Fixed broken again :(

[PapaZita]

Its a 91 road frame, with system ex read hub, sunrace cranks with a strong(ish) chainring on.
I think the main problem is because the chainring cant get over far enough to get the chainline spot on.
It must be something for me to keep having problems with it though

How far out is the chainline? And how critical is chainline really? Obviously a perfect chainline is desirable for quietness and efficiency, but things shouldn't just break. Geared bikes can run with really wonky chains and they don't usually break chainring bolts as a result. Is there something different about the forces on a fixed chainring?

Perhaps your chainring bolts were just made of cheese, or had been overtorqued. I've broken one in the past just while tightening it. It turns out they don't need to be done up nearly as tight as I'd imagined.

I can't see any reason why a broken chainring bolt should require you to replace your frame. Unless you just really really want a new frame, of course. My handlebar tape's a bit grubby, and there was this nice 953 frame in Mercian's window...

PZ.

 

[Deleted member 1258]

Dave R, i could do, would just mean me putting in my back wheel from the fixed.
Possibility, but we dont buy from the internet so it wont work out as cheap if i bought that from a shop. Thanks for the suggestion though.[/quote]

There would be no need to use your back wheel it comes with a flip/flop hub. just put a fixed cog on and turn the wheel round.

 

[Joe24]

Dave R, i could do, would just mean me putting in my back wheel from the fixed.
Possibility, but we dont buy from the internet so it wont work out as cheap if i bought that from a shop. Thanks for the suggestion though.

There would be no need to use your back wheel it comes with a flip/flop hub. just put a fixed cog on and turn the wheel round.[/QUOTE]

My fixed wheel is fixed/fixed on a better rim so i would use the wheel i have now

Chain line on fixed is pretty important. There is alot more force on a fixed chainring then on a geared bikes chainring.
The frame is old, but it was built up by me and a friend, the guy in the LBS, and painted by a mate.
I dont know if the chainring bolt broke or if it worked loose. And im guessing i wont ever know.
As for getting a new frame i still dont know. Im un-decided. The fixed is pretty bodged, and it being 130mm spaced made it hard for getting it set up as fixed, so it had to be bodged slightly, which worked but it just seems to have gotten unrealiable. Which it has. And me, or the person in the LBS can work it out.
The LBS doesnt have any fixed frames by the way, so i would end up buying one from elsewhere(planet x if its the pompino) and setting the bike up myself.

 

[Joe24]

I don't get this either. My fixed is an old Raleigh Record Ace frame from the tip, like FF I run the 42 tooth chainring on the outside of the arms, where the 52 went originally, I have the narrowest BB I could get and the chainline is not far off perfect.

It's this power/bendy frame thing I don't understand, I really do not want to get into a macho contest, but I reckon I probably generate more power than you, the frame does it's 531 steel bendy thing and off we go. No problems. I can't help but think that your lbs is having a laugh and fobbing you off by massaging your ego a bit. Have you tried another shop? Or do any of the knowledgable chaps on here live near you? I really think you need a second opinion of your problems here.

Remember, the frame they keep telling you is bending so far it knackers your chain rings because of your power, would have been state of the art for Merckx and Hinault and all those other really powerful riders.

LBS blamed the chainring bending on the frame bending because its old.
The chainring is on the inside of the spider, and its a downhill mtb double crankset with a stronger chainring mounted on the inside of the spider, to get the chainline better. It cant go on the outside because then the chainline will be poor.
As for shops, ive not taken it to another shop. I was going to at one stage, i called them up but they didnt seem too interested in doing much, said they would have a look and see what they could do.
I did think about putting a proper track crankset on to see what difference that would make, in the hope that it will be much stronger, but then the ring would still need to be mounted on the inside to get the chainline right. Its got a narrow BB in that can go in without the chainring catching on the frame.

 

[Fab Foodie]

LBS blamed the chainring bending on the frame bending because its old.
The chainring is on the inside of the spider, and its a downhill mtb double crankset with a stronger chainring mounted on the inside of the spider, to get the chainline better. It cant go on the outside because then the chainline will be poor.
As for shops, ive not taken it to another shop. I was going to at one stage, i called them up but they didnt seem too interested in doing much, said they would have a look and see what they could do.
I did think about putting a proper track crankset on to see what difference that would make, in the hope that it will be much stronger, but then the ring would still need to be mounted on the inside to get the chainline right. Its got a narrow BB in that can go in without the chainring catching on the frame.

OK, so the chainline sounds (and looks from your photos) pretty good.
I don't buy the frame flex theory, I'll hazard that my old 531 flexes more than any frame on this site even under my moderate power and I have never had any probs even hauling it over ditchling with a heavy saddle bag and a 42/15 set-up. It also doesn't matter a damn whether the chainring is inside or outside the spider, use whichever gives the best line.

Can you put it on a Turbo, hold the rear-brake and put pressure on the pedals and see how much the frame or chainring moves out of line?

Frankly I'm stumped... I've never seen a broken chainring before.

 

[fossyant]

Joe, your mechanical was only not checking the bolt's weren't tight.

So what if the chain line is out slightly - how much do chain lines go out on geared bikes.

TBH Keep the bike, and save up for a new fixed..... there is bugger all wrong with your current bike...only maintenance schedules I think.... don't be taken in by a shop - they will see you are young...kerching...here is a new shiny bit for you......

 

[Joe24]

OK, so the chainline sounds (and looks from your photos) pretty good.
I don't buy the frame flex theory, I'll hazard that my old 531 flexes more than any frame on this site even under my moderate power and I have never had any probs even hauling it over ditchling with a heavy saddle bag and a 42/15 set-up. It also doesn't matter a damn whether the chainring is inside or outside the spider, use whichever gives the best line.

Can you put it on a Turbo, hold the rear-brake and put pressure on the pedals and see how much the frame or chainring moves out of line?

Frankly I'm stumped... I've never seen a broken chainring before.

I could take it to someone in the clubs house and put it on a turbo, would have to put a rear brake on it but that wont take too long.
Guy in LBS 'says'(dont know if its 100% true) that other people have seen it and they can only put it down to the frame flexing or the chainring hitting something(when my chainring collapsed)
Didnt think of putting it on a turbo, so ill get this sorted(just emailed someone to see if i can go and use his)
Any more suggestions welcome. Im going to get onto YACF in abit, need to register first.

 

[Joe24]

Joe, your mechanical was only not checking the bolt's weren't tight.

So what if the chain line is out slightly - how much do chain lines go out on geared bikes.

TBH Keep the bike, and save up for a new fixed..... there is bugger all wrong with your current bike...only maintenance schedules I think.... don't be taken in by a shop - they will see you are young...kerching...here is a new shiny bit for you......

Bolts were only put on a few weeks ago so never thought of checking them

Im not sure if i would buy a ready built one. Id be more tempted to buy a frame and build up, like i would do if i got a new frame now. I sort of have enough money for it, but i sort of dont, if you get what i mean

 

[fossyant]

Check..and check.....or do them up bloody tight.... (hence I don't yet have carbon bits)

Get a club mate to have a look -one that knows some stuff....

 

[fossyant]

No frames degrade like that.....steel/alloy carbon may fail, be it crash, or not looked after.

My 3 steel bikes are between 18 and 14 years old - all still as stiff (oo'er) as the day I got them....

 

[Joe24]

Get a new LBS. Frames don't start to flex because they are old. I'm not a metalloroligist or anything, but I don't think steel gradually wears out and develops new properties does it? Take a look around you at things made of steel, when they get old they don't start bending and flexing all over the show do they? I hate to say it, but I think he is fibbing to you.

I think its time to scrap my LBS aswell. Im going to call around tomorrow to get some new chainring bolts for it, and fit those and see how it goes from there.
I talked with my parents about the new frame and they said i should build it up myself, and get the tools to do it aswell.
So if i do go ahead with a new frame then this would be what i do. Its only really replacing things(like the BB and cranks) that i have used the LBS for lately because i dont have the tools.

 

[Tharg2007]

it sounds like you lbs if full of shoot. They sound like they seem suprised that the frame flexes, this could be because a; they have very little experience with steel frames or b; they are pretending to be suprised so they can sell you stuff/repairs.
I have had chainring bolts come off my fixed too, my fault as i put them on tight and didnt stress test/check them for a while. Think i lost two while pootling, lucky i guess, took another off and respaced them round so i could ride home.

There is nothing like the flex of a steel frame, it feels great imo. you should be able to get the chainline spot on with a combination of 2 ring spider so you can place ring either side, washers, and different sized BB.

 

[fossyant]

Don't get alloy ones....... stainless is the way...... or Ti......my tighten as hard as can be fixation.....

 

[fossyant]

There is nothing like the flex of a steel frame, it feels great imo.

What what......

Mr Ribble 653 don't flex......and Frank certainly doesn't........

The feel is called springynessystuff......

 

[Tharg2007]

What what......

Mr Ribble 653 don't flex......and Frank certainly doesn't........

The feel is called springynessystuff......

haha it would flex under my torso