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Discussion Starter · #1 · (Edited)
Hi Everyone,

I thought I'd share a recent project I did on my commuter.
I've been using downtube friction shifters on a 8 speed Freewheel but the shifting was annoying requiring constant trimming. On the lowest geat, the lever sits almost parallel to the ground which snags my shorts.

So I thought about upgrading to a pair of STIs or bar ends. I don't like bar ends and STI are $$ so I came up with a cheaper alternative. I decided to mount a pair of rapidfires on my drop bars.

People have tried unsucessfully because the clamp Dia (22.2 mm) of the shifters are too narrow to fit over drop bars (23.8 mm).

I used Shimano STX-RCMC38 Rapidfire because it has a removable and meaty clamp to work with. A few minutes of sanding on the drum sander and Voila!

I'm quite pleased with the results. She works perfectly on the SunRace Freewheel
Here's how it looks.









 

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Mantis, Paramount, Campy
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Nice work.

Alternately you can just use a large flat blade screwdriver to spread the clamp a bit wider and slide it on.
 

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Discussion Starter · #3 ·
Absolutely
But the newer style clamps are much thinner with the pod/clamp and the brake lever integrated in one assembly.
Some people have tried just spreading the clamp but ended up cracking and ruining the entire assembly. Even Sheldon did this!

A beefy clamp is ideal for this application. If it breaks, just replace the clamp.
 

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Absolutely
But the newer style clamps are much thinner with the pod/clamp and the brake lever integrated in one assembly.
Some people have tried just spreading the clamp but ended up cracking and ruining the entire assembly. Even Sheldon did this!

A beefy clamp is ideal for this application. If it breaks, just replace the clamp.
Case in point; I have XTR m980 shifters and would not risk breaking the clamp unless I was an expert who knew what he was doing temperature, tools, materials and method wise. Thanks for posting your hack...now I just need a sanding bit... are any specific sanding bits better catered to aluminum? Cheers.
 

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Discussion Starter · #6 ·
No special sanding Abrasive is needed for aluminium.
I used a basic sanding drum kit and used the most coarse sleeve.
It took about 10mins on a drill press.

Rectangle Household hardware Silver Plastic 5-UK/images/library/stock/webbig/15110.jpg

Case in point; I have XTR m980 shifters and would not risk breaking the clamp unless I was an expert who knew what he was doing temperature, tools, materials and method wise. Thanks for posting your hack...now I just need a sanding bit... are any specific sanding bits better catered to aluminum? Cheers.
 

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Hi Everyone,

I thought I'd share a recent project I did on my commuter.
I've been using downtube friction shifters on a 8 speed Freewheel but the shifting was annoying requiring constant trimming. On the lowest geat, the lever sits almost parallel to the ground which snags my shorts.

So I thought about upgrading to a pair of STIs or bar ends. I don't like bar ends and STI are $$ so I came up with a cheaper alternative. I decided to mount a pair of rapidfires on my drop bars.

People have tried unsucessfully because the clamp Dia (22.2 mm) of the shifters are too narrow to fit over drop bars (23.8 mm).

I used Shimano STX-RCMC38 Rapidfire because it has a removable and meaty clamp to work with. A few minutes of sanding on the drum sander and Voila!

I'm quite pleased with the results. She works perfectly on the SunRace Freewheel
Here's how it looks.









just wondering how that "she" relationship is going...?
 

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I had same idea...

Nice work.

Alternately you can just use a large flat blade screwdriver to spread the clamp a bit wider and slide it on.
I am converting my MTB to some type of Gravel bike...I have drop bar with 31.8mm diameter and I am wondering can I install shifters (22.2mm) on 31.8mm (close to stem) with this method (longer sscrewdriver)? I am asking cuz I have revo shifters now and I cant put them on drop bar near stem (where I want my shifters)...I am planning to buy some compatibile rapid fire shifters and want to know would I be able to put them on 31.8 drop bar...can ring holder can be stretch that much without braking?
 

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That's way too big a difference. OP was talking about a 1.6mm difference, and even that people were breaking aluminum clamps trying to spread them to get past the bends.
You'd have better luck getting shifters that unbolt from clamp (or designed to bolt into brake clamp) and finding a 31.8mm clamp to adapt. My cross bike has dropper lever bolted to a 31.8mm clamp so it does exist.
BTW, for small bits as shown in OP, grinding aluminum with whatever prob doesn't matter, just that you'll quickly ruin the bits. For larger grinding wheels it is important and dangerous to not use correct discs. Aluminum clogs up grinding discs, and then when you go to use again, the clogged aluminum expands causing discs to explode apart. Chunks of basically rocks coming off a wheel at 10,000 rpm plus is bad news.
 
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