How to install a 17T front sprocket
So you want to upgear? Looking for more comfort on the freeway? Hoping to reduce strain on the engine (ok we hope it does this)? Hoping for more mpg (it's only going to be a few)? Or are you just tired of shifting through 17 gears to get to 25 mph. This is the place for you (tongue somewhat in cheek here).
If you want more power and are willing to sacrifice mpg, then go to a downgear thread. Much easier to do that, no mods needed.
A 17T up front nets you a 13.3% upgear.
I used the Sprocket Secialists 17T steel front sprocket. You can Google for them and call them and they'll set you up with the right sprocket.
You'll need to install a HealTech Speedohealer first however, that is covered elsewhere on this forum.
Stock gearing is 15-41, I actually went with 17-39 for a 19% upgear, but I won't be spending time on the 39T part of it for this how-to, it is covered in other threads. I also put on a new chain, I could have kept the OEM chain if I wanted to. I put on a better chain (love those DID X-Ring Gold chains), but the OEM chain is pretty decent in it's own right.
I followed the service manual for getting the sprocket cover off, removing the rear wheel, and I cut the old chain off with a grinder.
Special tools you will need for this work include
- a grinder (Less than $100 at Orchard Supply)
- a bench vise (I have a portable one that clamps onto a folding table.
- a multi-grade file (has a rough and fine side) for smoothing out the rough spots on the metal part after you grind it.
I want to give credit to some else on this forum who mentioned you had to grind a bit to get a 17T on. I don't know who it is though, so this builds on that original post. I mostly just add pics and a bit more detail.
And you'll need the usual assortment of sockets and wrenches. I have a huge collection from my automotive days, and I actually needed a 1/2" driver (18" breaker bar) to get the rear sprocket off, those five bolts were on really tight, and I put them back on that way.
I only needed the center stand on the bike to do all the work, no jacking or any other kind of suspension needed. The bike leans forward on the center stand and I didn't need to remove the front wheel.
It should be mentioned that if you like replacing your own chains, a grinder is a useful investment since it makes short work of removing an old chain.
I love the sparks too, makes it like the 4th of July, actually today is the 4th, kinda funny. :-)
The small metal crescent that needs to be ground is between the sprocket cover and the tranny housing and comes off normally when you remove the sprocket cover. It is not a structural piece, it is a chain retainer to keep the chain from flying off the front sprocket, so it fits tightly but doesn't actually touch the chain under normal circumstances. So you need grind it back to allow for the increased size of the front sprocket.
HINT: removing the sprocket cover requires you to remove two wiring harness clips, they are press fitted into the plastic shell, squeeze them from behind and they should pop out easily.
Following are the pics. I show my new chain and sprockets, before and after pics of the chain retainer (the before is marked showing where I am going to grind, I did this by eyeball, the tolerances aren't that tight). The way I determined that line was to install the new chain, and hold the retainer in place where it would go, and examine the new chain-line and marked where the chain becomes close to the chain-stay and where it backs away. All I did was mark the endpoints, I drew the line by hand later and went a little past each endpoint for margin of error. Once ground, I held it up to the chain again, and made sure it had a few mm of clearance, just like it did before. This mod probably means you should replace the chain retainer if you ever return to stock gearing. I intend to return the bike to stock gearing when I sell it, so I kept the old sprockets (they have 600 mi on them), and I am going to buy a retainer next week so I'll be ready a few years down the road when I do it.
I also show the grinder and bench vise with the chain retainer mounted and ready to grind.
2014 CB500X ABS - outfitted as a bagger for commuting.
Last edited by kurth83; 07-05-2014 at 12:24 AM.