harleyKmodel

I just posted most of this on the "Harley K Model" page of Facebook. Please bear with me if you find it there. I just want to cover all bases.
My 1956 KHK has a rear sprocket that is hanging on by just a few rivets; so, it looks like time to replace tire, chain, and both sprockets. My 1952 K model rider's manual says to use a 3.25 X 19 tire. My '56 KHK now has a 4.00 X 18 Bridgestone on the rear.
1. Front sprocket has 21 teeth. Rear has 49. I want to lower the engine speed on highway travel without seriously hampering off road use (camping, farm waterways, etc.) or carrying travel / camping gear. Looks like I need a front sprocket with more teeth. Does anyone have a recommendation?
2. My 1952 K model rider's manual says to use a 3.25 X 19 rear tire. My '56 KHK now has a 4.00 X 18 Bridgestone on the rear. It seems this rear tire is a bit wide. In fact, it has marks where it rubs against nuts/bolt heads on the inside of the fender. What is a good size for this bike? I do like to bend it through the curves at a good clip.
3. Are there any particularly good drive chains to use? Are there any that I should avoid?
4. Any other recommendations?
I look forward to your suggestions.

If

Tim,
I appreciate short responses, but yours really could use a few more words!

I run a 530 Non-oring chain. Diamond or DID quad staked pins. 4.00-18 rear with a 22T front sprocket 51T rear. If your 49T is ok, I'd use it. otherwise 51T ok too. Good for two-lane roads - 55-60mph - and you can go 60-65 short bursts on freeways. I don't run mine much faster than that - especially sustained higher speeds.

Remember, the more you gear it high . . .the more heat you create getting there. No two ways around that . . . you have to open the throttle more to get it to go. So, while high gearing serves to lower cruising speed -- it often creates other issues.

As to the 49 vs. 51 -- If you want to send me your drum and sprocket, I will gladly rivet a brand new 51 tooth sprocket for free and ship back to you -- but I get to keep your 49T. I have a couple of sprockets on the shelf if you're interested.

And, I'm 100% serious.

I'll even do a big twin rivet conversion for you if you like (they never come apart with the larger big twin rivets.)

https://www.shop.pbisprockets.com/produ ... oductId=10 49t rear drum sprocket.

WOW I was actually able to post.

I ran a 22t front with a Tsubaki Denselube chain with no mods to the oem sprocket cover. To run a 23t I had to make my own sprocket cover and then didn’t like the 23t/51t combo.

Tim,
What was the problem with the 23/51 sprockets? Was it geared too high?
George

Below is a plot showing KH road speed vs engine speed with various countershaft sprockets. Not knowing how strong your engine is it is impossible to say what gearing you may be able to pull. Nevertheless, you can see what ball park the engine rpm will be in when running a variety of countershaft sprockets at a specific speed in high gear. Your 4.00x18 will be a bit taller so the overall gearing will obviously be higher with the taller tire.

The 19" rims that were optional on the early Ks were superseded by the 18s for later production. You should have a '55 issued KH owners manual, not the '52 manual which was standard for the 45ci Ks. The '49 tooth rear sprockets have been obsolete for many years...

Re: 23/51

I was doing a lot of commuting on 45 mph roads in North Jersey and Southern NY State. I just didn’t like the range it was running in. I didn’t have a Tach. It just seemed too likely to lug. I was running an SU and had a nice smooth power band. Was running a 16” on the back with a hardtail.
Went back to the 22t and it felt better.