The diameters were not much different.
Stock Berg large 2nd
Stock HR large 2nd
Stock Berg large 2nd

Stock HR large 2nd

So in that last pic which gears are you running for the following:
Large 2nd: HR
Small 2nd: Berg Mann
Large 3rd: HR
Small 3rd: Berg Mann
Are the pin mods required to fit the gears...I'm assuming that was just something extra you've done for some extra BEEF :twisted: Final question just to clear things up...the HR gears use what pitch pinions...standard or metric?
Thanks Rob.
I will put the tooth count in here as it might help somebody in the future and also so everybody can double check me.
Pinion = 12
HR large 2nd = 52
Berg large 2nd = 42
HR/Berg small 2nd = 14
HR/Berg large 3rd = 40
HR/Berg small 3rd = 12
HR/Berg 4th = 49
Ratio with HR large 2nd
52/12 = 4.33
40/14 = 2.86
49/12 = 4.08
4.33*2.86*4.08 = 50.52
Ratio with Berg large 2nd
42/12 = 3.5
40/14 = 2.86
49/12 = 4.08
3.5*2.86*4.08 = 40.84
Looks like quite a bit. Another way I thought to think about it is since the 2nd gears are 10 teeth apart, it would be like running a 12t pinion in the HR setup vs a 22t pinion on the Berg setup. If you put it that way, its significant.
Very interesting, thanks for the numbers.
Your thinking is close but off. You would have to do it in percentages. The hr large second has approx 25% more teeth (or the berg large second has approx 20% less teeth). Therefore a 15 tooth pinion with the hr gear should be close to a 12 tooth pinion with the berg gear. Technically you would need a 14.85 tooth pinion to be exactly equal
Its pretty hard to argue with the math but it feels much better than a 3 tooth pinion drop.
Just to be clear in my head,... this mod would be the same as dropping to a 9.69 tooth pinion on the full Berg setup. If its that significant dropping 2.3 teeth, now I want to get a 9t pinion just to see how much difference that makes.
If you can find somebody that has a set of HR axles it would actually be really smart of them to trade you straight up. The HR 2nd makes the ratio too low on a 2.2 but perfect on a super. If somebody were smart and traded, then you would both be set.