Adjustable Shift Lever and Front Link Replacement
Posted: Sat Jan 30, 2021 8:21 pm
A couple years ago (drawing inspiration from all the people and designs in the past - credit where credit is due) I developed a completely adjustable shift mechanism comprised of a lever, and a torque-tube mounted pivot clamp.
The first piece is the P9-MS01 Adjustable Shift Lever. This is lever is split into three main components, and allows one to adjust the space between the two pivot points, and thus manipulate the amount of leverage, additionally it allows for independently setting the height adjustment of the knob. The lever can be left at a stock throw with a shortened lever height, or reduced throw and reduced height... etc. The throw adjustment is infinite in 1mm increments with the use of inexpensive spacers. The bores for the bushings are machined to a very high tolerance for a press-fit of Igus Z-series bushings. These greatly improve the feel over the stock "slip" fit nylon split bushings. Even in a stock throw application, there is a great improvement from the high tolerance bushings.
The second componet is the P9-MS02 Adjustable Pivot Clamp. This assembly eliminates the entire front link, guide bushing, and ball cup, buy replacing them with a torque-tube mounted platform and bearing car. The bearing car uses a double-row, high angular-contact ball bearing from Enduro to give perfectly constrained rotational movement. The bearing car can be moved vertically, again by installation of appropriate spacers, to match the lever spacing and maintain a parallel rear link geometry. This corrects the input angle to the transmission selector, and removes the normal binding present with a standard short shift lever alone.
I make a couple batches of these a year, and I happen to have both items in stock at the moment.
I documented the complete development on Rennlist, which I will link below, but this short clip shows the mechanism and how the shifting action works:
https://rennlist.com/forums/928-forum/9 ... esign.html
The first piece is the P9-MS01 Adjustable Shift Lever. This is lever is split into three main components, and allows one to adjust the space between the two pivot points, and thus manipulate the amount of leverage, additionally it allows for independently setting the height adjustment of the knob. The lever can be left at a stock throw with a shortened lever height, or reduced throw and reduced height... etc. The throw adjustment is infinite in 1mm increments with the use of inexpensive spacers. The bores for the bushings are machined to a very high tolerance for a press-fit of Igus Z-series bushings. These greatly improve the feel over the stock "slip" fit nylon split bushings. Even in a stock throw application, there is a great improvement from the high tolerance bushings.
The second componet is the P9-MS02 Adjustable Pivot Clamp. This assembly eliminates the entire front link, guide bushing, and ball cup, buy replacing them with a torque-tube mounted platform and bearing car. The bearing car uses a double-row, high angular-contact ball bearing from Enduro to give perfectly constrained rotational movement. The bearing car can be moved vertically, again by installation of appropriate spacers, to match the lever spacing and maintain a parallel rear link geometry. This corrects the input angle to the transmission selector, and removes the normal binding present with a standard short shift lever alone.
I make a couple batches of these a year, and I happen to have both items in stock at the moment.
I documented the complete development on Rennlist, which I will link below, but this short clip shows the mechanism and how the shifting action works:
https://rennlist.com/forums/928-forum/9 ... esign.html
