iandusud wrote: ↑22 Sep 2022, 9:31am
rogerzilla wrote: ↑21 Sep 2022, 9:42pm
The problem with V-brakes and drop bar levers is well known. There are special levers with more cable pull, but they are not great.
I'm using Tiagra 4700 levers on one of our tandems with a full length linear pull brake on the front and it works very well (believe me I wouldn't use this set if it didn't work well as we tour well loaded and tackle some very steep descents notably in the Yorkshire Dales).
On our other "hack" tandem we have full length linear pull brakes coupled to Tektro RL520 levers, which are specifically designed for linear pull brakes, and again these work very well.
If you can use full-size Vee brakes, this is the best way forward.
Two things govern whether or not your existing lever(s) will work full size vees.......the obvious one is how much cable the lever pulls, and I think the current (NSSLR?) levers pull more cable than the old ones. The less obvious one is the exact placement of the bosses on the frame/forks. If the pad is at the bottom of the slot, the brake will have a greater mechanical advantage and require more cable pull than if the pad is at the top of the slot. The slot is a significant proportion of the length of the arm (a sixth? an eighth?) so the effect is noticeable. Choose a brake with big chunky stiff arms.....skinny weedy arms flex and give brake squeal and "lost motion".
Mini vees are a lot less faff than cantis, in the general run of events.
For mini vees, Tektro RX 6 are good and not silly money....again, stiff brake arms ("U" section, as I recall) so you don't get too much flexing and lost motion. Use a noodle with an adjuster so you can back the adjuster off and get the wheel out
https://spacycles.co.uk/m7b0s101p3530/S ... h-Adjuster
Cantilevers with horizontal arms have a fixed mechanical advantage, this being the ratio of the distance from the pivot to the straddle wire attachment and the distance from the pivot to the brake pad.....so again, the precise height of the canti. studs governs the mechanical advantage of the brake on any particular bike.
"low profile" cantis with the arms almost vertical can be set up to give a good mechanical advantage, but the snag is they are "regressive" in action. ....you pull the lever, the straddle wire goes up and as the straddle wire goes up the mechanical advantage drops like a stone.....so you get a high mechanical advantage (MA) as the pad approaches the rim, and a low MA when the pad is in contact with the rim.....and what you want is the exact opposite.....the pads to move quickly (low MA) approaching the rim, and a high MA for the actual braking. Low profile cantis work much worse as the pads wear, specially if you take up the wear by adjusting the main cable. ....because that raises the straddle cable
The best canti. compromise is a mid profile brake. CX 70 were good and after-market pads fitted. My recollection is it requires a bit of fettling to get aftermarket pads to fit CX 50.
How to set them up is here
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