Results 1 to 17 of 17
  1. #1
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    78

    Prophet Lefty Shuddering Question

    Hello,

    I'm loving my Prophet 1000, especially with the nice weather we've had lately. While riding yesterday, I noticed that under hard braking (especially downhill), my Lefty is pogo'ing/shuddering quite a bit. I checked my calipers/pads, and nothing is rubbing or out of alignment. The wheel is locked onto the spindle nice and tight. I honestly can't figure out what the deal is. I have yet to check the SPV pressure, but I normally run it on the high end. I wish I could explain it better, but it's one of those things better seen in person. Can anyone help with my problem? Thanks in advance!

  2. #2
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238
    I noticed that last night too! It was probably the fastest downhill I've done with the bike and it did the same thing. I checked everything too and it all looked fine. I attribute to the needed "break in" period for the brakes.

    My LBS told me to get them muddy and really dirty and hammer on them to help break them in. I have noticed that they stopped making the loud screaching sounds. They're getting better and I'm worrying less and less as I get more rides on them.
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

  3. #3
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    78
    Quote Originally Posted by ryoninct
    I noticed that last night too! It was probably the fastest downhill I've done with the bike and it did the same thing. I checked everything too and it all looked fine. I attribute to the needed "break in" period for the brakes.

    My LBS told me to get them muddy and really dirty and hammer on them to help break them in. I have noticed that they stopped making the loud screaching sounds. They're getting better and I'm worrying less and less as I get more rides on them.
    Well, I normally wouldn't worry about it if it was just noise/screeching of the pads, but my lefty is bobbling so bad that Iit puts me on edge on downhill sections. Was yours pogo'ing, and if so, did that go away as well?

  4. #4
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238
    When you say pogo'ing, it was more of a studdering. It was only when I was pointed down a steep hill and hammered the brake. Whatever it was, it didnt feel right.
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

  5. #5
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    78
    Yeah, it's more a really fast pogo'ing - hence the studdering. The reason I say pogo'ing is because the wheel looks to be bouncing up and down very quickly on the lefty itself...

  6. #6
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238
    Maybe...but I was too busy looking where I was headed.
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

  7. #7
    All Lefty's, all the time Moderator
    Reputation: MendonCycleSmith's Avatar
    Join Date
    Feb 2005
    Posts
    15,791
    Just a thought, but have you upped the preload on your spring? (If not, try that) Or are you heavier, and maybe need a firmer spring? The only other controlling factor in all this is your oil level, which, unless you have a very noticeable leak, is mosty likely not the culprit. What does your dealer say?

  8. #8
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238
    Quote Originally Posted by MendonCycleSmith
    Just a thought, but have you upped the preload on your spring? (If not, try that) Or are you heavier, and maybe need a firmer spring? The only other controlling factor in all this is your oil level, which, unless you have a very noticeable leak, is mosty likely not the culprit. What does your dealer say?
    Dealer says it's the part of the break in period. It only happens under a heavy load (downhill) and during moderate breaking. My Lefty isn't leaking. I'm 6ft 210 for size. As far as the preload, I haven't touched it. It's really firm though - much more so than my older lefty.

    If it persist's, I'll make an issue out of it.
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

  9. #9
    All Lefty's, all the time Moderator
    Reputation: MendonCycleSmith's Avatar
    Join Date
    Feb 2005
    Posts
    15,791
    Quote Originally Posted by ryoninct
    Dealer says it's the part of the break in period. It only happens under a heavy load (downhill) and during moderate breaking. My Lefty isn't leaking. I'm 6ft 210 for size. As far as the preload, I haven't touched it. It's really firm though - much more so than my older lefty.

    If it persist's, I'll make an issue out of it.
    At 210, you need the xtra firm spring, if you don't have that, you ought to get one, I have a customer who is 20 lbs lighter than you, he went to it, and is very happy he did!

  10. #10
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238
    I'll check that out. I'm fairly certain that it was installed. I ordered the bike at my LBS with the actual Cannondale rep filling out the order. He asked me what my weight and height were and wrote that on the order. I don't have the tool required to pull the top cap off the Lefty, so I shall have to acquire one.

    Back to the LBS....

    Thanks Mendon!
    Last edited by ryoninct; 04-07-2005 at 06:50 AM. Reason: typo
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

  11. #11
    super absorbent
    Reputation: ChipAllen's Avatar
    Join Date
    Mar 2005
    Posts
    215
    The stiffer spring may help and is worth a look for a guy your size. It is very likely that it is indeed your brakes needing to get broken in. It can take a while to make a nice, smooth interface between the rotor and pads. Make sure that: A) You brake caliper is nice and tight on your fork mount, B) that your caliper is not noticeably skewed to the right or left and C) that your rotor isn't significantly warped.

    If all is cool with the above, then make it a point to do a few rides through some nasty mud and dirt as others have suggested. This will help "sand" down your pads a little so that the surfaces are more even and uniform. At high speeds, the slightest imperfection can translate into the studdering that you are observing. Give it some time and relax. I would stay away from the steeper downhills until you notice things getting better. Good luck.
    The more complicated it is, the more that can go wrong.

  12. #12
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    78

    Bonking ... not feelin' well

    Quote Originally Posted by ChipAllen
    The stiffer spring may help and is worth a look for a guy your size. It is very likely that it is indeed your brakes needing to get broken in. It can take a while to make a nice, smooth interface between the rotor and pads. Make sure that: A) You brake caliper is nice and tight on your fork mount, B) that your caliper is not noticeably skewed to the right or left and C) that your rotor isn't significantly warped.

    If all is cool with the above, then make it a point to do a few rides through some nasty mud and dirt as others have suggested. This will help "sand" down your pads a little so that the surfaces are more even and uniform. At high speeds, the slightest imperfection can translate into the studdering that you are observing. Give it some time and relax. I would stay away from the steeper downhills until you notice things getting better. Good luck.
    Sorry I didn't reply sooner, but I DO have the heaviest spring installed in my Lefty. I don't have an oil leak, and I have not adjusted the pre-load. I am also 6'2" and weigh 205 lbs. My rotor is not warped in the least, caliper is not skewed, and my caliper is mounted tight on my fork. Any other ideas?

  13. #13
    super absorbent
    Reputation: ChipAllen's Avatar
    Join Date
    Mar 2005
    Posts
    215
    Quote Originally Posted by LoveMyCannondale
    Sorry I didn't reply sooner, but I DO have the heaviest spring installed in my Lefty. I don't have an oil leak, and I have not adjusted the pre-load. I am also 6'2" and weigh 205 lbs. My rotor is not warped in the least, caliper is not skewed, and my caliper is mounted tight on my fork. Any other ideas?
    Like I said, if everything is cool with the caliper and rotor you'll just need to give the pads time to smooth out and have a good even contact with the rotor. Go for a few rides in the mud and keep using your barakes moderately over the next several days.
    The more complicated it is, the more that can go wrong.

  14. #14
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238

    Good job!

    Quote Originally Posted by MendonCycleSmith
    At 210, you need the xtra firm spring, if you don't have that, you ought to get one, I have a customer who is 20 lbs lighter than you, he went to it, and is very happy he did!
    Mendon -

    I popped open the Lefty......t'was a red spring. Black is on order.
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

  15. #15
    All Lefty's, all the time Moderator
    Reputation: MendonCycleSmith's Avatar
    Join Date
    Feb 2005
    Posts
    15,791
    Quote Originally Posted by LoveMyCannondale
    Sorry I didn't reply sooner, but I DO have the heaviest spring installed in my Lefty. I don't have an oil leak, and I have not adjusted the pre-load. I am also 6'2" and weigh 205 lbs. My rotor is not warped in the least, caliper is not skewed, and my caliper is mounted tight on my fork. Any other ideas?
    I think that covers everything mechanical, are you new to Cannondales? It may be that the plushness is a tad disconcerting? Is your weight in the back seat on descents? Are you grabbing huge handfulls of front with no rear in the mix? I am not intimating that you are clueless, just tossing out alternate possibilities. Try some 10 weight oil perhaps? Good luck, have fun!

  16. #16
    mtbr member
    Reputation:
    Join Date
    Oct 2004
    Posts
    78
    Quote Originally Posted by MendonCycleSmith
    I think that covers everything mechanical, are you new to Cannondales? It may be that the plushness is a tad disconcerting? Is your weight in the back seat on descents? Are you grabbing huge handfulls of front with no rear in the mix? I am not intimating that you are clueless, just tossing out alternate possibilities. Try some 10 weight oil perhaps? Good luck, have fun!
    Nope, I started with a Jekyll 800 before my Prophet My weight is on the back seat, and I wouldn't say I'm grabbing handfuls of front without rear - whatever it takes to slow my butt down :P It is really noticeable brake-jack. As a side note, my front brakes make the most awful noise under braking, but the rear ones are fine. While they work well, I have to say I'm a bit disappointed in these versus the Hayes that came with my Jekyll...

  17. #17
    a.k.a.-Cranial Disharmony
    Reputation: ryoninct's Avatar
    Join Date
    Dec 2004
    Posts
    238

    Good job!

    I'll tell you that my problems are gone! One - I installed the black spring. Two - I went out on two muddy steep loooooooong rides this weekend. Problem solved.

    Friday, the studdering was gone. I believe due to the stiffffer spring. But it was still squeeling in the front. Up until I dropped into a deep mud puddle. I took notice of the fact that my rotors were both very muddy. I pointed the bike down a hill and rode the brakes hard. I went home, washed the bike down and then rode it again yesterday. I rode the same trails that were producing the squeels and all was quiet.

    Mendon - As always, thank you for the tip! Your insight has been abundantly helpful.
    "Life sucks, get a fu*king helmet, okay?" - Dennis Leary

Similar Threads

  1. Lefty Height question
    By Dan Gerous in forum Cannondale
    Replies: 12
    Last Post: 10-17-2005, 04:06 PM
  2. bent prophet 600 lefty wheel
    By rshank3499 in forum Cannondale
    Replies: 29
    Last Post: 04-04-2005, 05:26 AM
  3. got a prophet demo today... and a question
    By passion268 in forum Cannondale
    Replies: 6
    Last Post: 03-04-2005, 12:19 PM
  4. lefty max 140 rebound Question?
    By yiucycle in forum Cannondale
    Replies: 3
    Last Post: 02-23-2005, 06:44 AM
  5. Prophet seat height question
    By LoveMyCannondale in forum Cannondale
    Replies: 12
    Last Post: 02-11-2005, 07:15 AM

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.