R80 gearbox issue?

[England-Kev]

My R80ST has started locking in first gear, and can be very hard to change from 1st to 2nd?

Do any of you have an idea why this might be

It selects all other gears fine, and drops into first fine, and it goes into nuetral fine when sat at the lights, it is only an issue from 1st to 2nd when moving.

 

[Voyager]

First, some questions . .

What sort of mileage has the box done ??

Have you changed the oil recently ??

Does it still lock when the box has warmed up or is it the same cold or hot ??

When the oil was last changed, was there swarf/paste on the magnetic plug ??

It doesn't take much clearance for these things to start acting up plus there are a couple of wear issues I've seen (cam plates coming loose on their hubs & a notch developing in the cam plate around the neutral position).

Lets get some facts then consider the easy options first .

Bob.

 

[England-Kev]

First, some questions . .

What sort of mileage has the box done ?? 72k

Have you changed the oil recently ?? I change all oils every Easter weekend

Does it still lock when the box has warmed up or is it the same cold or hot ?? Not sure

When the oil was last changed, was there swarf/paste on the magnetic plug ?? No

It doesn't take much clearance for these things to start acting up plus there are a couple of wear issues I've seen (cam plates coming loose on their hubs & a notch developing in the cam plate around the neutral position).

Lets get some facts then consider the easy options first .

Bob.

thanks Bob.

 

[Voyager]

Dr Bob's Remote Diagnostic Surgery:

Ok, so, highish mileage but looked after and presumably not given a hard life as its an ST and not a GS . . .

Everything works well apart from the 1st to 2nd change . . . . So not obviously worn bearings, selectors, Selector cams.

The problem with remote diagnostics is that its mostly guesswork and in the case of a gearbox impossible to determine without stripping the box.

My suspicion is falling on the nylon Indexing Roller in the gearchange mechanism. The slightly orangey round(ish) thing on the left of this picture:

They can become mis-shapen with age and then jam in the indexing slots - like this:

They will continue to roll as the gears are changed but the pointy-bit will drop into its favourite slot and will want to stay there.

Naturally they cost pennies to buy but the box has to be stripped to replace them.

Both of my boxes have sealed stainless bearings in place of the nylon rollers. It makes the box a bit 'clacky' but its positive and won't distort

All of this is complete conjecture but it sounds as though your gearbox is basically sound so I suggest you just use it until you can't stand it any more .

Bob.

 

[Canuck]

I don't know Bob... those rollers never disform from what I hear Still waiting for some time to try out those boxes you built for me

 

[Voyager]

I don't know Bob... those rollers never disform from what I hear Still waiting for some time to try out those boxes you built for me

Hmmmmm, you didn't recognise the pictures that came from your 100RS box then .

So how is the house building in the backwoods going - are you building yours or your Dad's first ??

Good to see that you are still keeping in touch .

(Hope the bikes are OK as well ).

Bob.

 

[Canuck]

Hmmmmm, you didn't recognise the pictures that came from your 100RS box then .

So how is the house building in the backwoods going - are you building yours or your Dad's first ??

Good to see that you are still keeping in touch .

(Hope the bikes are OK as well ).

Bob.

Oh i recognized them all right. As far as houses we have moved twice and now looking at a few more pieces of land.... Hopefully start building in julyish. Now back to our regular programming about gear boxes.

 

[England-Kev]

Now we are in the warmer ? days of spring, I no longer have this issue.

So why would the cold weather cause this problem?

 

[fayeslane]

The water in your gearbox was freezing?

 

[Voyager]

So why would the cold weather cause this problem?

Because you weren't using the bike much and the moving parts dried up .

Maybe that Indexing Roller is softer in the warmer weather .

Who knows . . . Keep using it and if it ain't broke don't fix it .

Bob.

 

[England-Kev]

The water in your gearbox was freezing?

I changed the gearbox oil yesterday as it happens, and it came out as clean as it went in last Easter