Newbie advice please - replacement stem?

[QuartzDad]

Haven't ridden a bike in 30+ years so like everyone else in lockdown I bought a bike - a medium Specialized Allez from ebay and my son has claimed it, so I've ended up buying a small Giant TCR for me as the Allez felt just a little too big - according to the Giant sizing chart I'm right between small and medium for height/inside leg.

So the Giant is lovely and smooth etc. but I get bad shoulder ache pretty quickly, swapped bikes with him on a ride and the pain went away.

Distance from saddle to headset(?) is roughly 50mm shorter on my bike than his. It looks I can add around 25mm by moving the saddle back - which I assume is OK? Can I buy a 25mm longer stem(?) to give me the added space? Does a longer stem introduce other problems?

Will probably go to my local bike shop to buy and get it fitted, just wondered how much I'm looking at for an appropriate stem? I'm the definitive newbie fat lad at the back so a bike fit or similar is way overkill at this stage.

Thanks in advance.

[firemunki]

Don't get a bike shop to fit a stem, it's very easy as long as you don't go ham on tightening the bolts. Not checked but I'd be very surprised in Park Tools don't have a video showing the process. Also, a good reason if you're planning on doing simple jobs on the bike to get a torque wrench.

An alloy stem can be had for less than 20 quid from eBay which is brilliant if you're not sure on fitting (you should see my collection!).

Also, shoulder ache and the like could also be the height of the bars but be aware raising them will make the effective reach less so could squish you up more.

Edited by firemunki on Tuesday 24th August 12:26

[firemunki]

Here you go:

https://www.youtube.com/watch?v=TPYGv6fMnBw&ab...

[Voguely]

If you think you might end up cycling quite a bit then it may be worth getting a proper bike fit done at a shop. That way they can measure the optimal distance for stems etc, rather than just guessing that you need an extra 25mm (might be that 15 or 35 extra is better). They'll also look at the various other measurements. Yes of course it costs money to have this done, but probably a small price for comfort and then at least if you decide to buy another bike or other components over time then you know exactly what your measurements should be.

[QuartzDad]

Thanks both, will give DIY a go.

[Castrol for a knave]

It looks like a combination of too short a stem and saddle to far forward.
Better a slightly longer stem (bi9ke will also be less twitchy) and move the saddle back a touch. Then, check you have saddle height correct as this will be affected by shifting things around.

Basically, you need to sit on the saddle while some one holds the bike, put your hands by your side and be able to maintain the same position without falling forward.

Your shoulder ache might also be bars - maybe go a bit narrower to 42 or even 40cm Assuming you have stock 44cm bars).

https://www.youtube.com/watch?v=vMmbXAWcgh4

https://www.youtube.com/watch?v=Kr8sJ4yJyts

[upsidedownmark]

Try to replicate the position of the old bike. There's no point in measuring from the saddle 'cos that can move. The only bit that can't move is the centre of the cranks. So figure out how far above & behind the crank axle the other one is, replicate it, THEN measure the handlebars the same way.
If the saddle is further forward, that will make the stem seem shorter, and will throw more weight onto your hands.

[mikey P 500]

As above start with moving saddle back (free) then could also flip stem over and put top spacer below the stem this will make bars higher. (Normally reduces back pain from being too low and likely the size small bike has a lower overall front end than the medium bike). would be worth measuring the current stem length (Centre to centre) and also bar width then you can plan how much longer you want to go. (Longer stem will make the steering feel slightly slower but it's marginal unless change length significantly).