When to replace a crank?

[Triskeliongirl]

Then go for it, but just replace what needs replacing with 7 speed stuff. If you can't find NOS stuff on ebay, often if you post what you are looking for in some of the more techie bike forums, someone will have something sitting in a spare parts box they will either sell real cheap, or send you for shipping costs.

Maybe you could use this bike to learn more about maintenance, since yes, the bike shops will be less inclined to help you with parts that are out of production, but most of what you'll need to do isn't that hard at all.

[ZenSojourner]

Actually the owner called it a "freehub" which would mean I could just replace cogs fairly easily without worrying about who made them, but I'm not sure if it's REALLY freehub or if it's the new design with the splines and all. Thank heaven for Sheldon Brown's website, he has an article on there for how to tell the difference. Missing Sheldon Brown.

The rear wheel is 2 years new, I probably don't really need to replace it.

The pedals are flat on one side and LOOK compatible on the other and since I STILL haven't clipped in to my SPDs on the Madeline replacing those pedals right away would be silly.

Rear cassettes are so cheap, I'm waffling about that. It would be even cheaper to just replace a cog or two as necessary. That really depends on the current cassette and what kind of shifting pattern I'd have to live with.

A new chain, I feel, is just a good idea when it's so cheap. Chain wear can be hard to eyeball. So a new chain, new rubber, and a bar tape rewrap for sure. Somewhere I've got a spare cyclocomputer.

The seat tube angle looks about the same as my Madeleine, which is comfortable for me. 73 degrees on the Madeleine, I could swear I read somewhere it was 72.5 on the Despatch but can't find that now. She's got a REALLY tall stem on there, if I'm going to ride in the drops I'll need to drop that down. A new stem shouldn't cost that much on the odd chance I can't drop that one down. It also actually looks longer than on my current bike, but we'll have to see how it feels. The longer stem plus the steeper head tube angle may eat up the slightly shorter top tube, can't tell 'til I ride it though. The head tube angle looks a little steeper than on my Madeline, which isn't surprising going from a touring bike to more of a sport bike. I'm wondering, if it is a bit steeper, if I'll be able to tell any difference in handling. I'm not exactly Lance Armstrong!

Sorry, I'm speculating based on JPGs of a bike I haven't seen in person yet, LOL! I just posted to the thread "how many bikes do you have" that one was enough for me, and now look what's happening.

You guys infected me, I just know it! Naughty! Naughty!

[aicabsolut]

I think even SunTour back in the day popularized the use of splined freehubs. Freehub is a generic term for non-fixed gear hubs. The cassette or new hub that your wheel will accept could vary greatly.

[ZenSojourner]

Right, that's more or less what Sheldon Brown says on his article on the subject. Just because people use the term "freehub" doesn't mean it's really a "freehub" as originally defined, the only way to tell is to look.

Which will happen along about this weekend. . . . should have my bike saturday afternoon.

[laura*]

Actually the owner called it a "freehub" which would mean I could just replace cogs fairly easily without worrying about who made them, but I'm not sure if it's REALLY freehub or if it's the new design with the splines and all.

Looking at that one picture, it seems the bike has Shimano RSX components. In 1998 the RSX group was a lower end group two levels below 105 and still 7 speed. The crankset looks like the A413 triple (w/ 26/36/46 gears!) and the RD, FD, and brifters match the Shimano A410 drawings I've downloaded from the 'net.

If the bike's previous owner installed a reasonably complete RSX group, I'd expect it to have a proper Shimano 7-speed freehub too.


In the last year I've faced a similar challenge of figuring out how to upgrade two older bikes: I decided to leave my 1994 MTB as a 7 speed and deal with the hassle of a mix and match setup.

As for the 1985 Tiawanese Schwinn that I'm slowly building up for indoor trainer duty, it's getting all new current generation parts. I had several options for dealing with the 126mm rear spacing:

1) Build the bike with an old 7 speed group.
2) Cold set it to 130mm as described by Sheldon Brown.
3) Load a 7 speed hub with 8 cogs from a 9 speed cassette and use the RD limit screws to keep a 9 speed shifter out of the last gear. I think this idea is also from Sheldon's site.
4) Narrow a 9 speed hub to 126mm.

I chose to narrow a new 9 speed hub. Normally, that would result in extreme wheel dishing. However, I was already going to be building a custom wheel, so it wasn't a problem to use an offset drilled Velocity Aerohead OC rim.

If you want to upgrade to 8, 9 or 10 speeds, but don't want to cold set your Terry, you could do the same thing. I checked and the Aerohead does come in a 24 inch version for a matching front wheel!


I don't know if either of my choices was correct. The Schwinn isn't finished yet. And I'm about to change the MTB's cranks a second time - from new ones to higher quality and better looking 1994 vintage used cranks.

Good luck with your new old Terry!

[aicabsolut]

FWIW, I have a Shimano 7 speed wheel with Mavic CXP21 rim sitting in my apartment. It was a free wheel that I was going to use on the trainer...until I discovered the 7spd part. I want to be rid of this thing. I can not attest to the state of the cassette (b/c I never used it, and it has been sitting around for the past several years in my friend's apt--she also never used it. she was going to convert it to a fixed hub then didn't). I can say that it's not new, but it might be in useable condition.

If you want it, I will just give it to you for whatever cost shipping would be. I am thisclose to just abandoning it on the side of the road.

[ZenSojourner]

<major snippage of lots of high tech talk>
1) Build the bike with an old 7 speed group.
2) Cold set it to 130mm as described by Sheldon Brown.
3) Load a 7 speed hub with 8 cogs from a 9 speed cassette and use the RD limit screws to keep a 9 speed shifter out of the last gear. I think this idea is also from Sheldon's site.
4) Narrow a 9 speed hub to 126mm.
<more major snippage of lots of high tech talk>

Well I'm impressed. LOL!

I hope to avoid doing anything too complicated (for my tiny pea brain I mean). But if I have to I'll definitely be referring back to this.

I swear I was more mechanically inclined when I was not that much younger. I did all the work on my former almost-fits bike. Now even a bar-wrap seems to be more than I want to have to deal with.

[ZenSojourner]

If you want it, I will just give it to you for whatever cost shipping would be. I am thisclose to just abandoning it on the side of the road.

Ah, something new for the "things found on the side of the road" thread, LOL!