vibration

Non bike specific questions

vibration

Postby strummer » Thu Dec 04, 2014 3:16 pm

is there much on these bikes?is one model worse than another?
strummer
Virgin - be gentle
Virgin - be gentle
 
Posts: 6
Joined: Mon Dec 01, 2014 7:37 pm

Re: vibration

Postby dave#22 » Thu Dec 04, 2014 7:24 pm

Hi, That's an interesting question and I'm sure you will get opposing answers.
For what they are, the engines are smooth and have little vibration (twin balance shafts), but I find the earlier DR750 (SR41) has the smoothest engine, but the least power, in my opinion the DR800 has more vibration, mainly due to the increased stroke and shorter conrod....and the increased power, but they have taller primary gearing as well.
If you are in any doubt, find someone near to you who has one and speak to them.
Dave.
dave#22
On Here A Lot
On Here A Lot
 
Posts: 249
Joined: Mon May 24, 2010 9:21 pm

Re: vibration

Postby BigBob » Thu Dec 04, 2014 8:46 pm

Hi, That's an interesting question and I'm sure you will get opposing answers.

Not from me. I agree with you Dave.
User avatar
BigBob
Admin
Admin
 
Posts: 3606
Joined: Sat Jan 23, 2010 10:46 pm
Location: ESSEX

Re: vibration

Postby nug » Fri Dec 05, 2014 12:47 am

My SR 43 800 did have more vibes than my SR 41 750. But then I fitted DRZ400 forks with solid mount bars to the 750 and I reckon the vibes where much the same. Knobbly tires add significantly to the bar vibes as well. A well lubed & correctly adjusted chain can make difference too.

Big singles vibrate :tup:
User avatar
nug
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 3180
Images: 14
Joined: Sat Jan 23, 2010 10:46 pm
Location: Lincoln

Re: vibration

Postby dave#22 » Fri Dec 05, 2014 10:09 am

I also found the DR800 SR43b vibrated more than my DR750 SR41, so I had various attempts to reduce the vibration,
1..I changed the TPS CDI for a SR43a (I felt it was advancing too early)....some improvement.
2..The bike was fitted with aftermarket stainless silencers, so I fitted a big bore stainless exhaust pipe and replaced the 2 into 1 collector under the seat with a stainless item.....more improvement.
3..I modified a 750 top yoke (with rubber mounts for the bars), bored out the stanchion holes from 41 to 43mm and added the bracket for the ignition switch and choke and fitted stainless bar end weights.....big improvement.
4..A low mileage SR41 engine (750) turned up, so with a few mods I fitted that, now I probably have the smoothest SR43b around...fitted with 800 primary gears and a 16t front sprocket and std 47t rear = tall gearing.
Dave. :tup:
dave#22
On Here A Lot
On Here A Lot
 
Posts: 249
Joined: Mon May 24, 2010 9:21 pm

Re: vibration

Postby nug » Fri Dec 05, 2014 10:24 am

Who's a clever boy then Dave :tup:

I have a set of 43 forks with a rubber mount top yoke which came of a bastadized 43 that I broke for spares. No idea what the yoke was off but it doesn't appear to be bored out.

What rpm are you doing at 70mph with your higher gearing ?
User avatar
nug
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 3180
Images: 14
Joined: Sat Jan 23, 2010 10:46 pm
Location: Lincoln

Re: vibration

Postby dave#22 » Fri Dec 05, 2014 2:21 pm

............What rpm are you doing at 70mph with your higher gearing ?.............

I'll have to get back to you on that, I'll probably use it on Sunday, so I''ll check then....When I had an 800 engine in I was running a 45t (special from B&C) and that was tall, but it was 30miles of motorway/dual carriageway for work each day.
Dave.
dave#22
On Here A Lot
On Here A Lot
 
Posts: 249
Joined: Mon May 24, 2010 9:21 pm

Re: vibration

Postby dave#22 » Fri Dec 05, 2014 6:46 pm

Hi Nug, I had to nip out this afternoon, so I used the SR43 just for you....I always use a Zumo GPS on this bike as speedo is in kms and the GPS is mounted high on a tall screen, so it's easily seen, but I was suprised how inaccurate the speedo is to the GPS.
.....112kph (70mph) on the speedo = 4,100 rpm.in top gear...actual speed on GPS = 61mph. :o

I have a Guzzi as well and the speedo is near spot on with the ZUMO with speed and distance covered. :tup:
dave#22
On Here A Lot
On Here A Lot
 
Posts: 249
Joined: Mon May 24, 2010 9:21 pm

Re: vibration

Postby nug » Fri Dec 05, 2014 10:34 pm

Sounds a bit off mate. Gps wont be wrong but the revs sound a little high for 61 mph. My 750 with 15/47 is about 4700 rpm at 70 if my mind serves me correctly. Mind you, who's to say our tacho's are accurate anyway ?
User avatar
nug
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 3180
Images: 14
Joined: Sat Jan 23, 2010 10:46 pm
Location: Lincoln

Re: vibration

Postby H_Lime » Sat Dec 06, 2014 10:00 pm

Image
These worked:)
User avatar
H_Lime
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 1332
Joined: Thu Dec 09, 2010 12:37 am

Next

Return to General Techie Stuff

Who is online

Users browsing this forum: No registered users and 1 guest

cron

x