Cheap road bike rear mech options

dannydc

Hi all

I've just upgraded my awesome dawes giro 300 from the original Sora cranks to a Tiagra hollowtech 2 compact. The rear cassette (8spd) and chain are also new. Problem is I think it could do with a longer rear mech arm as it collapses on the smallest cogs - probably fixable if I swap out a chain link as there's a bit of slack at the other extreme. The handlebars are the old-school threaded type and the gear shifters are the old Sora type with the button and swing-arm brake levers like in the first photo here:
http://singletrackworld.com/forum/topic/sora-or-105

Seeing as I don't really like the existing shifters for braking because they swing inwards and I might need to change the rear mech, is it worth upgrading the shifters, rear mech and cassette in one go? I know the mech and casette are cheap but the shifters not so much, so I'm trying to work out what the best way forward is.

I was looking at the Tiagra 4600 Double for £100 but was hoping to spot a pair on ebay for less! Also, would I have to change the existing front derailleur mech if I changed the shifters?

ta
Danny

arlowood

dannydc wrote:

I know the mech and casette are cheap but the shifters not so much, so I'm trying to work out what the best way forward is.

Also, would I have to change the existing front derailleur mech if I changed the shifters?

ta
Danny

No your front mech will be fine as long as you buy a set of shifters designed for a double front chainring.

My advice would be to upgrade to 10-speed. New front mechs and casettes are cheap as you say and you can mix and match between Sora/Tiagra/105 and Ultegra. Keep a close watch on the classified section on this forum for your 10-speed shifters. Recent offer had some 105 5700 shifters on offer at £50 with some slight cosmetic faults but otherwise working perfectly.

viewtopic.php?f=40091&t=12996380

StillGoing

Go to eBay. I recently sold a full Tiagra groupset in excellent condition for £100 that was taken off an old frameset.

Matthewfalle

Or chuck me some wedge for some unused Rival carbon shifters and cables I have in the garage then get a rear mech in the current CRC sale for nowt.

Job jobbed.

desweller

All non-electronic integrated shifters feature swinging brake levers to achieve a gear shift, so you'll still have to deal with that unless you switch to bar-end or downtube shifters.

Matthewfalle

But Rival are also carbon so will add 2mph to your top end for no extra effort.

Other carbon shifters are available but not from me for a bargain price .......

Moonbiker

I don't get why you need a new rear mech sounds like your chain is wrong length?

Do you mean you need long cage one as your new cassette has more than 28t?

One the dawes website the giro 300 has a 7 speed screw on freewheel so you must have new wheels on the bike with freehub for 8 speed?

SPECIFICATIONS

Sizes 700C Wheel, 48cm, 53cm and 58cm Frames
Frame Alloy
Fork Steel
Headset 1 1/8" Aheadset
Shifters Shimano SL-A070 STI Levers 14spd
Rear derailleur Shimano RD-A070 7spd
Front derailleur Shimano FD-A070 2spd
Chain KMC HV-500
Freewheel Shimano MF-TZ21 7spd 14-28T
Front hub36H Quick Release, alloy
Rear hub 36H Quick Release, alloy
Rims Double Wall Alloy, with CNC braking surface
Spokes14G
Tyres Kenda 700 x 23C
Chainwheel 170mm Crank / 50-34T Compact Chainrings
Bottom bracket Cartridge BB 115mm axle
BrakesAlloy Single Pivot Caliiper
Brake levers Alloy lever. Part of shifter
Handlebar72mm Reach, 120mm Drop, 400mm wide (48cm), 420mm wide (53cm) and 440mm wide (58cm)
StemA-Headset Stem, alloy, 90mm reach (48cm), 100mm reach (48cm & 53cm)
Seatpost 27.2mm x 300mm
Saddle Dawes Road Saddle
Grips Black Cork Tape
Pedals9/16" with toe clips
Weight 11.0kg

keezx

You can stick a 7 speed Cassette on a 10 speed HG freehub...
Cannot imagine that a new, not classic equipped bike should have a screw-on freewheel.

Matthewfalle

I can do you a deal on some used but work perfectly 105 shifters and rear mech if you want .......