Cassette noise
 

I have a Birdy 3 touring edition using the SRAM DD3 IGH with an 8sp cassette. I notice that there some noise coming from the cassette whenever it goes to the mid-gears between 5&6. The sound gets transmitted to the bike frame and amplified abit. (I know this is just mechanical where it shouldn't concern me if I can solve the problem.) This is certainly not the derailleur mis-shift clicking sound.

Does anyone has any experience with this kind of cassette noise in the middle of the cog?

I'm on a single front chainring and the RD is a Sora derailleu.

#1, go to a bike shop and have the derailleur hanger alignment checked, with the shop tool (Park makes them in the USA)

As its a folding bike the potential it was knocked out of alignment is a Given.



My tick tick tick, from chain passing through hard plastic pulleys got reduced by using softer nylon plastic Tacx pulleys .






....

and there's your problem... SRAM and Shimano parts do not play well together. The DD3 is specced for a dedicated shifter that incorporates both IGH and der. shifting into one controller unit... the SRAM pull ratio is different from Shimano's pull ratio... no bueno, mi amigo! i'm amazed it doesn't have other shifting issues.

https://www.sram.com/sram/urban/prod...ouw9kq7azk5u5j

I'm pretty sure that's not the problem, shifting is all fine.

Both the HG51 cassette and the Sora derailleur are from Shimano, except the non-integrated grip shfiter from SRAM. SRAM has at least 3 versions of shifter for the DD3.

As far as I know, certain SRAM & Shimano shifting components are compatible. I guess this stock combo is compatible.

Also my version of DD3-24 is not the retail version which comes with all SRAM component.

once again... Shimano derailleurs and SRAM shifters are not compatible.... the derailleur will move, but not in the correct amounts for each gear... i have managed to temporarily get a SRAM der. to work with a shimano index shifter, but it took mis-clamping of the cable to do so, and the results were noisy in the middle gears... sound familiar? you have a SRAM shifter hooked to a Shimano der.... odd that you got the same results, eh?
Shift index spacing is not linear... and the variations are endless. Shimano and SRAM have a long standing battle over the rights to shift ratios... this led SRAM to create their 1 to1 ratio line of shifting products. CASSETTES are the same spacing(except campy!)... chain widths are fairly standard because of that fact... the ders./shifters are still different cable pull ratios. To confuse matters even more, Shimano has now introduced a different pull ratio for road groups(Tiagra 4700 being the first of those groups)... cool, huh?

unless SRAM has paid Shimano for use of their pull ratio, the SRAM shifter is a DIFFERENT PULL RATIO than what the Shimano Sora Der. will need to operate correctly, and QUIETLY.

The specs I see for Birdy 3x8 Touring show SRAM MRX shifters. Isn’t the MRX series compatible with Shimano 2:1 rear deraileurs?

Lots of SRAM products are Shimano compatible - that's how SRAM got started.

On the specific problem, many cassette lockrings are way too loose. They should have their threads greased and be firmly torqued.