R400

[IdahoBrett]

I bought this bike because it needs work and the price was low enough for me. Tires are flat, rear wheel is bent enough there is a broken spoke, rear brake doesn’t work very well, front derailleur won’t downshift and chain seems loose. But everything else appears to my inexperienced eyeballs, just fine.

Until yesterday I knew nothing about truing wheels. After a 4 part, Park Tool youtube video and some reading on Sheldon Brown’s website I have a basic idea of the process.

I have never fixed up a bike before. I have no plans to upgrade components. Unless they need replacement. My plan is just to make it rideable once again.

Today I flipped the bike upside down on the floor (don’t own a repair stand. Yet.), and used some tie wraps to check out the wheels. Front wheel may need a minor truing. The back wheel I marked with tape where it is bent. The broken spoke is just about at the middle of the bend. I’d guess that’s why it’s broke (Sherlock Holmes aren’t I?).

Pics…

 

[black lightning 1987]

Looks like a pretty nice bike. Is the rim bent or just out of true because of the broken spoke? Is there a bulge in the rim at the spoke with the tape?

 

[IdahoBrett]

Looks like a pretty nice bike. Is the rim bent or just out of true because of the broken spoke? Is there a bulge in the rim at the spoke with the tape?

I’ll have to remove the tire to be sure. But I think it is bent. High spot to the non-drive side between the tape with the broken spoke hub hole in the center.

 

[IdahoBrett]

With tire removed I‘ve gotten a better look at the wheel.

Don’t believe it is bent. The biggest lateral deflection is at the broken spoke at the rim. In my inexperienced self I’m going with spoke tension. There is one non OEM spoke nipple as well, so I wonder if the overall spoke tension isn’t set correctly in part or in a large circumference of the wheel.

The broken spoke is on the drive side of the hub. So yeah that’s likely why the rim has a lateral deflection to the opposite side. I’m amazed that one broken spoke could cause such a distorted wheel. It’s why I initially thought the wheel was bent.

Hope it’s that easy of a fix. Not saying wheel truing is easy. I’ve only scratched the surface of knowledge and can tell it has to be practically an art form to properly build a wheel.

 

[black lightning 1987]

There's a lot more tension on the drive side spokes, so when one breaks the rim goes way out of true. Did the spoke break at the hub?

 

[IdahoBrett]

There's a lot more tension on the drive side spokes, so when one breaks the rim goes way out of true. Did the spoke break at the hub?

Yes

 

[black lightning 1987]

As I understand it, it's fairly common for machine built wheels to break spokes. I assume it's due to excessive tension on a single spoke that concentrates stress in the weak point of the spoke, which is the 90 degree bend at the hub. The spoke may have been overly loaded to compensate for a rim that was out of round or out of true laterally. It's possible that the spoke may have had a flaw as well. I would replace the spoke and get the rim close to true while checking spoke tension. If it takes more than 15% or so more tension on that spoke to get the rim true, there's probably another issue - likely the rim. Still might be a reliable wheel for a lot of miles if you can reduce overall tension a bit, or reduce the tension at the stressed spoke on both sides. That could result in reduced rim diameter at that spot but the spokes might last longer. Another option is just to replace the spoke, tension it up until the rim is reasonably true, and see how many miles you get out of it.

 

[IdahoBrett]

About what I gathered from reading about a single spoke breaking. Just replace it, make the wheel reasonably true and ride it. Also from what I read I’ll need to remove the cassette in order to replace the spoke. My LBS has a good supply of Park Tools. So I’ll get the FR-5 series tool.

 

[IdahoBrett]

Just returned from my LBS….my wallet is strangely lighter…

 

[black lightning 1987]

About what I gathered from reading about a single spoke breaking. Just replace it, make the wheel reasonably true and ride it. Also from what I read I’ll need to remove the cassette in order to replace the spoke. My LBS has a good supply of Park Tools. So I’ll get the FR-5 series tool.

It will probably run for quite a while doing that, but there's a reason the spoke broke in the first place. It's usually due to a single spoke being more heavily loaded than the rest.

 

[IdahoBrett]

New spoke installed. I got the wheel true “enough”.

I did “slip” with the spoke wrench. Twice. And yes the flats aren’t flat anymore. Not blaming anyone but myself here, but I believe the new nipple to be of softer metal than the originals. I adjusted some of those as well is how I figured that.

Brakes appear serviceable. I did some fine tuning on them. I wish I had on of those cable pliers. They look handy in the Park Tool video I watched.

A good quality bike repair stand is so much better than any MacGuyver’d setup that I did before.

Clean-n-lube is next. Then I’ll check chain and derailleurs…

 

[IdahoBrett]

Put new rubber on the rims. Did a detailed cleaning. It’s in better shape than I thought. I initially thought I’d be disassembling the crank and bb. No play or wobble. No reason to. I don’t know if I’ll pull the headset apart yet.

I ran out of time to reinstall the cassette. Maybe I’m being optimistic, but a couple more hours and it should be rideable as is. If so this isn’t a restoration. Just a clean, lube, and adjust.

 

[JohnnyD]

For a man without all the bells and whistles when it comes to bike repair tools you are doing some good work. Pretty relaxing finding a bike to work on yourself isn't it?

 

[IdahoBrett]

Thanks @JohnnyD Yes I do find I enjoy working on a bike. All my hobbies over the years have to have that component to it for me to be satisfied. I must tinker at some level. Albeit this is more of a rehab than a restoration. The bike is in better shape than I first thought.

I’ve been back and forth on buying a repair stand for three months. Glad I finally got one. Now that I spent that much I think I need to cost average the price of the stand by finding more Cannondale’s that need work

 

[JohnnyD]

Thanks @JohnnyD Yes I do find I enjoy working on a bike. All my hobbies over the years have to have that component to it for me to be satisfied. I must tinker at some level. Albeit this is more of a rehab than a restoration. The bike is in better shape than I first thought.

I’ve been back and forth on buying a repair stand for three months. Glad I finally got one. Now that I spent that much I think I need to cost average the price of the stand by finding more Cannondale’s that need work

I like the way you think. I've been debating picking up the the same PT stand and using the generic one I have now strictly as a paint/ bike washing stand. Maybe for a Christmas gift to myself.

 

[IdahoBrett]

Great idea! There is a generic one locally on CL. Might have to pick that one up. Outside and inside stands.

Bike back together. Chain wear is almost non existent according to the gauge. Rear derailleur shifts ok. Front, not at all. Cable tension is pretty slack. Off to YT for a Park Video for a refresher on how to adjust front derailleur…

 

[IdahoBrett]

The front derailleur needs replacing. I discovered the L and H screws were doing nothing to move the cage. I found the derailleur spring retention end broken off.

The derailleur is the Sora type. What is compatible? ie. Ultegra, Tiagra, 105 Thanks.

I understand the part of making sure it is a "triple" front derailleur. But am unsure as to whether or not the speed or number of rear cogs makes a difference. I know in some parts it does and are grouped together. Such as 7-8-9 speed are together. And 10-11 are another group.

 

[black lightning 1987]

I've had a Tiagra 9 FD break also, seems to be a common failure. Pretty sure that any 8/9 speed Shimano road triple FD will work. There's a good chance I have something here but it might be prone to the same failure. You might consider a Claris 8 speed triple FD.

 

[IdahoBrett]

I found some good data while looking for a fd. Yes a 9 speed triple front derailleur will work. As long as it is meant for proper tooth count. Shimano changed the spread from 10T to 11T some time after 2007. Along with their front chainrings going to 50/39/30 (and others ie. 10 speed). Versus 52/42/30. Using a newer FD, whether its for an 8 speed or a 9 speed causes clearance issues with the middle chainring.

I printed the stuff I found online as I was not on my home computer. I should start a post in the appropriate tech section and find the links again. Or I could just transcribe the info.

I have found a couple sellers of the 105 triple FD, 9 speed versions (new old stock) meant for the 52/42/30 chain rings. They will work for 8 speed, but will have some chain rub during “cross chaining”.

I did find that the return spring tab being broken being a common problem. Especially with the Sora FD. It is probably why the bike here in this thread got parked.

 

[IdahoBrett]

I somehow missed this label on the rear derailleur…doh!

edit: rear derailleur cable pull is the same 8 or 9 speed. That is the info that I’ve found