RRT2 Identification

[Goldseeker]

I have mentioned in other posts that I may end up putting touring footrests on my RAGS rep.. This raises the issue of re-setting the gear lever at 180'. As I have 1 up 4 down gear change at the moment, turning the lever will require a camplate change to retain the status quo. Needing information to achieve this I have searched this site and the net and have come across lots of stuff, some useful some not so. This info has lead me to question aspects about my gearbox.

It is stamped RRT2 and has the lug on the top of the case for the camplate plunger which, I understand, denotes that it is an RRT2. I haven't done many miles so far but have not noticed the infamous high 1st gear problem that is written about elsewhere. Roy Bacon's book states that the RRT2 1st gear internal ratio is 1.754 which is almost the same (1.759) as the STD box 2nd gear. When I pulled away in 1st gear it just didn't feel as if I was in 2nd, in other words I am now doubting the authenticity of the box.

This could mean 1> its a fake, but doesn't the top plunger location dismiss this? 2> its been modified to take std ratios 3> my 'feel' is not as accurate as I think it is.
Is there any other way of identification apart from looking inside and counting gear teeth?

Col.

[trevinoz]

Col,
           I think that whichever way you go, it will be a pain.
Either strip it or take off the primary case and count the revolutions of the mainshaft compared to the output gear.
Maybe calculate the engine revs against speed for each gear and road test. Or ride another A10 with standard gears and compare.
It is quite possible that standard gears have been fitted, a friend of mine has done it to his box as the close ratio mainshaft was not pretty where the needle rollers run in the sleeve gear.
Maybe you should ask the vendor  exactly what he has sold you. I imagine that the RRT2 box would have added a premium to the price.
Trev.

[Goldseeker]

Trev, I don't think the seller is any wiser than myself really. Like me, he assumed the box to be genuine because of the RRT2 stamping and top index plunger. I have found some useful info from the website of a company that makes a 5 speed conversion, see below. Will have to look inside but that isn't a problem really, just time which I have plenty of. It seems the main thing to look for is the large c/bore surrounding the layshaft bearing and the needle rollers in the sleeve gear (see photo). If the box is RRT2 but retrofitted with STD ratio first gear then the layshaft bearings will have bushes but the rollers should still be in the sleeve gear.

All good fun, don't you think?

Col.

Extract from article, copyright of Nova Racing Transmissions Ltd, Lincolnshire.

"Should you be in doubt as to which version of the BSA gearbox you have, there are a
number of differences to look for. A genuine Gold star shell has indexing plunger
housings drilled and tapped at both the top and bottom positions, whereas, a standard box
only has the bottom position for the plunger housing. Further investigation is still
required inside the gearbox as in recent years many shells have been modified in this
way.
If, on opening the gearbox you find needle bearings, this may not be indicative of a ?gold
star? shell, as again, many have been converted. Genuine shells have RRT2 and a
number stamped on the sandwich plate adjacent to the moulded on pattern numbers.
Once again this could have been added at a later date to give the appearance of
authenticity. The final identification is to examine the needle bearing housing in the
main shell. A genuine RRT2 has a deep annular machining around the bearing for a steel
thrust washer."

[muskrat]

G'day Col,
                 I was only looking at that site a couple of nights ago. Their 5 speed looks great. I will have to find a busier corner for the wife to pay for it !!!
Your box must have a reverse cam plate for that shift pattern, but that can be done to a std box. 1st way to tell is take the outer cover off and see if the layshaft has a bush or roller. RR means extra close ratio, T2 means torrington bearings on layshaft and sleeve gear.
Cheers

[trevinoz]

Col,
         I would be surprised if anyone only replaced first gear.
More likely is the whole works has been changed.
STD is a more user friendly box anyway.
Trev.

[Goldseeker]

Col,
         I would be surprised if anyone only replaced first gear.
More likely is the whole works has been changed.
STD is a more user friendly box anyway.
Trev.

Hi Trev, I have been at a Harley rally in Sussex since Thursday so couldn't reply sooner.

You are of course right, it would have been a complete cluster change including the layshaft bearings being changed to bushes, so only real identification left would be the counter bore.

Col.

[muskrat]

G'day Col,
                 I would have thought the bearings would have been retained and just the gears swapped for std. Why would anyone replace them with bushes ?
Cheers

[Goldseeker]

G'day Col,
                 I would have thought the bearings would have been retained and just the gears swapped for std. Why would anyone replace them with bushes ?
Cheers

Not sure really but have been told it is required. I would think that it is either because the shaft diameters are slightly different or that the std shafts are softer for bushes. 

Col.

[trevinoz]

Musky,
          Not sure if the STD shafts are the same as the T2 shafts but the STD are mostly used and could not run on needles because of the wear unless machined and sleeves fitted.
Seems like too much trouble for every day use.
Trev.

[Goldseeker]

After my last post I was thinking (or dreaming  ) about the g/box and I remembered that amongst the paperwork received with the bike was an invoice for a gearbox rebuild. As you can imagine there was a quick scramble to find said invoice and check it out for clues. Work was done by a Tony Westbrook from Crawley (anyone know of him?) and included 'Machining high gear' (?) and 'Supply 3 x needle rollers'. I surmised that 'high gear' meant sleeve gear and 'needle rollers' meant sleeve gear needle rollers.

I rang Tony and had a chat, unfortunately he couldn't remember the box (it was over three years ago) or why it had been rebuilt but he did say that it was unlikely that he would have put needle rollers in a standard sleeve gear. He also gave me a few other pointers to identify an RRT2 - external and internal, plus mentioned that it was possible to mix standard and close ratio gears.

I have to say that doing this 'detective' work has been most enjoyable and something that was not expected.

Col.