Gears shift when shock compresses

Dr_Tinkle

New bike Whyte T-129s.

Normal trail riding (not extreme)

When the rear shock compresses the gears shift to the next smallest ring on the rear cassette, sometimes fully, sometimes a half way shift.
Is this to do with the chain length, gear indexing or something different?
I just assumed that because it came straight from the shop things like this would be sorted.

Any advice would be most appreciated.

benpinnick

probably due to cable run. but then that normally causes upshift to a bigger cog not down. But worth checking the routing anyway.

nicklouse

poor cable routing. too short cables. mucky cables with too much friction in them. cables moved in the cable ties causing the above.

Dr_Tinkle

Thanks Nicklouse.
Assuming its routing or lengths then since bike brand new.
Is it just trial and error on cable length or is there an ideal length for each section?

Chunkers1980

Enough for all movement and smooth lines

nicklouse

Dr_Tinkle wrote:

Thanks Nicklouse.
Assuming its routing or lengths then since bike brand new.
Is it just trial and error on cable length or is there an ideal length for each section?

or they have moved and are being restrained by something.

Pics would allow use to tell you where the issue is likely to be.

Dr_Tinkle

Thanks so much.
Too late to go out there tonight so I'll inspect tomorrow and take pics if i can't solve it from this.
Will deflate shock so I can simulate full movement and see what gives.
Thanks for advice. Thanks also Chunkers.