Gear ratios

gunny_bedford

So following severe illness and moonsoon weather conditions I took my new steed out for a spin since changing over a number of components whilst not riding it. One change I made was stick on a 11 - 36 cassette to give me some more gears to climb with.
Things didn't start well with the gears crunching during changes, but I soon realised things were not good when hitting a steep climb and going down the gears, the chained jammed between the chainset and chainstay locking the rear wheel and nearly dumping me over the bars !!! I soon realised that nearly half the cassettes lower range was not useable without the chain jamming, regardless of what front ring I was in and depending on how much pressure I was exerting on the drive train.

I have a 2 x 10 set up:
28 - 42 sram chainset
11 - 36 xt cassette
Long cage xt rear mech
My bike is a 26" tomac carbide

At first I was going to blame my LBS for ballsing up the set up then thought about the gear ratios that need considering - I know they exist but have not got a clue how they work !!

So should my setup work or is it out of the ratios ?? If I need to change something what would be best to give me better climbing gears ? Cassette or chain rings ??

Thanks Neil

mcnultycop

Did you put a new chain on sized to new cassette? Or add links in the old one?

gunny_bedford

Yes sorry forgot the lbs rang up to say the chain needed lengthening so I got a new xt chain put on I am assuming it has been cut to right length or could this be the problem? I am just wondering if my set up is not workable due gear ratios or my lbs has done something wrong before going there to complain !

ride_whenever

Just take it back and say it seems to be jamming. Don't go in guns blazing like a c**t just pop in and be reasonable, give them as much information as you can and they'll certainly sort you out.

It sounds like possibly chain suck, is it old chainrings???

gunny_bedford

I have a good relationship with my lbs mainly due to me spending £1000's over the years buying shiny new treks road and xc . So would never go in " guns blazing like a c***t ???!! I just wanted to confirm if it is a incorrect set up by them or I have cocked up by getting a cassette that is too big for my set up.

gunny_bedford

Not sure how old the chain set is, got the bike 2nd hand and that was on it. The rings don't look that worn.

ride_whenever

The nice thing about lbs is that they're always supposed to hand you your bike back in a working condition unless otherwise agreed!

The gears clearly aren't working so ask them to sort it!!!

njee20

Worn rings.

gunny_bedford

So I am assuming that a 11 - 36 cassette can work with a 42 - 28 chainset and long cage rear mech ? With no issues ( if set up right)

The Rookie

Yes...and if parts aren't worn...sounds like worn rings and chainsuck to me as well...

gunny_bedford

Thanks for the replies, i rode the bike a couple of times before changing over things, it had a 11 - 34 cassette on then, it shifted perfectly, straight into every gear no issues, and that was with the same rings, unless having a bigger cassette and longer chain makes things worse if the rings are too worn ??

mcnultycop

New cassette and chain makes the difference, not size; the chainrings would have worn along with the old cassette.

coulddobetter

Not the gearing as it's what I run sram 2x10

The Rookie

The chain lengthens due to wear at the pins, instead of engaging every tooth it then doesn't, so the teeth wear, they wear to accommodate the now longer pitch (between each pin) chain, fit a new chain at the correct pitch and it doesn't fit to the worn rings - simplez!

coulddobetter

Only other thing is sram would recommend a medium cage derailleur on that set up.