Apaloosa front derailleur clearance problem

[dirtp]

Hi everyone, I recently finished building a Joe Appaloosa that I bought a while back, but I didn't have time to complete it until now. This forum helped me pick out the rims, in fact!

I totally love the bike, but I'm having a problem I was hoping someone could help me with. I built the bike with an 8-speed cassette, Shimano Claris 3x8 front derailleur, and Silver triple cranks. However, when I have the chain on the biggest chainring and the smallest cog, the front derailleur is less than 1mm from the crank arm. When I pedal moderately hard in this gear, the chain rubs on the outside of the front derailleur.

Has anyone else had this problem? Is it maybe because the 8-speed chain is wider than a 9-speed chain?

I have another 8-speed bike with a Silver triple crankset and a Deore FD and never noticed until now, but it has a similar problem with a super tight clearance between the crank arm and front derailleur.

Thanks very much for any help you can provide!

Jason

[Joe Bernard]

You might be able to solve this by sliding the derailleur up a bit so the chain is in the fatter open section of the cage. If you send me a pic I might be able to see what's needed, get me here:

joeremi62 gmail com

[Bill Schairer]

I would look at the alignment of the cage with respect to the chainrings. Would tweaking that do anything? With some setups, I have to give the front derailleur a little more outward travel. Sometimes that might even lead to the crank arm ticking against the cage. I friction shift, so make the shift and just trim back enough as part of the shift action to get rid of the ticking. Annoying when I forget which bike I’m on but no big deal.

Bill S

[dirtp]

Thanks, Joe, I'll send a couple of pictures tomorrow.

[dirtp]

Bill,

I think it's about as parallel to the chainrings as I can get it. I think if I twist it one way or another, it will rub on the opposite end. Thanks for the advice, though!

[Joe Bernard]

It could just be a funky fd, too. I had one on a 9-speed bike and I don't remember the cage looking appreciably wide like most 8-speed mechs I've seen.

[Collin A]

If the solutions above don't work, it may require a shorter spindled BB that would bring the whole crank closer to the bike ($30-ish). If the current one is 113, you could get a 110 and that should solve your problem. I would recommend trying the free options first :)

Good Luck!

Collin in Sac

[dirtp]

Joe - That could be it, although this is the same crank/FD combination that was sold on the original completes, except they used a 9-speed chain and cassette. But my other bike has a Deore XT 9-speed FD, and it seems to do the same thing. 

I talked to Vince at Rivendell yesterday, and he said the models on the showroom floor had more than 1mm of clearance. I think they're using a 10-speed FD now, though.

[Garth]

With straight crank arms and FD's clearances are always tight. At best you play with the FD angle and height so when fully extended it clears the arms and the big ring. It's really finding a sweet spot. Also, if the rings are not running true, in this case the outer, then you can end up with extending the FD out further than if straight and possibly rubbing inside. Every crank is little different. The type of FD also plays into this as triple FD's with those inner contours can in some cases, rub against the inside when pedaling hard if not aligned perfectly(vertical and horizontal) or the rings have a certain amount of wobble. I have found those wobbles is not the rings, it's the crank mold itself. Double FD's don't have those inner contours so in such cases can work better. Yes, a typical Shimano/Suntour road double FD shifts triple rings too.

[dirtp]

Thanks, Collin. The current BB is 110. I thought that might be it, too, but after discussing it with Vince, it seems like I would have the same problem with a narrower BB, since the problem seems to be the distance between the outer chainring and the crank arm, which wouldn't change with a new BB.

[dirtp]

Thanks, Garth. If I can't fix it through positioning, maybe I'll try the Claris 2x8 FD. The specs for the complete bike just say Claris FD, not whether it's 2x8 or 3x8. I just assumed it would be the 3x8 with a triple crank.

[dirtp]

Garth - I just looked at some pictures of the original complete Appaloosas, and it looks by the length of the front FD cage that they used the 2x8 version. I'll give Riv a call to confirm and maybe try that. Thanks!

On Friday, May 8, 2020 at 6:50:00 AM UTC-4, Garth wrote:

[tuolumne bikes]

If you're using friction, an older (mid to late 80s) fd may be the solution. Before front indexing, the outer fd plates were pretty flat. eBay time...

Carl

[John Casteen]

Jason,

I can't add anything directly to the good replies already, but here's another data point.  I've got the same frame, crank, and derailer you're working on, but with a 9-speed cassette and chain.  On the small cog and big chainring, the trailing face of the derailer is within .5mm of the crank arm.  It looks like I tweaked it inboard, just slightly out of parallel with the chainring, in order to maintain that clearance.  Sounds as though others have found the setup similarly tight.

John

[Nick Payne]

I can remember having that problem about 40 years ago on a tandem using Stronglight 99 tandem cranks and a Suntour triple FD, though there the inside of the stokers crank was actually brushing the derailleur cage in top gear. After thinking about it for a while, I figured that my 52kg wife and stoker wouldn't be unduly stressing her cranks, and I took a half round file and removed about a 1mm deep curved section from the inside of the crankarm so that it cleared the derailleur. The crank was still holding up fine when we sold the bike about a dozen years later, and was still holding up fine several years after that when the tandem was stolen from the cyclist who'd bought it from us.

Nick

[dirtp]

Thanks everyone for your assistance. I have a Schwinn Cimarron from 1986 with a triple chainring and a Shimano Deerhead front derailleur. It has a flat exterior cage, as opposed to the new Shimano FDs, which bulge out on the outside. It's that bulge that's catching the crank arm. The old Deerhead just looks like a modern double derailleur to me. The inside cage doesn't drop down very far, and there are no bulges or ramps. It works great. Maybe I'll try a 2x derailleur, or a Campy, as they seem not to have as many weird sculpted features.

Thanks for all the help!

On Thursday, May 7, 2020 at 7:40:38 PM UTC-4, dirtp wrote:

[Roberta]

I have what I think is an 2016 Appaloosa. If you'd like any pictures or measurements, I'd be happy to help.

[dirtp]

Roberta - Sure, pics would be great!

[dirtp]

John - Thanks very much. I think a 9-speed chain is about 0.5 mm narrower than an 8-speed chain. That might be just enough to solve the problem.

[Roberta]

I sent a video and got this response (slightly edited) : "It looks like you have the derailleur that's designed for the double chainring crankset, but it's being used with a triple chainring crankset. I thought this was what I saw in the photos I saw on-line."

In case someone else would need the same info...

[dirt p]

Carl - You're right, I checked my old Shimano Deerhead derailleur, and it's totally flat on the outer cage. There are some sweet NOS FDs on eBay. I might snag one and try it out. Thanks for the help!

On Fri, May 8, 2020 at 11:08 AM tuolumne bikes <tuolum...@gmail.com> wrote:

If you're using friction,  an older (mid to late 80s) fd may be the solution. Before front indexing, the outer fd plates were pretty flat. eBay time...

Carl

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[Joe Bernard]

This is correct about stock Appaloosa builds, there's been some confusion in this thread about which Claris derailer he has. I saw a pic and he indeed has the double, which you can see in my attached pic has an indentation on the leading edge of the outer cage plate. This setup on the Appa with a 9-speed chain works with the Sugino crankarm, but introduce an 8-speed chain and you've robbed space needed between chain outer plate, derailer cage plate and crankarm.

Of course this isn't an issue on a Claris 8-speed bike with a high-Q Shimano crank, you just center the derailer over the chain and the crankarm is still way over there. And now I'm reminded why 1x systems are great!

[tuolumne bikes]

You're welcome. Some of the older Sugino MTB triple cranks I still use have the same issue. There's not a lot of extra space between the big ring and the crank arm.

[dirtp]

Thanks to everyone for their advice. I eventually decided to order an NOS Suntour Cyclone Mark II front derailleur from the '80s with a flat outer cage. It works like a champ, is much better looking than a modern derailleur (to me), and was only $10 more than a new Claris.

I think I could have solved this problem by using a 9-speed chain on my 8-speed cassette, but at some point it became a personal vendetta to get the 8-speed drivetrain working on this bike.

Thanks again!