Bike chains (NLC)

The place to "speak geek"
Post Reply
User avatar
BiggestNizzy
Posts: 8932
Joined: Sun May 27, 2007 6:47 pm
Location: Kilmarnock
Contact:

Bike chains (NLC)

Post by BiggestNizzy » Sun Oct 08, 2017 8:52 pm

A few people on here know there way around a bike so I was looking for some help with getting mine back on the road.

It has 8 gears on the back and due to the front chaining and bearings being mangled now sports 3 at the front instead of the original 2. I have stuck a new chain on it as when the front went the chain got mangled too.

I was setting up the gears, no problems on the front ( I think) but my issues are at the back I have set the upper and lower limits no problem and I have to screw the other adjustment screw to the max so that it clears the gears. However when running on the smallest cog front and back the derailleur is folded back completely and it the chain rubs, if I remove a link in the chain when I go to the large cog back and forward it he derailleur pokes forward.

I have been considering a half link but I thought I would open it up to SE's collective knowledge?
Sent from my ZX SPECTRUM +2A

woody
Posts: 5624
Joined: Mon Dec 26, 2005 4:03 pm
Location: Southside Triangle

Re: Bike chains (NLC)

Post by woody » Sun Oct 08, 2017 9:56 pm

As benachie bike shed is a bit far, bring it round one evening or we could have a look at Pete's? He's probably more knowledgeable about that type of set up anyway.

User avatar
pshanks76
Posts: 251
Joined: Sat Aug 01, 2015 3:02 pm
Location: Kintore

Re: Bike chains (NLC)

Post by pshanks76 » Sun Oct 08, 2017 10:04 pm

It shouldn't usually need the B tension adjuster right in to clear gears but that shouldn't cause an issue if it is. Derailleur arm going fwd shouldn't cause an issue either, as long as it's not a full suspension as you'll need to check the chain is long enough when suspension is compressed. Have you changed any of the components apart from the front chainring setup?

Sent from my Nexus 7 using Tapatalk
Elise S2 135r no more... Crossed to the dark side with a Boxster 981s
BMW 330D x-drive m-sport touring
Autosleeper Duetto camper

User avatar
BiggestNizzy
Posts: 8932
Joined: Sun May 27, 2007 6:47 pm
Location: Kilmarnock
Contact:

Re: Bike chains (NLC)

Post by BiggestNizzy » Sun Oct 08, 2017 10:48 pm

pshanks76 wrote:It shouldn't usually need the B tension adjuster right in to clear gears but that shouldn't cause an issue if it is. Derailleur arm going fwd shouldn't cause an issue either, as long as it's not a full suspension as you'll need to check the chain is long enough when suspension is compressed. Have you changed any of the components apart from the front chainring setup?

Sent from my Nexus 7 using Tapatalk
Only thing changed is the front setup - no suspension to worry about either.
woody wrote:As benachie bike shed is a bit far, bring it round one evening or we could have a look at Pete's? He's probably more knowledgeable about that type of set up anyway.
Will drop him a message, not seen him in ages and have been meaning to drop in.
Sent from my ZX SPECTRUM +2A

User avatar
philthy
Posts: 2550
Joined: Fri Aug 04, 2006 1:01 pm
Location: Glasvegas

Re: Bike chains (NLC)

Post by philthy » Mon Oct 09, 2017 7:16 am

Shouldn’t really be running small to small anyways but the 3 rings at the front will now go from smaller to bigger than your previous 2 ring so the rear mech will struggle. I’d remove a link or two and try again, did you measure the old chain that came off for reference?
S1 Elige Audi 1.8T
S1 Elise Honda K20
VW T6.1 family bus

User avatar
BiggestNizzy
Posts: 8932
Joined: Sun May 27, 2007 6:47 pm
Location: Kilmarnock
Contact:

Re: Bike chains (NLC)

Post by BiggestNizzy » Mon Oct 09, 2017 7:08 pm

philthy wrote:Shouldn’t really be running small to small anyways but the 3 rings at the front will now go from smaller to bigger than your previous 2 ring so the rear mech will struggle. I’d remove a link or two and try again, did you measure the old chain that came off for reference?
Yes, I put the same length chain on measured and counted links to check it hadn't stretched. Removing a single link really starts to stretch the Derailleur and I start to get fowling. I will put it back together either tonight or tomorrow depending on when I get back and stick a couple of pictures up.
Sent from my ZX SPECTRUM +2A

User avatar
RDH
Posts: 2837
Joined: Mon Mar 13, 2006 9:10 pm
Location: Glasgow

Re: Bike chains (NLC)

Post by RDH » Mon Oct 09, 2017 11:09 pm

There's a wee bike shop on the main street round the corner from your work, if you're struggling for time?


Sent from my iPhone using Tapatalk

istoo
Posts: 725
Joined: Sat Mar 29, 2014 8:52 pm

Re: Bike chains (NLC)

Post by istoo » Thu Oct 12, 2017 8:37 am

If you went from a double to a triple setup on the front your rear mech will likely be a short/medium cage. is distance between the jockey wheels at the back.
when you are small/small to big/big the range is greater to the mech has to work more.
A long cage mech will help matters, but generally avoid the extremes of shifting.

If it an option to go back to a double? or put a cheap bashguard in favour of the big ring?
The cage should be just above the chain, by about 0.5cm in small small and in big big almost parallel (tight) not wise if you have an FS bike as it works against the suspension.

No idea how worn the existing drivetrain was but generally the chain will wear most, if you have changed the front cranks for a triple setup and a new chain, how is the rear cassette? if they are unevenly worn the chain will jump etc.

anyway woody can have a gander :)
S2 111s

User avatar
Scottish Scrutineer
Posts: 360
Joined: Sun Jan 27, 2013 10:29 am
Location: Dunfermline, Fife

Re: Bike chains (NLC)

Post by Scottish Scrutineer » Fri Oct 27, 2017 8:06 am

I agree with istoo, sounds like you've now exceeded the capacity (range) of the derailleur. A long cage derailleur may be needed, or fit a closer range cassette. As you now have a lower (inner) front sprocket, you could install a cassette which has a smaller lowest gear.
As a guide for chain length, fit the chain to the largest front and rear sprockets, bypassing the derailleur. Allow 2 links overlap and that will be a decent length.


Sent from my iPad using Tapatalk
Renny Thomson
MSA Scrutineer
Elise S2 (2002)

Post Reply