Acceptable rear hub play?

[Scooterslag]

Recently rebuilt a engine and fitted rear hub and there's a slight amount of play if you shake the wheel gripping the wheel 12.00 - 6.00 o'clock. Only used quality parts ( or have I? ) BGM layshaft, Genuine SIL hub, MB rear hub nut, washer etc. Torqued up to 120 foot pounds. My road bike has a similar set up ( except a Casa layshaft) and no movement at all. The engine is oil free at the mo - don't know if that would have a effect? Am I just being paranoid ? the engine hasn't been run yet so gearbox, endplate etc hasn't been under any stress and also rebuilt. What is a acceptable amount of play? cheers Paul

[bookertmgs1]

Spent hours & ££ trying to chase a similar issue.

Changed layshaft, rear hub bearing, end plate bearing, hub, end plate bush / track, checked gear box tolerances & made sure end plate is torque down correctly

can't get rid if it - I've made my peace with it now.

[nastro azzurro]

I wouldn’t be happy with any amount of play. I’d be chasing the issue until I’d eliminated any play.
Did you replace / check each component one at a time?

[Scooterslag]

I wouldn’t be happy with any amount of play. I’d be chasing the issue until I’d eliminated any play.
Did you replace / check each component one at a time?

The gearbox has been completely rebuilt with either new quality parts or OEM stuff in good condition. Looking around on here and other forums- it seems its one of those issues which comes with using different components from different sources . Thanks for your reply. Paul

[Scooterslag]

can't get rid if it - I've made my peace with it now.

I can see myself doing similar chap I will just have to keep a eye on it , thanks for the info. Paul

[Warkton Tornado No.1]

It’s not easy to analyse where any play will come from but with all good, OEM components that are essential to the rear axle/hub assembly there should be virtually none. The end-plate correctly tightened - especially with it’s location dowels in place - fitted with a good bearing insert, bearing, layshaft & rear hub bearing will have the most likely source of play being the rear hub bearing IMO. The OEM type manufactured specifically for Innocenti & Serveta are my preference but becoming harder to source. I would never use some of the pattern ones, especially those with non-metallic cages

If all of the above is as good as can be achieved, the only other issue I have found is the rear hub to cone fit, often overlooked. There are dodgy ‘soft’ cones - which even Scooter Restorations have supplied - which will show witness marks of the layshaft splines after only moderate use, but with a good cone lapped into the hub with grinding paste, any play can virtually be eliminated.

[hullygully]

try an af's uprated rear hub bearing, with just the layshaft in the brg (no g/box or endplate) there ain't no movement @ all

[Scooterslag]

try an af's uprated rear hub bearing, with just the layshaft in the brg (no g/box or endplate) there ain't no movement @ all

I'm going to try a thicker (2mm) rear hub shim from MB, don't want to get involved like bookertmgs1 did and still not get anywhere. Cheers

[Warkton Tornado No.1]

try an af's uprated rear hub bearing, with just the layshaft in the brg (no g/box or endplate) there ain't no movement @ all

The AF uprated bearing is a double row type so is likely to have virtually negligible play. Very good in that sense, but I believe that it puts the back wheel out of line a tad. I’m not sure whether that affects handling of a two-wheeled machine made from scaffold tubing but something that needs consideration.

Out of interest, I wonder whether many of us actually do try & achieve the best fit of hub to cone with grinding paste. It used to be common practice, even more so when swapping hubs over using any old correct angle cone from a near random selection…..Those were the days, when an end-plate was selected on the basis of achieving the best gearbox clearance of three thou’ & would work in any crankcase

[bookertmgs1]

I have lapped the rear hub cone to the hub with course and then fine grinding paste - but havent then checked fit with engineers blue after that.

Thats probably a winter job after the next couple of rallies.

confident that the replacement parts I've fitted are of decent quality - MB etc - the only questionable part would be the Scootopia Hub. I've read / seen comments about variable quality - but the only alternative would be a UNI hub - have seen similar quality issues with those too.

Think its worth clarifying the "play" - on mine - its only the slightest "rock" when the rim / tyre is fitted. Cant feel anything when just the hub is fitted

[Scooterslag]

I

Think its worth clarifying the "play" - on mine - its only the slightest "rock" when the rim / tyre is fitted. Cant feel anything when just the hub is fitted

Thats the same as mine though it is audible so hence me asking. Paul

[Warkton Tornado No.1]

I have lapped the rear hub cone to the hub with course and then fine grinding paste - but havent then checked fit with engineers blue after that.

Thats probably a winter job after the next couple of rallies.

confident that the replacement parts I've fitted are of decent quality - MB etc - the only questionable part would be the Scootopia Hub. I've read / seen comments about variable quality - but the only alternative would be a UNI hub - have seen similar quality issues with those too.

Think its worth clarifying the "play" - on mine - its only the slightest "rock" when the rim / tyre is fitted. Cant feel anything when just the hub is fitted

If the process of course through to fine grinding paste has been done to optimise the contact surface of hub to cone, followed by intensive cleaning prior to assembly, with a smear of grease upon fitting & torquing up, that should achieve as good a fit as could ever be achieved. The factories would never have gone to such lengths when new machines were available.

If any discernible play has been eliminated, that is excellent.

The play between the hub & the fitted wheel is another matter & the interfaces need checking. The rims mounting surfaces need to be flat with no burrs or excessive paint build-up on either side. I believe that the OEM M8 domed nuts (14 or 13 mm AF) were likely a higher grade in terms of strength than the commonly available replacements & even the OEM washers were harder than the norm. Despite the wheel rim nuts being nyloc, I think that the OEM washers were hard, single coil, rectangular section spring washers & their use will always contribute to the wheel rim to hub fit.