BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down   Sidecar gearing Empty Sidecar gearing on Wed Jul 10, 2013 8:06 pm

Rockman

avatar
Life time member
Life time member
I have a K75 rear diff on my sidecar. This makes it very "revvy" at highway speeds but is good for starting off etc. I'm considering changing to the standard 2.9 K100 diff (have one in the shed) for general road use. I do get a small overall reduction (2-3%) from the 15" wheel. Any comments?. What ratio are people using on these?

    

2Back to top Go down   Sidecar gearing Empty Re: Sidecar gearing on Wed Jul 10, 2013 8:22 pm

Guest

avatar
Guest
I'm just using the stock RT final drive set-up. I considered using a K75 one but basically I find the standard gearing more than adequate for my own needs. I like that I am still doing the factory ratios and speeds...4grand at 100kph etc. I find the motor produces enough torque to give me enough power all the way through the rev range, which of course is one the K's best characteristics even in solo trim. My outfit is quite light weight, though I haven't ever actually weighed it, I imagine it's lighter than most fibreglass set ups...DJP, HRD etc. In the end I suppose it comes down to horsepower.....and you can basically never really have enough ponies with a sidecar. I recommend the stock RT final drive.

    

3Back to top Go down   Sidecar gearing Empty Re: Sidecar gearing on Thu Jul 11, 2013 4:22 pm

sidecar paul

sidecar paul
Life time member
Life time member
Hi Rockman,
I use the RS gearing with a full profile 145x15 tyre; I don't want to use a low profile as that will lower my gearing. Never had any problems even towing an overweight trailer loaded with my ¼ scale traction engine.

I just love the torque of these engines.

As you have a spare bevel box, go for it, you probably won't notice any reduction in 'get away' speed, you'll just be changing gear a bit later.

Cheers,
Paul.


__________________________________________________
'84 K100RS (0014643) (owned since '85), 86 K100RS (0018891) with Martello sidecar (built as an outfit in '88),
'51 Vincent (since '67),'72 Montesa Cota (from new), '87 Honda RS125R NF4 (bought 2015) 
....No CARS never ever!
    

4Back to top Go down   Sidecar gearing Empty Re: Sidecar gearing on Sun Aug 11, 2013 5:51 pm

Crazy Frog

Crazy Frog
admin
admin
I am pulling a very heavy EML sidecar and I am using the original RT final drive.
I get a lot of torque and the bike is pulling fast up to 120kms. Sometimes, I would prefer an RS final drive to get a lower engine RPM.
With the 15" wheels, the engine revs at 4 to 4500 rpm at 100km/h.
My problem is that the bike is a pig on gas when riding on the highway. At 100-110, the 7 liters fuel level light comes on at 165km.

CF


__________________________________________________
Sidecar gearing Frog15Sidecar gearing Logo2101986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

5Back to top Go down   Sidecar gearing Empty Re: Sidecar gearing on Sun Aug 11, 2013 7:33 pm

Rockman

avatar
Life time member
Life time member
I'm still running the lower K75 gearing. I had a good look at the spare final drive I had and the splines are close on stuffed so I wont be using that. At 100 kmh I'm running at around 5000 rpm and get 12-14 km/litre so its not too bad. If I spot a good K100 drive at  the right price It'll go on but I'm not in a hurry. Cheers Phil

    

6Back to top Go down   Sidecar gearing Empty Re: Sidecar gearing on Sun Aug 11, 2013 10:03 pm

AL-58

AL-58
Life time member
Life time member
I've run RT gearing on most of my previous outfits, it seemed to be the best choice overall. My current outfit is running RS gearing with a 165/80-15 rear.  It works OK, but I'd like to either fit an RT rear or drop the tyre to a 155/80.

Flat running its fine, but it's not that good in hilly country. 

Al


__________________________________________________
'87 K100RS/HRD sidecar (1100 motor)  sc25 
'92 K100RS-16v (Paint it Black)

'87 K100RT with Paralever backend

"When I'm too old and too foolish to handle a sidecar I'll buy a Sportsbike"

Sidecar gearing K-dogs10
    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum