Contemplating a Birch Folding Bike Purchase: Wise Investment or Regrettable Decision?
02-17-24, 03:40 AM
#126
Senior Member
The steerer tube is short, not longer than the one of a classic fork (it goes only till the folding hinge) and its a one piece machined item with thick walls that integrate the lower part of the stem hinge (the hinge is not soldered on a tube like for many folding bike stems) same for the upper part of the stem, also one piece machined item stem hinge+stem tube.
The design is identical to a Aheadset fork with two thick clamp bolt (on the side of the fork near the fork folding release lever) and one bolt in the classic Aheadset cap to adjust the bearing preload.
There was never any failure reported on the Birdy stem.
The Aheadset type of fork+stem mounting is the most used nowadays in the bicycle industry.
The design is identical to a Aheadset fork with two thick clamp bolt (on the side of the fork near the fork folding release lever) and one bolt in the classic Aheadset cap to adjust the bearing preload.
There was never any failure reported on the Birdy stem.
The Aheadset type of fork+stem mounting is the most used nowadays in the bicycle industry.
If the steering tube has no issues with breaking, R&M should not make people replace them after a couple years, to have the full warranty. Yes? I mean, if no actual problem, believe me that this unnecessarily dings their reputation. Just doesn't make sense.
"Machined" tube, if lathe-turned on the outside, that can contribute to premature fatigue failure, even tiny circumferential grooves. A drawn tube there or very fine finish, is called for a tube under bending. Depends on the notch-sensitivity of the material.
The Aheadset design was a big advance, in my opinion, so much easier to adjust headset, without danger of brinelling the cups, so easy to do on older designs with 32mm(?) wrench.
Last edited by Duragrouch; 02-17-24 at 03:46 AM.
02-17-24, 04:34 AM
#127
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Its a forged one piece with the steerer and lower part of the hinge for the lower part of the stem, also forged one piece for the upper part of the hinge + stem tube.
On the not height adjustable, the forget one piece top part of the stem integrate the handlebar clamp, on the height adjustable, there is another smaller diameter piece that slides into the upper part of the stem.
On the not height adjustable, the forget one piece top part of the stem integrate the handlebar clamp, on the height adjustable, there is another smaller diameter piece that slides into the upper part of the stem.
02-17-24, 04:39 AM
#128
Senior Member
Its a forged one piece with the steerer and lower part of the hinge for the lower part of the stem, also forged one piece for the upper part of the hinge + stem tube.
On the not height adjustable, the forget one piece top part of the stem integrate the handlebar clamp, on the height adjustable, there is another smaller diameter piece that slides into the upper part of the stem.
On the not height adjustable, the forget one piece top part of the stem integrate the handlebar clamp, on the height adjustable, there is another smaller diameter piece that slides into the upper part of the stem.
