Rear Cog Removal
Rear Cog Install
Front Sprocket
I have to admit, I approached splitting the frame with the same irrational fear a toddler might have as he gets his first haircut. The first time you start mucking around a frame's integrity (or one's head) a certain amount of caution is in order. The fear, as stated, was irrational ... its easy peasy.
The split on my frame (Version #1) is at the dropout. The chain stay and seat stay fit like a glove and are squished together between the dropout and the dropout bolts. Simply remove the two dropout bolts completely and the dropout falls free on the wheel side of the frame. The frame can then be easily spread enough to get the belt through. None of the documentation said anything about belt direction, so I assume it can go on either way. I inserted the belt so the print on the belt itself read correctly once installed.
I won't go through all the do's and don'ts of belt handling. If you've purchases the belt, cog, sprocket and carrier, you will have at least four documents explaining this.
Reinstall the dropout and slide it all the way forward (the belt's loosest position). Slide the brake-side dropout all the way forward as well. Now its time to install the wheel. With the belt around the front sprocket, insert the wheel and push it forward so the belt can be slipped around the rear cog as well. With the belt lodged in the teeth of both sprockets, pull the wheel back and into the dropouts, just as with a chain. the belt will be quite loose. The pic below shows loosened dropout bolts and the adjusters backed all the way out so the dropouts could slide all the way forward.
With the dropout bolts still loose, tension the belt by turning the two dropout adjusters equally until the belt reaches a tension of 28-40 lbs. You will need a Gates belt tension tool to do this and should take several readings each time you measure tension as the results vary a bit from reading to reading. The tool is easy to use and comes with simple and adequate instructions.
Once the correct belt tension is reached, tighten the dropout bolts. Since maintaining belt tension is vital, reap on the dropout bolts pretty hard to ensure they don't loosen. Bolts coming loose is a common argument against sliding dropouts. I hadn't previously had any issues, but two of the bolts were a bit loose when I started this conversion, so they can get loose. By the way "reap on the bolts pretty hard" is a perfectly acceptable mechanic's phrase ... at least in my garage. Lastly, tighten the adjuster nuts so the adjusters stay as set. Conversion complete.
I used a 50 tooth CDX sprocket, 20 tooth CDX cog and a 115 tooth CDX belt, info on which can be found on the Gates Crabon Drive webpage. At the bottom of that page there's a link to a "Drive Calculator" (first image below) to help find sprocket/belt combinations that will work. The Wolverine's chain stays can adjust, via the sliding dropouts, from 425mm to about 445mm on all frame sizes, so select from the results that fall in that range and have the gear ratio you want. I use Sheldon Brown's Gear Calc Tool (second image below) to help with choosing a gear ratio.
No comments:
Post a Comment