how to terminate cable housing as it enters frame's down tube for internal routing

myhui · Aug 31, 2013

My Taiwan-made CF frame supports internal cable runs on the down tube. But the hole at the top end of the down tube for this run is large. A thick housing can fit in there, not just the cable. Hence I either route the housing into the down tube -- which I think is not the intended way to do this -- or I find some piece to insert into the big 7mm diameter hole to stop the housing, so that the cable can be under tension while it is inside the down tube.

Where do I find that piece? Or, in a rush, do I just slip the housing into and through the down tube, have it emerge the other end, and attach it to the front derailleur? I don't have a cable stop at the bottom end of the cable if I do that.

We have discussed this before, and I was told sternly to not use housing for the full length of the cable run.

I have purchased and read Zinn & the Art of Road Bike Maintenance, 4th Ed., but the book does not mention this detail, as it assumes the reader is replacing the housing on an already-built bicycle.

bikeguy0 · Sep 2, 2013

Possibly dumb question but have you placed a housing ferrule on the housing and checked to see if it fits? Usually these a plastic piece that inserts into the frame like these:

That way you can run internal housing if you want to. It is possible this frame is meant to not have internal housing so the carbon on the frame is moulded so that a ferrule fits in there and stops the housing.

cxwrench · Sep 2, 2013

There were not any fittings supplied w/ your frame? If this is the case, welcome to generic Taiwanese frame hell.
One thing you can't do is run full-length housing to the front derailleur like you can w/ a rear derailleur. You MUST have some kind of housing stop at the bottom before you get to the derailleur. Are you sure the hole in the frame is 7mm?

myhui · Sep 2, 2013

I just contacted the manufacturer GotoBike in Taiwan.

They do indeed sell a USD $6 bag of parts that will convert each hole to a properly sized cable stop. That was how the frame was intended to be used: insert those inserts for mechanical shifting, and leave them open for electronic shifting.

Thanks, guys, for all your help.

Now let's talk about cycling: with SRAM Red 2012 gruppo, integrated stem on carbon handlebar, and 50mm deep dish tubular wheels, the feel of the bike at the controls is very plastic-y. The frame is sure stiff, and the wheels are definitely feather light, but I come away from a ten mile ride ( with no front der ) with the impression that this is a rather delicate machine that cannot take any abuse at all. I tried a few sharp turns to see if I can roll those taped-on Tufo tubular tires, and they didn't roll one bit. I better not get fat while I'm using this as my primary commuter bicycle, otherwise it may crumple beneath me.

cxwrench · Sep 2, 2013

Tape is for presents, glue is for tires. Trust me on this.

myhui · Sep 2, 2013

cxwrench said:
Tape is for presents, glue is for tires. Trust me on this.

Unrelated to that ...

The tubular tire lasted less than 0.5km away from home before I rode through a field of shattered automotive glass and the (possibly over-inflated) rear tire blew.

I thought this is the most durable tubular tire available:

Tufo Hi-Composite Carbon Tubular Tire

but it couldn't handle the abuse. It was a 2mm long, clean slice.

I am open to suggestions on what is the most durable tubular tire available, and I'll give it a try.

I don't have a sealant, so that cost me 30 minutes swapping out the cassette, changing brake pads, re-adjusting rear der, to go back to a heavier clincher tire and wheel until I get the sealant and attempt a fix.

myhui · Sep 2, 2013

bikeguy0 said:
... have you placed a housing ferrule on the housing and checked to see if it fits?

I don't need a ferrule, since those do not stop the housing. I want the housing to press forcibly onto the down tube when it enters the down tube, such that the cable (and not housing) inside the down tube can be under tension.

cxwrench · Sep 3, 2013

myhui said:
Unrelated to that ...

The tubular tire lasted less than 0.5km away from home before I rode through a field of shattered automotive glass and the (possibly over-inflated) rear tire blew.

I thought this is the most durable tubular tire available:

Tufo Hi-Composite Carbon Tubular Tire

but it couldn't handle the abuse. It was a 2mm long, clean slice.

I am open to suggestions on what is the most durable tubular tire available, and I'll give it a try.

I don't have a sealant, so that cost me 30 minutes swapping out the cassette, changing brake pads, re-adjusting rear der, to go back to a heavier clincher tire and wheel until I get the sealant and attempt a fix.

There are no magic tubular tires that will prevent punctures. If you end up buying the most puncture resistant tires you can find, you might as well not even ride tubulars. They will ride like crap (much like Tufo's). The best thing you can do is not ride through lots of glass. If you regularly encounter this kind of thing on your rides, tubulars don't really make much sense for you.
You should be prepared for a flat w/ tubulars just like you would be w/ clinchers. Bring a spare tire whenever you ride. Having sealant in the tires before you puncture is always a good idea.

And really...tape sucks. Glue your tires. Again...trust me on this one.

myhui · Sep 3, 2013

Well, OK, I'll just have to be prepared for flats, and lots of them with these Tufos then.

Here is the bike, so far, with full cable housing for the rear der, and clincher in the back, on wheels I got used from someone upgrading a Trek Madone he bought three years ago. But I would much sooner go back to the tubulars.

cxwrench · Sep 3, 2013

myhui said:
Well, OK, I'll just have to be prepared for flats, and lots of them with these Tufos then.

Here is the bike, so far, with full cable housing for the rear der, and clincher in the back, on wheels I got used from someone upgrading a Trek Madone he bought three years ago. But I would much sooner go back to the tubulars.

1) Put the sealant in the tires BEFORE you flat...that's the whole idea.
2) Don't ride that bike til it's finished or you'll end up having a bunch of new problems to deal with.
3) Check your chain length...that might be short.

myhui · Sep 3, 2013

So the sealant will spread around the tire all by itself before I get a puncture? I guess it must, otherwise it will never work if it remains as one gob.

The last problem was solved this evening: a creaky BB was due to an insufficiently tight crank arm. After that, this new bike rides just fine. I've gone out four times today in 92F temp just to clear up all the problems. The chain is on the tight side, but I did measure three times before I cut. Yes, it will reach around the big-big combo. I already miss my CF tubular rear wheel. The rear wheel on the bike now is already very good ( it came on Trek 's top bike !), but it lacks the acceleration of the CF tubular wheel.

Both brakes are in their final configuration already. The rear brake does have bare cable inside the top tube. The frame has cable stops for the rear brake on both ends of the top tube.

I chose tubular since I was afraid the side walls on the CF clincher wheels will be weak.

I already tried going downhill, accelerating more, then slamming on the brakes to try to heat up those CF rims, but they only reached around 50C. Maybe the hill wasn't steep enough.

wim · Sep 3, 2013

You could shorten the rear derailleur cable a bit. I would eliminate the loop from the bottom bracket to the chain stay completely and let the cable be a straight run along the chain stay for as long as possible The loop from the chain stay to the rear derailleur could also be tightened up a little.

mikerp · Sep 3, 2013

myhui said:
I already miss my CF tubular rear wheel. The rear wheel on the bike now is already very good ( it came on Trek 's top bike !), but it lacks the acceleration of the CF tubular wheel.

When you put the alloy rear wheel on the bike did you swap out the brake pads? If not you should clean the pads up before using the CF rim.
Also do yourself a favor and glue the tires on, if you wait on this chances are you will be posting a picture of the rim missing material when you try to remove the tape.

myhui · Sep 3, 2013

Yes I did swap the brake pads. I said that earlier already.

I've rode 20 miles on the front tubular and purposely tried all sorts of extreme turns and so far the tires have stayed on.

cxwrench · Sep 3, 2013

myhui said:
Yes I did swap the brake pads. I said that earlier already.

I've rode 20 miles on the front tubular and purposely tried all sorts of extreme turns and so far the tires have stayed on.

Read both my posts and mike's post above again. He states clearly what can happen when you remove a taped tire from a carbon rim...it can pull layers of carbon off your previously perfect rim. The other downside as I have posted is that tape DOES NOT ADEQUATELY HOLD A TIRE ON A RIM. Period. You may think you've tested this and are confident in your experience, but glue is a much better method of attaching tires to rims. Which is why EVERY tire used by EVERY pro racer is glued and not taped. It's a proven method and tape has problems that have been experienced by many. You are not breaking any new ground here and would be wise to benefit from the combined decades of experience advising you.
After seeing that you've ridden this bike before it's finished and have taped your tires on I don't even want to ask what pressure you're inflating them too...

myhui · Sep 3, 2013

What pressure should I inflate them to? I've tried 120psi. Now I'm running 100psi in the front.

I use my hands to try to rip the tire sideways, and I know that the tape provides quite a strong bond.

As for getting carbon off the wheel when I have to change the tire, I'll report on that when I come to it.

As for riding the bike prematurely ...

Well, you have to know my background. I once delivered newspaper stacked two feet high on my modified chopper's front basket at 6am on 8 inches of fresh snow. I didn't spill my load. I was just a boy then. I'm still acting like a boy now, on purpose this time.

cxwrench · Sep 3, 2013

All righty then, you just go ahead and do what you want. Hopefully nothing happens, but if it does you know what I'm gonna be saying. I (and the others) don't just post advice like this because I'm bored...

myhui · Sep 4, 2013

Seems like the major problem with tape is that carbon material comes off when you change tires, if I read the previous posts correctly.

I'll be on the look out for that when I change the tires eventually. This may not happen until several months from now if the sealant proves effective in fixing the puncture.

myhui · Sep 4, 2013

I want to dip the Tufo taped tire into some special solvent that will dissolve and neutralize the glue.

Then, if I cut the tire first, then it'll just peel off cleanly from the rim.

cxwrench · Sep 5, 2013

myhui said:
I want to dip the Tufo taped tire into some special solvent that will dissolve and neutralize the glue.

Then, if I cut the tire first, then it'll just peel off cleanly from the rim.

WTF...? :skep:

how to terminate cable housing as it enters frame's down tube for internal routing

myhui

bikeguy0

cxwrench

myhui

cxwrench

myhui

myhui

cxwrench

myhui

Attachments

cxwrench

myhui

wim

mikerp

myhui

cxwrench

myhui

cxwrench

myhui

myhui

cxwrench

Top Contributors this Month

Recommended Communities