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Specialized Sirrus upgrade

oxomanoxoman Posts: 10,988
edited July 2013 in The workshop
I currently have the Basic Sirrus and am thinking of upgrading it from standard spec. Swapping 32 nimbus tyres for 25's gator skins and possibly changing straight bars for some drops, anybody already done this. I like the upright position but at the same time starting to do more distance and faster and thinking i might improve if i go a bit lower on the bike. Might possibly swap front chain rings from 48/38/28 to something with a better spread. to give me a bit more speed without compromising the bottom end as some pretty steep hills around me. Was looking to leave the rear set Shimano HG-31, 8-speed, 11-32t unless somebody can convince me its worth upgrading. I don't fancy losing the bottom end as after a 12 hour shift the granny ring comes in handy at times on my way home.
Too many bikes according to Mrs O.


  • I have an old (2001) Sirrus and have considered, and made, various changes so my thoughts are:

    Tyres - Mine came with 28s rather than 32s but dropping to 25s makes some sense provided the rims aren't too wide for them. If they are, try a 28 that has a reasonable maximum pressure (i.e. > 100 psi). Consider something other than Gatorskins if you live somewhere chalky - my Nimbus's never got a puncture but I've had 3 in 2-3000 miles with the gators, all due to flint shards. I'm trying Duranos next, FWIW.

    Drops - This is an expensive change (new bars, stem, controls, front mech) and you might have fun with brakes since most drop levers aren't compatible with V-brakes. Also, drop bars normally require a shorter top tube so the geometry may not let you get a good position/handling with drops. To get lower, try flipping your stem. I did this, which helped, though I felt the need for more hand positions due to the greater weight on my wrists so I then switched to butterfly bars (which have MTB diameter so I was able to reuse all my controls). This is better than before - though still not quite as comfortable after 20 miles as the drops on my road bike.

    Chain rings - I very much doubt you need to go higher than 48-11. I've got 50-12 on my road bike, which is a slightly lower gear, and have no problem pedalling at high 30s mph (downhill ;-) ). If you find 48-11 limiting, you could perhaps look at your cadence - increasing it may be beneficial. What I have done is to move from 11-32 to 11-28 on the cassette, as this gives less of a jump between some of the gears - but this would give you less bottom end which sounds like it might be an issue for you and where you live.


  • oxomanoxoman Posts: 10,988
    Thanks for the reply, i hadn't thought about the complexity of the brakes just the gears. Not sure if Linear pull brakes and V brakes are the same though. The only reason i thought of Gatorskins is they are lighter and still pretty bomb proof. Most of my current routes are road with the odd detour onto either limestone paths or grit trails. The daily commute is all roads and not all smooth either. My cadence is increasing as i get fitter, i have been concentrating on getting up the hills / inclines quicker rather than outright speed on the flat or downhills.
    Too many bikes according to Mrs O.
  • Linear pull and v brakes are the same. I have added drops to a sirus (looks a bit odd because you're very high up compared to a road bike) you need new long drop caliper brakes, shifters and a front mech to make it work.

    Dolan Preffisio
    2010 Cube Agree SL
  • @CarlosDSanchez - I know this post was several years ago but I'm really interested in how you managed to retro fit these handlebars & long drop brake calipers to the sirrus.

    Any information can remember or provide would be greatly appreciated?

  • Hi Jon, the handlebars are straight forward, just remove the old ones and fit drops. You will need to get hold of some suitable STI's - I think shimano 2300 are 8 speed, sora are 9 speed and tiagra up are now 10 speed. You will also need an in line barrel adjuster because the cable stops on the frame aren't threaded or the right size to fit a regular one. Brakes might be more tricky as I don't know if the newer Sirrus still has the correct size/position hole through the fork crown or on the bridge at the seat stays. Only way to find out is measure the diameter of the hole and the distance between it's centre and the centre of the brake track on your wheel, so long as it's less than 49mm (I think) long drop calliper brakes should work.
    Dolan Preffisio
    2010 Cube Agree SL
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