V50 Monza Gearbox Question

[Chris Smith]

I.m rebuilding this bike and can anyone tell me what the eccentric bolt that engages with the gear selectior does, and how to set it up. Chriis

 

[Trinorman]

Chris,
I copied the below exchange from somewhere (Wildguzzi?) for future info. It might be just what you are looking for. You might also do a search on that site, Wildguzzi.com.

Here's the info. Hope it helps.
Chris

Gearchange is adjusted via eccentric bolt A and locknut B (see Figs. 107 & 109 in the V50/V35 Manual). Expert advice is that the quality of the gear change on the these gearboxes is extremely sensitive to adjustment and may be affected by as little as a 60 degrees (i.e. one flat on the hex head of bolt A) turn of the adjuster bolt. Some came from the factory properly adjusted, others not. Sometimes owners/mechanics have messed about with the adjustment. If the gearbox changes well, do not ever disturb the adjustor bolt. It can be very difficult to find the correct adjustment again. Jumping out of 2nd gear is said to be typical of poor adjustment.

So you may only need to adjust to solve your problem. At least that's not expensive in terms of money, but the time and hassle may be a different matter.

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The description of the problem provides this reader with the belief that a mal adjusted preselector (inside the box) may well be the problem. If so, the culprit is item 'F' in figure #90 in the service manual for the bike. The good news is the adjustment is outside the box, no disassembly is required!

The bigger problem is most riders do not understand that the entire range of adjustment for this small eccentric bolt is consumed in 1/2 of a turn. A well intentioned rider well play hell getting the gear selector properly adjusted until they realize that a turn of 10 or 15 degrees may have a dramatic effect in cleanly picking up the gear. Faced with a similar problem on a 200 cc Ducati, my friend said "I turned it 2 or 3 turns in both directions, and in never got better". 20 degrees is 1/3 of one flat on a hex nut. Tiny increments are called for.

The recommended path is to study figures #90 & item 'C' in figure 96, stuff a pencil and a small notebook in a pocket along with two wrenches to loosen the locknut and to turn the adjuster, and head for a quiet stretch of road.

Knowing that any eccentric may reach its endpoint in as little as 1 degree of rotation and a maximum of 179 degrees, loosen the lock nut, turn the eccentric 10 degrees (1/36 of a full turn) record the angle and direction in the note book and take a ride going thru the gears several times. Did the change help or worsen the problem? Mark the notebook. Try, try again.

Unfortunately, not knowing where the eccentric is, we must resort to trial and error.

So at the end of the day, I must ask, does the rider have the patience, and does the rider understand the nature of the problem. Do they fully understand what is required to make the adjustments, and how very fine the adjustments must be? Sadly, my experience has shown, this is not easily done by most riders.

However, it can be done. Patience and tenacity will always pay handsome rewards.

I.m rebuilding this bike and can anyone tell me what the eccentric bolt that engages with the gear selectior does, and how to set it up. Chriis

 

[Chris Smith]

I.m rebuilding this bike and can anyone tell me what the eccentric bolt that engages with the gear selectior does, and how to set it up. Chriis

I.m rebuilding this bike and can anyone tell me what the eccentric bolt that engages with the gear selectior does, and how to set it up. Chriis

Great that's exactly what I needed - Thanks