SunTour Cyclone downtube shifter bracket keeps slipping
 

Hi. Have a U08 with Cyclone Suntour shifter whose bracket keeps slipping down the tube. How do I keep it in place? Thanks.

Brewer

Tighten the clamp!!

seriously, is there a small tab or something brazed to the bottom of the tube to help hold them in place? you might try a small shim to help it grip better

It may help to wrap something around the tube, like a piece of inner tube or something. French bikes have a 28 mm tube diameter, while that clamp was probably made to fit a 28.6 mm tube.

Those look like Cyclone endless band shifters, they don't have a clamp in the normal place. Remove the right hand side lever, there should be a slotted screw head to turn and tighten it up.

Scott

+1 to Scottryder.

and Those Cyclone shifters can be a real PITA to tighten down enough. As Bianchigirl said there is usually a small nubbin brazed onto the underside of the downtube and you want the clamp band to be above that. Its there to keep the shifter clamp from being pulled down the DownTube by the pulling force of the shifter cables.

Tightned the sides - tightens the clamp. Turned the bike upside down and worked the shifter with wheels going - keeps coming loose. No bump under the tube - smooth all the way down. Not much room between the clamp and the tube re: wrapping something around the tube. Adding a shim (soda can lid / small piece of rubber under one side of the band) might work.

Are these shifters worth the effort to make work? Are there other shifters (not expensive) that do the job better?

What about adding a brazeon? Is that hard to do?


Googling for Suntour Cyclone endless band shifters -
http://www.sheldonbrown.com/org/brown/index.html

In 1984, I fell in love with the Shimano Dura-Ace SIS shift levers. The old SunTour units slipped all the time and had never been satisfactory. I wasn't convinced about indexing, but loved the feel of the Shimano levers, so I bought a pair, originally intending to use them in friction mode.
Once I had the indexing levers, however, I had to try to get indexing to work. I drilled out the housing stop of the SunTour Cyclone rear derailer, and tapped it to receive an adjusting barrel, in the hope that I might luck out and have a workable shifting system. Mirable dictu, it worked!
The short cage Cyclone can't handle the take up if I try to use the 28 tooth ring with any of the smaller rear sprockets, but I never have any occasion to use those gears anyway, so it works fine for me.
Most recently, further in the spirit of breaking the rules, I installed a set of Campagnolo Veloce 10-speed Ergo shifter...still with the 30 year old Cyclone and the 6-speed Regina Oro freewheel...and that works too!

Even Sheldon Brown had pblms with his shifters!! So sad to recently learn of his passing away. Very grateful to his words of inspiration and knowledge to keep moving forward bicycling and with life.

You're not tightening the lever itself are you? I'm surprised it's still slipping ..

Scott

http://bikeforums.net/attachment.php...hmentid=206345

Tightening the side edge. Lever is free.

After it originally slipped, I took the shifters off then added them back. Possibly, from what I read here, I need to remove the shifters, insert a bread tie into the shifter (without a cable that stayed intact), dissassemble that one - get a correct exploded view of how all parts go together - then put both back the correct way in case I accidentally changed part order when removing the shifter assembly to check it out why the bracket was slipping.

Without that Nubbin on the downtube just about any shifter can slide like this....the problem is compounded by the fact you're using these Cyclone shifters. I had a helluva time getting mine tight enough, and even then I didn't think they were all that great. I ended up ditching them after a week and went with bar ends.

You dont wanna add a brazeon. You'll wreck the paint.

One workaround you could do that would stop the slippage for sure is to install the shifters above the pump peg. The pump peg will prevent them from slipping down

Yes!!!! Will try that.

Other U08 upgrades -

Front Derailers - Any recomendations? Currently none on the bike - there are two large sprockets on the front crank.

Rear Derailer - currently using Suntour rear derailer. Can change gears from lowest (smallest) to 4th gear - doesnt reach / engage 5th gear. Why is this? Tried adjusting the "H" screw. Won't go to 5th gear. See below .......

Wheels: Was given a 622 Campagnolo Omega Strada Hardox wheel from a member here (thank you again!!). Added a Suntour 5 sprocket flywheel. I'd like to use this wheel on the bike. Need to decide tire. On the bike now, tires are - Front: 28 - 630 (27 X 1 3/8) / Rear: 37 - 630 (27 X 1 3/8). Can I have a 630 front / 622 rear? Do I need to get a 622 wheel to match the 622 rear wheel?

Will be changing chain / cables as well. Read that's a must when changing flywheels.

Note - bike was standing for years in my recording studio. Will be cleaned up as it's fixed!

I'd match the Front Derailleur to the Rear, but that's just an aesthetic thing...functionally you can use just about anything.

Rear Derailleur - You are adjusting the wrong screw. The small gear is "H" or High gear. The Big one is Low, or "L". Back the "L" stop screw out a bit and you should be able to get the Big Cog. I get the two confused frequently and remember it by Low = Slow, High=Spry

next question is 'how do I remove these'

Ok, remove the cover you have pictured. Remove lever. You'll see a threaded stud with a flat area to put a small wrench on. Tighten gently. Repeat on opposite side.

Is this what you've been doing? Sorry if you have, I'm just trying to get a clear picture of what you've tried.

Scott

Btw, the correct term for what you're calling a Flywheel is a "Freewheel"

You could try putting a piece of cloth handlebar tape under the band, between it and the frame.

A Rivnut would make a decent stop and could be installed without spoiling the paint. I saw istructions for making an installation tool out of a quick realease somewhere on Bike Forums a while back.

A different set of shifters with a conventional band would be a less intensive solution.

-Kurt

Agree.

I get what Suntour was trying to do, reduce the shifter weight by a few grams. However, it really wasn't worth the effort. For me anyway.

Scott

They're not the only band on shifers that can slip, especially on metric tubing.

+1 I had Shimano Light Action clamp-on shifters slip on a frame that had no nubbin on the downtube.

Dissected the other shifter and created an exploded view. Added shifters above pump brazon. Now need new shifter cable.

Really need to get the wheels taken care of - replace rear wheel ( wobbles a bit) with new Campagnolo Omega Strada Hardox wheel with SunTour Freewheel (not flywheel - thanks). See what works with the front tire - can I keep the front 630 with a rear 622?


BTW as this is a NYC bike, it was kept dirty on purpose by former owner to prevent theft when locked on the street. People wrap heavy thick chains around their waist / head / shoulders - chains are huge - brutally heavy - as are the locks. Very medieval looking.

well mismatched wheels is a wonderful turnoff for theives. There's nothing really wrong with having a 27" and a 700C...all kinds of bikes over the years have used different sized wheels.

You just gotta be ok with having to buy 2 different size tires, which doesnt really seem like a big deal.

That bar position is pretty far out. Most folks rotate em down quite a bit.

The bike should have had a single braze on for the Simplex shifters and I have typically mounted other dt shifters above that and this has a nice benefit in bringing the levers a little closer to your fingers.

That frame looks like it has had a hard life.

Great comment about different size wheels. Thanks. Recomendations on adding life to the frame? Cleaning it to start. Uploading front handlebars - Italian Bullhorns - says the former owner.

All photos taken with my Droid 1.