LCGB Forums

Trying to fit up an AF clo5e box. Everything turns freely without the Christmas tree in. it then locks up solid with the tree in when torqued down.



your thoughts would be much obliged

that race might not be fully home, did you fit the clutch spider and torque to lift the cluster? not familiar with the AF but I thought they were more strait forward with the shimming which is numerous on the cyclone I have.

I used a AF cassette & torqued it down but I suppose I’ll have a spider somewhere to use.

Not until the last decade or so have I fitted any gearbox in the manner that I do now. Ultimately, I find this method saves time, especially with regard to setting the correct running clearance of 0.003" to 0.011(?)" (or whatever the maximum is, which I never settle for )

Firstly, just the gear cluster alone with the endplate, it's fastening & dowels, to check that it freely rotates, & whether it may require any or no shimming @ the needle bearing end. It's debatable as to whether a shim is mandatory for the needle bearing end & often, in the case of homemade close ratio 'boxes there may be a weld/braise radius that does not allow one to be fitted. Otherwise, it's best to shim to control the bearing float & keep the needle in it's designated area.

Secondly, as above but just all loose gears alone (with endplate etc but no cluster!) for clearance check to precisely 0.003" using the collection of size engraved shims that I have amassed, many refaced on a surface grinder. This may involve swapping of end plates (never had a problem with that principle) or changing the bearing bush within. Obviously, the hub nut needs to be torqued up, often just with spacers if need be. This process also serves to show up any deficiencies in the sliding cursor, which is far too common with the cr@p replacements available, but another subject in itself

Lastly, fit the whole assembly which should spin up nicely. However, it is worth ensuring the best possible edge alignment of the gears by being prepared to shim up the cluster just under the endplate. Fussy, I know, but those gears of ours are not very wide & sometimes the cluster can pull up too far

In the end I stole another endplate off another bike! Fits much better, managed to get both sides turning freely the gears freed up with a 1mm gear shim then I noticed it’s to be a 1.4 - 2.0mm for the tree & gears to line up in the paperwork. I’ve now opened a beer so time to call it a day

Had fitted a double rear bearing before buying the 5 speed hoping I don’t have to pull it out to fit these strange shims!

Cyclones are much easier to fit IMO

Thanks for the info folks

I may be wrong but sometimes with the AF close ratio box it can sometimes be necessary to leave the Xmas tree/gear cluster shim out (the one that sits under the cluster) AF themselves recommend doing this if you encounter the gearbox locking while tightening the end plate down & say it won't affect the running of gearbox by omitting the shim. hope this helps

The Christmas tree shim is not in there. I’m thinking it may be something to do with the double bearing which I suspect is sitting slightly high on the inside of the casing.

Knowledge fitted that type of bearing not long ago, I’m sure he’ll be along sometime to explain

I’ve knocked the bearing back out in doing so I’ve ferked the circlip that collars it. I’ll likely troll a few bearing sites as I doubt any of the dealers will sell it on its own! On an up side I should be able to throw in two of the 0.2 shims (or the Scottish accurate measuring system better known as a ”bawhair”) & the box should fit

Hi Scott, regarding your concerns around end plate being warped, I doubt very much this is the issue, the reason the exchange of end plate appeared to be better will more likely be down to the wear on the end plate. With regards to AF close 5's the advice on the instructions as you say states 1.4 to 2mm, however you can only work to the clearances you have, many factors contribute to that, from the casings used, choice of rear hub bearing, layshaft and and plate, including the wear on the end plate boss. Also double check the shims dimensions as I've found on many occasion that they can be in correct, a few thou difference can make a difference. I've fitted many AF 5 and cyclones 5 speeds in both road and race engines, with shims varying from 0.8 to 2.2mm, one in finishind runner up in the LCGB BSM championship 2 yrs in a row is fitted with a 1mm shim, the gearbox, shims etc all in excellent condition, the real secret to 5 speeds is ensuring the 5th loose gear and the 5th on the cluster are in perfect alignment, place 5th in situ, along with cluster, tighten end plate and draw cluster out to its fixed position, and hold the loose cog down with your fingers so its seated correctly on the layshaft. You will need to drill hole in your end plate, to see this, adjust the cluster height accordingly with shims on top of cluster, AF dont supply these, however MB do crank spacing shims that will fit, do not shim beneath the cluster as that needs to be as open as possible to allow for good lubrication, dont worry about the needle bearing moving its not an issue, the main foucus should be getting the 5th in perfect alignment, then look at layshaft/gear stack shimming. here's some pics of one I fitted this wk=eek, notice the extra hole drilled evn on the casa endplate to ensure I was able to check 5th gear alignment,

Good Luck and Stay safe!


ps I'll add some pic later

Apologies for poor quality pics, me laptops playing up

free pic host







Good Luck and Stay safe!

Thanks Scotty I shall take that on board when next in the MC. Having never seen the casa endplate I’m assuming the centre hole is the drilled one? I’ll update as I get back to this.

Take care big man!

I’m at the point where I have had the 5th gear in checked its Sitting perfect. The spider was also torqued down with everything spinning freely. I have fitted the gearbox torqued down the endplate it’s all turning freely selecting all gears, I then go to torque down the spider & it’s locked solid!

Have tried thinner clutch shims to no avail

Any ideas folks

The shims under the clutch won't make any difference. When you are tightening the nut it must be pulling the cluster up somehow to a point where it's interfering with the mesh.

Maybe it needs a shim between the cluster and the endplate bearing to prevent or limit the pull?

Did you get this sorted?