Login required to started new threads

Login required to post replies

Fit assistance requested: stem length
Quote | Reply
Hi

I have a Tarmac SW SL6 Size 52 and intend to replace stem and bar.

Now, I have a 6 deg 100mm stem with a 3T bar, 103 mm reach. I want to change to a new bar with 77 mm reach and a 17 deg stem. Do I take a 100 mm or a 110 mm stem?
  • I think my set-up currently is long enough. I do not want to stretch further, I feel fine.
  • Applying the test of knee/elbow overlap in the down position when positioning your pedal parallel to the downtube: They definitely do. They say this is an indicator to move the stem forward.
  • Looking down from my riding position at the front wheel: the hub appears clearly in front of the stem.

Any advice on how to tackle this?10 mm stem length might be a minor thing. I am inclined to go with 110mm.

Thanks!
Quote Reply
Re: Fit assistance requested: stem length [Feehliks] [ In reply to ]
Quote | Reply
The exact position of the hoods relative to the front of the drops may not be the same for both bars depending on the curve of the drops and how you set up the hoods, but assuming it is:
A 6deg stem mounted pointing "down" will be at about 11deg off horizontal for a 73deg steerer angle. Thus 98mm approx reach for a true 100mm stem
A 17deg stem will be level for a 73deg steerer so stem length = stem reach.

98mm stem + 103mm reach = 201mm total
201mm total - 77mm reach = 124mm stem

So if you want your hoods in the same place, surely you should be looking for a stem around 124mm. 120mm should be easy enough to source.
Of course if you reduce the reach of the bars by 26mm and the length between drops and hoods is preserved, then the tops will be about 26mm further away.

What you haven't mentioned is why are you changing to a bar with 77mm reach if you're happy with your current position?
I've assumed you will prioritise maintaining your position on the hoods.

Edit: You're dropping the bar by about 19mm due to the stem angle change, and may find a tweak to your reach desirable as a result.
Last edited by: Ai_1: Nov 25, 20 2:33
Quote Reply
Re: Fit assistance requested: stem length [Ai_1] [ In reply to ]
Quote | Reply
Thanks! That is very clear!

There are several reasons why I want to do this:

My current bar feels quite flexy and the long reach (between top and hood) makes you awkwardly shift back and forth (3T Aeronova).
It would not fit with the clamp of the stem that I have in mind.
Lower the bar by changing to 17 deg.
Weight savings and the stem and bar I am looking at fit the looks of my bike way better.
Quote Reply