Converting 700c hybrid into Mtn Bike

[Blademun]

I have some friends over at the lbs who go on regular rides around town, through local trails and generally everywhere. They also go on mtbing trips to some of the good trails here in Florida. i'd like to come with them but I only have a road bike and a hybrid. I can't afford a new Mtb. I tried to follow them on a ride through a simple nature trail and slipping around on my Hybrids 25c road tires wasn't fun. (Well it was in a "omg this is scary" kinda way)

My Hybrid is a Marin Highway one, 04 model without the carbon stays. I have been thinking about turning it into a mtb. While looking through the lbs catalog I found a Suntour NRX 6000 fork that they'd sell me for 60$. Also found some nice WTB 700x38 29er tires I forgot which variety but they all seem about the same except for size.

My bikes been heavily modified so here is modified specs:
04/03 XT derailers, LX shifters/brake levers
Tektro Mini-V's(awesome brakes)
Sun Assualt rims with Ultegra hubs, 32 spoke.
Truvativ Elita triple crank
sram 12-25 road cassette
crank bro Mallet pedals.

The entire upgrade (fork and Tires) would cost about 90$. Would it be enough to handle some moderate off road use? Or should I stick with my carbon fork and just upgrade the tires? Thats the main question in my mind.

 

[Retro Grouch]

That cheap fork isn't going to help you very much. I'd just stick on the wider tires, inflate them to around 40 or 50psi, and see how it goes.

 

[daveornee]

I have some friends over at the lbs who go on regular rides around town, through local trails and generally everywhere. They also go on mtbing trips to some of the good trails here in Florida. i'd like to come with them but I only have a road bike and a hybrid. I can't afford a new Mtb. I tried to follow them on a ride through a simple nature trail and slipping around on my Hybrids 25c road tires wasn't fun. (Well it was in a "omg this is scary" kinda way)

My Hybrid is a Marin Highway one, 04 model without the carbon stays. I have been thinking about turning it into a mtb. While looking through the lbs catalog I found a Suntour NRX 6000 fork that they'd sell me for 60$. Also found some nice WTB 700x38 29er tires I forgot which variety but they all seem about the same except for size.

My bikes been heavily modified so here is modified specs:
04/03 XT derailers, LX shifters/brake levers
Tektro Mini-V's(awesome brakes)
Sun Assualt rims with Ultegra hubs, 32 spoke.
Truvativ Elita triple crank
sram 12-25 road cassette
crank bro Mallet pedals.

The entire upgrade (fork and Tires) would cost about 90$. Would it be enough to handle some moderate off road use? Or should I stick with my carbon fork and just upgrade the tires? Thats the main question in my mind.

First I would see what tires will work and fit in the frame space with some clearance for mud/sticks/rocks.

 

[garage sale GT]

Why don't you try the tires and see if you still slip and slide, due to the front of the bike bouncing around too much?

Also, I am sure you already measured how much space there is in your frame for fat tires but just in case you didn't, make sure you don't buy anything too narrow.

Just out of curiosity, what are you riding on? Pine needles over sugar sand?

 

[Blademun]

Yeah I measured, I can get up to a 1.8 inch tire in but I prolly wouldn't want anything more then 1.5. The terrain in Florida is 90% sand; a mixture of dense, wet sand, roots and grass, and sugar sand. There are alot of pine needles too.

I had a pair of vittoria semi-slicks that came with the bike. They were 700x38 and seemed to do ok. I've worn them bald though so they are no good anymore. When I was riding on them hitting a patch of roots or wood was painfull, even with the 38mm tires. I know on one trail I had to get off the bike and just walk because the roots were so big and dense that I was being thrown off the bike. This was a swampy area I was riding in at that time. That memory is whats making me consider a front shock.

Maybe later I could consider a true 29er fork. Those are way expensive tho'

 

[alfeng]

...

Maybe later I could consider a true 29er fork. Those are way expensive tho'

OR, you can probably get a SOLID MTB fork which can fit a 29er tire instead of a 29er suspension fork ...

I recently got a "solid"/steel MTB fork (disc mount only) which appears to have more than enough clearance for a 700x58/29er tire.

I think you just have to look for one that is so-called "suspension-corrected" ... of course, some suspension-corrected, solid MTB forks may have narrower shoulders than others. Maybe, I got lucky!?!

BTW. I don't recall what it cost, but I know I paid under $50US on eBay (shipped, CONUS) ...

 

[artemidorus]

I think you just have to look for one that is so-called "suspension-corrected" ... of course, some suspension-corrected, solid MTB forks may have narrower shoulders than others.

Why do you need a suspension-corrected fork for a bike that never had front suspension?

 

[garage sale GT]

Because 29" forks are expensive.

 

[alfeng]

Why do you need a suspension-corrected fork for a bike that never had front suspension?

NEED? Well, it isn't a necessity by any means, but an obvious advantage for XC (?) trail riding is that the attitude of the bike will be better on dowhill sections ... and, equally, the angle of the headtube relative to the horizon becomes more slack ... I'm going to guess it is about a 2º difference ... so, a 73º (?) headtube angle on the OP's hybrid will probably be closer to a 71º headtube angle with a solid, suspension-corrected MTB fork -- the net result should be that his front tire won't be deflected as easily by trail hazards.

FWIW. When I put a suspension fork on my fairly OLD, TREK frame which previously had a solid, threaded fork, the resulting geometry was essentially the same as an off-the-show-room hardtail ... the conclusion I drew at the time was that if the travel were accounted for (eliminated ... with the fork in theoretical compression), the resulting attitude of the frame would have been the same as the original geometry. I don't know if that made sense the way I expressed it, but it was a revelation to me (at the time) ...

While I didn't realize until AFTER I received the fork that it was suspension-corrected ... the fact that it is just gives me another option for how I might use it -- with a 26" wheel, with a 29er wheel and turn the bike into a 69er, or possibly it might be worth getting a hybrid frame and building an inexpensive 29er!?!

Anyway, I think that SOME solid MTB forks have more/less "correction" than others, and if someone is interested in a solid 29er fork, then I think most contemporary, solid MTB forks will "work" because most of the NEW ones currently being sold are suspension corrected, AFAIK ... but, some may not be.

 

[artemidorus]

NEED? Well, it isn't a necessity by any means, but an obvious advantage for XC (?) trail riding is that the attitude of the bike will be better on dowhill sections ... and, equally, the angle of the headtube relative to the horizon becomes more slack ... I'm going to guess it is about a 2º difference ... so, a 73º (?) headtube angle on the OP's hybrid will probably be closer to a 71º headtube angle with a solid, suspension-corrected MTB fork -- the net result should be that his front tire won't be deflected as easily by trail hazards.

FWIW. When I put a suspension fork on my fairly OLD, TREK frame which previously had a solid, threaded fork, the resulting geometry was essentially the same as an off-the-show-room hardtail ... the conclusion I drew at the time was that if the travel were accounted for (eliminated ... with the fork in theoretical compression), the resulting attitude of the frame would have been the same as the original geometry. I don't know if that made sense the way I expressed it, but it was a revelation to me (at the time) ...

While I didn't realize until AFTER I received the fork that it was suspension-corrected ... the fact that it is just gives me another option for how I might use it -- with a 26" wheel, with a 29er wheel and turn the bike into a 69er, or possibly it might be worth getting a hybrid frame and building an inexpensive 29er!?!

Anyway, I think that SOME solid MTB forks have more/less "correction" than others, and if someone is interested in a solid 29er fork, then I think most contemporary, solid MTB forks will "work" because most of the NEW ones currently being sold are suspension corrected, AFAIK ... but, some may not be.

Sorry, alfeng, the penny hadn't dropped for me that a hybrid would have 700C wheels - I was thinking 26"/559.

 

[Blademun]

Ah, Ok, that answered my next question before I even asked it. My bikes current headtube angle is 71 degrees. With the fork thats on it, I am pretty much 'on top' of the bars instead of behind them like I am on some of the nice mountain bikes at the shop. So I will need to get either a suspension corrected fork or a actual suspension fork to slacken the angle of my bike.

btw a 69er would look pretty odd, wouldn't it.