Wheel Help and Advice
- 325/18 Front Ribbed Tire
- The spokes you’ve sent for my 1970 T120 front wheel are almost 1/4″ too long.
- 350/18 Rear Tires
- Wheel Building Problems
- I found a conical thin steel spacer in the BSA forks on my 1970 B44VS, fitted above the top bush, below the oil seal. It was in with the conical part pointing downwards however the parts book shows it pointing upwards.
- Customer asked how to tell an Atlas rear wheel from that of a G15Mk2/CS
- Norton and Triumph Fitting Belt Drive Kits
325/18 Front Ribbed Tire
We get asked almost daily for 325/18 rubbed front tires. The tire manufacturers don’t do it because “there’s no demand” sounds a bit Monty Pythonish!!! Actually Mitas (Czech) make one – it’s cheap and I can get them because they are DOT approved but have a bit of as pattern in the middle unlike the traditional ribbed tires. We bring in from the UK Dunlop K82′s (DOT Approved) in 300/18, 325/18 and 350/18. Suitable for front or rear fitment, same pattern as the K81 – TT100.
The spokes you’ve sent for my 1970 T120 front wheel are almost 1/4″ too long.
Immediate response is how can something we’ve sold literally hundreds of without complaints suddenly be wrong? I took a NOS original spoke and compared it to the ones we sent and it matched OK – actually 1/16″ too long but that wouldn’t matter. Customer sent spokes back together with specimen from his original wheel. I have to admit the “original” looked like a genuine article and have arranged to get the “wrong” ones shortened. I can only assume that Triumph got a batch of wheels (either from Dunlop or Jones) which were dimpled deeper than usual and made spokes shorter to suit.
350/18 Rear Tires
We get asked regularly for 350/18 rear tires; please someone make some! For the smaller bikes we have been importing K82′s. These are DOT approved and are a cheaper version of the K81 (TT100). They are ideal for smaller bikes – ie up to 500cc. We carry them in 300/18, 325/18 and 350/18. Other sizes are avaiable to special order from the UK.
Wheel Building Problems
Problems come up almost daily. In my opinion this is a black art best left to the experts. Please don’t call me and tell me the spokes we have supplied are bent a few degees differently from your original ones. It is normal wheelbuilding practice to adjust the bends to suit as you fit the spokes. One of the leading wheelbuilders in the UK insists on purchasing all straight spokes and bends them to suit as he fits them. Please don’t tell me you or your wheelbuilder has 35 or 45 years experience and the parts we have sent are wrong. We have seen the results of the attempts of some of these people and it can be quite frightening. If you seriously think the rim or spokes we’ve set are wrong, send the whole job back to us and if the parts are wrong we’ll get it built free of charge. The vast majority of wheels returned by customers are fine and our wheelbuilder gets them built OK.
I found a conical thin steel spacer in the BSA forks on my 1970 B44VS, fitted above the top bush, below the oil seal. It was in with the conical part pointing downwards however the parts book shows it pointing upwards.
There are quite a lot of errors in the parts books and we what we can to catch them. Looking at the cut away diagram in the genuine Workshop Manual, the spacer points downwards – the outer lip of the oil seal abuts against the outer lip of the spacer, the conical end of which thereby keeps the top bush in it’s place. The spacer is drawn pointing downwards in several other BSA parts books.
Customer asked how to tell an Atlas rear wheel from that of a G15Mk2/CS
I am supposed to know this stuff and no doubt my expert friend, Anthony Curzon, will be able to amplify this answer in due course. I would have thought there was no difference – they all use WM3/18 rims and while spacers are different to suit the Norton vs Matchless swing arm I would have assumed the wheels themselves are the same. Looking in the 1966-68 Parts Book the Atlas & G15Mk2 have the same part no so build offset will be the same. The CS uses a different part no but this I believe would be due to the use of 8 gauge rear spokes requiring thicker 5/16″ nipples vs 1/4″ for the Atlas and G15 Mk2. There may also be a difference re the rim locks – I’ll look into this a bit more and add to this answer when I have more information.
Norton and Triumph Fitting Belt Drive Kits
Installing a primary belt drive kit is simply a matter of replacing the front sprocket and rear clutch chainwheel with the pulleys supplied. The guide plate on the front pulley goes to the outside. Belt tension at it’s tightest point (check at least 3 places by rotation) should half that specified for a chain. Don’t worry if the belt overhangs the rear pully inwards by up to 1/8″ as long as it doesn’t rub against anything. It will move out when the motor is running.
Primary chain tensioners should not be needed however all Triumph cases are not exactly the same. If the belt is too slack the tensioner can be used but you must remove the friction material and only a polished steel surface can touch the belt. If belt is too tight (very rare) get back to use to discuss options.