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View Full Version : Thumb Pump!, / Throttle Thumb!



barbwire44
02-05-2002, 03:20 PM
Ok, well if you guys remember my last post on arm pump, well it's healed! The last race my arms didn't pump up and after researching the problem I have discovered the real problem I am having is known as throttle thumb or thumb pump! After 20 minutes or so my thumb will just quit working i mean i can't even give it more than 1/4 throttle for any period of time! (it sucks). Any ideas? or suggestions? I ordered a little device call the thumbthing to try but im having my doubts to wether or not it will work. Any help would be appreciated. :D

400exRacerX
02-05-2002, 03:25 PM
It happens to me too. Last year I just sucked it up and used my palm when my thumb got tired. But when you use your palm you have to position your self awkward. I am trying this springy thing you squeeze with your fingers to build you fingers, thumb, and forearm muscles up. I also started training.

004exkid
02-05-2002, 03:45 PM
That happened to me last race season. It was getting towards the end of a hare scramble and I was running pretty strong. Probally top ten of 40 and all of the sudden BAM! The throttle wont go in ?! I ended up using my palm and wrist to finish the race and was the last guy on the lead lap :mad: I had always rode dirtbikes before so I switched to a twist throttle and solved the problem. I still need to work on my grip. At the end of a very rocky race I have a hard engouh time holding on to the bars not mention trying to use the clutch.

rhino99
02-05-2002, 04:53 PM
My buddy who races nationals has got two things that he does to help with this. The first one is he took an ice cream scoop, put a stiffer spring on it and he just sits and pushes it in and out all the time when hes just sitting there watching TV or whatever. He also took a set of handlebars, cut one handle off and mounted an old thumb throttle housing on it, the then attached a spring to the bars and to the throttle and works with that at home, he doesnt take that one out in public, as he gets weird enough looks doing the ice cream scoop. But he said that they both work wonders!

400exRacerX
02-05-2002, 08:11 PM
Yeah I just picked up these hand exercisers tonight and I'll see how they do. Its basically the same principle as your friends ice cream scooper. I also had a hard time keeping my hands on the handle bars towards the end of the day. It would hurt just to grip the handle bars not to mention pulling in the clutch, brake, and throttle.

Chef
02-05-2002, 08:38 PM
I rode for 6-8hours a day, 6 days straight, and at the end of the week the muscle that connected to my thumb detached from everything else and you could see it up on top of my forearm. Well, you still can, and I havent gotten Thumb pump for about a year now! just try riding for a hard week solid like I did, it will hurt when you move your thumb for a couple days at the end of the week, but you will never regret it..

400exRacerX
02-05-2002, 08:46 PM
I only ride once a week or twice if I'm lucky......I have a job and can't ride everyday.:mad:

Adams44
02-05-2002, 09:13 PM
Same here, I used to ride for days @ 8 to 10 hours and never had a problem.........that is until I broke my thumb when I caught my right tire on a tree full out in 4th. I couldn't move it for a long time. That was two years ago. I ran the full GNCC circuit this year and it only got a little better. I would extend my fingers over the bar and pull on the thumb throttle in wide open sections.

I need some help too!

What ever you do DON"T HIT TREES! I don't think my thumb will ever be the same.

Adams44
02-05-2002, 09:17 PM
P.S. Those plastic thumb throttle extenders aren't worth a s**t. But if somebody knows of an aluminum clamp on, that would really do wanders.

Also, change your throttle cable. Kind of like a clutch cable, they are hard to tell when they are getting worn, but when you change it WOW. I also removed the spring in the throttle housing on the bar, cut the accelerator pump spring and grinded on the main spring. It is a lot better, but nothing like my R, those flat slide carbs were effortless when you cut the spring down to about 5/8.

02-05-2002, 09:39 PM
I had the same problem but i realized i was straining my hand, so i position my throttle at a different angle and it worked, some people have shorter fingers and cut thier grips down and move the throttle closer to thier hand, since ive changed my position i have no trouble

02-05-2002, 09:41 PM
.. oh yeah the reason u cut your grip is cuz alot of people hold thier hand towards the end of the bars and thats why they stress it and cut down the grips...

400MXer
02-05-2002, 10:59 PM
The key is training, you need to ride a lot, and work out. At the begining of last season, my thumb did the same thing, so i just started riding more, and by the 2nd race, no more thumb pump. But i have had arm pump..................IT SUCKS!!!!!!!!!!

SGA
02-05-2002, 11:23 PM
Yeah, my thumb was fading fast this weekend in a hairscramble. Was gonna put a twist thottle on, but everything I read about it says thats bad news. I noticed during the race that my hands were at the end of the bars & my thumb was extented to the throttle. think i'll shorten the grips a little. Pulled the thumb lever cover on the 400. The small spring is really weak, but the carb main spring is really strong, too strong in my opinon. Thats hondas doing to prevent lawsuits from people who don't maintain their quads. I think i'll get a lighter slide spring. Shortening it will not help as it holds the same tension all the way through its travel.

Smoker
02-06-2002, 05:27 PM
Twist throttles aren't that bad, it's just an adjustment. It'll be strange at first but once you get used to it you'll never want to go back (at least in my case). The only thing you have to watch are the big bumps and landings when you get jolted back and in an effort to hold on, hammer it. You'll get arm pump of course but at least when it's beat you can push your hand into the grip and hang your arm to keep it gassed. Unless you absolutely hate twist throttles try one. You can always sell it on E-bay... :p

Tommy 17
02-06-2002, 06:02 PM
j.w if anyone else did this with their throttle... did any of u cut off the black rubber part... it seemed to help on mine and i like it better... i ruffed up the surface with some sand paper and my thumb sticks to the gas alot better it don't slide off like it use to b4 at times... just a idea for yinz...

Z400central
02-12-2002, 02:05 PM
Ok im a newbie, but why did honda make a thumb throttle? and can u change it to hand throttle like motorcycles? and if u can, how is it done? thanks!!!!:)

SGA
02-14-2002, 09:51 PM
Tried this weekend to loosen the carb main spring on the side of the carb, no luck. Theres nothing to attach it to if you loosen it 1/2 turn. All the way loose was not tight enough to close the throttle. I could have jury rigged somthing, but I don't take chances on throttle return springs. You can't loosen the slide spring, its on a floating assy. Maybe I can find a lighter spring off of a old carb somewhere.

barbwire44
02-15-2002, 10:41 AM
I tried out my thumbthing and i'll tell ya it did help, it's not a tremendous help but it is a noticeable one. And i would say definately worth 20 bucks, If I had to do it over i would buy the x-large for more comfort.

K_Fulk
02-24-2002, 10:56 PM
What worked for me with mx races anyways was i just drank a lot of water before the races and it kept my arms from cramping up like they used too. Just stay away from pop before races beacuse they just dry you out more.

02-25-2002, 01:35 AM
some other things that will help with arm pump and thumb pump is cutting of the elastic on the sleve of the jersey. it alows blood to flow easier and cools more. putting silicon in the bars. aluminum bars. and one thing i do is when my thumb cramps up i turn the whole thumb throttle down and under the bars and use my index finger. it's much easier with this finger.

02-28-2002, 11:56 AM
Ok, you can call me a whimp, but I went ahead and got me one of those ice cream scoops with the lever mechanism from K Mart. I did 100 reps..... man was my thumb hurting, waited 10 minutes, did another 100..... ouch!!!!! My girlfriend sees what I'm doing, takes it and does 130 and say,"What's the problem?"

If she only knew what I went through racing on Sunday....:grr