Roger M

I pulled this out of the rafters this morning. I put it away when Thomas quit riding his trailer bike behind it, about ten years ago.

Well, he's finally grown into it. I put some streetish tires on it so he can meet up with his friends at the park.



92? MB-1

Pompiere

My son took his 1986 MB-2 to college for five years. Amazingly, it did not get stolen, although it is a little weather beaten. He didn't want to take it to his new job, so I can use it as a blank canvas to play with.

RustyJames 

I posted this in the saved from the trash thread. Steel, no bouncy front forks and it doesn’t shift properly but it was free and included a set of knobby tires with tubes. I wiped it down and hosed down the shift levers and derailleurs with WD-40 which helped the shifting but not perfect. The chain rings are shot so it will get new (used?) cranks. Not fancy but not bad for free.

Pre-cleaning pics.







BTW - I know nothing about MTBs and finding appropriate cranks is a minefield. Over thinking it?

Frkl

The chain rings on that are almost certainly steel, and don't look all that bad in terms of wear from the pics. Grime, yes, but the teeth look ok. More likely is that your chain is stretched. You could probably get away with popping the cranks off, giving them a really good clean, and replacing the chain. If you get new cranks you should replace the chain, anyway, so it's a 0 risk experiment.

MTB cranks are just a different forest, not really a minefield. Depending on the dropout spacing and some other things, the chainline should be about 47mm-ish, measured to the middle chainring. On a road bike the chainline is measured to point between the two chainrings. Before you take off the cranks, measure the stock chain line. When the cranks are off, measure the spindle. You can get a replacement for the BB if it is running raw based on that.

Otherwise, any modern crank you buy will have a spindle length recommendation and a chainline spec. You can adjust the spindle length recommendation to maintain the stock chainline, if you want, but in reality a few mm doesn't make a big diff on derailleur systems.

If you want to go 1x, use the middle chainring position with the recommended spindle length to achieve the spec chainline.

Regarding the shifters, old rapid fire shifters gum up like crazy. If you want to try again to clean them, open the plastic covers and use a mild degreaser while working all the cams etc inside with tweezers. It can help to heat up the shifter first, warm water or a blow drier works. After the parts are all moving ok, rinse them under hot tap water and shift up and down repeatedly to clear out the solvent. Finally, use a light oil to drive the water out and relube. Don't use grease. WD 40 works, but theoretically will degrade the plastic bits and doesn't leave much lubrication behind when it dries (it was designed as a Water Displacer, to dry aerospace parts, not as a solvent or a lube like everyone uses it today).

I have revived completely stuck units this way.

mechanicmatt

Those are not bad cranks. Just low end. What makes you think they are no longer usable? Those are steel rings, so they should have worn slowly.

Pore shifting is more likely caused by rusty chains, the need for new cables and housing, and maybe time to replace shifters. Maybe a cheaper route to investigate first.

Lubing everything can go a long way too from chains to cables to shifters. I like TriFlow for stuff like that but others have different kinds they like.

RustyJames 

I’ll do some lubing and see what I get from that.

I was going to replace the cranks because I’m finding new cranks are cheaper than chainrings. Pic of the big ring. The middle has similar wear.

Frkl

It's Of course hard to tell from a picture, but to me that's not really consequential wear. No tooth on a Hyperglide chain ring or cassette for that matter looks completely like another. That is why they shift well. Really worn teeth look like shark fins.

But you are right, it is often more cost effective to replace inexpensive cranks sets completely when a ring wears out. But not always. Remember that a new crank set may need a different bottom bracket spindle length, so there is that cost too.

Nice cleaning and polishing job btw.

cyccommute 

I agree. Here’s a comparison. New on the right, obviously.

worn vs unworn by Stuart Black, on Flickr

Frkl

Yup. That's what a shot ring looks like!

RustyJames 

Thanks for the compliment. Clean parts are happy parts!

The top of the cogs are shorter above the “Dual SIS” sticker but mo bettah shifting makes sense. (Most of my fleet is friction shifting, pre 1980.) I’ll continue to clean, lube, etc until I’m happy with it.

Frkl

I'm pretty sure it's just Hyperglide being Hyperglide. The teeth are different heights, and none are "full height" in comparison to a classic road chainring pre indexing and/or pre-ramped and pinned.

madpogue 

And?..... IOW, that describes almost every bike posted here. Rigid fork == one less set of moving parts to worry about.

And +1 the above re. the chainrings. They're not minty fresh, but they're most definitely not shark-finned. FIRST place to look if you suspect driveline issues is the chain. A clean, shiny, well-lubed chain that's elongated will still shift poorly. Only way to know is by measurement. START there, along with the obvious derailleur adjustments, etc. BTW, I'm over-generalizing here, but any crankset with removable chainrings is generally of good quality.

Overall a pretty well-appointed bike, free or otherwise. Nice rims. (Front wheel is on backwards.) Wonder who built those frames for Performance BITD.

Frkl

The rear drop out rack/fender mount looks like some I've seen on Diamondbacks, but that's neither here nor there.

droppedandlost 

What bars are those? Looks like something that would be about perfect for me.

wrk101

To me, part of the fun of these builds is taking parts out of your bins (ideal), or from the local co-op (2nd choice), and building up a bike you enjoy to ride. As such, sometimes they won't be color matched, or aesthetically pleasing. But if they work for you, great! And if you did it with left over parts, double great. On mine, the stem is a different color than the seat post. So I am breaking some kind of rule there.

Frkl

I actually get a lot of pleasure out of carefully planning either a restoration or a radical modification, so as to ensure that the bike is both enjoyable to ride and aesthetically pleasing.

It doesn't necessarily have to be true to the original aesthetic of the bike, or some received wisdom like matching seat post and stem, but it does all have to "work" together based on my goal for a particular build.

mechanicmatt

Soma Dream Bars...they're 31.5" wide, like so wide, I may cut mine down a bit, but very fun to ride with.

hzqw2l

I'm guessing an 84 model Mt Hood although some components have an 83 date stamp.

As found original classic down to the tires.

Frkl

Look at that! And the wheels are original? The anodizing is spotless. If you are going to ride that, please please get a second pair of wheels so those don't get worn!

swampyankee2

Love those crossed seat-stay frames. I saw a polished aluminum GT Edge that I wanted badly, but the frame was cracked at the seat post clamp.

Smokinapankake

Pics of that sweet cycle computer mounted at the front wheel please. And looks like a Cannondale velcro mounted water bottle to boot. What a great find!

hzqw2l

Belt drive Sachs Huret.
Rims are Ukai. Slight pad rub both rims but still very nice.

Fat Tire Trader 

My favorite



1983
Cunningham Indian

attylah

….. now it feels complete. 1986 Raleigh Crested Butte Mountain Tour.

DiegoFrogs

That's really nice. I wish mine came with the original wheels.

Did the first toptube cable guide pop off, or did the housing just come loose from it?