Need help with my Grande... Zippy? anyone?

I recently got a 1980 Grande and am starting to do some repairs. Right now I'm having a problem with what may be a pretty basic thing.... the pedal mechanism. Something seems to be broken or loose inside the case where the pedals fit into, because the bar holding the two cranks for the pedals is very wobbly, making it difficult to keep the chain on. My problem is that the pedal cranks seem to have rusted over too much to get them off... I work on my mountain bike alot, but there's no easy way (like just using a hex-wrench) to get these things off and get inside. Any suggestions for my dilema? Thanks.

Also, is there anything posted about the best way to get the engine off of the Grande frame to work on it?

Re: Need help with my Grande... Zippy? anyone?

Jonathan Wyatt /

I found some old posts that casey had with this problem. Some of the suggestions sound good. But I still can't seem to get the pedal cranks off. The screw is jammed and bent in there. How should I get them out without ripping up my cranks or anything else?

Re: Need help with my Grande... Zippy? anyone?

If the pin is bent, you may have to drill it out.

Other than that, it works like a cottered crank on a bicycle.

You will find that there are two nylon bushings that the pedal shaft goes through that may be worn out.

Vespasupershop.com would have them.

Jim

Grande Pedal Problems

Jonathan Wyatt /

Hey Jim thanks for responding. I'm not too familiar with a cottered crank. The pin that is screwed into the pedal cranks doesn't have a head (flat, phillips, hex) on it at all so how would I unscrew the pin? If cottered cranking removes it... how do I do that?

So the nylon bushings are inside the subframe? If I am able to get the cranks off and get inside the subframe, you think that replacing these would solve the wobbling?

Let me know what you think... especially about getting those pins out...

Not like a mountain bike

Matt Wilson /

Its more like a 1970's era road bike cranks. Loosen the bolt and bang the pin out.

Don't remove this pin unless you need to because you will often have to replace it afterwards. You can get them from any bike shop thats been around a while.

Matt

Re: Need help with my Grande... Zippy? anyone?

Ron Brown /

Jonathon,

Here is way too much info on cranks and cotter pins, sone new, some from older posts.

The cranks are held on by "cotter pins". They are smooth and round with a tapered flat on one side which wedges them in place when you tighten the nut.

The best way to remove them, if they are in good shape, is to loosen the nut until it is flush with the end of the threads, then whack it with a brass hammer. When it comes loose, take off the nut and tap it out.

"Some rules. Cotter pins are installed with the threads in opposite directions. Cotter pins must have perfectly smooth flats, if you can't clean them up with a file, get new ones. Most bicycle shops should have them. With the left side pedal pointed forward, the right side cotter pin should have the thread pointed down, the left side, thread up."

This is a little more specific because it puts the heavyest loads on the widest part of the cotter pin. I also like to re-tighten the cotter pins after they have had a few minutes to seat or after the first ride.

Do not hammer the cotter pin in! Once the flat on the pin is notched from hammering, there is no way to tighten it. Make sure the tapered flat is not notched from previous use, that the crank and/or spindle are not worn to a bad fit by running with a loose cotter pin. Tighten the pin with a wrench while wiggling the crank to align it. Re-tighten after riding a little.

Re: Grande Pedal Problems

Jonathan Wyatt /

Thanks Ron and Matt. I have taken the nuts off the to cotter pins already and I have tried to hammer them out. One of the pins seems like it is almost out but is still lodged... what type of wrench would latch onto it to pull it out? I've tried pliers and an adjustable allen wrench.

For the other pin there is an added problem, when I unscrewed the nut, part of the pin broke off with it. So the pin isn't long enough to really hammer out in the first place. What do you recommend for this?

I appreciate everyone's help. Hopefully we'll get this problem solved soon.

Re: Grande Pedal Problems

Jon:

A book on bicycle repair from you library will show you how a cottered crank works.

The only diference here will be that instead of bearings, you have bushings as I described before.

Once you remove the padal arm and pull out the shaft with the sprocket, you will see haow simple the setup is.

Jim

Re: Grande Pedal Problems

Ron Brown /

You need a flat ended punch. Concentrate on getting one side out, then work on the other side off the ped

Ron

Re: Need help with my Grande... Zippy? anyone?

Hello Jonathan

Hopefully you have gotten the pins out by now, if not, do as the other poster said in previous posts and tap the pins out with a flat end punch. You will have to buy new pins. You can buy them from a local bike shop or From Fabio at the Vespa Super Shop. If you buy them at a local bike shop you may have to file them down a little so they fit properly. There are slightly different widths in these pins so check it against on e of your pedal cranks.

On to why your pedal wobbles and the chain won't stay on.

You will notice the Grande has a "subframe" that the pedal crank goes through. The rear wheel and engine also attach to this Subframe.

What has happened is, someone has been riding with the left and right pedal in an UP and DOWN position and the DOWN pedal has hit the ground. When this happens the subframe is usually damaged and the round hole where the pedal shaft goes through the subframe belongs elongated or tear dropped shape. The pedal shaft no longer fits securely through the holes and thus the wobble occurs and the chain comes off.

How to fix.

Remove the left pedal crank arm. Squirt some WD40 around both sides of the pedal crankshaft where it goes through subframe. Now tap the shaft through the subframe noting where all pieces are so you will know how to reassemble.

When you get the pedal shaft out you will see two black plastic grommets (one on each side of the subframe) that fit in the frame that holds the shaft in place. One probably will come off with the pedal shaft.

Inspect the right side of the subframe that is usually the one that is damaged or torn. It is very difficult to bend it back out because that area of the subframe is boxed in. There are two ways to repair the damage, one is a quick and temporary way and the other is a permanent way.

The quick way is to cut a piece of metal that is about the same thickness or gauge as the subframe metal. Cut a piece that is about 2-3 inches wide by about 6 inches long. Use a pair of pliers to shape this metal into a cone shape (like an ice cream cone shape). Stick the small end of the cone in the damaged subframe hole and tap it in and leave about a 1/8 to 1/4 of an inch lip so the cone doesn

Re: Need help with my Grande... Zippy? anyone?

Follow Zippy's advice, but take the second approach. One of my Grandes came with a butchered subframe. One of the back wheel mounts had torn through, and the pedal hole was torn. It had clearly been used as a dirt bike (there was all kinds of dirt built up in the centerstand and in the cylinder head fins). I welded washers in both places and it works perfectly. I can put as much pressure on the pedals as I need, and there are no problems.

Chris S

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account