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-   -   Compatible shifter and FD for Ultegra 6503 ? (another flatbar conversion) (https://www.bikeforums.net/bicycle-mechanics/1226026-compatible-shifter-fd-ultegra-6503-another-flatbar-conversion.html)

keraba2 03-16-21 05:20 PM

Compatible shifter and FD for Ultegra 6503 ? (another flatbar conversion)
 
I've had a 2001 Trek 5200 since new, and love it to death. I love how light it is, and its triple chainring set-up. I've probably put 25,000 miles on the 20 years that I've had it.

Once, the right brake/shifter broke. I noticed that a current Sora brake/shifter also had 9 gears. I bought it without thinking, and it worked perfectly. I've had it maybe 10 years?

I would now like to convert the bike to flatbar, since I think the hoods are aggravating my left shoulder. When I ride another bike that I have, the shoulder seems fine (but the bike weighs a ton).

I bought a Sora SL-R3000 (9spd) and R3030 (3spd) (flatbar shifters), because I assumed that they would "just work" as well.

It seemed smart to check the amount of cable that each component used before swapping parts. I measured it by pulling the cable all the way in, placing a piece of tape on the cable, clicking all the way out and measuring the difference.

As you can probably guess, the rear shifter is pretty close, but the front shifter is off. The 6503 right/back is 21mm while the 3000 moves 23. Unfortunately, the 6503 left/front shifter moves 7mm while the R3030 moves 13mm - nearly 2:1.

So I'm trying to figure out the easiest way forward at this point, if any:

- Is the back shifter close enough?
- For the front shifter, should I buy a matching derailleur or should I try to find a closer shifter?

The Sora derailleur (FD-R3030-F) lists these qualities:

Applicable Top-Mid tooth difference 11T - ?
Chain line (mm) 45 - ?
Chain stay angle 63 - 66 - ?
Mounted braze-on - I assume this is what I want. My frame has a little place to screw it on.
Top gear teeth 50T - Mine is 52T. Is this bad?
Total capacity 20T - ?

I believe my chainrings are 30-42-52. They're original.

Any advice would be appreciated.

thanks!

dedhed 03-16-21 05:46 PM

https://productinfo.shimano.com/#/co...453&acid=C-455

Check FD - 3503

Ross200 03-16-21 08:04 PM

Are you measuring the trim detents present in the ST6503? Many of the newer front shifters do not have that fine trim capability.

keraba2 03-17-21 06:34 PM


Originally Posted by Ross200 (Post 21971048)
Are you measuring the trim detents present in the ST6503? Many of the newer front shifters do not have that fine trim capability.

Hi Ross,

I'm not sure what you mean by "detents". I'm measuring how far the tape moves when I shift from high to low.

Ross200 03-17-21 08:51 PM

6510 and some old Sora front shifters have intermediate trim positions for eliminating cage chain rub in certain gear combinations. If the chain is rubbing, push the lever part way to the next click. The amount of able pulled to get to these "in between clicks" would likely be about half what is required to make the shift all the way to the next ring. So one could speculate 7 mm vs 13 mm. These trim positions are eliminated in some of the newer shifters.

Sometimes the only way to mix and match Shimano is to mount it up and play.

keraba2 03-17-21 10:02 PM

ah, I want to be clear that I did not measure the distance between 2 gears. I measured the *entire* spectrum, from big chain-ring to small, on each shifter. I did not stop on the middle ring, or an intermediate click.

Now *maybe* one could leverage the intermediate clicks on the Sora shifter to guide the Ultegra derailleur. (I don't know if this is what you were referring to.) Perhaps if one lined up the middle chain-ring, then the derailleur stops would prevent the wider swing of the Sora shifter from moving it further. I just wonder if those intermediate clicks could hold it there. As you said, I guess it has gotten likely enough that it's worth playing with.

Jeff Wills 03-17-21 10:21 PM

If you can track one down, try a FD-R443 or FD-R453. This is what I used with a triple "flat-bar" shifter and a 52T large chainring.

Shimano FD-R443 Front Derailleur Band On (sjscycles.co.uk)
Shimano R453 Front Derailleur - Harris Cyclery bicycle shop - West Newton, Massachusetts

keraba2 03-18-21 04:54 AM

Thanks for the suggestions. I didn't find any, but I did run into a Microshift R539. It looks like a perfect match, but I don't know the pull ratio. Does anyone know, or have a compatibility chart?

freeranger 03-18-21 06:27 AM

Recently read where a conversion was done using Microshift Mezzo: Back in the Rotation - Bike Forums
Believe these should also work (though more expensive-and they are avail. in black too): SL-A09 / SL-T09 – microSHIFT

keraba2 04-14-21 07:44 PM

To close the loop here, what I ended up doing was completely unpredictable. Since the pull ratio of the new lever was higher than the old, I essentially lengthened the lever arm on the derailleur. I got some of that epoxy that compares itself to "metal", and I put a tiny blob of it on the tip of the derailleur arm, above the bolt where you connect the cable. Then I ran the cable *over* that blob and back down to the bolt. (I carved a tiny channel for the cable to rest in.)

It works perfectly. The full range of the lever produces the full range of the derailleur, and the stops are in the right places. I'm very disappointed that Shimano doesn't just do this for us, providing 2 connect points on the derailleur arm.

KCT1986 04-14-21 08:21 PM

Great and innovative way to "hack" the problem.

Need you to post pictures when you can. Others may be able to use this example.

70sSanO 04-15-21 09:43 AM

If you can measure how much extension you needed, it would be interesting to see if an older mtb front derailleur would work.

They don’t work with older road shifters because they don’t pull enough cable; the attach point is further out.

If it does work, it would be a great option. Of course it would be blind luck as Shimano would never intentionally do anything that would allow for the continued use of 25 year old components.

John

Retro Grouch 04-15-21 01:25 PM

If it was my bike, I'd find a friction shifter to use on the front. It's much easier to set up, it works better because it trim-able, and it's cheaper too.

Of course, I'm a Retro Grouch.


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