Cycling Logo

Related Topics:

Anonymous
Anonymous Posted on May 19, 2010
Answered

21 speed mongoose front derailer bent/ destorted from crash shifts ok back and forth from large gear to middle gear and back. will not shift to smallest (3) at all! not quite sure of how to bend back into place? ps all the stops are backed off

Answer This Question
  • Anonymous May 20, 2010

    your telling a retired maintenance/ machinist/fabricator of over thirty years experience of trouble4 shooting and repair techniques to take it to bike shop all i asked for was the working fundamentals and some specs. i straightened and adjusted it from geometry and logic. all 21 gears are now working, and rims are turning true. what a great bike! why does mongoose put such cheap non adjusting shimano derailleurs on this beautiful Xr75? its a shame! well thanks

×

1 Answer

Anonymous

Level 3:

An expert who has achieved level 3 by getting 1000 points
Superstar:

An expert that got 20 achievements.
All-Star:

An expert that got 10 achievements.
MVP:

An expert that got 5 achievements.

  • Master 8,546 Answers
  • Posted on May 19, 2010
Anonymous
Master
Level 3:

An expert who has achieved level 3 by getting 1000 points
Superstar:

An expert that got 20 achievements.
All-Star:

An expert that got 10 achievements.
MVP:

An expert that got 5 achievements.

Joined: Apr 02, 2009
Answers
8546
Questions
4
Helped
2765579
Points
24828

Get it replaced at a bike shop.

  • Anonymous May 20, 2010

    One never knows the mechanical aptitude of someone asking a bike-related question.



    My go-to starting point for adjustment and repair information is Park Tool http://parktool.com/. The Repair Help - How To's Section takes you all over the bike with excellent advice and illustrations.



    You might want to view http://parktool.com/repair/readhowto.asp... and see if you can get the front derailleur set up to spec.



    It has been my experience that until a rider understands the 'art' of derailleur adustment and cable maintenance, proper operation is pretty much a matter of blind luck, especially if the bike was not set up by a reputable Bicycle Shop.



    Happy Trails.

×

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

Front deraillur skips middle sprocket when shifting from large one to middle one it goes to smallest one
bent derailer straighten it
Read full answer
Oct 10, 2014 • Cycling
0helpful
1answer

How do I fix my daughter's switchback that will not shift gears?
this can be one of a few things, the most likely being the cable is loose and needs tightened, it is broken somewhere between the shifter and derailer, or a derailer set screw has been turned in not letting the derailer move freely you should try tightening the cable first and see if that helps
Read full answer
Jul 08, 2014 • Mongoose Switchback
0helpful
1answer

Just bought a Novara Randonee. I have had problems with shifting. A couple of times the chain has locked up when shifting the front derailler. Tonight, the back derailler started shifting on its own as I...
There could be multiple causes for the front derailleur problem, which I assume means that the chain gets jammed between the derailleur and chainwheels. It is not possible to tell you what it is over the Internet, especially as it could be a combination of factors. You can start to look into it by attempting
Front Derailleur Adjustment. Detach the shift cable and make sure it moves smoothly back and forth as you move the shift lever. If not then the cable needs lubrication or replacement first. How To Replace Road Bike Gear Cable . Once the cable is OK proceed with derailleur positioning and adjustment from start to finish, skipping no steps. If you are not confident following the steps, or the problem continues, you need to get help at a bike co-op or shop.

The rear derailleur problem is most likely due to a sticking shift cable, such that you moved the shift lever but the cable did not move as many gears, until it later slipped to the correct gear. Follow the brake cable procedure above to see if that helps.

p.s. The problem of course has nothing to do with the bike brand/model.

I’m happy to help further over the phone at https://www.6ya.com/expert/donald_f2ed37026a3ac881


Read full answer
Jan 19, 2018 • Novara Randonee
0helpful
1answer

I have a 21 speed mountain bike. it was wrecked, and now my front gear derailer is not locking into position, it always returns to the first gear unless i hold it in gear. any quick fix solutions as i...
The answer is to tighten the shift handle. The resistance to movement is inside the actual shift knob - it may be worn (tightened again and again) until there is no take up. Usually, you can turn the screw that holds the shift handle on, to tighten it. The pivot screw holds a One Way Clutch to assist in selecting gears.

I suggest that you uncrew the shift screw and add a small peice of paper to the "stack" to increase total width. Then you can turn the screw (at the pivot point) to increase friction of the handle.
Read full answer
Jul 27, 2011 • Cycling
1helpful
1answer

For shifting gears up on the front gear derailer, i cant move up the chain, and therefore can't move up to the 3rd gear, but i can go down fin the the second and first gear.
http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

http://www.parktool.com/blog/repair-help/categories/derailleur-systems

and don't try to use large chainrings with large cogs or small with small (cross-chaining is unnecessary and potentially damaging).
Read full answer
May 21, 2011 • Trek 3900
0helpful
1answer

I have a mongoose dxr 21 speed 26 in. i want to make sure the gears shifter and the chain are right to shift right. When I shift it clicks and doesnt seem to go in correct gear.
http://www.parktool.com/blog/repair-help/categories/derailleur-systems
Read full answer
Apr 10, 2011 • Cycling
0helpful
1answer

Ihave a shimano 20" aluminum 21 speed and have
http://www.parktool.com/blog/repair-help/chain-installation-derailleur-bikes
Read full answer
Mar 04, 2011 • Shimano Xtr Mountain Bike Dual Control...
0helpful
1answer

I need to change my back gear cable
Shift your rear derail down to the smallest cog on the cassette. Loosen the nut that holds the cable onto the derail. If you are reusing the outer cables back the inner cable out to the shifter. If your replacing the outers also, note where they are installed. There should be an allen screw on the bottom of the shifter that will free up the shifter and expose the knob on the end of the cable. Pull out the old cable and install new in reverse. Insert the cable into the clamp on the derail. Pull the cable taught with pliers while tightening nut on clamp. Run through the gears while on middle ring on front. Turn barrel adjuster on derail in and out to dial in shifting. That should do it. Good luck and let me know if you have any problems.
Read full answer
Oct 04, 2010 • Mongoose Exile 26 Men's Full-Suspension...
0helpful
1answer

Have a mongoose with single rear derailleur - how does the shift work?
You have a 21 spd and you have two derailleurs, one front and one rear. To shift you must always be pedalling forward, not backwards or you can chip teeth on your chainrings and cog. To shift, remember left hand controls front, brake and derailleur, the front derailleur is what gives you the ranges, gears closest to the bike are the easiest, so, small ring it the front are your easiest range, middle, mid range, large hardest but fastest. It is best to remember that it is the number of teeth that are hitting the chain to give you the speed you want. Rear Derailleur is your fine tuner the largest is the easiest, same as above. NOW DO NOT KITTY CORNER YOUR CHAIN, SUCH AS LARGE COG IN REAR TO LARGE IN FRONT CHAIN WHEEL, AND DO NOT USE SMALL IN REAR TO SMALL IN FRONT CHAINWHEEL. The reason you do not do that is: you can stretch your chain, yes you can stretch your chain and it serves no purpose, if you are pedalling to easy change your range(front). I hope this helps you understand how to shift now. You may contact me for any further questions, I have been in business for 38+ years
Read full answer
Sep 25, 2010 • Mongoose Exile 26 Men's Full-Suspension...
0helpful
1answer

My shimno sora front derailler shifts perfectly to the small and large chain set cogs, but on the middle, the chain rubs along the cage.
Set the rear derailleur to the lowest gear (big cog) and the front to the lowest gear (small chain ring). Disconnect the derailleur cable. Screw in the adjuster for the cable tension all the way (this adjuster is on the shifter of a mountain bike or the down tube of a road bike). Pedal to make sure the chain is not rubbing on the derailleur cage. If it is, adjust the "L" setting on the derailleur until the chain moves by without touching the cage. Now pull taut and reattch the cable and shift the front to the big ring while pedaling. If it does not shift up well or completely, hold the shifter past its normal shift and adjust the "H" screw so that the derailleur allows the shift. Shift into the highest cassette gear and keep pedaling. The chain should not be touching the front derailleur's cage when you pedal. Adjust with the barrel adjuster until the chain moves freely without touching the derailleur cage.

i hope this helps
-matthew
Read full answer
Oct 30, 2009 • Cycling
Not finding what you are looking for?

View Most Popular

Cycling

Related Question

Front deraillur skips middle sprocket when shifting from large one to middle one it goes to smallest one

  • Cycling

155 views

Ask a Question

Usually answered in minutes!

Popular Questions

Instructions for a Schwinn Airdriver 1100 pump.

Cycling

Lost manual to Bell wireless bicycle computer

Cycling

I cannot get Blackburn flea to take a charge

Blackburn Flea Rear Flasher Bicycle...

How do I raise the handlebars on the Carrera bike

Cycling

Battery cover & battery type for ergometer older unit

Schwinn Original Airdyne

Top Cycling Experts

ADMIN Andrew
ADMIN Andrew

Level 3 Expert

66820 Answers

Kardoc

Level 3 Expert

7501 Answers

Tony Parsons
Tony Parsons

Level 3 Expert

6405 Answers

Are you a Cycling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

PDF Manual
PD-M324_parts - kopie.pdf....

Shimano PD-A525

PDF Manual
ME-709 manual 01-02-19.pdf....

MARCY ME 709...

PDF Manual
TrakStand Ultra.pdf....

Blackburn TrakStand...

Loading...