[a4anurag]

Originally Posted by Majumdarda

One thing that I have observed is that these rubber blocks tends to fall off quite easily and the fitting is also not tight enough. At least on Amun-Ra, some are missing.

Is this something very serious?

Lol. I thought they mean nothing and just some decoration so removed it off the day I took delivery. I have been using my Karizma since 4 years with 23K on odometer. No issues faced till date so technical guys should say what use it really has.

Anurag.

[Jimmy_u]

Originally Posted by Majumdarda

Last night, was my first night ride on the Mumbai Pune old highway, covering a distance of approximate 100 kilometers (Lonavala Up and Down). There was another rider with me too and we had a great time, atop the Tiger Point, at around 9:30 PM.

This is one Ride I would want to be a part of Sir, do let me know next time if its a weekday,I could plan to join, my weekends are occupied now as we have recently been blessed with a baby girl.

Cheers and happy riding
Jimit

[Sutripta]

Originally Posted by a4anurag

AFAIK and IIRC the rubber blocks that are placed between the fins help by two ways:

1) They dampen the high pitch sound produced by the engine and lesser vibration (resonance).

+1
The cooling fins 'ring'. The rubber blocks prevent/ lessen it.

2) Air moving over the fins will pass straight without much heat carryibg but the rubber blocks can create turbulence hence sone extra heat can be removed along with the air that swirls around.

Unlikely.

Regards
Sutripta

[a4anurag]

Originally Posted by Sutripta

The cooling fins 'ring'. The rubber blocks prevent/ lessen it.

Sir,

If those rubber blocks have a use on the vehicle then why are they so flimsy and fall off within a few days of purchase?

Why aren't they fixed there to improve their working efficiency and life?

Anurag.

[ArizonaJim]

Majumdarda:
Don't worry about the missing rubber dampers.

As was mentioned, they are there to dampen out high frequency vibrations.

When I got my fuel injected 500cc UCE Royal Enfield I didn't like the look of the dampers. They seemed to clutter up a otherwise nice looking engine.

Being an design engineer who spent a lot of my life dealing with jet and turbine engines, I've seen the results of high cycle fatigue failures so I studied the fins on the UCE. They seemed to have adequate connecting ribs between them to dampen out any destructive vibrations so my worry diminished.

Because the summer time temperatures can reach over 115 degrees F (46.1 degrees C) cooling is a concern here.
It seemed like the rubber dampers were covering up a substantial amount of surface area on the engines cooling fins and covered fins do not cool the engine.

With this, and my dislike of the look of the dampers in mind, I removed them all shortly after getting my motorcycle.
In 2 3/4 years and over 13,000 miles (21,000 km) of riding I have never had a problem with high frequency noise, fins cracking from HCF or the engine overheating.

[Sutripta]

Originally Posted by a4anurag

If those rubber blocks have a use

These have a use, just not important. Just like say the ferrite bead on electronic cables. Equipment normally works just fine without these also.

Why aren't they fixed there to improve their working efficiency and life?

Things falling off REs I can understand, but ZMAs? Strange. Overenthusiastic cleaning?

Regards
Sutripta

[a4anurag]

Originally Posted by Sutripta

Things falling off REs I can understand, but ZMAs? Strange. Overenthusiastic cleaning?

Lol. I removed then the day I got the bike home after delivery.

Will Harley's and Triumph too have these rubber blocks placed in between?

Anurag.

[P.S.]

The salesman in the showroom in Gurgaon either had no clue as to it's function (he said it's to prevent in-transit damage) or we're overestimating their function. Former sounds more logical.

Originally Posted by Jimmy_u

This is one Ride I would want to be a part of Sir, do let me know next time if its a weekday,I could plan to join, my weekends are occupied now as we have recently been blessed with a baby girl.

Firstly congratulations on the baby girl. Hope she has a long, healthy happy life.

OT: Your signature here says Esteem 'diesel'. wasn't aware of it.

[Majumdarda]

Amun-Ra was registered under my name of 4th of October 2013 and yesterday was 4th of March 2014.
Exactly in 5 months I have covered 5000 kilometers on the odo. This was a moment worth capturing (even while going to office, stopping the vehicle on a narrow stretch of road, with the traffic police jeep just behind me )
Thank you Amun-Ra.



@ Jimmy, These short rides are just scheduled on the go, with no pre-planning etc. The next time I am going, I would off-course be sending you a text. But my personal advise, is do not waste time. Do not be dependent on others in such short rides. It is just 100 km both ways, so there is no need of worry. Take some time out, (say three hours), fill up the tank and then go to Tiger point post 8 PM. The stars will be there to welcome you, if not anyone else.

Ride safe.

Best regards,

[Sutripta]

Originally Posted by a4anurag

Will Harley's and Triumph too have these rubber blocks placed in between?

Not for the liquid cooled ones, I'm sure!

Originally Posted by P.S.

The salesman in the showroom in Gurgaon either had no clue as to it's function (he said it's to prevent in-transit damage) or we're overestimating their function. Former sounds more logical.

It is to prevent high frequency vibrations. The cooling fins have the same form as the prongs of a tuning fork.

Of course it's possible that some manufacturers have copied it (tick a checkbox) without actually engineering anything.

Regards
Sutripta

[Mpower]

Originally Posted by Sutripta

Not for the liquid cooled ones, I'm sure!

Whys that? Fin is a fin whether its on Air or LC !

[a4anurag]

Originally Posted by Sutripta

Not for the liquid cooled ones, I'm sure!

Originally Posted by Mpower

Whys that? Fin is a fin whether its on Air or LC !

I just saw the rubber blocks placed in the HD bikes that are liquid cooled.

Anurag.

[Sutripta]

Originally Posted by Mpower

Whys that? Fin is a fin whether its on Air or LC !

Functional fin <> cosmetic fin.
Going by

Originally Posted by a4anurag

I just saw the rubber blocks placed in the HD bikes that are liquid cooled.

extreme case of form over function.

@Anurag, any pictures. Which one, Street or VRod?

Regards
Sutripta

[a4anurag]

Originally Posted by Sutripta

@Anurag, any pictures. Which one, Street or VRod?

Regards
Sutripta

No pictures buddy! The HD 750, I remember seeing had black blocks in between the silver fins.

Shall try for pictures to get things clear.

OT:
We are going off topic here. Let's continue this on a new thread before the MODS/owner revolts.

Anurag.

[Mpower]

Originally Posted by Sutripta

Functional fin <> cosmetic fin.
Going by

extreme case of form over function.

I realize that but what is different about the geometry of a cosmetic fin? maybe you dont need to worry about thermal mass/sizing or air flow path, but it still has a natural frequency and will resonate.

BTW all the so called cosmetic fins also offer some some amount of cooling effect. If you didn't plan for it then you will end up overcooling