Escape from 39-25

rollingscone

Hi All,

As mentioned in the Campervan thread my current gearing ratio of 39-25 (bike was a gift) is killing me on hills and since my knees are already fairly knackered this is not something I can just HTFU through in good conscience.

However with my budget being effectively zero I was looking at just replacing the rear casette and downgrading to Tiagra since I don't think I'll be at a level where Ultegra will make a difference at any time soon (or ever) but I was told that my derailleur might not be compatible with a larger casette and the better option for now would be to get a compact chainset...again the price I was quoted was beyond my current means.

Does the attached photo of my rear derailleur show whether there is any room for manoeuvre on the size of the rear casette?

Inquitus

Just put up an ad asking to swap your 11-25 Ultegra Cassette for an 11-28 Shimano Compatible cassette in the cycling adverts subforum. I am sure someone will bite.

petethedrummer

rollingscone wrote: »

my knees are already fairly knackered

Wait for second hand stuff. People are often selling 2300, SORA and Tiagra stuff here and on adverts.ie.

http://www.boards.ie/vbulletin/showthread.php?p=84583724
http://www.boards.ie/vbulletin/showthread.php?t=2056962661

Put up a wanted ad and someone might sell one they have lying around.

funkyjebus

You can use up to a 28t cassette on that derailleur. You might need more links in you chain, but I'd say you'll be grand.

I know how you feel, first time I went over sally gap I had a 39-23, I died a little inside that day.

On a side note, you need to clean that chain and cassette, especially if you want to swap with someone.

rollingscone

What about the range on the derailleur?

Brian?

A 28 will be grand on that derailleur.

smacl

Agree with Petethedrummer, wait for 2nd hand or check ebay. The difference between 39/25t and 39/28 may not be enough to save your knees. I'd wait for a long cage dr and 32t cassette, a triple, or a compact crankset and 28t cassette. Given you've already got ultegra, you might well be able organise a direct swap.

rollingscone

funkyjebus wrote: »

You can use up to a 28t cassette on that derailleur. You might need more links in you chain, but I'd say you'll be grand.

I know how you feel, first time I went over sally gap I had a 39-23, I died a little inside that day.

On a side note, you need to clean that chain and cassette, especially if you want to swap with someone.

Duly noted. I just ran it through a lidl chain cleaner but I've a feeling I'll need to apply an old toothbrush and some more degreaser/chain cleaning fluid to get it looking good enough to eat.

cdaly_

I wonder could you hack a medium cage onto the ultegra derailleur? That would allow for a larger sprocket. You might also get away with the larger sprocket so long as you make sure never to use it while in 53 on the front.

Alternatively, would the ultegra double crank be drilled for a granny ring?

Incidentally, if you're in the Glasnevin area in business hours and want to drop by, you could try out a 32t sprocket on your existing setup and see if it's possible...

smacl

cdaly_ wrote: »

Alternatively, would the ultegra double crank be drilled for a granny ring?

I was thinking the same thing, but a quick google suggests that you'd also need a new left sti, as most shimano double levers are different to triple. (Would possibly work for campag)

I'd be interested to know if you could change the cage though, could be just the cheap and dirty hack required.

funkyjebus

cdaly_ wrote: »

I wonder could you hack a medium cage onto the ultegra derailleur? That would allow for a larger sprocket. You might also get away with the larger sprocket so long as you make sure never to use it while in 53 on the front.

Alternatively, would the ultegra double crank be drilled for a granny ring?

Incidentally, if you're in the Glasnevin area in business hours and want to drop by, you could try out a 32t sprocket on your existing setup and see if it's possible...

I doubt they crankset (at ultegra level) would be drilled for a granny, but I'm open to correction. But as you have discovered, you will have shifting issues.

Not sure a medium cage would allow a larger sprocket. The medium cage will just allow a longer chain. I would have thought the issue with a using more than a 28t would be the B adjustment (ie your jockey wheels will be rubbing your cassette). I know on my ultegra 6600 rear mech, the most I can go is 28 (which I have). Again open to correction though.

fixie fox

Why not put a 34 on in front? That would make a massive difference.

cdaly_

smacl wrote: »

I was thinking the same thing, but a quick google suggests that you'd also need a new left sti, as most shimano double levers are different to triple. (Would possibly work for campag)

Ah yes, forgot that bit...

funkyjebus wrote: »

Not sure a medium cage would allow a larger sprocket. The medium cage will just allow a longer chain. I would have thought the issue with a using more than a 28t would be the B adjustment (ie your jockey wheels will be rubbing your cassette). I know on my ultegra 6600 rear mech, the most I can go is 28 (which I have). Again open to correction though.

I'm running a 32t with a med-cage 105 mech without problems. Then again, that's on a triple so the med-cage is needed there. OP might get away with a short-cage...

fixie fox wrote: »

Why not put a 34 on in front? That would make a massive difference.

A 34t has a 'compact' 110mm BCD (bolt circle diameter) while a 39t has a 'double' 130mm BCD so the 34t won't fit.

Brian?

Have you Ultegra cranks you'd like to swap?

cdaly_

As previously mentioned, getting a (free) worn out MTB cassette with a 32t from your lbs and it's a pretty simple job to dismantle your cassette and substitute a few MTB sprockets.

I'd suggest you replace your 21 with your 23, your 25 with the 27or 28 from the MTB cassette and add the 32 from the MTB cassette. You'll end up with the same top 5 or 6 gears and a big range in the last 3 gears...

fixie fox

cdaly_ wrote: »

A 34t has a 'compact' 110mm BCD (bolt circle diameter) while a 39t has a 'double' 130mm BCD so the 34t won't fit.

Yes, you are probably right - even though I run a 38 110mm it is probably 130. A change to a compact would probably be te best option if it could be picked up cheap second-hand.

mirv

Ah here. He's clearly got a double crankset so he can't put on a 34 or 30 ring without it costing him a new set of cranks so that's out the window.

He might get away with a tiagra 12-30 or 12-28 cassette and it'll probably be enough to have the one or two extra gears. He might need a new chain though for the extra length and to adjust thr b-screw on the rear dérailleur to allow him to shift into the 28/30t cog though. If youre going to change the cassette for one with a larger range you'd be wise to opt for one without a 11t cog as the gaps between the cogs will be very noticable otherwise.

rollingscone

So after some ponder time I think my preferred option would be the compact chainset and a 28 on the back (not the cheapest I know but...my pretty).

Gave the drivetrain a thorough degreasing this morning and it came up all shiny and silver, I genuinely thought it was a darker cover, however when I lubed and oiled it again once it dried it looked nearly the same as it did pre-cleaning?

doozerie

Wipe off any excess oil with a rag after you oil the chain. You don't need, or want, oil on the outside of the chain you just need it inside the rollers. Oil on the outside will just attract dirt and spread it around the drivetrain which will contribute to wear and tear (and makes it a bigger pain to clean next time round too).

The routine is to apply oil, rotate the cranks backwards a couple of dozen revolutions or more to give the oil a chance to work its way inside the rollers, and then wipe off the excess. In the process you might find that the newly applied oil "washes out" remaining dirt in the chain so it ends up on the outside, and can make the chain look as filthy as it did before you cleaned - sometimes it can take 2 or more efforts at degreasing to remove all of the crud from inside the chain. Another possible source of muck that can end up on the newly oiled chain is any residue on the chainring(s), the cassette, and the jockey wheels.

rollingscone

How's this?

doozerie

rollingscone wrote: »

How's this?

The biker in me is appalled at the grot on your rear rim. The domestic god in me is appalled at the oil stain on the floor. I am now in torment. Shiny crank though!

rollingscone

doozerie wrote: »

The biker in me is appalled at the grot on your rear rim. The domestic god in me is appalled at the oil stain on the floor. I am now in torment. Shiny crank though!

That'll be me guiltily cleaning for the rest of the night.

rollingscone

Right,

Writing from a home of much cleaner bikes and floors, I didn't really see much out there in terms of second hand compacts and I don't really think swapping is an option because I quite simply do not know the mileage on my Chainset.

My current preferred option is to just get a Tiagra compact and a 11-28 (would I get away with 12-30 on a short derailleur?) from wiggle.

My LBS quoted me €140 for doing the job, or I could get the chainset and cassette online and fit it myself which would be an uncomfortable learning experience.

Now please forgive my thundering ingorance, but I'm assuming that if I go for the DIY option, I'm looking for 175mm crank arms, a BB130 compatible chainset that will work with my existing 1.37 x24 BB threading?

mirv

You're looking for a shimano or fsa chainset if you don't want to change your BB unless it needs replacing. You'll need a BB tool, cassette lockring tool, chainwhip, adjustable spanner, and some grease and a set of allen keys for the change.

Removing the cassette and chainset/bb shouldn't take more than 30 seconds if you do it right and the threads and splines aren't siezed or corroded. You'll spend more time on cleaning the BB and BB shell, and cassette splines and lockring threads properly than you would on putting things back together once everything is properly cleaned and greased. Don't be afraid to try - the only variable is that whether you've a british or italian threaded BB shell and its width (most likely 68mm) - it's pretty much as easy as lego.

Also, I'd advise on getting a 12t smallest cog rather than 11t, unless you're cavendish or you have extremely low cadence. You'll appreciate the finer gaps in the midrange more than a ridiculously high top gear.

mirv

Also, if you're going to change both the cassette and the chainset then you should definitely get a new chain. The old chain is most likely worn going by the cleanliness of your drivetrain in those pictures, and it'll wear out an otherwise brand new drivetrain.

smacl

rollingscone wrote: »

My LBS quoted me €140 for doing the job, or I could get the chainset and cassette online and fit it myself which would be an uncomfortable learning experience.

You'd also need a BB tool, a tool to remove the cassette lock ring, and a chain whip. All cheap enough, but if you're not happy doing it I give it to the LBS. AFAIK, you'd probably need a medium cage deraileur for a 30t cassette, but I could be wrong on this.

rollingscone

FWIW the LBS checked out the chain and were satisfied with it on (presumably it would be in their interest to flog me a new one).

Apart from my erroneous belief that the group-set was supposed to be that colour I did keep it well oiled and I'm not sure the friend who gave it to me had put many miles on it.

Have ye trusty old Lidl Bike tool kit and a few other bits so tools would be doable. It's just the knock my confidence took after my last experiment resulted in needing a new back wheel.

rollingscone

Ok so I fit the new crankset and cassette this monring, checked everything for wear, cleaned the splines and BB and regreased them.

All good so far.

BUUUUuuuuuuuuuuuut, my chainline is crooked with the smaller cog on the compact and the biggest cog on the rear. Does this just mean I need extra links/longer chain or is it a bigger problem? (I'm assuming it's too extreme to be a derailleur adjustmnet?)

rollingscone

Turns out I had left it in the higher gear...no problem there.

All good now apart from the indexing on the front derailleur. Can **** up but not down.

Edit: Indexing meltdown - I can't adjust the high limit screw in far enough for there to be a 1mil clearance from the chain.

smacl

rollingscone wrote: »

Turns out I had left it in the higher gear...no problem there.

All good now apart from the indexing on the front derailleur. Can **** up but not down.

Edit: Indexing meltdown - I can't adjust the high limit screw in far enough for there to be a 1mil clearance from the chain.

Have you checked that you don't simply have too much tension on the cable? Shifting down is done by the cable loosening enough to to allow the FDR spring drag the chain back onto the small ring. The limit screw is simply to stop it bringing the chain so far that it falls off the small ring. Too much tension on the cable, and you can't shift down, it should be almost slack when the chain is sitting on the small ring.

rollingscone

I have the cable detached at the moment. I'm nearly sure it was ok earlier when i started the process the first time, but now I just can't get any room on the inside fo the chain.

smacl

Which cog are you in at the rear? It should be the largest one when setting the low limit screw for the small ring at the front, and you barely need to see daylight between the chain and the inside of the derailleur. The bike needs to be the right way up, and ideally you need tension on the chain when checking it. I do my front derailleur adjustments with the bike sitting in the turbo, which works well.

rollingscone

Am in the biggest rear cog and small front cog, bike is upright.

At the moment the chain is rubbing on the derailleur when I turn the cranks.

smacl

rollingscone wrote: »

Am in the biggest rear cog and small front cog, bike is upright.

At the moment the chain is rubbing on the derailleur when I turn the cranks.

I'm assuming that it is rubbing the side of the derailleur cage near the frame. If so, you need to loosen the low derailler screw so the spring can move the cage away from the chain and nearer the frame. You should also check the height of the derailleur; when pulled away from the frame it should pass the big ring by about 2-3mm. You could also be getting rubbing if the rotation is not correct, i.e. small ring, big sprocket has the inside of the cage close to, but not touching, the chain.

rollingscone

Yeah, tried that. no joy. The cables are knackered, so it could be that being taken in and out was the last straw, had been planning to replace them anyway so I'll proceed with that and in teh unlikely event it helps, it helps. If not; it was scheduled maintenance.

rollingscone

Still stumped

I should point out that the Scott 509 frame I have has a weird integrated derailleur braze that doesn't allow for lateral adjustment.

smacl

rollingscone wrote: »

Still stumped

I should point out that the Scott 509 frame I have has a weird integrated derailleur braze that doesn't allow for lateral adjustment.

You just replaced the cranks, right? If the derailleur cage is rubbing off the chain, regardless of how you set the limits screw, it suggests to me that the small ring is too near the frame, or the derailleur is too far from the frame. If you haven't changed the derailleur, and it worked ok with the old crank set, you may have some kind of compatibility problem. Could be fixed by something as simple as a spacer between the small ring and BB, but it's not something I've much experience of.

Sounds like you need one of the wise old men of cycling to help you out here. Calling Doozerie. Doozerie to the front lounge.

(Either that or the LBS).

rollingscone

I changed the crankset and cassette.

smacl

rollingscone wrote: »

I changed the crankset and cassette.

Last thing maybe is to set the limit screws about half way, put the chain on small ring big sprocket. Take the derailleur off the bike entirely, and see if you put it back on in a position (e.g. height / rotation, remembering derailleur still has to pass the top of the big ring by 2-3 mm) where you don't get any chain rub but the chain is very close to the inside cage. If you can't do this, you've got a problem. If you can, tighten the derailleur in this position and use it as a basis to start adjusting. Also worth setting the barrel adjusters midway prior to fixing the cable, so you can make fine adjustments in either direction. Best of luck!

rollingscone

No joy.

The cage is inside the the large chainring (still detached from the cable), I'm messing around with washers on the retaining bolt to see if I can alter the angle that the cage sits at when tightened but hope is fading fast.

rollingscone

Ok I put some BB spacers on and it looks just about workable, will try to avoid spending too much time in the 28t cog just in case.

smacl

rollingscone wrote: »

will try to avoid spending too much time in the 28t cog just in case.

You say that, but as the capillaries are bursting like balloons in your forehead and cheeks halfway up the side of slieve maan, you won't really care whether or not your front mech sounds like an alley cat in heat