Stiff front end

Information on forks/springers/shocks
Post Reply
jlaley
Posts: 79
Joined: Tue Oct 17, 2006 12:18 am
Bikes: 2004 FLHRSI
1954 FL
Location: Rochester NY

Stiff front end

#1

Post by jlaley » Sat Jun 19, 2010 5:21 pm

My '54 has a very harsh ride to the front end. I bought it with 2" over tubes. I originally left the front as it was and tried it. Unforgiving to say the least. I drained the oil and refilled with 10wt and still the same. Took it apart and rebuilt it. Kept the 2 over but put new lower legs on it and since I didn't know what it had for springs, I bought a set of Progressive springs for it. All the valving is new too. All that and no different at all. This jars you when hitting bumps. I haven't ridden anyone else's old bike for comparison, but this isn't enjoyable to ride any distance. What can I be missing? I've always thought they were a soft ride.



DaveSwanson
Site sponsor
Site sponsor
Posts: 186
Joined: Wed Oct 17, 2007 6:34 pm
Bikes: 1936 VLH, 1936 VD, 1956 FLH, 1956 KHK,
Been thanked: 2 times

Re: Stiff front end

#2

Post by DaveSwanson » Sat Jun 19, 2010 5:50 pm

I put 10wt in my 56FLH and it shook me to death. I went too far the other direction, drained the 10 and put 30wt in. Shook my fillings again. I put 20wt in and it is just right!

jlaley
Posts: 79
Joined: Tue Oct 17, 2006 12:18 am
Bikes: 2004 FLHRSI
1954 FL
Location: Rochester NY

Re: Stiff front end

#3

Post by jlaley » Sun Jun 20, 2010 12:42 am

I wouldn't think those changes would make that much difference but if you say so. My thoughts were the thinner the oil the more movement it would have to a lesser bump. Maybe I'll have to experiment again. Thanks Dave

RUBONE
Moderator
Posts: 5100
Joined: Sat Nov 15, 2008 4:09 am
Bikes: Multiple H-D, Ducati, BMW, Triumph, BSA,...
Has thanked: 13 times
Been thanked: 499 times

Re: Stiff front end

#4

Post by RUBONE » Sun Jun 20, 2010 12:51 am

Two things to consider:
Lighter oil will allow quicker compression but it also allows quicker rebound, allowing a sharp metallic clank at every stroke.
And you say you changed springs but left the 2" over tubes. Did you also leave the spring spacers? Very necessary to provide the proper amount of pre-load to the springs so that they can do their job.
JMHO
Robbie

jlaley
Posts: 79
Joined: Tue Oct 17, 2006 12:18 am
Bikes: 2004 FLHRSI
1954 FL
Location: Rochester NY

Re: Stiff front end

#5

Post by jlaley » Sun Jun 20, 2010 3:13 pm

Yes, I left the spacers in so the preload is there. There just doesn't seem to be any dampening to this front end. It's not fun to ride this way.

Pomike
Posts: 243
Joined: Thu Jul 03, 2008 5:54 pm
Has thanked: 1 time
Been thanked: 10 times

Re: Stiff front end

#6

Post by Pomike » Sun Jun 20, 2010 4:37 pm

You should definitely not have this problem. Roll the bike and hit the front brake. The bike should dip and then come back up. When the bike has been siting and you pull it off the side stand, the forks should come up and be ready to work. Are you using fork oil, or something else? Why keep the over tubes?
Mike

jlaley
Posts: 79
Joined: Tue Oct 17, 2006 12:18 am
Bikes: 2004 FLHRSI
1954 FL
Location: Rochester NY

Re: Stiff front end

#7

Post by jlaley » Sun Jun 20, 2010 7:38 pm

Mike, I kept the 2"over because I like the way the bike sits with it. Looking at the bike it doesn't really look different than stock, pretty level. Rolling the bike and hitting the brakes, the forks do compress a little but not too much. Maybe the Progressive springs weren't the springs I should have used. I'm beginning to think so.

Panacea
Posts: 1865
Joined: Fri May 24, 2002 1:00 am
Bikes: 64FL 99FLHR 01FXSTD
Location: Mpls. MN.
Has thanked: 14 times
Been thanked: 57 times

Re: Stiff front end

#8

Post by Panacea » Sun Jun 20, 2010 11:30 pm

I'll bet you have too much air pressure in the tire, The manual calls for 12-14 lbs. I know that spec is for tires from the fifties but the specs on the modern tires are cause for a harsh ride...Mike

jlaley
Posts: 79
Joined: Tue Oct 17, 2006 12:18 am
Bikes: 2004 FLHRSI
1954 FL
Location: Rochester NY

Re: Stiff front end

#9

Post by jlaley » Mon Jun 21, 2010 12:12 am

Mike, I've been lowering it as I go. It's a modern Dunlop and I'm down to 16lbs. It doesn't look soft but how low can I safely go?

john HD
Moderator
Posts: 3677
Joined: Sat Aug 20, 2005 7:24 pm
Bikes: '42 WLA X 2, '55FL, '93 Ultra Classic, '91 Fatboy, '97 883, '71 Suzuki Duster 125, '83 GPz 750.
Has thanked: 52 times
Been thanked: 77 times

Re: Stiff front end

#10

Post by john HD » Mon Jun 21, 2010 12:34 am

might want to call dunlop on that one.

i have been running ATF in my fork for 2 years now with good service.

i figure it is about right viscosity wise, 20W i believe.

john

RussW
Posts: 170
Joined: Sun Apr 08, 2007 3:49 am
Bikes: 1961 FL
2007 Kaw. Vulcan 2000
Location: Western Mass
Been thanked: 4 times

Re: Stiff front end

#11

Post by RussW » Mon Jun 21, 2010 2:02 am

I've got 2" over tubes on my '61, and found the Progressive springs used with the supplied spacers were WAY stiff. Talked to Progressive Suspension, and learned that preload on their springs should be set so that, with your weight sitting on the bike, the front end should compress approx. 20-25% of the total travel distance of the forks. I seem to remember that my Glide had about 4.5" total travel (did this years ago), so I set preload where front end compresses about 1" from the weight of the bike + my weight. Used 10W fork oil, ended up with a much more comfortable ride.

Motorcyclemike
Posts: 227
Joined: Fri Apr 04, 2008 6:25 am
Bikes: Knucklehead and a Triumph
Location: North East Kansas
Has thanked: 36 times
Been thanked: 2 times

Re: Stiff front end

#12

Post by Motorcyclemike » Mon Jun 21, 2010 9:09 pm

Ok.......Pre Load !

I guess i need to set mine too......i have 2 inch over tubes and 20 wt oil..... with progessive springs !

How do i set the pre load?
Mike 2

RussW
Posts: 170
Joined: Sun Apr 08, 2007 3:49 am
Bikes: 1961 FL
2007 Kaw. Vulcan 2000
Location: Western Mass
Been thanked: 4 times

Re: Stiff front end

#13

Post by RussW » Mon Jun 21, 2010 9:40 pm

Add or subtract from the length of the top spacer (you will need to shorten it) until you arrive at the proper length spacer to preload the springs the correct amount. Trial and error, you can use washers to shim the spacer if you cut it too short. A hassle to do because of all the assembly/dis-assembly, but at least the fork tube cap gets easier to reinstall each time you shorten the spacer!

Panacea
Posts: 1865
Joined: Fri May 24, 2002 1:00 am
Bikes: 64FL 99FLHR 01FXSTD
Location: Mpls. MN.
Has thanked: 14 times
Been thanked: 57 times

Re: Stiff front end

#14

Post by Panacea » Tue Jun 22, 2010 3:32 am

jlaley wrote:Mike, I've been lowering it as I go. It's a modern Dunlop and I'm down to 16lbs. It doesn't look soft but how low can I safely go?
If you set the pressure too low she won't want to corner without a fight, try 20-22...Mike

jlaley
Posts: 79
Joined: Tue Oct 17, 2006 12:18 am
Bikes: 2004 FLHRSI
1954 FL
Location: Rochester NY

Re: Stiff front end

#15

Post by jlaley » Thu Jun 24, 2010 10:16 pm

Thanks guys, I'll try changing the pre-load and see what happens.

Post Reply

Return to “Forks/Shocks”