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The 2-Stroke Garage => Turning Wrenches => Topic started by: Dvsrd on September 21, 2020, 12:20:32 PM

Title: 10 mm shorter swing arm bolt for RD350A
Post by: Dvsrd on September 21, 2020, 12:20:32 PM
I am now converting my RD 350A to cable actuated rear brake, and replacing the passenger peg/ muffler brackets with some alloy brackets that only mount to the 2 M8 lugs each side
This makes the stock swing arm bolt 10 mm too long. For now, I'll use aluminium spacers, but a 10 mm shorter bolt would be much better.
So, will a bolt from an other model or other brand fit?
Maybe TR350 or early TZ?
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: m in sc on September 21, 2020, 12:26:16 PM
just make a spacer, or thick washer.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: Dvsrd on September 21, 2020, 12:46:19 PM
Just about to fire up the lathe and make 2 alloy spacers, 5 mm thick.
It is just that a shorter bolt would give just that little extra clearance for the brake cable and shifter linkage.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: m in sc on September 21, 2020, 01:10:39 PM
use steel. ask how i know.

Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: Dvsrd on September 21, 2020, 02:29:01 PM
Quote from: m in sc on September 21, 2020, 01:10:39 PM
use steel. ask how i know.


Point taken 😁
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: 1976RD400C on September 21, 2020, 04:14:17 PM
Can you thread the bolt with a die 10mm more and then cut it off in your lathe to make it shorter?   :umm:
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: Jspooner on September 21, 2020, 04:50:08 PM
Quote from: 1976RD400C on September 21, 2020, 04:14:17 PM
Can you thread the bolt with a die 10mm more and then cut it off in your lathe to make it shorter?   :umm:

I did this for the pivot bolt on my TZ replica. The frame is a TR3 frame and one side is threaded for the bolt to screw into with out a nut but I left it long enough to put a nut on it.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: oxford on September 21, 2020, 05:06:08 PM
Quote from: m in sc on September 21, 2020, 01:10:39 PM
use steel. ask how i know.

Curious as to what alloy you had problems with?  I have heard 6061 is not really ideal for wheel spacer bushings, 7075 is a much better option.  I believe this came from Leo in the triples board.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: m in sc on September 21, 2020, 05:36:22 PM
was 6061. but 7075 will also compress. steel is better for this application, just is. or, cut the end off as said and weld a 'new' end on. there's 10 different ways to do it.

Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: Dvsrd on September 21, 2020, 06:44:20 PM
Quote from: 1976RD400C on September 21, 2020, 04:14:17 PM
Can you thread the bolt with a die 10mm more and then cut it off in your lathe to make it shorter?   :umm:
It is easy to cut more thread in the lathe ("single point"), but I do not have a spare bolt in case I later want to go back to original setup.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: oxford on September 21, 2020, 09:18:07 PM
Quote from: m in sc on September 21, 2020, 05:36:22 PM
was 6061. but 7075 will also compress. steel is better for this application, just is.

No arguments here.  I was just wondering.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: suey1958 on October 16, 2020, 07:36:19 AM
I have the same issue, not so much a clearance problem but sure would look a lot nicer if it was shorter instead of using a washer(s).
I have replaced the the grease fittings on both sides with short allen screws that are flush with the pivot bolt ends. They are of course removeable to replace grease zirks to add grease.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: bitzz on October 16, 2020, 11:03:17 AM
Pretty sure all the TR and TZ swing arm pivot bolts are the same length, about 10mm shorter than the RD
The TR and TZ bolts have a M16x1.0 thread and the RD has a M16x1.25 thread.
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: m in sc on October 16, 2020, 11:26:45 AM
cut the threads off except 1 past the bolt.  :whistle:
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: klaird on October 16, 2020, 06:39:46 PM
Is it possible to reverse the bolt and have long end on the left side?
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: m in sc on October 16, 2020, 06:59:53 PM
Quote from: klaird on October 16, 2020, 06:39:46 PM
Is it possible to reverse the bolt and have long end on the left side?
yup.

Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: suey1958 on October 18, 2020, 07:55:06 PM
Probably will do as Mark suggested and just trim some off for a better look.
That bolt originally had two nuts on it from the factory. My stock 350 has two and also partzilla shows two.
Are having the 2 really necessary or will 1 be OK?  Thanks
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: Jspooner on October 18, 2020, 09:24:10 PM
Quote from: suey1958 on October 18, 2020, 07:55:06 PM
Probably will do as Mark suggested and just trim some off for a better look.
That bolt originally had two nuts on it from the factory. My stock 350 has two and also partzilla shows two.
Are having the 2 really necessary or will 1 be OK?  Thanks

The second one is a lock nut. 
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: m in sc on October 19, 2020, 07:33:48 AM
you can use a 400 nut as i think it only is the one (thicker), or get one from mcmaster. they have nylocks that big. .02
Title: Re: 10 mm shorter swing arm bolt for RD350A
Post by: suey1958 on October 19, 2020, 08:17:31 AM
Thanks, I was aware that the second bolt was a lock nut but wasn't sure it was really needed. The nylock sounds like a better option. Thanks again