- Thread starter minimutly
- Start date
Martin Hocking
Member
- Messages
- 463
- Location
- Norfolk
Yeah I suppose that makes sense.
Like I mentioned in my previous post nova racing are the people to talk to if you need a motorbike gear making. It might be worth asking them. If they can’t help (they are geared up to make more metric stuff), they might be able to point you in the direction of somewhere that can.
I’ve not had any dealings with them but as I understand it they do make their own stuff.
This is their place taken from
This article in 2016.
I’m sure someone else will be along with a better suggestion soon but something to think about in the meantime.
Best of luck.
I was at the site of the 2025 Autograss National Finals today, just up from Pendine in West Speedlimitville, and spent half an hour talking to the owner and proprietor of Elite Transmissions. Talked over my requirements, outstanding issues, and have agreed next steps. So, with any luck, once I get my "best estimate" of required ratio and shaft dimensions we should be in the position of moving this forward - without me going down the road of another steep learning curve.
So fingers crossed, all I have to do is modify the mini casing to take the Yamaha gears ( and guestimate the right ratio of primary to input ratio)
So fingers crossed, all I have to do is modify the mini casing to take the Yamaha gears ( and guestimate the right ratio of primary to input ratio)
Famous last words "all I have to do"...
I've cut out the end of an A+ gearbox casing, just a scrap one that had been outside waiting to be melted down. I've started working on ratios to get somewhere near the ideal "drop gear" ratio - in doing this decided to modify the Yamaha Vmax second motion shaft to take a mini fd pinion, it's not ideal strength wise but will vastly open up the gearing possibilities.
So that's been today's job - select suitable bearings for the diff end of this shaft (based on the biggest inner diameter I could get on the shaft), I have plenty of room so decided to use two 60/28 koyo bearings, and machine the hardened shaft to remove Yamahas spline and cut the I'd of a mini pinion on the end. I wish I knew more about hardening and tempering steel shafts and gears. The shaft has machined to diameter ok, next will be deciding how to cut the coarse spline.
The input shaft will need attention soon, this needs to have a spline on the input end for the new input gear to locate to, with an overhang to locate a roller bearing. This spline will likely need grinding - that's another rabbit hole to go down for me...
I've pulled the gear selectors and barrel from the Vmax casing, the good news is there is plenty of space beneath the gear shafts for all of this, it just needs to be in the right place relative to the shafts, the plan being to make a new end plate for the bearings, selectors and barrel, then use a specially made long reach boring bar on my vertical mill to bore down through these holes and line bore them. Long way to go, involving some tig welding, spine cutting and buying in apir of gears,but I'm not seeing any showstoppers so far.
I've cut out the end of an A+ gearbox casing, just a scrap one that had been outside waiting to be melted down. I've started working on ratios to get somewhere near the ideal "drop gear" ratio - in doing this decided to modify the Yamaha Vmax second motion shaft to take a mini fd pinion, it's not ideal strength wise but will vastly open up the gearing possibilities.
So that's been today's job - select suitable bearings for the diff end of this shaft (based on the biggest inner diameter I could get on the shaft), I have plenty of room so decided to use two 60/28 koyo bearings, and machine the hardened shaft to remove Yamahas spline and cut the I'd of a mini pinion on the end. I wish I knew more about hardening and tempering steel shafts and gears. The shaft has machined to diameter ok, next will be deciding how to cut the coarse spline.
The input shaft will need attention soon, this needs to have a spline on the input end for the new input gear to locate to, with an overhang to locate a roller bearing. This spline will likely need grinding - that's another rabbit hole to go down for me...
I've pulled the gear selectors and barrel from the Vmax casing, the good news is there is plenty of space beneath the gear shafts for all of this, it just needs to be in the right place relative to the shafts, the plan being to make a new end plate for the bearings, selectors and barrel, then use a specially made long reach boring bar on my vertical mill to bore down through these holes and line bore them. Long way to go, involving some tig welding, spine cutting and buying in apir of gears,but I'm not seeing any showstoppers so far.
