|Changing the sprockets and chain on the CB750 Nighthawk is not a child play. You need force, you need some skills with the tools. But sometimes a man has to do what a man has to do and do his own maintenance on the bike to be a real “biker”.
Chain and sprockets for the Honda CB750 Nighthawk
After looking at the Tsubaki site I went (and that was a mistake) for the Tsubaki Chain kit HO-128, a 525 chain with 112 links and JT Sprockets, JTF1332.15 (15 teeth) front and JTR1332.40 (40 teeth) rear (these sizes are clearly indicated here). After installing the chain and sprockets I found out that I should take on link out from the chain (now it’s a little bit too long). If you look at the JTSprockets site, here you will see the recommended chain and sprockets would be:
- chain 525 with 110 links
- front sprocket: 15 teeth
- rear sprocket: 38 teeth
Once again, the recommended DID chain is: DID 525 V9/110 links, and the RK chain is RK 525 SM0Z5/110 both with 15/38 sprockets. In Europe, Regina recommends the same, which means the Tsubaki chain was simply too long.
Changing the chain and sprockets on the Honda CB750 Nighthawk
Before starting, you should know that if you are not using an endless chain, you will need a “press chain tool” which is used to fix the master link. Other than that, just regular tools and one extra pair of hands (to help from time to time) are needed.
Note: I’m only discussing non-endless chain change here. If you want to install an endless chain, you need to remove the swing arm.
Let’s go step by step:
- place some newspapers under the bike (you don’t want to get dirt on your new chain when installing)
- with the bike on the central stand, remove the bolts from the drive sprocket cover. You will probably not be able to remove the cover directly; if so, remove the “do not open” plastic bolt – don’t worry, if the bike is on the central stand, it shouldn’t spill any oil. With the “do not open” bolt out, is easier to remove the cover (just be careful, you don’t want any mud in your oil). After taking the cover off, put the do not open bolt back.
- Put the bike on the side stand, shift into 5th gear and ask someone (the extra pair of hands are needed) to apply the rear brake.
- Remove the drive sprocket (you will need to use plain force). Because I was short of tools, I used the wheel tool from my car and make it longer with an old handlebar.
- Cut the old chain (at this moment you need to be sure you are able to put everything back together) and remove the chain
- Remove the drive sprocket
- Clean the sprocket area (usually there is a lot of mud+chain oil)
- Install the new sprocket with the numbers facing out. Tighten the bolt (but not too much yet)
- Now, getting to the rear sprocket. Remove the rear wheel, and leaving the driven flange installed, step on the tire and ask someone (the second pair of hands) to remove the bolts (probably once again using the handlebar as a way to apply more force)
- Install the new sprocket, put the bolts back and tighten them well
- Put the rear wheel back, and adjust the distance as close as possible to the front wheel for the moment.
- Put the new chain on the drive sprocket, then over the driven sprocket in a way that both ends are re-united just in front the rear wheel
- Using your riveting or press tool, install the master link
- Adjust the chain slack as usual
- Tighten the front sprocket!
- Put the drive sprocket cover back (you might need to remove the “do not open” bolt – remember the bike should be put on the central stand first)