Put 29 inch wheels on 26 inch frame?

[bkpr]

Hey everyone. Short time reader, first time poster.

I have purchased a 2006 Kona Unit 19" second hand, same as this: http://www.konabikes.co.uk/2k6bikes/unit_2k6.php

It came with a bunch of upgrades:
- Juicy 5 disc brakes
- White Ind 16t freewheel
- 42t blackspire downhill SS chainring
- V12 pedals
- Kona Project 2 forks
- new thompson stem, ea70 monkey bars, WTB seat, carbon post etc...

I've been riding it for about 12 months, I love it, but have decided I'd like more top speed. I use it 95% for commuting, and the rest on light trails with the girlfriend.

I wanted to know whether I could install 29 inch wheels onto the 26 frame. Using guesstimation, it appears that an extra 3 inchs will clear the arch of the forks and the rear frame section, but wanted any info if this is a good idea or not, for example, will the frame be under any excess stress from such an upgrade?

I've seen a UK forum post where some had posted photos of such a modification to a Kona 26 Unit, but sadly the photos aren't online anymore. This leads me to believe it's possible...

Another route I've considered, is to increase the chainring size, but anything over a 42t will hit the chainstay, so no go there.

Also, at the moment I'm running Maxxis overdrive tyres:
http://www.maxxis.com/products/bicycle/product_detail.asp?id=225
...so they're not very high profile, but I'd like the option to be able to whack something a little more knobbly on for some medium off-road work sometimes. (I guess I could just whack the 26 wheels back on for this?)

If anyone has any advice/suggestions, I'd greatly appreciate it.
Thanks in advance!

 

[John U]

It is possible, you just need to sure of your clearance which may mean you will need to have fairly narrow tyres. I think the Cannondale Bad Boy is effectively a 26inch frame with 29inch wheels and some fairly low profile tyres.

I am not too sure about the stresses involved but a 29 with low profile tyre is probably going to similar to a 26 with a massive tyre.

watch out for toe overlap with the front wheel

 

[mushroom]

Just to elaborate on what John said about toe overlap- make sure that when you steer the wheel left or right that it doesn't hit your foot when the cranks are at 9 and 3 o'clock.

 

[bdstorer]

Totally achievable.

A friend of mine turned his old 26" wheeled Kona Stuff into a 700cc urban courier rig a few years ago..

The only two things to watch are:

- Front wheel toe/wheel overlap (already mentioned)

- Raised BB which will effect how the bike handles

 

[bkpr]

Thanks for your quick responses!

Since posting I've found that these types of franken-bikes are called 69/96ers (presumably 69 = 26 on front, 29 on back and vice versa). Made it easier to search for info. Yes, the front wheel overlap is something I'd never have thought of. Will check it out.

A couple more questions:
1. Are 29" wheels the same size as 700c wheels? i.e., two common mountain bike sizes are 26" and 700c/29"? (If that is the case, I may be able to get my LBS to fit some 700c wheels to try out for a little while)

2. Any recommendations on brand of larger wheel to go for? As I said before, I ride 95% semi-aggressive commute (gutter hops/small jumps/some occasional small stair rides). Something that is fairly sturdy, and hopefully light? (sorry, being a bit lazy, I can do a search online tonight, but maybe you've got some personal experience

Thanks again

 

[bdstorer]

1. Are 29" wheels the same size as 700c wheels?

2. Any recommendations on brand of larger wheel to go for?

Yep.

If you take a look at the Wheelcraft section of the Dirtworks catalogue check out the Commuter/29'er wheelset the "Orbit" (29"/700cc) or the "Latitude".. Reckon the Latitude is better value @ $499 for a pair.. built with Sun Ryhno Lite rims and DT Swiss 370 Hubs.. Tidy as and good value!.. The front only retails @ $220.. bargain!

 

[lebronmtb]

Wouldn't the arch increase by 1.5" not 3"? If you have 1.5" room on the downtube, fork crown, seat pole it should fit

 

[Techno Destructo]

Just to add to the thread, a commuting buddy of mine has recently put 700c wheels on his 26" hardtail with rigid forks. They fit nicely, however, as stated... the front forks are rigid and therefore don't have any brake arch to contend with.

He loves it. Much faster, corners much more aggressively....

Thumbs up!

 

[bkpr]

Cheers everyone!

Just got home, grabbed my GFs 700c front wheel, whacked it on my forks, clears the crown but about 20mm (she has the same maxxis overdrive tyre as mine). The back was a little closer, around 14mm.

There could be a problem though, it's a single speed, and I've just bought a new chain and chainring to replace the old 'stretched' one. I fear the new chain will be slightly shorter when it's fitted. The kona has a nifty rear disc brake mount system where the whole brake assembly can be slid backwards/forwards to tension the chain and leave the brakes in alignmnt with the rotor, but I think the assembly'll have to slide forward for the new chain. could be cuttin' it fine. What's the minimum clearance you'd think would be safe? I ride in the wet sometimes, but not through thick mud, just puddles and occasional wet sandy patches along the river.

I guess I'll just chat to the LBS guys at Abbottsford cycles about it when I take it in for a service later this week.

@ bdstorer: how exactly does the BB being a couple inches higher affect handling? I imagine it's due to the centre of gravity being a bit higher, but what exactly does it mean? And is the effect dramatic for a couple inches?

Also @ bdstorer: those orbit wheels look great! But I don't know much about wheels :S I have Sun Rims Mach IVs at the moment (can see any branding on the hubs). Would any 6-bolt hubs will accept my 16t White Ind freewheel?

@ anyone: do you think the speed boost would noticeable? Currently, when I'm caning home from work, I often get to a cadence which is flat-out and looks wacky, and I wish I had a little bit more speed to peddle towards.

Thank you all for the quick responses so far!

EDIT @ lebronmtb: yes, I meant the extra 3 inch sized wheels — the tyre is indeed 1.5 inch closer to the frame

 

[n plus one]

As you now know it can be done - I've already done it on the same bike in the past too.

For reference purposes neither 26 inch nor 29 inch refer to rim sizing - both are rough approximations of combined rim & tyre combo. Not aimed at you or anyone - its just funny that very few people seem to realize this.

As for gearing going to a true 29er combo, effectively a 700 x 58 tyre give or take, is the same as going down 2 teeth on the rear cog.

Your 700 x 38 combo will be about half way so I'd guesstimate you'll gain the equivalent of going down 1 tooth.

Oh yeah, higher bb = less stability, but its minor.

 

[bkpr]

Thanks again.

You guys/gals are champions

 

[ovadahill]

.....

A couple more questions:
1. Are 29" wheels the same size as 700c wheels? i.e., two common mountain bike sizes are 26" and 700c/29"? ........

Will 700c tyres fit on a 29" wheel? I want to put Maxxis Detonators on a 29" but I note that the Maxxis website only lists Detonators in 26" and 700c sizes.

What is the equivalent of a 1.3" slick tyre?? -- is a 700c 28 close?

 

[jaseh]

Will 700c tyres fit on a 29" wheel? I want to put Maxxis Detonators on a 29" but I note that the Maxxis website only lists Detonators in 26" and 700c sizes.

What is the equivalent of a 1.3" slick tyre?? -- is a 700c 28 close?

Yes they fit, just change the gearing to suit.

I run 700x35 tyres on my Redline MC 29er for commuting.

Also whack a 14 or 15t on the rear for a bit more speed.

 

[n plus one]

What is the equivalent of a 1.3" slick tyre?? -- is a 700c 28 close?

MTB and road tyres are sized the same (barring differences between manufacturers etc) just one is metrench and the other is Steve Urkil.

1.3 grinches = 33 multimeters.

Try a 32 or a 35 ?

 

[b_S]

Oh yeah, higher bb = less stability, but its minor.

Definitely worth noting though - the bike will take some getting used to and you'll have to relearn its limits in terms of aggressive riding.

 

[bkpr]

Yes, I'd take it easy until I felt comfortable enough to sideswipe taxis again.

Bike being fully serviced on monday. Ordering (or not) of wheels to follow directly afterwards. Will let you all know how I get along, and post some pics if it goes ahead. (also post pics if it doesn't go ahead as the bike will be in it's best form after the service since I've owned it)

Thanks again everyone.

 

[ovadahill]

Would a 700c/29er wheel fit in a Salsa 26" rigid fork? - If it did I think the lower bottom bracket give a better commuting geometry than the Salsa 29" fork.

What sort of carbon forks are available with disk brake mounts? (I recall seeing a BMC with an in house brand starting with S??)

 

[ovadahill]

What sort of carbon forks are available with disk brake mounts? (I recall seeing a BMC with an in house brand starting with S??)

Scor Captain Ahab Carbon forks -- where do I get these??

 

[n plus one]

Would a 700c/29er wheel fit in a Salsa 26" rigid fork? - If it did I think the lower bottom bracket give a better commuting geometry than the Salsa 29" fork.

Do you mean with a full sized mtb tyre or a roadie/hybrid?

I assume you're thinking about going 96er?

 

[ovadahill]

Roadie tyres 700x28c front and rear (on a 26" MTB frame) using the Salsa 26" chromoto fork (or Scor Captain Ahab forks if I can source one -- the Token carbon forks with disc mounts look good but I haven't contacted supplier re price).