Proper Downshifting

[plumcrazy]

Hello Gentleman!

My first post but many read. Great site, fantastic community and trying to insure our next generation continues the tradition of caring properly for our passion, bikes.

I have a 47 knuckle and cant seem to find a straight answer on the proper way to downshift to first. Should the bike come to a complete stop or a slow rolling one? I get a little "clunk" when its rolling faster than 5mph and dont want to create issues down the road. Any help would be appreciated.

Thanks!

[larry]

You can double clutch.

[plumcrazy]

You can double clutch.

Thanks Larry for the reply. Can you explain that for me please? In my head i'm thinking when im in 2 or higher, your saying clutch to "N", release while coasting, then re-engage clutch and shift to "1"? is it ok to do this whils still moving or do you rev match? We have an old Austin Healey that is a "sync" gearbox, so it has to be at a stop before shifting to first is attempted....

[kitabel]

Your A-H has a "non-synchronized" 1st gear, which means that either you:
1. come to a stop, or
2. match the engine RPM, or
3. clutch in, out of 2nd, clutch out, clutch in, select 1st, clutch out
More modern automotive boxes generally use synchronizer rings on all gears (A-H is probably 2, 3, & 4 only) to speed up the new gear to aid engagement.

Any H-D box with shift clutches, either as a separate part (big twin, 45) or machined into the actual gear (Sportster) can be shifted in any direction, but the "clunk" you hear is the difference in speed between the old and new gears. For an example of an actual problem: Indian has sliding gears without a shift clutch as an engagement aid.

[exeric]

On my handshift bikes (which is all I have), I prefer to be in neutral as I'm coming to a controlled stop. I also want to be in neutral at a stoplight, or stop sign so I can shift into 1st by motor speed, and generally have my wits about me before I take off. If you have to make a panic stop, you probably won't have time to downshift, and even if you can get into 1st, it's just going to lock up the rear wheel. Under normal riding conditions, I don't think it's healthy for the bike to downshift into 1st; but, to each his own.

[plumcrazy]

Thank you Kitabel, makes perfect sense and very grateful for the lesson being here instead of a broken part! Love the knowledge here!
K

[plumcrazy]

Hi Eric!!

Thanks for the reply and great tip, totally simplifies what to think about coming into a stop! I'm new to a hand-shift, humble and grateful for all the tips! Question, when your coming into a light @15mph ish" and it goes green, are you going to rev match down to 1st or straight into 2nd? I guess what im asking is about whats better for the bike, dropping down or gently "lugging" up?

On my handshift bikes (which is all I have), I prefer to be in neutral as I'm coming to a controlled stop. I also want to be in neutral at a stoplight, or stop sign so I can shift into 1st by motor speed, and generally have my wits about me before I take off. If you have to make a panic stop, you probably won't have time to downshift, and even if you can get into 1st, it's just going to lock up the rear wheel. Under normal riding conditions, I don't think it's healthy for the bike to downshift into 1st; but, to each his own.

[kitabel]

My preference is too just use light throttle (rather than down-shift), and I prefer an engine with heavy flywheels which make this easier to do. After some practice, the engine will let you know when it's happy. Bikes with hand controlled spark advance may find it useful to slightly retard the ignition when accelerating from low RPM.

[Rubone]

When you live in an area with lots of elevation changes, steep hills, and questionable road surfaces as I do you shift in motion often as coming to a standstill is not a viable means of riding. Clutch and throttle control along with spark control keep it all in motion with little to no clash. There is about as much elevation change within 1/2 mile of my home as the total in some states!

[plumcrazy]

Thanks Robbie! We live in NH and any direction you travel from our house has hills.

So when your driving, how often are you adjusting timing? I've been putting around the neighborhood and haven't adjusted out of fully advanced that often, mostly 1-3rd...Sounds like a thing that comes with experience. In our cars, (almost all are 60's) I use vacuum to advance me early and not exceed a number. Say a chevy 409 engine, I'll set the total advance to be all-in @34, but come in with it early (low rmp) when i use vacuum. Some cars we cant use vacuum due to high compression and i get the dredded ping and know im over. So in that case I lock it out. Here is it the same, advance early and at higher rpm you retard it so as not to be to much? Will you get the same "ping" with too much and lug under a certain RPM?

[exeric]

Obviously you know all about timing control, which is very useful on Big twins. Many people only retard to start, and then leave it in advance. H-Ds manual advance is an essential control.

Where I live, it's flat, but if you have to deal with hills, a front brake is important. Harley's front drum brake isn't the best, but it can be finessed, and made to work pretty well. There are a number of posts on this forum by people who have done things to the front brake system to maximize it's efficiency. A search should bring up many of those posts.