The Chainlink

I am very sad today as I think I have to put my bicycle out of its misery.  Its a 28 year old Raleigh Aleyseka.   It has shown great service.  I purchased it new and had many years of great riding.   Last night, I hit a pot hole.   Then it suddenly felt "loose".  I thought I had hurt a wheel.   I looked back and saw when I pushed on the peddle, the wheel wobbled.  Okay.  A Wheel.  So I got off and looked at the wheel.  It looked fine.  Then I saw the problem.   The right chainstay right at the drop out had broken.  

I assume, at this point, that the bicycle is "dead" as all of my research says this is not easily fixable (and certainly not worth fixing on a 28 year old Reynolds Steel Frame with old components).

So, what do I do.   Should I take it to working bikes?    Should I strip off some components and take it to working bikes (likely very little is usable....   the derailleurs are old, the brakes are cantilever, the handlebars are an "out-of-date" road shape. )  Should I strip off some of the components and put it in the alley?  Should I find a way to keep it?    Should I fix it?

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There are canti brakes, like the dia compe 986, that don't use the spring holes. 

I had my chain stay crack right where the wheel mounts in Bolivia 6 months ago and it was fixed very easily by arc welding a thin piece of rebar to the broken area. Since the other chain stay that was still intact had taken double the load for about 50 miles, I had the welder reinforce that side as well. Of course, it's not gonna look pretty and will add a few grams of steel to your frame , but it's a very quick, cheap, easy and effective fix. I think the other (cleaner) way is to weld bronze into the crack with oxygen.

Here's what the left side looks after welding..3000 miles later

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Beauty


Good.

Here's another fine example of something they made in the UK (or possibly Oklahoma?) in 1990 or so....the Raleigh Randonneur

http://imgur.com/a/Olc2i


Crazy David 84 Furlongs said:

Apparently I like good older frames.  I took my early Trek multispeed and put it back into service.    Uh....   it turns out that it has a lugged frame and is made of Tange tubing.  I also saw that my third old frame (a Lotus Challenger) which needs a new headset and fork is also a lugged frame made from Tange 900/1000 tubing....   

So instead of your brake hitting 4mm to high on the 700c rim after the conversion from 27" they will hit 12mm too low? This is an improvement?

Depends on the bike, I think.  My project has 1cm between the bottom of the brake slot and the boss.  The brake slot has 1cm of play.

Sound good?


My mechanic has a hissy fit and said that the Elevn Post extenders will rip my canti mounts off eventually and that putting an M6 through the middle of the base of the posts will not be adequate to prevent this from happening.  The posts are designed for M6 bolts, and cutting off the top where the brake mounts in order to fit the Elevn Post extenders didn't seem like a huge deal, since all the brazing would have been intact.  AND replacement studs could be put without any brazing or welding on if there was ever a problem.  I mean, COME ON, there is 1cm of metal to thread into after the top of the post is cut!

Honestly, if anybody knows a good engineer or knowledgeable mechanic, I'd like to talk to them.  I'm having a little trouble understanding why dropping the posts 16mm with the post extenders would cause so much trouble, where, as I said, all the original brazing would stay intact and there would be 1cm of thread for the M6 bolt into with 3 millimeters thick diameter of metal all the way around the bolt down to the base of the post.

My mechanic also went on to say that I would need a brake stiffener to make sure the post extenders wouldn't rip anything off, so.... 

HELP!!!!  I want to ride my bike! :-(

James BlackHeron said:

So instead of your brake hitting 4mm to high on the 700c rim after the conversion from 27" they will hit 12mm too low? This is an improvement?

It's called leverage...

The extenders move the brake down and are putting pressure from the longer lever arm they create into the posts in a direction that was never intended. They will be subjected to a greater force trying to rip them off than you would ever see without them.

Matt M. 18.5KM said:


My mechanic has a hissy fit and said that the Elevn Post extenders will rip my canti mounts off eventually and that putting an M6 through the middle of the base of the posts will not be adequate to prevent this from happening.  The posts are designed for M6 bolts, and cutting off the top where the brake mounts in order to fit the Elevn Post extenders didn't seem like a huge deal, since all the brazing would have been intact.  AND replacement studs could be put without any brazing or welding on if there was ever a problem.  I mean, COME ON, there is 1cm of metal to thread into after the top of the post is cut!

Honestly, if anybody knows a good engineer or knowledgeable mechanic, I'd like to talk to them.  I'm having a little trouble understanding why dropping the posts 16mm with the post extenders would cause so much trouble, where, as I said, all the original brazing would stay intact and there would be 1cm of thread for the M6 bolt into with 3 millimeters thick diameter of metal all the way around the bolt down to the base of the post.

My mechanic also went on to say that I would need a brake stiffener to make sure the post extenders wouldn't rip anything off, so.... 

HELP!!!!  I want to ride my bike! :-(

James BlackHeron said:

So instead of your brake hitting 4mm to high on the 700c rim after the conversion from 27" they will hit 12mm too low? This is an improvement?

If post breakage was a problem using these extenders, I'd expect to see reports of carnage they caused on the web. I wasn't able to find anything with a few Google searches. Is post breakage a known problem?

I would be less worried about post breakage than just plain old power/feel-robbing flex.  

Canti brakes already often suffer from sponginess from the fact that the posts splay outwards as the chainstays/fork blades twist against the force of the brake arms pressing inwards on the rim.  On caliper brakes the brake bridge only really has to hold the brakes against the spin of the tire.  That's why Sheldon Brown's home-made brake drop bolt hardware made of reflector brackets actually worked.  I've done similar with sidepull brakes and it works very well.  

But with cantilevers and V-brakes (and U-brakes) the pivot posts also have to contend with spreading forces as well as the braking forces.  The spreading/clamping force is actually much greater than the braking forces.There are some frames that have issues with spongy brakes because of the posts spreading as the stays/forks twist and that is why brake booster arches were invented for them.  

With the type of canti-post drop hardware that the OP is thinking of using not only will there be the two places of force applied on them (braking/rotational force & spreading/twisting force) but a third new force will be introduced:  a splaying force as the hardware will want to swing outwards to the sides like a pendulum of a clock.  So the poor canti posts will need to withstand the rotational push/pull (depending if front or rear brake) of braking force, the twisting force of resisting the squeezing of the brakes against the rim, plus the new pendulum force that is trying to twist the posts as well -a force that on a regular canti post is only what is necessary to spring the brakes back open.  That spring plate was never meant for that kind of force, only enough twist to push back the brakes when the springs open them back up when the brakes are let up on the lever.  

I personally think this hardware is not going to work very well for the OP.  While it might not "rip the posts off of the frame" it will certainly result in really spongy ineffective brakes.  That's the whole problem in the first place with trying to do a 27" -> 700c conversion in the first place.  A good mechanic can find a set of cantilever brakes that will still hit the rims, but tuning them for good feel and power is pretty hard.  The brake booster arch I linked above helps a lot.  I think it might even help with using the drop hardware.

In the end I'd suggest just buying a nice set of 27" wheels or having them built up around some strong CR18 rims. Pana Pasela makes an excellent tire for 27" rims.  Or if you really want to go 700c then just don't use the canti studs and use a set of Dia Compe centerpull brakes.  They work really well and can be bought at Working Bikes for $2 set.  They have literally hundreds of them piled up in the brakes section to pick from.  Rebuild them and they are just as good as the ones that VO sells today new for $85 each (better if you ask me as drop-forged is stronger than CNC milled)  Also, you might need the 750 model rather than the 610 for a little more reach and WB has both.  Centerpull calipers are every bit as good as cantilever brakes if you use good pads like KoolStop and can swallow a 35mm tire and fender no problem.

I use them on my own bike and they stop just as well as the Ultegra dual-pivot calipers I had on there before with Sheldon-style drop bolts. 

Have these been mentioned yet? Offset brake pad holders that add 7mm of reach. http://www.bdopcycling.com/BDop%20Offset%20Holders.asp

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