GUIDE: Repairing Shimano RX100 (A550) STI Levers

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Fri Mar 29, 2013 6:52 pm

Another guide, now for the RX100 STIs. These were in lovely condition, and its obvious they did not get much use over the years. However, the left hand shifter did not click at all. Right hand was quite stiff when clicking. Obvious signs of the gummed up grease.

RX100 levers are not symmetrical. The right side lever is different to the left side lever. So I will be going through both left and right sides in this guide.
Image

Image

This is the right lever. Remove the hood, and use a 2mm allen key to remove this grab screw. It does have a little bit of threadlock, so it may be a little hard to unscrew.
Image

Use the same hex key to push out the pivot. Now you can take the lever away from the body.
Image

Next, use a 5mm hex key to remove the screw holding on the name plate. Make sure youre holding onto both the name plate and the lever when unscrewing.
Image

You will be greeted with this spring. This is different to the assembly of the new Sora(3300) and 105(5500) levers. Id say its much more easy to dismantle and rebuild because the spring is here.
Image

Now flip to the back side of the lever. Push the smaller lever over so the screw is visible. Unscrew with a small Phillips, and watch out for the small washer underneath.
Image

Now, just pull the lever right off. No springs underneath like on the new levers, so its very simple.
Image

Very simple. The internal gears have been reached, and now you can ahead with cleaning it. I am using fuel, but you can use your degreaser, or whatever youd like.
Image

Image

Silly me forgot to take pics of when it was all clean. Oh well, you can find the pawls, and grease those areas up.

Now onto the left lever. As you can see its different in shape.
Image

Image

Remove the hood, and use a 2mm allen key to remove this grab screw. It does have a little bit of threadlock, so it may be a little hard to unscrew.
Image

Use the same hex key to push out the pivot. Now you can take the lever away from the body.
Image

Next, use a 5mm hex key to remove the screw holding on the name plate. Make sure youre holding onto both the name plate and the lever when unscrewing. (Yes this is the pic of the right side, but its the same thing as the left)
Image

Its odd that the spring stayed like this when I pulled it off. It should be like the pic of the right side. Pulled it out, and noticed the spring that was supposed to be bent at a right angle was bent to almost straight again. Rebent to a right angle, and everything was fine again.
Image

Gummy grease!
Image

Image

Now the left lever has a plastic cover which may get in the way of cleaning. Using a toothbrush, you'd get to most places, but there are places where you cannot get to. This is where I got my airbrush out and filled it up with some fuel. At max air pressure, I sprayed, and blocks of grease flew out. Keep repeating this til theres nothing else coming out.
Image

Image

Image

You can go ahead and grease the pawls.

Final result after a polish of the levers. Would've liked to remove the rashes from the name plate, but preferred to keep the RX100 logo there.
Image

Image

Image

Oh, and I will offer a service to rebuild STI levers. So far I have done the Sora(3300), 105(5500) and the RX100 as above, but I am sure that I can get around to doing the others without too many problems. I will also gladly take in any broken shifters, or ones that do not work anymore. Please PM me if youre interested!
Last edited by find_bruce on Wed Nov 22, 2017 7:21 pm, edited 1 time in total.
Reason: Restore photo links

User avatar
find_bruce
Moderator
Moderator
Posts: 10579
Joined: Mon May 09, 2011 8:42 pm
Location: Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby find_bruce » Fri Mar 29, 2013 7:57 pm

Another excellent, makes me want to get a pair so I can overhaul them :D

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Fri Mar 29, 2013 8:45 pm

Thanks, and you should! Its fun.

Next up will be the RSX, which I would say are 99% the same as these. Oh well, its also gummed up, so another rebuild in maybe 2 weeks.

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Thu Apr 25, 2013 7:52 pm

RSX is up!
viewtopic.php?f=34&t=63753" onclick="window.open(this.href);return false;
VillaVelo, by the Vuong brothers

Blog: https://villaveloframes.wordpress.com/
FB & IG: @villaveloframes

User avatar
Milar
Posts: 136
Joined: Sun Feb 20, 2011 11:11 am
Location: Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby Milar » Thu Apr 25, 2013 8:26 pm

Thanks for the guide. I have these shifters on one of my bikes, they are working fine now but this might be a good rainy weekend job to keep them tip top.

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Wed Jul 03, 2013 5:27 pm

600 guide is up!
viewtopic.php?f=34&t=65831" onclick="window.open(this.href);return false;
VillaVelo, by the Vuong brothers

Blog: https://villaveloframes.wordpress.com/
FB & IG: @villaveloframes

PeppeX
Posts: 83
Joined: Tue May 28, 2013 9:50 pm

Bike Question

Postby PeppeX » Sun Oct 13, 2013 1:00 pm

Hey Quang,

Just looked at your RX100 reparing thread. I opened the left shifter and the spring is there. But I can't seem to slot everything back in place, because the spring has the right angles bit sticking out and I guess they are suppose to go into the little hole in the lever and there is another hole/slot in the cap. But they do not match up? Do I need to twist the spring to make sure they are in the slot before putting the screw on?

Hopefully I am making sense

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Sun Oct 13, 2013 1:44 pm

Yes, the right angle bits are supposed to go into the hole in the lever, and the other does go into the slot behind the name plate. Place the spring into the lever hole first, then you will need to align the name plate so that the spring falls into the slot. Then while pushing down on the name plate, you twist it into place. Then do up the hex screw to keep it all together.
VillaVelo, by the Vuong brothers

Blog: https://villaveloframes.wordpress.com/
FB & IG: @villaveloframes

User avatar
martc101
Posts: 150
Joined: Wed Dec 22, 2010 1:23 am

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby martc101 » Mon Apr 21, 2014 10:48 pm

Thanks for this guide, will be rebuilding a pair in the next week or two so will let you know how goes...

banksy20
Posts: 1
Joined: Fri Nov 21, 2014 2:19 pm

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby banksy20 » Fri Nov 21, 2014 2:26 pm

Anyone know where you can still get shifter hoods for this model??

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Fri Nov 21, 2014 9:38 pm

Very unlikely that you'd find new ones. Best bet is to find other shifters with good condition hoods.

ST-1055 hoods are what you want. RSX a, 105 and RX100 all used that hood. Pretty sure 6400 and DA fit it too.
VillaVelo, by the Vuong brothers

Blog: https://villaveloframes.wordpress.com/
FB & IG: @villaveloframes

User avatar
singlespeedscott
Posts: 5510
Joined: Sun Jan 20, 2008 4:35 pm
Location: Elimbah, Queensland

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby singlespeedscott » Sat Nov 22, 2014 6:43 pm

I bought 2 sets on eBay last month for $20 each. The seller still had a few left. Just do shimano hoods search and then start trolling.
Image

velocipedist
Posts: 5
Joined: Thu Feb 09, 2012 12:46 pm

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby velocipedist » Mon May 04, 2015 10:46 pm

I don't suppose you've got a source for the spring and o-ring (plastic retainer) which go under the front cap?

The spring is Shimano part no 66E 7300 - pictured here in the write-up above:
Image

I've picked up some rx-100 shifters - the left one works, but the right side is missing the spring and o-ring. The o-ring I can live without, but the spring is kind of important :)

Its for the resurrection of my old tange double-butted Fuji which came with ST-A551 8-speed rx-100 downtubes on it. I'm trying to keep it all rx-100. The spring appears to be identical on ST-1055 and ST-6400 too - but I'd rather not have to buy a whole shifter just to cannibalise the spring out of it.

My bike: viewtopic.php?f=34&t=82010" onclick="window.open(this.href);return false;

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Mon May 04, 2015 10:55 pm

O ring is not necessary. I believe it's there just to keep dirt away from the spring. I have a few of these around. Unfortunately I have run out of that spring myself. I sold a spare right lever just last week, which I thought had the spring, but it did not. Luckily I had a broken 5600 lever around, which I stole the spring from and made some modifications to get it to work with these older levers.

I'll have a look in the bag, where the smaller bits may have fallen to the bottom, but, I'm really thinking I don't have any spare ones.
VillaVelo, by the Vuong brothers

Blog: https://villaveloframes.wordpress.com/
FB & IG: @villaveloframes

velocipedist
Posts: 5
Joined: Thu Feb 09, 2012 12:46 pm

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby velocipedist » Tue May 05, 2015 2:26 pm

Yep having taken apart the right-side shifter, the o-ring is just for dust/grit protection of the spring.

I asked the California-based rebuilder of the same series of STI shifters, and he also has none, so I've just sent an enquiry to Shimano in Australia asking whether the parts are even available new.

Parts diagram in german: https://www.paul-lange.de/support/shima ... 550-94.PDF" onclick="window.open(this.href);return false;

I've also just spent 10 minutes researching what it would take to make the missing spring - seems like its not too hard.

After measuring the left-side spring, critical dimensions are:

OD 20mm
Gauge: 1mm
Pitch: 1.5mm
Turns: 3.25
Material: Carbon spring steel (its magnetic - so not stainless).

So one option is to order some size 17.5 Piano wire (aka Music Wire - just carbon spring wire) which has 1.016mm thickness, wind it on something like an M20 (or maybe M18) threaded surface, which is also 1.5mm pitch, and then heat treat it to relax the coils.

The challenge is getting a left-threaded M20 bolt to use as an arbor for winding the spring for the right-side shifter as it needs to twist the opposite way. I'm thinking some brass rod, some beer and a friend with a serious lathe should take care of that (beer for afterwards! beer and metal lathes don't mix :)).

If Shimano come back saying its available then great, but the backup plan is to try the piano wire.

User avatar
QuangVuong
Posts: 1794
Joined: Sun Feb 24, 2013 5:04 pm
Location: Villawood, Sydney

Re: GUIDE: Repairing Shimano RX100 (A550) STI Levers

Postby QuangVuong » Tue May 05, 2015 2:36 pm

Pitch doesn't really matter too much. Keep the diameter and turns about right, and you should be right. That spring just provides a return force to bring the lever blade back to the normal position.

Good luck with making one.
VillaVelo, by the Vuong brothers

Blog: https://villaveloframes.wordpress.com/
FB & IG: @villaveloframes

Who is online

Users browsing this forum: No registered users