Slipping (new) cassette

secretsam

Fitted a new cassette to the old Sirrus the other day, plus new chain, took the opportunity to upgrade the wheels at the same time (had a pair of Fulcrum R7s lying around)

Anyway, this morning rode into work, all fine until I got to the end - pulling away from some lights I had massive chain slip, which happened 2-3 times pulling away from lights. Am sure I fully tightened the cassette, so what might it be????

maddog 2

setup?

maybe the jockeys aren't aligned to the sprockets?

maybe the jockeys are worn?

maybe the chain has a tight link?

get it on a workstand and see what happening.

rolf_f

Can't see how the jockey wheels themselves could cause chain slip no matter how worn......

Stiff link entirely possible though. I had that late last year. Despite being used day in day out, something got into a link and no amount of manual woggling was enough. I had to apply a slight bit of too and fro force on the pins with the chain tool on my multitool to bring it back to life. Very easy to spot once I looked at the chain.

If this is the problem, it should be very obvious if you back pedal (worn teeth should behave normally on back pedalling).

secretsam

Stiff link it may be - will check that out. Also may be the chain is slightly too long...

andyrr

Could the front chainring be so worn tht the new chain is not meshing properly with it ?
Guess the chain being too long could also cause this - worth checking this (probably a youtube video to help with that if you need it.)

secretsam

andyrr wrote:

Could the front chainring be so worn tht the new chain is not meshing properly with it ?

Also entirely possible!

tim_wand

Stiff link

Turn the drive train backwards and watch the chain run through rear mech cage , it will kick at the point were the stiff link is in the chain.

loosen the pin by pushing it backwards and forwards with a chain link tool , but be sure to not push it beyond the plates on either side of the chain.

secretsam

Will be well pleased if it's a stiff link, easy to fix!

Chain seems to slip between gears when it happens, bashed me lunchbox on my top tube the first time it happened, deeply unfunny

andyrr

Could even be the cable needs a slight adjustment - maybe got altered during the chain and cassette swap.
Also, as you've put new wheels on the indexing could be slightly out.

secretsam

Oh Lordy not indexing, is that complicated? Never been brave enough to sort that out, seemed OK when I tested it on the workshop stand

tim_wand

Is it a cassette style freewheel, have you got all the spacers in the right place and the whole cassette lined up properly on the free hub splines.

damocles10

There is a lot of this happening at the moment - I had a very similar experience last week - advice was to clean the rear derailleur, which fixed the issue temporarily, started happening again today, back to the drawing board. This is actually quite a dangerous situation.... please do not ride out of the saddle ( I managed to control the slip by making sure I did not back pedal or coast while stopping at the lights to ensure the chain was engaged. Sometimes the chain would slip a bit and make a really horrible and loud noise) you can lose control very easily and hurt yourself in traffic.

Does the rear derailleur line up on all gears, I would check the cable for resistance from dirt too or maybe replace it if has been used for a while, has the derailleur arm been bent - troubleshooting this can be a real pain (literally).

damocles10

Actually this prompted me to reinvestigate....took the back wheel off (Zipp 404) and the freehub is slipping - most annoying....looking into it now. I did take it off last week so maybe some has gone wrong with reassembly.

gggrrrrr...

Chris

damocles10

Freehub pawls are not engaging the wheel despite cleaning and degreasing.....oh well.

ride_whenever

Well that's solved it, new pawl springs and you're laughing

Bozman

+1, for - "it's happening a lot."
I've seen numerous posts on here, I've had it and my mate had the same, we had both swapped the chain and cassette, the chain just slipped under load but the shifting was flawless.
After about fifty miles and a few near nut cracking slips I adjusted the rear mech with two quarter turns, it cured it but it may have been a coincidence.
My mates slip disappeared after about 100 miles and plenty of cleaning, he's adamant that it's got something to do with the factory grease.

damocles10

I have spent around 300 quid troubleshooting this on new parts this week. Oh well, it's good to have spares.

I will look in to getting new Pawl springs, hopefully the hub has not been worn beyond repair.

However, I am pleased I have found the solution as it was driving me nuts and it's not a good look pulling away at the lights and slipping off the chain. I just hope it helps others troubleshoot...check the free hub too.

Chris

jermas

I've experienced the same, with new chains and new cassettes slipping. I had two new shimano cassettes and two new kmc chains a while ago and all combinations slipped. I continued riding, and after about 100 miles, all slipping stopped. I know in theory they shouldn't need to "bed in", but it seems that sometimes that might be the case.

secretsam

So it might be the factory grease, etc??? That's entirely possible as I didn't do anything to the chain, just used it out of the box. Coincidentally I bought a shiny new Park Tools chain cleaner along with the cassette and chain, so will give it a clean up and see how we go. Will also check chain isn't too long and doesn't have stiff links.

Regarding indexing, she shifts like a beaut, no problems there at all - up and down the gears like a rat up a drainpipe. Will have a play at the weekend and ride it in next week, if there's still a problem I'll pop round the corner to the LBS near work - they seem a pretty good bunch.

darkhairedlord

I suffered terrible chain suck on my old mtb after changing the cassette, chain and chain-rings. Degreased the chain and re-oiled, problem went. The chain was SRAM but I think the factory grease they put on these is a bit too treakley. On another occasion I had chain problems caused by drag in the free-hub. Soaked it first in jizer, then wd40, 3in1, finaly ep90 gear oil. Runs as sweet as grandma's sewing machine...

secretsam

Right

De-greased the chain and took out a couple of links, no good.

Am beginning to wonder if I put the cassette on tightly enough...

vanleapo

Sounds like the front chainrings to me.

secretsam

vanleapo wrote:

Sounds like the front chainrings to me.

Really? Why has it only shown up now, when I've changed the cassette and chain, no problems before?

Bl00dy bikes, never ending source of expenditure

vanleapo

Because you have changed your chain.

My guess is that the old chain and chainrings had worn together so worked OK with each other, but the new chain just won't mesh with the worn teeth on the chainrings.

Easiest way to test this theory is borrow a rear wheel from somebody and see if the problem is still happening.

Also, inspect the teeth on the chainrings, and compare them with a new chainring. If they look sharp then they will need replaced unfortunately.