rapid robs stink? or do I?- Mtbr.com
Results 1 to 11 of 11
  1. #1
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    329

    rapid robs stink? or do I?

    I run rapid robs at 40psi on my Flash 1 alloy 29er. The rear tire spins when going uphill unless I keep some weight on the saddle, so I really cant pump up the hills like I can on my roadbike. This is worse when on leaves or when wet and sometimes it slips when I pedal too hard even if Im in the saddle.

    Are these tires bad?
    Will I need some weight on the saddle no matter what?
    Do I just need to improve my technique?
    I dont think I want tubeless but will a lower PSI like 25 help with this type of traction?
    any other tire model help?

    thanks in advance for any help or flaming!
    Epic Flash Boris F65X + road bikes

  2. #2
    mtbr member
    Reputation: gcappy's Avatar
    Join Date
    Jul 2012
    Posts
    1,640
    Absolutely. Drop the pressure immediately. Start dropping a few pounds at a time until the bike feels squirrel y. Go back up a pound or two and you will be good. Make sure it's not so low you get rim strikes. Usually a pound or two more in the rear than the front. Your traction will dramatically improve and so will the ride.
    Tubeless is way better if you have the rim and tire combo to pull it off. I run 29x2.35 Shwalbe Nobby Nic's on Stans Crest rims. I run 20 PSI front and 21 PSI rear.

    Will I need some weight on the saddle no matter what?-Yes
    Do I just need to improve my technique?-Yes
    I dont think I want tubeless but will a lower PSI like 25 help with this type of traction?-Yes
    any other tire model help?-Yes

  3. #3
    mtbr member
    Reputation:
    Join Date
    Dec 2007
    Posts
    141
    That is waaaay too much pressure. gcappy is dead on. oh and you should really consider going tubeless!

  4. #4
    mtbr member
    Reputation:
    Join Date
    Feb 2012
    Posts
    33
    ^^^ gcappy is exactly correct. I run 23psi (tubeless) in the back. When I was tubed, I went down to 28psi before pinch flats became a problem (although I'm 155lbs geared up).

  5. #5
    mtbr member
    Reputation: LyNx's Avatar
    Join Date
    Oct 2004
    Posts
    24,078
    How much do you weigh Don? Before anyone can go dishing out info that you're running too high a pressure this needs to be a known. Just guessing from your description of what's happening that you're not a big enough boy to warrant that high a PSI or else the tyres would be conforming under such weight. I'd try dropping the pressures down, go down in little increments at a time, initially I'd drop the rear to 35 PSI and then go down in 2 PSI increments until you hit the sweet spot. Coming from the road you think 40PSI should be soft, but not for an MTB unless you weight north of 250lbs.
    Quote Originally Posted by Harold
    You're doing mtbr wrong, you're supposed to get increasingly offended by the implications that you're doing ANYTHING wrong.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Oct 2006
    Posts
    988
    Agree with above - plus aren't Rapid Robs Schwalbe's more basic compound?

  7. #7
    mtbr member
    Reputation:
    Join Date
    Jan 2012
    Posts
    13,020
    Those tires are the old Racing Ralph tread pattern with ORC Performance single compound, harder than Evo. An Evo compound tire would add some grip on wet rocks and moss. Lower pressure should handle dry leaves.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    329
    Quote Originally Posted by LyNx View Post
    How much do you weigh Don? Before anyone can go dishing out info that you're running too high a pressure this needs to be a known. Just guessing from your description of what's happening that you're not a big enough boy to warrant that high a PSI or else the tyres would be conforming under such weight. I'd try dropping the pressures down, go down in little increments at a time, initially I'd drop the rear to 35 PSI and then go down in 2 PSI increments until you hit the sweet spot. Coming from the road you think 40PSI should be soft, but not for an MTB unless you weight north of 250lbs.
    I weigh 190, probably 200 with the gear. Maybe i will start in the mid 30s for pSI and see how they do.
    Epic Flash Boris F65X + road bikes

  9. #9
    mtbr member
    Reputation: LyNx's Avatar
    Join Date
    Oct 2004
    Posts
    24,078
    Yup, I weigh about 170-175lbs geared to ride and my pressures for the rear run between 24-30 depending on the trail and 20-24 front, again trail dependent. As for the actual tyres, they're a budget XC tyre it would seem from research, so not loads of grip, but sounds like you definitely need to work on technique.

    Remember this is trail, not tarmac, there isn't unlimited grip so you can just hammer, you have to fight for traction as well, that is the "fun" of riding trail, to find that find balance between maintaining traction and getting power down to get you up climbs, sometimes you have to stay on the saddle and move your weight for/aft to make the climb, others you can stand and then sometimes you have to sit, but with a little out the saddle to make certain parts

    Quote Originally Posted by donn12 View Post
    I weigh 190, probably 200 with the gear. Maybe i will start in the mid 30s for pSI and see how they do.
    Quote Originally Posted by Harold
    You're doing mtbr wrong, you're supposed to get increasingly offended by the implications that you're doing ANYTHING wrong.

  10. #10
    mtbr member
    Reputation: t0pcat's Avatar
    Join Date
    May 2012
    Posts
    527
    i didn't think robs were bad in the dry but don't like them in wet i know the compound is not as good as whats in the ardent in wet
    “An adventure is misery and discomfort, relived in the safety of reminiscence.” Marco Polo

  11. #11
    mtbr member
    Reputation:
    Join Date
    Apr 2004
    Posts
    2,064
    i had no problems with he rapid rob and i weigh about 220 and ride a hardtail so i do keep the rear tire at around 40 psi to avoid pinchflats (yes with tubes, lets not bring that argument in here).

    i found if anything the rapid rob tires to be incredibly grippy and soft to the point where in after two months of regular riding i had worn the tire (on the back) down to an almost slick.

    in that time i loved the tire but wouldn't buy another since it seems to wear twice as fast, if not more, than other tires.

    to the poster: i bet technique is most of your issue. it is definitely a pretty grippy tire in my experience and i had no trouble with grip at the pressures you described. that said if you weigh less or can get away with lower pressures it will certainly help as well.

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 2020 VerticalScope Inc. All rights reserved.