Pre load Gear changing

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jackonz
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Pre load Gear changing

Post by jackonz »

Am hoping someone can enlighten me in the subject of gear changing on an Airhead, cant recall if I read it somewhere or what but it was around making changing gear less clunky and the method being to load the gear lever before pulling the clutch lever, is it true or what, mine is bad between first and second going up as in very clunky but the rest not too bad.

Any and all advice greatly deprecated.
Phil J

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Kurt in S.A.
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Re: Pre load Gear changing

Post by Kurt in S.A. »

That's what I do on all my gears. Pre load the foot shifter, pull in the hand lever, make the gear change, and continue to hold load on the foot shifter as you let out the hand lever and apply power. Works for me. 1st to 2nd will likely always be a bit more clunky than the others. I used to have false neutrals between 4 and 5 but not so much.

Kurt
Rob Frankham
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Re: Pre load Gear changing

Post by Rob Frankham »

Gear pre-loading is one of those subjects that is quite controversial. some claim a 'quicker' and smoother gear shift. My take is that it:

1) isn't necessarily quicker.
2) Isn't necessarily smoother and
3) Places unnecessary wear on the shift forks and shift hubs in the box.

Assuming that the vehicle clutch is working right and the gears are being fully disengaged the most important factors for a smooth change are that the change is made in the right rev band and that the halves of the change hub are only moving slowly in relation to each other when they move in to engagement. The key to this is the slight engine rev increase (blib) as you go down the box and a momentaryrev drop as you go up it. The other important thing os not to try to hurry the change. The slight pause as the box goes through the 'false neutral' between gears will allow the various moving bits to align.

Airhead boxes are not the most forgiving when it comes to changing but, as long as the clutch is properly adjusted and you don't hurry the change, it is quite possible to achieve a smooth change.

The only time I would advocate pre-loading the clutch lever is if you are ever stuck in the position of having to ride without the clutch (e.g. broken clutch cable) when a pre-loaded leverr and a very gentle hand on the throttle will get you home 9 times out of 10...

Rob
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Kurt in S.A.
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Re: Pre load Gear changing

Post by Kurt in S.A. »

It isn't a whole lot of pressure. One benefit is that you take up any slack in the mechanism prior to actuation. The gear oil in the box should go a long way to add the protection to keep sliding parts from touch each other and reducing wear. YMMV.

Kurt
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Airbear
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Re: Pre load Gear changing

Post by Airbear »

Winding up to high revs in the low gears is where I get the clunky and potentially destructive changes. My approach is to change from first to second at quite low speed, usually within 25 metres from take off. Second to third can be more difficult, especially when accelerating uphill after a hairpin bend. Here I will delay the shift after pulling in the clutch - maybe one to two seconds - until the revs coincide and the dogs are happy to latch in. The other gears snick in without problems and blipping the throttle works to go down through the gears.
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Jeff in W.C.
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Re: Pre load Gear changing

Post by Jeff in W.C. »

Rob knows his stuff far better than me and he's probably forgotten more than I'll ever know. However, I think it may depend on what type of gear lever you have on your bike. You didn't indicate the year or bike. The earlier Airheads had the gear lever directly bolt to the transmission. Later ones used a linkage. On my 1988 R100 RT, there was some looseness in the linkage that made for imprecise shifting at times. I found myself in a false neutral too often and shifting from 1st to 2nd was the worst. Pre-loading, or taking up the slack in the linkage, made for better shifting. This last winter I did some maintenance that included replacing the pivot bolt and bushing in the gear shifter that removed almost all of the looseness in the linkage. If you have the linkage and some play, I would consider replacing the pivot bolt and bushing.
Jeff in W.C.
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jackonz
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Re: Pre load Gear changing

Post by jackonz »

Jeff in W.C. wrote: Mon Aug 28, 2023 11:23 pm Rob knows his stuff far better than me and he's probably forgotten more than I'll ever know. However, I think it may depend on what type of gear lever you have on your bike. You didn't indicate the year or bike. The earlier Airheads had the gear lever directly bolt to the transmission. Later ones used a linkage. On my 1988 R100 RT, there was some looseness in the linkage that made for imprecise shifting at times. I found myself in a false neutral too often and shifting from 1st to 2nd was the worst. Pre-loading, or taking up the slack in the linkage, made for better shifting. This last winter I did some maintenance that included replacing the pivot bolt and bushing in the gear shifter that removed almost all of the looseness in the linkage. If you have the linkage and some play, I would consider replacing the pivot bolt and bushing.
The bike is a 1978 R80/7 and has a linkage but from what I can tell its the early linkage without rose joints, am told changing it to the later linkage will give huge improvement and adjust ability for the gear lever position.
Phil J

Nelson NZ.
barryh
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Re: Pre load Gear changing

Post by barryh »

The rose joint linkage should obviously be superior but I've found the "bent wire" linkage works well enough if it's unworn and axial play at the lever pivot is shimmed out. Besides differences in the linkage type I believe there are variations in the gear change lever pivot in that some have a bearing sleeve inserted and some pivot directly on the alloy bore. Very regular application of a grease gun would seem like a good idea to help keep wear at bay. I've always done it at least every 1000 miles.
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Re: Pre load Gear changing

Post by RPGR90s »

40+ years riding Airheads and Oilheads. I've found that light pressure on the lever AND at the right RPM, can make nearly imperceptible and smooth shifts. If I'm lazy and pull the clutch, let the RPM's drop and move the lever, then the gearbox makes some amazing sounds. :(

It's all a matter of timing, light pressure and minimal dis-engagement of the clutch (thanks for the lesson R. Pridmore)
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melville
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Re: Pre load Gear changing

Post by melville »

I converted my /6 from bent wire to rose joints and it was a big improvement. I'll be doing the same with the /7 and the RS.
Call me Mel. Some years ago- never mind how long precisely- having little or no money in my purse, and nothing particular to interest me at home, I thought I would ride about a little and see the other parts of the world.
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