bikingdude

Hey folks, planning to do a cyclocross project in the spring, and currently the frame I have in mind for it only has a top pull FD cable routing, hence rendering it incompatible with my road down pull FD and shifters. However, I've recently found out that one could use a "cable pulley adapter" to solve this issue. Have any of you folks got any experience with these things?

dsbrantjr

I do not have personal experience but I understand that this is commonly done, presumably successfully. A pulley is not a new or high-tech piece of machinery. Here's a nice one from Problem Solvers: https://problemsolversbike.com/produ..._clamp_-_17312

fietsbob

Keith Bontrager made his Cyclocross race frames including one as standard kit.

You could add a housing stop on the down tube, another clamp band, & the plastic guide under the bb
and have the cable run under the BB as well ..

I Own an Italian , steel CX frame with top tube rear, down tube front shifter routing..

of course 1 by , a 42t chainring & double chainguards in CX has a long history.. No FD needed..




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Andrew R Stewart 

Many thousands of bikes have gone for millions of miles with these ft der cable rerouting pulleys. But they do add one more part to deal with. The first issue I think of is that they are usually in the direct line of fire from the road crap flying off the rear tire, so cleaning and the bushing/bearing maintenance can be important in bad conditions. The next is that one can route the cable one of two different ways around the pulley (as in clockwise or anti clockwise). One way will likely also route the cable to better actuate the der through its arc. Andy

fietsbob

there were some made with a cover, to resolve the Mud spew issue..

ksryder

Yeah they're fine. The Problem Solvers adapter is probably the best option. I've heard of people using shower door pulleys too.

Andrew R Stewart 

Ha Ha! Can I sell you this bridge? It uses sealed bearings that never go wrong Andy

fietsbob

I think the NL made Empella CX frames included them..


that was before 3D printers.. so now.. make your own.. add O ring/gaskets around the cables..

By the way you have a week between races on the weekend to prep for the next one..




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CliffordK

I have a frame that has just an extra braze-on boss for one of those reversing pulleys. Actually, one bike uses it, and I never think about it, although cable routing seems to be best if I give the cable a twist when going around the pulley. It still works fine.

However, the CX70 is also a top-pull derailleur which is worth considering. No need for the reversing pulley.

aggiegrads

To address the second part of your question, top or bottom pull should be invisible to your shifter.

bikingdude

Thanks for the replies. I did some research and found a "Sturmey Archer Shift Cable Pulley" on Amazon. Would this work for what I need? And also to reply the comment about discerning whether it is top or bottom pull; it is generally mentioned on the manual and generally, road front derailleurs (sti shifters and derailleurs) are exclusively bottom pull.

superdex

the answer is one chainring.

bikingdude

Considered but a double set-up adds versatility.

xenologer

Don't bother with a clunky pulley
just buy a different derailer.
Plenty of Shimano's offerings come in top/down/multi pull variants for the same derailer cage.

skimaxpower

+1

FD is a cheap part.

CliffordK

MTB derailleurs may or may not work on a Cross bike. Some of them are pretty bulky, and could extend too far behind the seat tube.

However, the CX70 derailleur should work... or at least would be worth trying.

Spaghetti Legs 

My first cross bike I made my own with a grooved plastic disc from the hardware store and a bottle cage bolt. Worked fine. I “upgraded” to a real one with a cover on it. They’re not that clunky and gunk isn’t really an issue, by the time you get enough mud and gunk on that part, your FD, RD and everything else is covered too. I’ve never given the piece a second thought. As long as the bolt fitting is on there, just buy the part ($10 maybe?) , install, and ride.

fietsbob

more than one bike will too.. bike swaps mid race is allowed in CX..



IDK what your course terrain is .. some course's sections and conditions, running is faster than gearing down..

and shortest lap time, done repeatedly , wins..







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ksryder

I know folks who would cut a throat for a top-pull CX70. Fantastic derailleur, in my experience. (PS it even works with Campy shifters, even though they'll swear up and down that it won't.)

superdex

tell me more? more versatility during a race? during a ride out in the countryside? What's the goal of the project?

superdex

Shimano Ultegra CX70 2x10sp Band On Front Mech | Chain Reaction Cycles

?

ksryder

Hyperbole. People like them, is what I was getting at.

superdex

made it sound like they were hard to obtain, so I was curious

RocThrower

I run the Problem Solvers pulley on my Macho Man with a 5800 FD. Absolutely no issues and shifts great.