2000dan2000

Hey everyone, greetings from Colorado.
Names Dan, new member here and really a new member to the bike community. I know next to nothing about these things and have really learned everything I do know in the past few weeks while working on restoring the new/old bike. I picked this old Batavus up off of CL a few weeks back to use a city tourer/commuter. I put a lot of elbow grease into her and replaced a few broken parts and got her back on the road however, a few issues still remain.

Question: The old Simplex RD is, well, sh*t. Most of the teeth on the pulleys have broken off so I'm going to upgrade it. Question is, will a newer more modern RD work with this? I should be able to re-use the old hanger no? Any issues I should know about before picking up a new RD?

Also, I would like to replace the saddle with something else however the seat post on this bike has a different mounting system on it where a new saddle with the round attachment bars won't fit. The seat post diameter is different than that of my more modern mountain bike (smaller) is there an old standard size that the old bikes use?

Anyways, thanks in advance. I have been bitten by the vintage bike bug so I'm sure I'll be trying to pick everyone's brain here more and trying to learn as much as I can.
Cheers,
Dan

Wogster

New RD's should work, the only thing is, most of the newer ones have more speeds, so you may need to run a narrower chain, to get through the RD. Although I don;t think the 6 speed Suntour on my Raleigh is any wider through the cage then the 8 Speed Shimano on the Norco mountain bike. If the only problem though is the jockey and idler wheels, then take the old ones to a bike shop, you may be able to get new ones that are a close match.

SJX426 

Those derailures are prone to breakage over time as they are made of Delrin. There are other Simplex options such as the one depicted here (https://www.velo-orange.com/deandsh.html), for the broken jockey wheels, this URL has replacements. The derailures are french so the threading is unique. I am sure others will respond with more detailed info.

Measure your seat post diameter. There may be a more modern post available. Here is another site with options: https://www.universalcycles.com/shopp...p?category=167.

If you have a post/clamp/seat combination, it was the standard approch in the 70's.

2000dan2000

Thanks for the replies. The idler and jockey wheels (see, I learned something new already!) are both broken yes, but the plastic case has a crack in it as well so I figured I'd just upgrade to something a bit more sturdy. I did not know about different chain widths, that's something I'd like to avoid, buying a new chain that is.
Maybe my best option is to bring it to the local bike shop and have someone put their hands on it figure it all out.
Thanks for the links!

DiegoFrogs

I'd go with an older Suntour derailer with the "claw" adapter. Most of them work remarkably well.

2000dan2000

Thanks for the heads up. I would like to keep it all vintage if I can but I also need to keep as affordable as I can for the time being, those Suntours look like they may fit the bill, cheaper than the old Campy stuff I've been eying at any rate

redneckwes

Nice Batavus,

I have a similar frame in the dark brown color.

I'll second the Suntour deraileur, they work wonderfully.