derailer fine adjustment pain!

bill m

hey guys,
just bought a boardman comp road bike, two months ago, after a three year lay off.Great bike and very happy with it so far.One thing though, its a bitch to fine tune the front derailer to stop the chain from hitting.I almost have it ,but cant get it that extra hair on the high gear on the first set(small sprocket) without losing it on the bottom of the second set(large sprocket).Any ideas.I brought it back to Tarren in halfords who seems to know a thing or two and he did one or two things,and it was a 6 week check up so it didnt cost me.He told me about the pushing the lever on the handle bar out slightly and then clicking it back when ive changed,which worked in the shop but not on the road!!Any help or suggestions would be greatly appreciated
bill m

Greyspoke

Unfortunately it really is just a matter of trial and error between adjusting the cable tension and the two screws that limit the range of movement of the mech. Also, make sure you don't run the chain from the small ring at the front to the smallest sprocket at the rear or from the large rng at the front to the largest cog at the back - apart from being bad for the chain it could cause the chain to rub on the derailleur cage.
Apart from that, if the cage is not parallel to the chainrings that can cause rubbing too.

bill m

nice on greyspoke,i appreciate the response,
i just want to make sure i understand what you are saying regarding the following(don't run the chain from the small ring at the front to the smallest sprocket at the rear or from the large rng at the front to the largest cog at the back - apart from being bad for the chain it could cause the chain to rub on the derailleur cage).Do you mean not to use the highest gear on the first level(small sprocket on rear to small sprocket on front) and the lowest gear on the second level(large front sprocket to large rear sprocket)Its an eighteen speed,and if thats what you are saying,whats the point of having them although it would solve the problem!
...im probably misunderstanding this and if i am...talk to me like im a four year old:D,or do you simply mean dont pedal backwards in these gears,which i wouldnt d in any gear although ive seen alot of guys do it...WHY !
Thanks for your time greyspoke

bill m

just thought about that,and if it is what you meant...it actually makes sense.Why would you go up to the highest gear on the first level, its probably only to be used on the second level where it will give the best result for speed?and whats the point in dropping down to the lowest gear on the second level when theres a whole load of 1st level gears to go through...i think i have it?!
thanks greyspoke...

ashleey

Is yours a 10 speed SRAM force? If so I have the same on my bike and after a sportive last week the cable has stretched requiring some fine tuning. The park tools website has excellent maintenance tutorials to help and in what order to approach the problem. Firstly check the derailleur is parallel to the chain rings from above as a loosening clamp from road shock could have caused a slight movement on gear change. Then follow the advice on cable tension ie no slack when chain is on small ring but not tight either. Look for a 'barrel adjuster' where cable goes alongside frame at the point where it is not in a cover. This is for fine tuning tightness. Then adjust the high and low screws as per the directions on the site. I can't remember precisely but you do it to avoid rubbing when chain is on big front and small back ring and vice versa. You should only turn the screws when it is not in these gears and then go back into the gear with maximum chain cross to test your adjustment. Hth

cython

bill m wrote: »

just thought about that,and if it is what you meant...it actually makes sense.Why would you go up to the highest gear on the first level, its probably only to be used on the second level where it will give the best result for speed?and whats the point in dropping down to the lowest gear on the second level when theres a whole load of 1st level gears to go through...i think i have it?!
thanks greyspoke...

That's exactly it. Basically running big ring-big sprocket, or small ring-small sprocket is not only a bad idea, but also unnecessary. Usually either the same, or at least a similar gear ratio can be obtained by means of another combination.

For example, large-large on my bike would be 50/26=1.923, but I could get a very similar combination/ratio by using a 17-18 tooth sprocket (middle of the cassette) on the back with my 34T chainring on the front (resulting ratio being 1.9-2). The advantage of this particular combination is that it doesn't require the cross chaining that the previous one entails.

Greyspoke

bill m wrote: »

nice on greyspoke,i appreciate the response,
i just want to make sure i understand what you are saying regarding the following(don't run the chain from the small ring at the front to the smallest sprocket at the rear or from the large rng at the front to the largest cog at the back - apart from being bad for the chain it could cause the chain to rub on the derailleur cage).Do you mean not to use the highest gear on the first level(small sprocket on rear to small sprocket on front) and the lowest gear on the second level(large front sprocket to large rear sprocket)Its an eighteen speed,and if thats what you are saying,whats the point of having them although it would solve the problem!
...im probably misunderstanding this and if i am...talk to me like im a four year old:D,or do you simply mean dont pedal backwards in these gears,which i wouldnt d in any gear although ive seen alot of guys do it...WHY !
Thanks for your time greyspoke

You're thinking correctly! If you set the bike in either of those two gears and take a look from the rear down the line of the chain, you'll see the problem - there's too much of an angle on the chain between the front rings and the rear sprockets which could be leading to the chain rubbing on the cage.

bill m

Nice one ashleey and cython.Mine is a 9 speed 105 shimano, .Its a 2010 boardman comp road bike,sweet machine, where as the 2011 has a 10 speed sram force,but my wheels are better spec and it has the bb30 shimano crank adapters where as the 2011 doesn't and my tyres are better spec also!
Yeh i had a look at what greyspoke said on the bike and it solves the problem.Mind you the chain touch was bare minimum but any noise at all drives me demented.I was checking out the book you mentioned ashleey on amazon and will buy it,thanks for the advice.Its much appreciated.
Im just getting back into it so very rusty and the last one i had was a very old spec.gear levers on the down bar and 6 speed!!
The cable does get a bit slack on the small front cog but if i tip the left brake lever over a touch it tightenes up and the derailer moves a hair.It's something Tarren(in halfords drog.) pointed out to me when i bought the bike.A clever touch i think.Id sooner not have all that mularky though and it just run true...
might see you on the road sometime lads
any more advice please load it on..it all helps a great deal

bill m

Nice one Greyspoke
thats a load off.
Theres a lot of knowledge out there that you just don't get unless you ask,and they don't tell you this stuff when you buy a bike.
As i said ,its been a few years since i last rode a bicycle and i didnt get into it as much, I just used it for commuting when i lived in dublin.I've A lot to learn so i appreciate the advice...

ashleey

Shimano actually have a 'trimming' adjustment as part of the mechanism so you can nudge the front derailleur by moving the lever while you ride. Sort of a half move rather than a full click if you know what I mean. No need to buy the book, just head for the park tools website:
http://www.parktool.com/blog/repair-help

Gear adjustment in a 9 or 10 speed modern bike is all about precision and I'm with you on the noise. Must be part of OCD that is more common among cyclists(?). Anyhow, they tend to need constant attention for perfection but it's worth the trouble and satisfying when you get it just right.

Also, the advice on a crossed chain is spot on, a straighter chain is more efficient when riding and will last longer.

bill m

fantastic,that site is perfect.Cheers Ashleey.Yeh i figured out the nudging the lever thing.It works for the most part but not 100 and 1%.Its good to know im not the only one with cyclist ocd!!
i ride a triumph t100 motorcycle as well and the other biker's say im as bad!.But for me its gotta run right, plain and simple!I got it sorted now though.looking forward to taking it out tomorrow
thanks again for all the help Ashleey,
bill

ashleey

Great. Glad it worked out.

Greyspoke

I'm sure someone has already mentioned it but new cables will stretch a little initially so expect to have to do a little adjustment until it all settles down. I like perfectionists!
Enjoy the bike! (and the Triumph!)

Limestone1

OP its called 'cross-chaining' :

http://www.activesports.co.zw/train_health_nutrition/mtb_cross_chain.htm

bill m

perfectionist to the point of anal greyspoke,thats me!
yeh, i know about the bedding in period but glad to be reminded of it.the feedback here has been brilliant,thats what its all about,
cheers mate
b

bill m

Limestone1 wrote: »

OP its called 'cross-chaining' :

http://www.activesports.co.zw/train_health_nutrition/mtb_cross_chain.htm

great article man thanks a million
b