Author Topic: Hardtail vs rear suspension  (Read 7069 times)

0 Members and 1 Guest are viewing this topic.

Offline 2stroke

  • New folks
  • Posts: 15
Hardtail vs rear suspension
« on: January 23, 2012, 08:30:41 PM »
I hope to be in Worthington this April with my street bike and old drag bike in tow.  I am interested in building something new specifically for lsr and would like some input on whether to go with a hardtail or springs and shocks.  I'd like to put together an altered class machine as that would give me that much more room to be "creative".   The engine will be a heavily modified Yamaha RD400, beyond that, the sky (more likely my wallet) is the limit.  Thanks in advance.
2stroke

Offline dw230

  • Hero Member
  • *****
  • Posts: 3165
Re: Hardtail vs rear suspension
« Reply #1 on: January 23, 2012, 09:13:09 PM »
What is going on in Worthington in April?

DW
White Goose Bar - Where LSR is a lifestyle
Alcohol - because no good story starts with a salad.

Don't be Karen, be Beth

Offline 55chevr

  • Hero Member
  • *****
  • Posts: 2446
Re: Hardtail vs rear suspension
« Reply #2 on: January 23, 2012, 09:22:52 PM »
I believe "2 stroke" is referring to Wilmington ...

Joe

Offline dr j

  • Full Member
  • ***
  • Posts: 143
  • Honda CRF250 & RS125 & 1954 Moto Parilla 175
Re: Hardtail vs rear suspension
« Reply #3 on: January 23, 2012, 10:19:27 PM »
2stroke,
Having raced at Maxton for the last 4 seasons I recommended shocks due to the many patches and bumps.  None of us have ridden at Wilmington but have all heard about how smooth it is.  So now it should not make a difference to the engine whether you have rear shocks.  If you have a rigid frame then you can get your seat mounted much closer to the rear tire.  But remember that the tires expand quite a bit at higher speeds so don't get it so close that it rubs. 
Jarl- Moto Madcap
Sharpsburg MD
BUB2012- Morini 350- 4 Mod Pushrod records, Parilla 175- M-VG rec
250cc 4stroke Nitrous Motorcycle- 131.8mph
250/4 Naked Motorcycle-115.6mph
APS/F-125/2 115.2mph
P/PV-175/4 Moto Parilla-59.7mph
29 Retired Maxton Class Records on 3 bikes and 4 engines

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5503
Re: Hardtail vs rear suspension
« Reply #4 on: January 24, 2012, 01:43:06 AM »
Rear suspension will help you hook up and reduce wheelspin if it is a rough track.  This is a performance advantage if your bike will have a lot of power.

Offline oz

  • Sr. Member
  • ****
  • Posts: 587
  • Geordie Power.
Re: Hardtail vs rear suspension
« Reply #5 on: January 26, 2012, 01:33:55 PM »
I am still an advocate of rigid if its a smooth surface it is to be used on. I can and often do build frames with mono/twin shocks but tend to lean toward rigid if i can get away with it.
Oz
Newcastle born and bred a City built on Coal and Steel and a people built of stronger stuff

Offline 55chevr

  • Hero Member
  • *****
  • Posts: 2446
Re: Hardtail vs rear suspension
« Reply #6 on: January 26, 2012, 03:40:09 PM »
I race rigid drag bike frames and it is not an issue either at Maxton, Loring or Bonneville below 153 mph ... As that is the fastest I have gone that is all I can attest to.


Joe

Offline Old Scrambler

  • Sr. Member
  • ****
  • Posts: 721
  • Going Fast - Slowly
Re: Hardtail vs rear suspension
« Reply #7 on: January 28, 2012, 08:56:21 PM »
The purpose of suspension is to push the wheel down to stay in contact with the earth's surface. You have several choices but consider this.........on pavement your tire will tend to be at somewhat lower pressure than on the salt. If your running at maximum rpms and the traction goes.......do you have a rev-limiter?  I would consider a hardtail or Vincent (soft-tail) design for an A-frame with a torque monster motor.
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline Nortonist 592

  • Hero Member
  • *****
  • Posts: 1510
    • http://www.artfv.com/design/fashion/
Re: Hardtail vs rear suspension
« Reply #8 on: February 04, 2012, 02:03:15 AM »
My sidecar is in the 125 range and its rigid all round.  No problems at Bonneville or El Mirage.  I don't believe its necessary especially with an RD400.
Get off the stove Grandad.  You're too old to be riding the range.

Offline Koncretekid

  • Hero Member
  • *****
  • Posts: 1203
Re: Hardtail vs rear suspension
« Reply #9 on: February 05, 2012, 07:40:43 PM »
No problem with my special build 500cc BSA with rigid suspension and 50 psi at either Loring or Bonneville, as far as handling is concerned.  However, quite a few things came lose at Loring, like the oil filter, idler shaft, and the rear fender, which took quite a hike on the return run.
Tom
We get too soon oldt, and too late schmart!
Life's uncertain - eat dessert first!

Offline Nortonist 592

  • Hero Member
  • *****
  • Posts: 1510
    • http://www.artfv.com/design/fashion/
Re: Hardtail vs rear suspension
« Reply #10 on: February 05, 2012, 07:59:02 PM »
Kk.  They're singles. They all vibrate.  If it ain't welded on its fair game for vibration.  : - )
Get off the stove Grandad.  You're too old to be riding the range.