Sora Shifters compatibility?

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woody2359
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Sora Shifters compatibility?

Postby woody2359 » Mon Nov 26, 2012 18:39 pm

Been lurking about on here for a good while now but created an account yesterday to buy some Sora shifters that were advertised as I wish to convert my Giant Escape commuter from a riser bar to a drop bar.

Just want to make sure that the Sora shifters will be compatible with the Shimano RD-M430 rear and Shimano FD-M390 front derailleurs that I've got on the Giant. I've bought the 3x9 shifters and it's a 27 speed so I figured it should be ok.

Thoughts?

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supersonic
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Re: Sora Shifters compatibility?

Postby supersonic » Mon Nov 26, 2012 19:09 pm

The front derailer will not work. What size chainrings are you running?

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woody2359
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Re: Sora Shifters compatibility?

Postby woody2359 » Mon Nov 26, 2012 21:42 pm

Chain rings are:
26/36/48T

I love it when I get an idea and rush in without researching whether or not its possible!

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supersonic
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Re: Sora Shifters compatibility?

Postby supersonic » Mon Nov 26, 2012 22:07 pm

Lol, we all do that! Shimano roadie shifters pull a a different amount of cable than MTB shifters (for the front mech)

It can be hard to find a road front mech that will work perfectly with what you have. This is close enough to function well though:

http://www.bike-discount.de/shop/a74563 ... =GBP&cn=gb

Assuming the clmap for the frame is of the right type.

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woody2359
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Re: Sora Shifters compatibility?

Postby woody2359 » Mon Nov 26, 2012 22:58 pm

Great, thanks for the advice. I'm in two minds now:

Option A: Convert my hybrid as I want, with drop bars and the front mech you've recommended; this'll leave me with a capable bike (although I'll still spin out downhill) for the commute. Price to change - approx £90 (plus any LBS set up fee when I realise I've buggered it up.)

Option B: Sell my Giant as it is, and buy a used road bike for the commute. I've got a Felt for non work related cycling, but I'd need full mudguard mounts as I wouldn't want to rock Crud road racers every day. Figuring I'd get about £200 for my Giant, Price to change - £200

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supersonic
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Re: Sora Shifters compatibility?

Postby supersonic » Mon Nov 26, 2012 23:39 pm

Why not fit clip on tri bars and give them a whirl?

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woody2359
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Re: Sora Shifters compatibility?

Postby woody2359 » Tue Nov 27, 2012 00:20 am

Tri bars on a triple, mudguarded up, 35mm tyre hybrid...I can almost hear the SCR titters from behind this laptop!

I was tempted just to put drop bars on and slide on the original brakes and shifters, just to get me out of the head winds, but that still leaves me spinning out with that triple chainset. I don't use the lower ring at all.

I think that to upgrade to a useable chainset, plus bars & shifters I might as well flog the Giant and get a cheap road bike for year round commuting. Something that if it's peppered with road rash and a few knock off scuffs after a couple of years, I won't be bothered that much. I've seen positive reviews for the Btwin Triban 3. Might go down that road.

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The Rookie
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Re: Sora Shifters compatibility?

Postby The Rookie » Tue Nov 27, 2012 08:52 am

I have a photo of an old steel frame step through ladies shopper bike with a front basket and tri-bars......so you give some people a laugh - so what!

On my flat bar hybrid if I want to drop my profile I hold the bars just either side of the stem, on a straight and level road I can generally run a gear higher like that, less aero drag and a better pedaling position, I'm even considering putting some foam grips there....

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woody2359
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Re: Sora Shifters compatibility?

Postby woody2359 » Tue Nov 27, 2012 09:46 am

Unfortunately that's not an option, I've got riser bars that are already crowded with lights and the such, so any flat space is at a premium.

I try to drop my profile as much as I can, but still end up spinning out. The Escape is a MTB based hybrid instead of road based so also feels pretty heavy, it's done me well and got me back into cycling but I think I'm going to let it go.

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supersonic
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Re: Sora Shifters compatibility?

Postby supersonic » Tue Nov 27, 2012 14:28 pm

Drop bars are about 45cm wide - so space will definitely be at a premium now!

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jejv
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Re: Sora Shifters compatibility?

Postby jejv » Fri Nov 30, 2012 00:03 am

This can make sense. This is my effort:
Image
That's 47mm Smart Sams @30 psi with 53mm SKS mudguards. Mudguards off road are good if the mud isn't too claggy.
It usually has 28mm Rubino Pros, but time to switch to Nokian W240s now.

Quite a versatile bike.

The FD-4503 than NL suggests will work fine even with 46-34-24. The problem is that it is designed for a 45mm road front chainline, rather than the 50mm that your FD-M390 MTB mech is designed for ( http://techdocs.shimano.com/media/techd ... 760854.pdf ). [From my experience of messing this up] I doubt an FD-4503 will shift well with a 50mm chainline.

Shimano's definition of front chainline (not on their website any more): http://www.xza5.net/pipe214/CTC_10032/h ... inline.pdf
[Note that this is quite different to what Sheldon Brown thought front "chainline" was]

So you would probably want a Bottom Bracket ~10 mm shorter than you have now. That's possible if you have a chainset that uses a 118-122mm bottom bracket now. If you have 115mm now you're probably OK. What is the chainset on your bike ?

If you prefer - or have to use - a chainline that's out by a BB size or so (+/-1.5mm chainline, +/-3mm BB), that'll probably be fine.


But then there's brakes. V-brakes won't work well with Sora shifters. So you will have to switch the bike to cantilevers, or possibly short V-brakes. See Tektro CR520/720 above. Road brakes have less leverage than V-brakes. Road brake levers have more leverage than V-brake levers.

And there's some other details:
- How are you going to adjust the gears (for best shifting, adjustable on the move) ?
- How are you going to adjust the brakes ?
- Where is the cable stop going to go for the front cantilever brake ?

Jagwire do nice gear adjusters that plug into Sora/Tiagra/105 shifters.
For adjusting the brakes, I use the adjusters on the cross-top-levers, but could put adjusters on the cable stops.
The Kona cable stop on the fork crown needed some grinding to fit the fork crown profile well.

There's a few threads about this stuff on the CTC technical forums.

So: It's more work than you think, but you might end up with an unusual, but versatile bike. I know of two others similar to this in Cambridge.

This is what a "Hybrid" Should look like in the shop. Drop bars, wide range of not-too-high gears which are not too gappy even for roadies, useable big ring for normal folk, good choice of tyres from fancy slicks to useful knobblies. Rack and mudguards. Long wheelbase. Relaxed steering.
Last edited by jejv on Wed Jan 02, 2013 15:13 pm, edited 1 time in total.

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jejv
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Re: Sora Shifters compatibility?

Postby jejv » Fri Nov 30, 2012 00:29 am

woody2359 wrote:Unfortunately that's not an option, I've got riser bars that are already crowded with lights and the such, so any flat space is at a premium.

There are gadgets designed to solve space problems with narrow(er) bars:
http://www.sjscycles.co.uk/accessory-fi ... pt785_pg1/

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Tigger con carne
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Re: Sora Shifters compatibility?

Postby Tigger con carne » Fri Nov 30, 2012 12:42 pm

I'm anticipating similar problems on my MTB to road commuter bike. I've also acquired some Sora levers/shifters for a mini drop bar (On One Midge bars). Seemed like a good idea at the time..
Glad I read about the need for a road front mech!

Anyway, I understand that you can use road brake levers with cantis or mini V brakes as I think is what they use on CX bikes. Is this right?

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jejv
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Re: Sora Shifters compatibility?

Postby jejv » Sat Dec 01, 2012 10:07 am

Tigger con carne wrote:Anyway, I understand that you can use road brake levers with cantis or mini V brakes as I think is what they use on CX bikes. Is this right?

Yes.

First get some Swisstop green or Koolstop Salmon or salmon/black pads.

Mini-Vs. Not tried them. 10-20% shorter than standard Vs. So still a lot of leverage, maybe a bit too much, esp at the back; so probably need to adjust frequently. May have problems with tyre/mudguard clearance. With our oversized tyres & mudguards, even full V's have marginal clearance. Can get adjusters that fit on the end of the noodle - neat, simple solution with no extra cable stops.

Cantis. Not rocket science but does require a bit of thought & care in setup. Lot of rubbish on the intertron about canti setup, but in the last few years, more people get it. "Narrow" cantis (arms pointing up: Tektro Oryx, Avid Shorty 4) generally have better geometry (more leverage) than "Wide" Cantis (Tektro CR520), but the ability to adjust the length of the straddle wire is more important, so a CR520 setup might be more powerful than an Avid Shorty setup, because the Shorty straddle wire isn't adjustable for length. Shorter/flatter straddle -> more leverage. At the front, want straddle wire as low as possible; at back, high straddle wire. With adjustable straddle wire: for wide cantis, less spacers between pad and brake arm -> more leverage, for narrow cantis, more spacers-> more leverage, but this is a lesser effect. With a fixed length straddle, more spacers between pad and brake arm will make the straddle flatter and increase leverage.

With canti's need a fork-mounted cable stop at front (kona uphanger) and a cable stop at the back - best combined with seat-post clamp [ e.g. http://www.ebay.co.uk/itm/black-34-9-cy ... 0672539325 ]. Need threaded adjusters somewhere (Dawes don't seem to bother!). Can put adjuster on front uphanger. Cross-top-levers give us adjustment.

Avid Shorty Ultimate (not tried them) seem to be the best. Long arms, adjustable straddle, arms can be set at wide or narrow configuration, threaded straddle length adjuster. I would use narrow at front, wide at rear.

Carefully set up Tektro CR520s may be the next best thing:
http://www.ebay.co.uk/itm/tektro-cr-520 ... 0579082780
[Yes, those are CR520s]
Don't bother using the Tektro pads, though.

Adjustable straddle cantis have a safety problem: if the brake cable snaps or becomes detached from the straddle hook, the straddle wire can get caught in the front tyre, esp if it's knobbly. Hence the fixed straddle wires, and the front reflector brackets on old MTBs that go underneath the straddle. Mudguards do the same job.

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woody2359
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Re: Sora Shifters compatibility?

Postby woody2359 » Wed Dec 05, 2012 14:55 pm

That Giant looks great with drop bars, a very versatile bike I think. Well, what with all the different components that is needed I've just bought a second road bike instead for the commute and I'm going to sell the Giant. Probably take a hit on the price as it's only 8 months old but I'll have exactly what I want then.


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