Hitchcocks Forum

Right, before I get shot down, I’m not trying to take business from our hosts.

It looks distinctly likely that my Transalp is written off. I recently bought a new front tyre, a Tourance 100/90 x 19.

It looks like this may fit the front of Gupta, my 350 Bullet, 3.25x19. It appears a bit fatter, but I can test.
Unfortunately Metzeler do not do a size to fit my rear wheel; 3.50x19.

Heidenau Scout 60 may fit, anyone know? I will write to them.

Now, I know for some, looks are important. To me, grip is infinitely more important as I ride all weathers.

Of course I could just offer the Tourance to my local bike shop in return for some money off my next MOT....

100 mm is 4” wide. It might be a bit wide for the front.

100/90 roughly equates to 4.10, which roughly equates to 3.50. Strange but true ...

Okay, I was hoping.

Re the Tourance I have, it reminds me of a (politically incorrect) joke about the Scottish man who found a pair of crutches in his attic, so went downstairs and broke his sons legs

Okay, I’ll buy a stick and run down the road with the tyre. It did look a lot wider than the one on Gupta.

I’ve just bought a Kenda 90/90-19 K6318F (enduro type) tyre, mainly because I’m hoping it might last longer than the 3,000 miles the other tyres I’ve used have done. I reckon it’s too wide for the front of my 350 Electra so it will go on the back wheel. My bike has the later, lightweight mudguards with no separate stays. The problem is that the fixing studs are on the inside of the fork sliders, just about level with the tread of the tyre. When I fitted a square block treaded 3.25 tyre there was hardly any clearance from the side blocks of the tread so I had to fit a 3.00 instead.

The 90/90 is roughly equivalent to a 3.00 section tyre in old money.

As for the rear wheel, our hosts list a custom swinging arm with more clearance to at the front allow fitting 4.00" section rear tyres.

Part No. 92602, SWINGING ARM WITH BUSHES, WIDER FOR LARGER TYRE, BLACK, £269.00(Excl. VAT) £322.80 (Incl. VAT)

Whether you want to pay that much is another matter.

A.

Out of curiosity I’ve just been out and measured the widths of both tyres on the bike and compared them to the 90/90.

The existing rear is a MITAS 3.50-19 but as it sits on the wheel, it’s actually nearer to 3” at its widest point.

The existing front is a CEAT 3.25-19 ribbed type and again, on the wheel it’s close to 3”.

However, the Kenda 90/90-19 is a full 5/8” wider than both of them. It will still fit nicely inside the swing arm.

I’ll probably swap the MITAS to the front because it will suit the KENDA tread pattern better and tbh, I’m not keen on ribbed treads, especially on cold, wet, muddy roads. So the CEAT can be held as a spare.

As for buying a wider swing arm....er, no! I’ve spent far, far too much time and money on this bike already and I have a car project to finish next. That might involve an ECU change so the piggy bank cork is staying in for that.

I’ve had some slips that I think shouldn’t have happened, rear tyre is an Avon Mk2 something, can’t recall; very square section.
Top speed of Bullets may not be high, but I don’t slow for bends. Happy (well not delirious) to sacrifice mileage for stickiness.

Nominal sizes of the manufacturers are "nominal". A Mitas 4x19" fitted easily on the swinging arm of my Electra(X) but a Heidenau K34 4x19" did not.

Too true.

I ordered a 4" x18" Avon AM26 for one of my bikes a few years ago, the actual width was 4⅝" or 16mm oversize, it fouled the front of the swinging arm (and the inside of the rear chain guard) so that I could only have used it at the rear half of the chain's adjustment. The Avon 100/90 profile AM26 is just a tad narrower and squeezes inside the Chennai swinging arm and chain guard comfortably at 108mm. That extra 5/16" or 8mm all round seems critical.

A.