for the vast majority of situations.

trevor.hall12

With b screw adjustment you tend to be able to go 1 cassette up from the recommended with Shhimano without any issue

Mad_Malx

trevor.hall12 said:

With b screw adjustment you tend to be able to go 1 cassette up from the recommended with Shhimano without any issue

yes. I'd get the 34 and give it a go, and then change deraiileur if you need to.
If you do need to to change, Shimano road 9 and 10s derailleurs have same pull (except newer 10s Tiagra), and MTB 9 speeds will work fine too.

daniel_b

This seems VERY cheap (£12.99), and would seem to allow the fitment of up to a 36T rear cassette.

Good idea - quality decent enough?

https://wiggle.co.uk/shimano-altus-m2000-9-speed-rear-derailleur

whyamihere

Altus is fine, no quality problems there. An MTB mech is a good call, as well as the 36t capability they have enough capacity to fit a triple at the front if you wanted super low gears.

daniel_b

Also just spotted a 12-36 on Merlin - I doubt she's going to be needing 50/11 anytime soon, so this would give her an even lower gear, but with presumably no worse gappy gearing than an 11-34.

I'd like to try and avoid the triple route for multiple reasons if possible.

N0bodyOfTheGoat

My Marassa hybrid came with an Altus rear mech in summer 2020, it has the triple chainring which is great for gear options but the front mech severely limits the max rear tyre size, been using those 12-36 cassettes on my H3 turbo and rear wheel... All Good.

Mad_Malx

daniel_b said:

Also just spotted a 12-36 on Merlin - I doubt she's going to be needing 50/11 anytime soon, so this would give her an even lower gear, but with presumably no worse gappy gearing than an 11-34.

I'd like to try and avoid the triple route for multiple reasons if possible.

I'm pretty feeble, but since the dawn of compact chainsets I've never really needed a 50-11

ktuludays

most of those era shimano rear mechs allow for cage removal for servicing, the cages are interchangeable between mechs so you could easily upgrade the cage on your current rear mech for a longer one if you can find a cheap enough donor mech.

I had a 105 10 speed ss rear mech and swapped the cage from an XT mtb mech to give better range on the rear cassette. xt mech was £5 on ebay as it was "sticky" in use.

Mad_Malx

Cage length is only part of the issue, to take up excess chain length. The derailleurs with short cages aren't designed to work with big ranges in the cassette, because the ramp is different. If the cassette goes from 11-36 the top jockey wheel has to move a lot further down than 11-30. Even if you sort the loose chain it might not shift well, or clear the big cog

daniel_b

I have gone for the £13 derailleur, £24 12-36 cassette, and won't need to spend money sending the 11-32 back, as luckily my turbo bike is good old 9 spd.

Pretty pleased with that, 34/36 smallest gear should get her up most inclines I would have thought.

I have got a nos pair of 5700 10spd shifters knocking about, so did consider switching to those (I think I would have just had to get a long cage 10spd rear derailleur instead), but I might save those for further down the line, or might still need them as spares for my partners bike.

Will check to see if I have a new 9spd chain in stock, as I realise the current one will be too short.