Did the two speed jackshafts work real well or were they just technical gimmicks ?
I have a Bird Super 2 with the comet automatic 2 speed on it . You do not feel it shift on acceleration . The draw back is the shifting in and out at cruising speed . Seems like I have to go slow or fast to make it happy . Out riding the neighborhood is okay but not cruising around at the Dragstrip pits . The manual 2 speed that the Boonie Bike has does not like being shifted while moving . The tab breaks or bends the end of the cable . Prefers you start out in low or high . This is just my experience with 2 speeds .Here are some pictures .
Whenever I hear "TT500" I don't think of Rupp. I think of Yamaha who manufactured a pretty-cool 500cc 4-stroke dirt bike back in the 1970s called the TT500. The older brother of a friend of mine back then had one and they were pretty-popular.
Until I joined this forum I had never heard of a Rupp TT500.
Until I joined this forum I had never heard of a Rupp TT500.
We have had 2 Sears Ropers both with the Comet 2-speed jackshafts. They have performed well for what they were designed for. Keep in mind these are not "variable" speed like a torque converter. As yankee-bears has already stated it is pretty much low speed or high speed. Are you thinking about purchasing one to put on a bike? Unless you are performing a restoration or want the bike to be period-correct (which was our case with the Sears Ropers) I would recommend a torque converter over a 2-speed jackshaft for the better performance.
Michael
Michael
If a 2 speed jackshaft had the same low speed ration and the same hi speed ratio as a torque converter.....
woundnt the 2 speed jackshaft be a LOT more reliable in either low speed workhorse use or extreme long distance
operations at hi speed ?
I hear so many complaints about the belts wearing out and not being adjusted correctly and as they wear a lot of slippage
occuring causing loss of HP etc. ???
Why do you say or how can you explain a torque converter being better performance ? How do you define performance ?
woundnt the 2 speed jackshaft be a LOT more reliable in either low speed workhorse use or extreme long distance
operations at hi speed ?
I hear so many complaints about the belts wearing out and not being adjusted correctly and as they wear a lot of slippage
occuring causing loss of HP etc. ???
Why do you say or how can you explain a torque converter being better performance ? How do you define performance ?
If a 2 speed jackshaft had the same low speed ration and the same hi speed ratio as a torque converter.....
woundnt the 2 speed jackshaft be a LOT more reliable in either low speed workhorse use or extreme long distance
operations at hi speed ?
I hear so many complaints about the belts wearing out and not being adjusted correctly and as they wear a lot of slippage
occurring causing loss of HP etc. ???=QUOTE]
Here's my take on them. First a disclaimer; I have 2 bikes with them but am not an engineer or clutch specialist.
Now that's out of the way, here goes.
They were designed and used just prior to TQ becoming mainstream and affordable.
"woundnt the the 2 speed jackshaft be a LOT more reliable in either low speed workhorse use or extreme long distance
operations at hi speed ?"
Because the diameter of the secondary clutch and more importantly the "contact patch" of the clutch shoes is fairly small and is not made to pull/hold a lot of power. On a nice level surface they will stay engaged fairly well, but when presented with an uphill grade they will slip and cause heat thereby increasing wear and ultimately premature failure if used in this manner for an extended period of time.
Secondly the wear bushing on the secondary clutch tends to wear at a pretty good pace, It is all but impossible to lube that bushing without getting some oil up onto the secondary clutch shoes.
They get enough oil splatter from the dual chains going to the primary engine clutch.
In contrast the TQ runs much smoother and the long belt helps to shed heat. TQ has less parts and larger surface area, handles power better.
Now do the TQ belts wear every time you ride? You betcha.
And yes you can burn through a belt in one afternoon if you abuse it or if it is not lined up properly. Or if your final gearing is too far off.
I have owned many snowmobiles and they really shed a belt once the secondary clutch gets out of alignment.
The one piece TQ units are better at this since the length is already set and the alignment is easy to dial in with the supplied spacers.
Bottom line is if the 2 speed was superior they would have continued to make them, they didn't because they are not better than a TQ.
You will eventually swear at both systems.
If someone would just make a small fluid drive add on transmission we would be on easy street. Don't see that happening in the near future.
HTH
JMHO your Torque may vary
Keith
woundnt the 2 speed jackshaft be a LOT more reliable in either low speed workhorse use or extreme long distance
operations at hi speed ?
I hear so many complaints about the belts wearing out and not being adjusted correctly and as they wear a lot of slippage
occurring causing loss of HP etc. ???=QUOTE]
Here's my take on them. First a disclaimer; I have 2 bikes with them but am not an engineer or clutch specialist.
Now that's out of the way, here goes.
They were designed and used just prior to TQ becoming mainstream and affordable.
"woundnt the the 2 speed jackshaft be a LOT more reliable in either low speed workhorse use or extreme long distance
operations at hi speed ?"
Because the diameter of the secondary clutch and more importantly the "contact patch" of the clutch shoes is fairly small and is not made to pull/hold a lot of power. On a nice level surface they will stay engaged fairly well, but when presented with an uphill grade they will slip and cause heat thereby increasing wear and ultimately premature failure if used in this manner for an extended period of time.
Secondly the wear bushing on the secondary clutch tends to wear at a pretty good pace, It is all but impossible to lube that bushing without getting some oil up onto the secondary clutch shoes.
They get enough oil splatter from the dual chains going to the primary engine clutch.
In contrast the TQ runs much smoother and the long belt helps to shed heat. TQ has less parts and larger surface area, handles power better.
Now do the TQ belts wear every time you ride? You betcha.
And yes you can burn through a belt in one afternoon if you abuse it or if it is not lined up properly. Or if your final gearing is too far off.
I have owned many snowmobiles and they really shed a belt once the secondary clutch gets out of alignment.
The one piece TQ units are better at this since the length is already set and the alignment is easy to dial in with the supplied spacers.
Bottom line is if the 2 speed was superior they would have continued to make them, they didn't because they are not better than a TQ.
You will eventually swear at both systems.
If someone would just make a small fluid drive add on transmission we would be on easy street. Don't see that happening in the near future.
HTH
JMHO your Torque may vary
Keith