26" mtb wheelset on 27" 80's centurion

[kwogfive]

Hello everyone Kwog here,

I like bikes, in fact I just took a sledge hammer to a piano to make room for more bikes to hang on the dining room wall!

I am doing the Katy trail in Missouri this weekend and there has been a lot of rain. I bought the widest 27" tire from Nashbar and had a clearance issue due to height (hit the bottom of the brake), I am trying to get a bigger contact patch so I don't sink in the soft spots. Has anyone attempted to put a 26" mountain bike tire on an older bike that came equipped with 27" tires. I thought I could swap out the brakes for some off of a bmx bike to cure the reach issue. I also am having questions about the rear spacing, the MTB wheels that I could use have 8 speeds, the Centurion is a 6 cogger in the back. Just curious if anyone has tried this or knows of a link to some info on this type of conversion successful or not.

I am trying to prevent myself from spending the money on another diamond frame bike when I really want my next purchase to be a recumbent. If I can make the Centurion more of a jack of all trades that would solve my problem.

I've done the google search and I was hoping maybe you folks would be able to help me.

Thanks in advance,

Kwog

 

[alfeng]

I am doing the Katy trail in Missouri this weekend and there has been a lot of rain. I bought the widest 27" tire from Nashbar and had a clearance issue due to height (hit the bottom of the brake), I am trying to get a bigger contact patch so I don't sink in the soft spots. Has anyone attempted to put a 26" mountain bike tire on an older bike that came equipped with 27" tires. I thought I could swap out the brakes for some off of a bmx bike to cure the reach issue. I also am having questions about the rear spacing, the MTB wheels that I could use have 8 speeds, the Centurion is a 6 cogger in the back. Just curious if anyone has tried this or knows of a link to some info on this type of conversion successful or not.

I am trying to prevent myself from spending the money on another diamond frame bike when I really want my next purchase to be a recumbent. If I can make the Centurion more of a jack of all trades that would solve my problem.

I think the odds of a 26x2.1" tire fitting between the chainstays of any Road bike are low ... if your Centurion were a Touring bike, then I would say the odds would be better ...

I have a 90s vintage GIANT Nutra frame that I can fit 700x52 (29er) tires into.

I think your adventure on the Katy Trail should be done on a Hardtail MTB (that is, if bikes are allowed on the Trail -- check first!).

BTW. HARRIS CYCLERY sells the largest 27" tire that I know of (it may/must be available from other retailers, too):

40-630 27 x 1 3/8"
Very Aggressive knobby tread, blackwall, 40-65 psi -- $24.95
27 Inch Bicycle Tires from Harris Cyclery (ISO/E.T.R.T.O. 630 mm)​

 

[alfeng]

I also am having questions about the rear spacing, the MTB wheels that I could use have 8 speeds, the Centurion is a 6 cogger in the back. Just curious if anyone has tried this or knows of a link to some info on this type of conversion successful or not.

The rear spacing on your Centurion is undoubtedly 126mm ...

A MTB's rear wheel will have 135mm spacing ...

You can EITHER re-space the frame OR re-space the rear wheel's OLD (over locknut distance) ... or, both so that the both frame & rear wheel is 130mm.

The dropouts on a frame whose rear dropouts are re-spaced need to be re-aligned. This can be a DIY project ...

Re-spacing a frame simply needs a little knowledge and a lot of patience ... NO ADDITONAL LEVERAGE OTHER THAN WHAT YOU CAN PROVIDE WITH YOUR UPPER BODY STRENGTH SHOULD BE USED. Remove the rear wheel, grab the dropouts, & use only whatever you perceive to be 30 lbs. of force ... measure, repeat.

Re-aligning the dropouts is most easily done with a pipe wrench whose jaws sandwich a couple of pieces of scrap plywood which shroud the dropout ... STEEL DROPOUTS ARE SOFT ... use whatever you perceive to be 5 lbs. of force. Repeat as needed.

 

[kwogfive]

It worked well up front but the tapering chainstay near the bottom bracket won't allow anything approaching 2.0 to fit. It looked pretty ridiculous having that big tire up front and a skinny in back. By the way the Katy Trail allows bikes, hikers and horses for about 20 miles. 225miles car free!

Kwog