I need a rear tire for my six days for racing. I bought a Pirelli 110/100/18 and it looks way too big. After searching the posts here, I see that Cheng Shin C755 4.10-18 is recommended. Would someone mind confirming this? By the conversion charts I have looked at, it doesn't sound that different than the 110. Is the Pirelli I bought too big as I suspect?
Thank!
3:50 x 18"
I know that is the stock size. Why can't I find an mx tire that size? Sources anyone? Much appreciated.
I have a 350 x 18 Barum on my 69 Steeltanker...but I do not race that bike...doubtful that a 400 section tire would clear the swing arm.
Perhaps a 400 will fit on a CMF...someone else will have to offer an opinion on that.
That 110/100 will surely be too big.
I do use a 100/100/18 Maxxis on a 73 Husky 125 WR that is used for CC races.
Works quite well.
Perhaps do a search for a good 100/100
Richard Colahan
1969 V1225
Upper Black Eddy PA
Since you have not stated whether you have a Six Day Steeltanker or Six Day CMF, the tire answer can be different for each of these models. The Steeltanker has fewer choices.
Several of us have numerous times stated that the Duro H335 is an excellent choice for a rear tire. It fits the short swingarm on Steeltankers very well.
I have used both Cheng Shin and Duros and find the Duro far superior for my riding in both Cross Country and MX events on my Steeltanker.
The CMFs Pentons have a longer swingarm and can take a wider and higher profile tire, but I am not sure why you want anything bigger on a 125cc.
Also, Duros are much easier to find than Cheng Shins.
Bill Ryburn
V1893
Thank you for replies. It is not so much that I want to put a large tire on my cmf framed bike. I tried to match what was on there which was a 4.00-18 not knowing this was not stock. The swing arm on my bike is from a later bike and not stock so fitment may not be my issue. I have gathered from this site that I don't want to put too large a tire on the smaller engined pentons. My concern is changing the handling of the bike too far from design. I am not familiar with Barum and Duros. I will keep them in mind. Thanks again for your time.
For what it's worth, used to run a 3.50 Metzler on the 100 & 125
The 4.00 always seemed like too much tire. Harder to "break loose" when you wanted it to,
I think it is important to note that one manufacturers 3.5 or 100 or 110 width is not the same as the next. Some have larger side lugs which make the overall profile wider. Although the rim side is fixed the outside diameter also varies. You really need to get that overall dimension(s) although at times it's not so easy to find published. I run a Metzler 100/100 MC5 on my '74 Berkshire which has worked well in all conditions.
Dale Fisher
Penton Owners Group - Memberships
Facebook - Cheney Twinshock Racing Group - Administrator
'70 Six-Day 125 - V2017
'71 Six-Day 125 (Dave Fisher's) - V5553
'72 Mudlark - W257
'73 Jackpiner - 175 21159727
'74 Berkshire 100 - 40171056
And some silly other bikes...
Agree with the opinion that same sizes differ in reality per manufacturer.
And as a point of reference...my modern era Honda CRF250X...which has significantly more power then a 70's Sachs 125...specs a 100/100/18 tire. A 110/100 actually seems like too much tire for that bike.
Don't fear that a "smaller" tire will hurt...It's more likely to be just right!
Richard Colahan
1969 V1225
Upper Black Eddy PA
The Pirelli is WAY too big. The Cheng Shin and Duro 4.10-18 tires are much smaller than their number indicates, much closer to a Metzler 3.50-18. As far as I know the Cheng Shin is no longer available, and the Duro is now the only option that is small enough. The Duro HF335 is a much better tire than the C755 anyway.
Brian
My memory is a little foggy, but was there a Metzler 3.75 x 18 back in the 70's? I thinks that was what we (at Piasecki's) were running on our 125's
Jeff
Duro 4.10X18 with a Pirelli MT16 front.
A Cheng Shin can be also used but is a bit smaller tire.
Not trying to get off track on the subject, but has anyone tried the IRC Volcanduro VE33 tires? My RM restorer friend uses them and they have a 100/100-18, and look vintage. It is listed more for intermediate to hard terrain. Mike
Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Try kings tires, I have 100/100/18 on my super rat. looks about to be a 3.75x18 in size
The VE33 is too big for a Steel Tanker or CMF Sachs Penton. That would be a great tire for a Jackpiner.
Brian
I had my Berkie at the Penton display at the Seattle supercross, I was talking to a tire manufacturer about tires. Wanted to know if there's a market for the smaller tires. Cant remember who it was. It sounded like to me they had the rights to the Metzeler mold and are thinking of making a metzler copy 3.50 and 4.00
Pirelli owns Metzler so it was probably them.
Brian
I am finishing a 69 Steel Tanker that has a Cheng Shin C-755 3.50 X 18 rear tire on it which rubs the Chain Guard and it is not acceptable. The widest part of the rear tire measures 3.93 inches.
My estimate is that the widest part cannot be greater than 3.75 inches.
Anyone know of a rear tire that is close to 3.75 inches in width?
Thanks for any ideas.
Tony
Bill Ryburn has a 4.10-18 Duro HF335 on his Steel Tanker and it does not rub the chain guard.
Brian
Brian is correct. The 4.05" maximum width Duro does not rub the chainguard on my late '69 Steeltanker (V1893.) I just measured the distant from the chainguard to the opposing swingarm tube, at the point of the widest part of the tire, and the width is 5".
With the Duro I have about 1/2" clearance on each side, and I had a little more when I was running the CS.
My Steeltanker is running the original Radelli rim and has never been re-spoked. Also has the original chainguard.
Could you possibly have a re-spoked rim that is offset to the right? Or have incorrect spacers at the hub? Do the sprockets align correctly? How much clearance doyou have on the opposite side from the chainguard?
The CS should fit, so something isn't right.
Bill Ryburn
I was not going to say that, but if the 3.50-18 Cheng Shin does not fit, something is wrong with your wheel offset or spacers. The Chinese tires like the Cheng Shin C755 and the Duro HF335 are actually much, much smaller than their listed size. The C755 3.50 is an extremely narrow tire and should not have any problem fitting a Steel Tanker or CMF without rubbing.
Brian
Quotequote:Originally posted by brian kirby
The VE33 is too big for a Steel Tanker or CMF Sachs Penton. That would be a great tire for a Jackpiner.
Brian
Brian, They now have a 100/100X18 VE33. Much smaller than the 110/100X18 that you are thinking of.
The VE33 is a copy of an early 80s Trelleborg. I put them on my PV Husqvarnas.
Dwight,
How well do the VE33 work in various terrain? Thanks, Mike
Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Quotequote:Originally posted by Dwight Rudder
Brian, They now have a 100/100X18 VE33. Much smaller than the 110/100X18 that you are thinking of.
The VE33 is a copy of an early 80s Trelleborg. I put them on my PV Husqvarnas.
I was thinking of the 110, but a 100/100 would still be too big for a Steel Tanker wouldnt it?
Mike, the VE33 is the only good tire you can get for the 17" rear wheel on Husky's and its a fantastic tire. Its an intermediate tire and works really well everywhere.
Brian
Thanks all for comments. Here is my project. I ended up getting a cheng shin 4.1X18. It looks about same as 4 X 18 that is on there.
(http://i298.photobucket.com/albums/mm251/lamarilium/image-1.jpg) (http://s298.photobucket.com/user/lamarilium/media/image-1.jpg.html)
Can anyone identify the rear swingarm? I understand it to be off a later '70s 250
Just installed a 4.10 x 18 on my 72 125 six days restoration. Just fits, and clears the chain guard too. Tight fit though.
Prior to restoration it had a 4.50 x 18 on it before, hence a damaged chain guard from tire rub.
LOL
Quotequote:Originally posted by jasonlamar
Can anyone identify the rear swingarm? I understand it to be off a later '70s 250
Looks like a stock swing arm to me. A KTM engine swing arm wont fit a Sachs without a lot of modification.
Brian
Oh... So its just red. I was told the three shock positions was not stock. Ok, that clears that up for me. thanks!
I need to get a new photo of this swingarm uploaded. I am trying to get a chain guide mounted and the tabs are not on the bottom for the typical '73 six days. there are the front "pins" where the guide attaches, but the rear mounts are on the top of the swing arm. does this sound familiar to anyone? I have the correct chain guide for my model, but it won't hook up. It was great to see everyone at the potluck at Mid-ohio. I wasn't able to stick around for the meeting but did enjoy seeing everyone that was there.
(http://i298.photobucket.com/albums/mm251/lamarilium/iphone8-6-2015%20100.jpg) (http://s298.photobucket.com/user/lamarilium/media/iphone8-6-2015%20100.jpg.html)
Here is a pic of my swing arm. The chain guide I bought needs to hook up to tabs on the bottom of the swing arm. Are the chain guides for high breather frames different than cmf?
The three rear shock mounts are stock, the front mount is a modified shock mount not a chain guard mount. Both the top chain guard and bottom chain guide mount have been removed.
Brian