1960 R60/2 rear drive not vented

Hello every one. Ok I'm building a /2 conversation.the bike is 90% done. Just elect and waiting on the exhaust system from epco. It is a 1965 frame,1960 swing arm and a 1960 R60/2 rear end with no vent. The motor I'm using is a 1977 R100s w 40mm carbs. I have five /2 bike,61r69s,65r60/2,67r50/2 two 69r60us. Know all my /2 have a vented rear drive. With the r100 motor in this /2 should I put a vented rear drive on or just leave the none vented one on. I'm thinking I might build up to much psi in the rear drive with running this 1000cc motor and maybe blowing a seal. I just rebuilt the hole rear drive so it has new seals in it. I also have a r69s rear drive and a r60/2 vented drive on the shelf.I don't know if I should change it out or not, or just ride the bike and watch what happens. I think I'm problem going to blow the rear end with all the power from the r100s motor. It is going to be a solo bike only. Vent or none vent

The R 60 FD wasn't vented

The final drive on the pre-/ 2 wasn't vented as far as I know. I would swap it with the 69S or 60/2 rear and call it a day. Don't know if you would blow out seals but the gearing is a little lower in the R 60 rear. Sounds like a wild ride, did you beef up the brakes at all?

I'm not sure what the direct connection is between the size of motor and whether you need to have a vented rear drive or not. Will the rear drive "know" there's a large engine attached ahead of it??

What's the rationale for choosing the '60 drive version the other possibilities? I would choose the final drive that works best in terms of gearing and road speed in combination with the transmission.

Beyond that, if you use the unvented rear drive, I'd suggest filling it a little less than spec which is to the bottom of the threads in the fill hole. Maybe a quarter of an inch below and you would still be fine and allow a little more expansion room as the fluid warms up.

I'm running stock brakes, I know a /2 does not stop on a dime or even a dollor. I won't the bike to look like a total stock /2 with a r100s motor in the frame. I picked this rear drive because it was with the swing arm I'm using. And yes a 1960 is a /2 and it was a very early run bike with a none vent rear drive.

First modern Anti-lock

You are a brave soul! I would go ahead and put a vented final drive in. Did you modify the earles front end to fit the front engine cover?

Every thing has been done, fork and frame have been modify. The gas tank has to fuel vales also. Using /5 headlight bucket and speedo, that way I pick a 77 r100s because of mech tach. /5 wireing harness. Look under my profile for pic

Agree

20774 said:

I'm not sure what the direct connection is between the size of motor and whether you need to have a vented rear drive or not. Will the rear drive "know" there's a large engine attached ahead of it??

What's the rationale for choosing the '60 drive version the other possibilities? I would choose the final drive that works best in terms of gearing and road speed in combination with the transmission.

Beyond that, if you use the unvented rear drive, I'd suggest filling it a little less than spec which is to the bottom of the threads in the fill hole. Maybe a quarter of an inch below and you would still be fine and allow a little more expansion room as the fluid warms up.

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Good Pictures Looks like a fun bike - My guess would be you will not and do not plan to use the full power of that motor but you got it if needed!!

Good pics

I have a friend whose doing an R 75 conversion right now. I thought about it and had an original Granada red US bike with out the motor, just my luck the original block was located about 100 miles away from me so now its a restoration. Hey I'm looking for one of those R 100S engine badges in decent condition, do you have any info on who would have something like that, I got the last one from re-cycle and as far as I know they still don't have anymore. If you do just PM me and let me know.

Check moto bins or s meyer... I think I have a set, ill check for u and let u know

46211 said:

Check moto bins or s meyer... I think I have a set, ill check for u and let u know

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Please keep any "horse trading" off the forum...use PMs as needed.

Thanks...

46211 said:

I picked this rear drive because it was with the swing arm I'm using.

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Changing FDs on a /2 swing arm is about a 20 minute job. OK, an hour if you like getting everything nice and clean while it is apart.

Pick the FD with the gear ratios you want. Any /2 era FD will fit that swing arm.

You have enough /2 bikes to try both of the common gear ratios.

Tire size is also significant factor - the earlier bikes came with 25/8 rear and 3.50x18 tires both front and back

The later bikes came with 27/8 rear and 4.00x18 rear tire - the overall engine speed for given mph was about the same with either combination

For 1000cc in solo bike use 4.00x18 tire and 25/8 rear drive to get the highest combination

Other gear sets can fit into the rear drive - I once had a rear drive with 32/11 gear set - I ran it to destruction over many miles and had some trouble with a R100/7 engine on this higher ratio with standard clutch - it was too easy to fry the clutch

I tried a 27/8 rear with 3.50x18 tire on sidecar with the 1000cc engine and found it to feel too tractor driveish

44006- the rear end is a 25/8 . The tire I'm using is a 4.00-18 on the rear. I'm hoping to have the bike done in a couple of weeks. I will be taking it to a lot of rally this year.

You are set up to go like hell and have fun but be careful

Suggest you read posts 28,30 &32 from earlier post

"Earles Fork Frustrations" posted on 07-30-2008