V35 Changing gear ratios

My brother has purchased a lovely little V35TT, however the chances of him off roading it are slimmer than a slim thing
the plan is to ride it to Mandello next year, alongside myself with my 750 Breva ( ooh the power)
I suggested that he changes the gear ration to let it spin less, as high speed and acceleration are not on his agenda
at present it spins at 6K giving 60mph
is it an easy swap to fit the standard V35 gear ratios ?
neither of us will be doing the work as he is IT based and I am an idiot
so we plan to leave it to our trusty motorcycle engineer Tony Botto as he is going to give the machine an overhaul prior to the trip
ie a year before hand
has any one done the swap, or can you fit V50 gears, he will keep all the origional parts with the bike so as not to destroy its history but a cruising speed with less revs would make the journey easier as it seems relatively under-geared any way
And advice gratefully received

Having lived with a V35 Imola ii, the 350 needs to rev to pull in top. My Breva likes to be reved, but can potter along using the torque. The V35 needs to be hustled regardless. You’ll find lengthening the gearing will only make top gear ineffectual or redundant.

He could drop a 500 or 650 engine in to make it more capable if he could find a decent one. It would be a straight forward swap.

The barrels are taller, so the exhaust likely won’t fit. The cards are smaller on the V35 also. One would need a donor bike, not just an engine.

Personally, I’m not a fan of butchering stock bikes and the result is often not satisfactory. Save yourself the hassle (and money!); I’d just cruise slower and enjoy the 350 for what it is. Or go on a bigger bike!

No one here seems to be answering the question. I think all the stuff in the box is the same, there are just a couple of cogs that need to be swapped at one end. I know no more than this. It would be an engine out job to do of course but otherwise quite simple.

I would recommend that you talk to Nigel at NBS, he has probably done this work in the past and may well be able to supply the parts you need.


Pretty sure the GB is common and the bevel box ratio differs.

OK, gearboxes are my soft spot, so let me add a word. Firstly, V35 TT/NTX is slightly different from standatd V35-V50 line, engine-wise. This is very - very! - short stroke engine with V50 barrels and just much shorter stroke, so nothing like stock V35. And the gearbox primary ratio is( depending on chassis number, 12137 roughly), 12/24(earlier) or 12/25(later), which is much shorter than stock V35 13/24 or Imola II 13/23. But: having V35III for couple of years, which is known of being weakest of all small block models(27bhp), with 12/24 ratio and 6krpm at 60mph(what a sound, btw!), I successfully used standard V50 gearbox, although at the same time swapping factory 18" wheel for Imola II 16" - a roughly 10% difference down due to diameter. Well, this was the model with cast alloy wheels, it won’t be that easy in your case. But I dare to say, have a try. What you need is donor gearbox PAST ca.1982, where gearbox shafts are 12 splines, not 10. The highest you can go is 14/23 from stock V50(not Monza! 15/22), but I would at the same time fit lowest possible profile tyre to make gearing high, but not AS high. There’s other thread from month ago where I have put some links to my pics how primary gearing looks like and how easy is to make a swap. I played with them as I wanted to find sweet spot - and I liked the outcome. Have a try. Let me clarify, if you got stock V35 and V50, and you use V50 box in V35, the 4th on longer box is the same speed as 5th on shorter. But both primary ratios are noticeably longer than those fitted to late V35 (III, TT, NTX etc), as I mentioned above. There’s easy way to identify what gearbox you have, given it is dismantled from motorbike, by counting number of spins. Anyway, I would suggest just full box swap, as then you got factory one untouched. The bevel ratio is the same up to V65/V75: 8/31, there were shorter ones 8/33, but later, in IE Nevadas/Brevas 750.
And anyway, I think it won’t be ratio what will defeat the rider, but seat…:>

And here separate post on counting the spins. Any box, say, somebody told you it is off Imola, and you want to know for sure. All you ave to do is put it on the bench, engage 1st gear and make exactly one full turn of output shaft(bevel box end - easy way is to fit driveshaft). You count how many turns there was on clutch splines end/input shaft.

If 5 and 2/3 - late TT/NTX
if 5 and 1/2 - early TT/NTX
if exactly 5 - V35C, V35Florida, Imola I, stock V35
if 4 and 1/3 - Nevada 350
if 4 and 1/6 - Imola II
if 4 and 1/2 - stock V50 and V50C
if exactly 4 - Monza I
if 3 and1/2 - Monza II

I mentioned here just slim input shaft of course, as V65 and over have fat one and even longer gearing, so we’re not interested here. The longest ratio gearbox of all small block is Lario/Nevada, models where 16" wheel comes as standard. In case somebody wants to cruise 80mph at tickover:)

WOW, thats a lot to think about
Thank you Adamdingo

first point he wants to keep the machine standard, so no engine change or gearbox change or wheel changes
its an 84 model with disc brakes all round
I had not realised that the engine was so different to a standard V35
I was hoping it was just a case of finding the correct transfer gears and exchanging them as it will only be used on long runs and a slight drop in revs would improve fuel economy , its doing about 50mpg at the moment but has not had many long runs so it probably need a good carb clean and tune up
I followed him home and it was running rich, but its hardly been used the past few years and things block up and stick
I reckon ridden carefully 70mpg should be possible
he did say its sewing machine smooth and does not vibrate at 60mph
but if he needs more power he has a Versys 650 or would buy a cali
but he wanted a slim lithe bike
I may have to think about putting some weight on myself to handicap me on the journey !! ( more !!)
we are avoiding motorways and taking the old roads, possibly an entire week and avoiding Suisse entirely

any one who has read tales of a gaspipe officer will know my riding style
lots to think about
hopefully when the current madness ends he can get out on it a bit more
mine is all ready and polished !

No butchering is on the agenda
It has survived this long as is now quite rare

so its just an overhaul all the fluids, seals on driveshaft, new ht leads and plug caps, fuel pipes and brake lines and master cylinder and caliper cylinder overhaul kits plus check wheel bearings and head bearing and fork oil
the sort of stuff you do on any older bike before a mammoth trip
its just if it was easy to swap the cogs we would
speed is not needed, I am quite happy at 50mph all day, my usual touring speed
and I will be carrying the heavy stuff on my breva as usual
while the third member of the party on his V7 also travels light , just his grooming kit and leather polish !! on his V7 11

70 mpg - I deeply doubt. But 55+ - possible. You really do not want to change gearing a lot, stock V35 box will do the job, that’s 10% lower revs. All the other V35s, even if bit longer, are harder to source and V50 I think may be a pain when in hilly areas. %0mph is a brilliant speed to take a look left, a look right - I wish you all the best!

50mph ? I agree.

In my touring days in a 1935 Austin 7 Ruby, I think my comfortable cruising speed was 35 - 40mph. An even better speed for looking left and right. :smiley:

Mind you the braking distance was appalling, so you had to make sure the road was clear ahead for miles before admiring the countryside.

What an interesting thread! It just shows the value of the club forum in putting people together and sharing knowledge. It is particularly important for those of us who are interested in servicing and fixing our machines ourselves, but don’t have the benefit of the experience of a mechanical training. Carry on the good work adamigo & co!

My brother initially wanted a V35, I took him to Mandello last year and he was overcome by the decency, good manners, and the passion of the italians, so his Kawasaki will be taking a back seat
we looked at a couple of V35s but he is 6 foot 6 or so, there is absolutely no chance of him riding one of those !
so the Tutto Terreno is ideal