Steering crooked CM400T

[Brad from Lasalle]

The CM400T I picked up had hit something with the previous owner. The bars are crooked to the right when driving straight. The headlamp bucket was broken, the right side headlamp chrome overfork side cover is dented and the right side of the handle bar is lower than the left. The gauge cluster is also tilted to the right and the fender is damaged. I pulled everything apart and found the lower steering stem fork tube holes were misaligned so I replaced the lower stem. I took apart the shock tubes and rolled them on the countertop. No obvious wow in either. When I reassembled everything the crooked bars were less but still crooked. Does anyone think it is possible that the upper stem aluminum housing is also bent? I had loosened all fender attach bolts and even the front axle nut but I couldn’t get it to align and stay that way. Thoughts?

 

[LongDistanceRider]

Possibly the bars are bent, easy to check. Just use a straight something and hold against the bar mounts to measure from the bar ends to the straight thing.
Most of the time it's just a case of loosening the lower triple clamp bolts and the axle, then wiggling the bars left/right until it sits straight.

 

[Brad from Lasalle]

Possibly the bars are bent, easy to check. Just use a straight something and hold against the bar mounts to measure from the bar ends to the straight thing.
Most of the time it's just a case of loosening the lower triple clamp bolts and the axle, then wiggling the bars left/right until it sits straight.

the bars are in fact bent, I forgot to mention that. I plan on trying to straighten them this weekend. The right side handle is lower about an inch compare to the left. I am thinking about getting a couple 2x4x6’ boards and C clamping them to the front and rear wheels to ensure they are aligned, then see how far off the bars are and if twisting the forks with the lower clamps and axle nut loose can get them aligned.

 

[mike in idaho]

Remove the handlebars and lay them on a flat surface, it will be obvious if they're crooked. Did you check the front axle for straightness?

 

[Brad from Lasalle]

Remove the handlebars and lay them on a flat surface, it will be obvious if they're crooked. Did you check the front axle for straightness?

Mike, thx. I have straightened the handlebars as they were bent but I did not check the axle. What makes me think it is the top of the tree is bent is the cluster itself is tilted down to the right not twisted to the right. I keep plugging away at different things. I ordered to stop piece for the steering stem just in case. It’s due in the end of next week.

 

[Brad from Lasalle]

Mike, thx. I have straightened the handlebars as they were bent but I did not check the axle. What makes me think it is the top of the tree is bent is the cluster itself is tilted down to the right not twisted to the right. I keep plugging away at different things. I ordered to stop piece for the steering stem just in case. It’s due in the end of next week.

I checked the axle, it is good. My bars were straightened and when looking at them on the bench laying them flat they no longer rock due to the twist they had. When put on the bike the rh side is still lower at the end by 1/2 to 3/4” . The top stem piece is my last attempt which I will get next week.

the bike runs pretty well, there is a little hesitation after take off from a stop and light back fire when letting off the throttle. Higher range power seems ok but I haven’t taken it over 40mph yet. Need brakes to work better before doing that!

I had to order a front master cylinder / handle assembly as this one is sun cooked, eroded and cracked, the piston is leaking as well onto the handle. I also ordered a front fender from British Columbia to replace my damaged one. Next I need a lh collector box cover. I made a tin shield to cover the rusty box for now, you can see it in the picture.

One bummer is it appears as though battery acid was spilled onto the muffler and frame on the left side so it’s discoloured the Chrome and paint looks like it may have ate it away. No polish or steel wool is helping to make it go away. Looking forward to a ride.

does anyone have an idea if seat covers with Honda on the back are still available? This one has a few holes and a tear in the back.

 

[ancientdad]

You might find a seat cover on eBay, I know some here have had good luck. If it doesn't have Honda on the back, there are also stencil sellers on eBay. I bought a stencil for the Chinese seat on my 450 and it turned out pretty good. (I just looked for the seller and he isn't there anymore)

 

[Brad from Lasalle]

You might find a seat cover on eBay, I know some here have had good luck. If it doesn't have Honda on the back, there are also stencil sellers on eBay. I bought a stencil for the Chinese seat on my 450 and it turned out pretty good. (I just looked for the seller and he isn't there anymore)

View attachment 8621

that looks really good. Ok thank you for the info. There is so much on eBay that is priced right if you live in the US. Every time I order there is shipping and import fees that jack up the total. Ugh…

 

[ancientdad]

There is so much on eBay that is priced right if you live in the US. Every time I order there is shipping and import fees that jack up the total. Ugh…

I know, and it's a shame it's that way. You'd think there would be an option for eBay to transfer products to the UK under their own sales management like David Silver does if something is in the US warehouse and a UK buyer needs it. I suppose even if someone over here bought something for someone in the UK and shipped it personally, you'd still have some issues with customs and possibly VAT but obviously I don't know enough about it.

 

[LongDistanceRider]

that looks really good. Ok thank you for the info. There is so much on eBay that is priced right if you live in the US. Every time I order there is shipping and import fees that jack up the total. Ugh…

We have a member in Vancouver BC who has a PO Box in Pt. Roberts Washington. US purchases go there and he takes leisurely drive to pick them up. I'm sure he declares everything :lol:
Detroit is just across the bridge from you.

 

[Brad from Lasalle]

We have a member in Vancouver BC who has a PO Box in Pt. Roberts Washington. US purchases go there and he takes leisurely drive to pick them up. I'm sure he declares everything :lol:
Detroit is just across the bridge from you.

Unfortunately with the border closure I have been limited to Canadian available items or pay lots for the international shipping. It is what it is. Once it opens up , hopefully soon, I can start to use the UPS store in downtown Detroit. You can send parcels to the store without a PO Box and they will call you. 5 bucks a day for holding the parcel while you come to get it. Usually I pop over after work and grab it. Gas , about 40 mins in time and $ 12.00 in tunnel fees later , I am back to Canada so not too bad.

 

[ancientdad]

Unfortunately with the border closure I have been limited to Canadian available items or pay lots for the international shipping. It is what it is. Once it opens up , hopefully soon, I can start to use the UPS store in downtown Detroit. You can send parcels to the store without a PO Box and they will call you. 5 bucks a day for holding the parcel while you come to get it. Usually I pop over after work and grab it. Gas , about 40 mins in time and $ 12.00 in tunnel fees later , I am back to Canada so not too bad.

I'm an idiot, I wasn't paying attention to you being in Canada - I'm always thinking of the UK in these situations. $12 in tunnel fees? Wow, along with the $5 a day to hold it for you, still not cheap.

 

[old timer]

I had a similar problem an a CB 77 and found the triple tree bent down on the right side.

Bill H

 

[Brad from Lasalle]

I had a similar problem an a CB 77 and found the triple tree bent down on the right side.

Bill H

thank you Bill. That is what I am leaning towards as well.

 

[Brad from Lasalle]

I received the replacement upper clamp today and when I swapped it out things got worse. So I pulled the entire front end off the bike again and was mixing and matching pieces to try and get it to align without forces. I found the the new used upper clamp I just got is bent, you can see it when placing it on the flat counter top… feel like I was ripped off on that one…. Now that I am digging deeper in to this it looks to me like the lower fork tube may be bent. Since when I attach the top of the trees the lowers are out of alignment to get the axle inserted. I guess that could go both ways, hole the bottom and the uppers are out, hold the uppers and the lowers go out. I have to use extreme force to get the wheel to align to the upper clamp/bars and headlight.

Anyone have methods you can share to check the fork lower tubes? I already had them apart and rolled the upper tubes on the Formica countertop and there was no wobble to those.

I am also looking for any ideas on things to check next. There is really only 4 parts to this, 2 forks, lower clamp and upper clamp.

thanks!

 

[LongDistanceRider]

Rolling the tubes will reveal a large bend assuming the surface is actually flat. A straight edge and bright light on one side will allow you to check the entire length, there should be zero light between the straight edge and tube.
The tubes should slide into the lower and upper evenly. Insert one tube in and snug it, then attempt to slide the other in w/o manipulating either upper or lower. Repeat on the other side. If they both insert smoothly then the triples are both good and all the holes are in alignment. That leaves the fork tubes.
PM sent

 

[Brad from Lasalle]

Rolling the tubes will reveal a large bend assuming the surface is actually flat. A straight edge and bright light on one side will allow you to check the entire length, there should be zero light between the straight edge and tube.
The tubes should slide into the lower and upper evenly. Insert one tube in and snug it, then attempt to slide the other in w/o manipulating either upper or lower. Repeat on the other side. If they both insert smoothly then the triples are both good and all the holes are in alignment. That leaves the fork tubes.
PM sent

I took the forks apart again and pulled the uppers out. They do have a bend in them both. I can see light when rolling them and when I put a straight edge on the tube it rocks where the lower tree clamp is. I have them cleaned out and will drop them at the local motorcycle repair shop as he has a press to straighten tubes with. I will update the post when I get them back and reassemble the tree to the forks with the wheel attached .

 

[ancientdad]

I took the forks apart again and pulled the uppers out. They do have a bend in them both. I can see light when rolling them and when I put a straight edge on the tube it rocks where the lower tree clamp is. I have them cleaned out and will drop them at the local motorcycle repair shop as he has a press to straighten tubes with. I will update the post when I get them back and reassemble the tree to the forks with the wheel attached .

Now you've gotten to the heart of it. I wasn't suspecting the top bridge being too bent, it takes much more leverage up there compared to the steering stem and though the aluminum will bend, it's less likely, just like the lower legs (sliders) are more stout and less likely to bend. In worse situations I've seen the top bridge get cracked at the clamping area of one tube when things are really bent, it generally breaks at some point instead of bending. If the shop has decent experience with straightening fork tubes you should be fine, a minor bend like yours is absolutely repairable when done right.

 

[Brad from Lasalle]

Now you've gotten to the heart of it. I wasn't suspecting the top bridge being too bent, it takes much more leverage up there compared to the steering stem and though the aluminum will bend, it's less likely, just like the lower legs (sliders) are more stout and less likely to bend. In worse situations I've seen the top bridge get cracked at the clamping area of one tube when things are really bent, it generally breaks at some point instead of bending. If the shop has decent experience with straightening fork tubes you should be fine, a minor bend like yours is absolutely repairable when done right.

thanks for the info. I totally agree about the upper not really being a factor unless it took a direct hit on something as it is locked in there pretty good. The allowable fork runout is .008” , so if I can see it with my eye on the table then I know it it’s much worse than that. Keeping my fingers crossed that this will correct my issue. At least with taking this apart again, it gave me an opportunity to do some more cleaning and painting of the black components.

The place I bought the upper clamp from on eBay refunded my money last night when I told them it was twisted and not able to put the rh fork tube inside the opening without major force. I really like businesses like that who take care of the honest customer base.

 

[ancientdad]

The place I bought the upper clamp from on eBay refunded my money last night when I told them it was twisted and not able to put the rh fork tube inside the opening without major force. I really like businesses like that who take care of the honest customer base.

Good that you got cooperation from them, these days it's not the norm for that to happen, more like the total opposite. Can't trust anyone anymore unless you've known them for a long time.

 

[tomeben]

I took the forks apart again and pulled the uppers out. They do have a bend in them both. I can see light when rolling them and when I put a straight edge on the tube it rocks where the lower tree clamp is.

Great job working through this and finding your fork/alignment issue. Good deal it’s repairable, and that you found a reputable eBay seller.


Tom - 1982 CM450E

 

[Brad from Lasalle]

Update info. Starting with I am pulling what’s left of my hair out…. Picked up the fork tubes from the repair shop, The mechanic said he got them within .004” which is within spec. I reassembled the sliders on the tubes and put everything back together. I put the steering tree lower clamp in the neck of the bike then added the upper ball bearings and put the capture nut on the top. I slid the left fork tube up to the witness marks for the lower clamp and snug torque it just to hold it. Did the same with the right side. I then put the upper cap on and all 3 holes lined up perfectly with the fork tubes and steering stem. I left the large center nut loose and also just loosely install the upper fork clamp bolts. My confidence level was pretty high that these would now be aligned. I installed the handle bars on the top clamp.

when I got on the bike and held the bars straight to the headlamp bucket I looked down at the axle with no wheel installed, it was quite crooked to the left. See pictures.

I then put the wheel on( no fender) in order for me to put weight on the forks so I could loosen the lower clamp bolts and not drop the tubes. With the 4 locking bolts and center steering nut loose I can twist the heck out of this to get it close to aligned but when I hold it there and tighten the bolts it pulls it somewhat back off alignment, no where near as bad as the pics though. This is the same phenomena I started this journey with. I turned each lower slider independently 180degrees and the axle still aligned to the other side so I don’t think the lower slides are bent.

Now I am really stumped on this one. I am open to any suggestions.

thx

 

[ancientdad]

At this point I'm guessing the steering stem has been flexed from the bend in the tubes. Did you roll the tubes before reassembling the forks to see how accurate his measurements were? If the tubes are truly straight, you can clamp one fork in the steering stem and use the length of the assembled fork to slightly twist the one side of the steering stem where the tube clamps to get it straight again, I've seen my father do it many times after straightening fork tubes. Maybe set a straight edge across the clamps of the steering stem to see if they're parallel.

 

[Brad from Lasalle]

At this point I'm guessing the steering stem has been flexed from the bend in the tubes. Did you roll the tubes before reassembling the forks to see how accurate his measurements were? If the tubes are truly straight, you can clamp one fork in the steering stem and use the length of the assembled fork to slightly twist the one side of the steering stem where the tube clamps to get it straight again, I've seen my father do it many times after straightening fork tubes. Maybe set a straight edge across the clamps of the steering stem to see if they're parallel.

I should have loose assembled the fork tubes in the lower steering stem clamps before I put it on the bike. That’s how I realized the original one was bent as the unit rocked when placed on a flat table top. I have replaced the lower clamp already. I may still need to pull it apart and assemble them on the table to see if they are straight/parallel. I did roll the tubes on the countertop and looked with the flashlight to see if they was any bend and I couldn’t see any like before I took them to the mechanic. I am going to try and see if brute force can get this aligned and if it still functions ok once straightened. If it doesn’t I will pull it apart again and verify the tubes to clamp alignment.


update July 6– I put some twist in the assembly with my son on the bike adjusting the bar rotation, then once it looked straight I tightened all the fasteners . After doing that 3 times, since you need a road test to validate it, we finally got it pretty straight. Everything looks pretty good and drives ok.