Ajustable Stem Ahead System

[foxychick]

I was looking to purchase a stem, has anyone used this type of stem, do they come loose a lot of the time, can anyone recommend a particular brand cheers.

[axel_knutt]

I used adjustable stems for years, but quills, not threadless. I had no problems with them but I was careful to buy ones that can't slip. The pivot on mine was designed like a hinge with a splined pin, so that once the pin was inserted it couldn't move even if the bolt worked loose. The first one I had was an ART, but it hasn't been available for >16 years, the second was from RoseVersand, but they stopped trading in the UK after Brexit. The only reason I stopped using the ART one was that it had taken a whack in crash, so I changed it as a safety precaution.

[Vantage]

Plenty of riders use them without incident including myself at one time.
As long as the hinge bolts are tightened properly there's no real reason for them to come loose.
Probably not a good idea for rough mountain biking though.

[gregoryoftours]

They can get a bit creaky over time, may need periodic stripping and greasing to alleviate it, and they need checking regularly to make sure they're nipped up tight. The bar clamp size will be either 25.4 or 31.8, so ok for flat bars/risers and modern road drops but not for some older road drop bars.

Unless you want to change the position regularly I'd probably use one to find the actual stem extension/rise that best fits and then buy a rigid one of those measurements.

There are different types; the 2 most common ones are these:

The second one sits an inch or so higher than the top of the steerer so are extra useful if you want to raise your bars by quite a bit. They both work fine.

[SimonCelsa]

Hello Foxy Chick,

for some unfathomable reason I have 2 of these in my spares box, one is from one of my daughter's previous bikes, the other I can't remember.

Here's a basic picture which reveals it as a 1 1/8" ahead stem, approx 4" (100mm) length, clamp diameter 31.8mm.

It appears to be unbranded and wouldn't have cost very much. However, I do not recall any problems in service, maybe the odd creak when straining uphill but no movement or slippage.

If suitable, you are welcome to it, maybe a £5 donation to guide dogs for the blind or something similar, up to you. Drop me a PM if you'd like it and I'll get it off towards the end of next week, RM 2nd class. Unfortunately they are identical i.e both black so if you're after a silver one......!

I'm off on a short Highland blast early tomorrow, back on Tuesday / Wednesday so I may not answer any message straight away.

[foxychick]

Thank you for your very kind offer but i want a 70mm one to shorten the reach on my bike. Thank you for your input.

[foxyrider]

Thank you for your very kind offer but i want a 70mm one to shorten the reach on my bike. Thank you for your input.

bear in mind that 100mm straight will translate to maybe as little as 60mm when tilted

[gregoryoftours]

Thank you for your very kind offer but i want a 70mm one to shorten the reach on my bike. Thank you for your input.

If you already know the kind of angle you want on it as well as the reach it might be a better idea to buy a fixed stem of that type - less parts to go wrong, overall stronger and lighter, and less chance of creaking. But if you want to experiment with the angle then fair enough. As has been mentioned the reach shortens quite a bit as the stem is tilted up, so an adjustable stem that is 100mm when horizontal becomes about 75mm effective when at 45°

[foxychick]

After taking advice from members i have decided to go for a 90mm fixed stem with a 45 degree rise, thank you so much for your kind input.

[LancsGirl]

If you want to change stem height/distance/angle, this online calculator is really useful:

http://yojimg.net/bike/web_tools/stem.php

There are some other handy bike related calculators on the same site.