New Project

[Ivanerrol]

So.., I just picked up 2010 Specialized Sirrus Comp for a quite reasonable price.
E5 frame with rubber comfort Zertz inserts front and rear. Carbon seat post.

Road component equipped - Tiagra 27 speed but 105 Rear derailleur.
Tektro mini vee brakes with Avid levers - this combination is there to slow you down rather than getting you to stop on a hurry.

Bike came with Mavic Cp 22’s 622/15’s with 38mm tyres - P.0. Wanted a comfortable commute. Way out of the wheel/tyre size recommendation
Replaced the wheels with some Shimano RS10’s + 25mm Vittorio’s.

Since I have a set of 27 speed Tiagra STi’s on some Specialized drop bars left over ftom my Allez conversion to flat bar, I’m considering installing these on the Sirrus to see how it goes.

I have some Tiagra front and rear brake calipers - I’ll install them on as well.

Frame is XXL. 60cm seat tube, 61cm top tube.
I might need to install a short stem to keep the reach acceptable. I’m 188cm.

The local LBS’s opinion on the Allez drop to flat bar/upgrade to 4700 conversion was - great bike to excellent bike.

We will see how we go from flat bar to drop.

[Ivanerrol]

The machine in question

[Duck!]

What generation spare Tiagra shifters do you have? If they're the current 2016-onward 4700 series, they WILL NOT work with the older derailleurs; you'll need matching derailleurs. If they're an earlier series they'll be fine, just ensure the number of gears in the cassette matches the shifters.

One thing to note, the Sirrus being a flat-bar will have a comparitively long top tube for its size. Chucking a drop bar on it will considerably lengthen the reach when you're on the hoods.

[Ivanerrol]

Shifters are older 2009 Tiagra models 27 speed.
Sirrus is 2010 model Taigra 27 speed
Re derailleur is old 9 speed 105.
No problemo

I will install a short stem riser to shorten the saddle to drop length.
The bike is big - XXL - long top tube.

[Ivanerrol]

Need long reach road calipers.
The older 4600 Tiagra calipers I have dont reach to the wheel brake surfaces.
I’ll try the mini vees - they are allegedly compatible with STI’s

[Ivanerrol]

I have measured the distance between handle bar stem and seat tube centres on both my Specialized 58 Allez and the 60mm Sirrus.
Because of the more up right head tube on the hybrid the distance between either bike is only 1 cm.
So should be no issue with reach.

[MattyK]

So, you got a drop bar bike and converted it to flat bar. Now you've got a flat bar bike and are converting it to drop bar?

O.K.

[Ivanerrol]

The drops on the hybrid sit much higher than on the road bike. With my sciatica the higher drops on the hybrid mean I dont need to get down so far.
Meanwhile I’m very happy with the Allez flat bar setup.

[Ivanerrol]

The Specialized frankenbike is semi complete.

The Tektro mini vees work O.K. with the STi levers however they are a P.I.T.A. to adjust and every time the wheels need to be removed, the cable needs to be released and then readjusted.
I see a pair of long reach road calipers in the future.

I was running around with skinny 24mm slick tyres. This bike is huge XL 60mm seat tube. For my mild MS it seemed a bit wobbly. 28mm feel much better.

Those clod hopper pedals have got to go.